Oil & gas industry of Ukraine

journal@naftogaz.net www.naftogaz.com/naftogaz_galuz

6/2013 Development of the gas market in Ukraine

Kolbushkin Y.P.

Mathematical simulation of oil wells performance

Kachmar Y.D., Tsiomko V.V., Babiy M.B.

Reliability of the instrumental accounting of natural gas

Vlasyuk Y.M., Compan A.I., Vlasyuk L.Y.

DEAR COLLEAGUES!

Please, accept the warmest and the most sincere congratulations with

the forthcoming New Year and Christmas!

Seeing off the old year and meeting the New Year is always a

good occasion to recall about common achievements, to thank for the

fruitful work and to determine the plans for the future. Contrary to

all difficulties, we successfully resolved a number

of complex issues and overcame a lot of obstacles on

the way towards strengthening of our Company’s position. Every

day we put significant efforts to continue the development of oil and

gas industry and increase the economic potential of our state.

New Year is new tasks. We are about to face the new challenges, but together we will be able

to implement the most ambitious plans, since the success of our Company depends on the professionalism and

commitment of every one of us.

Let each day of the New Year of 2014 give you new opportunities and increase the achievements,

bring good mood and good luck! Let the year be full of new creative wins and achievements.

I wish happiness, good health and prosperity to you and your families.

Merry Christmas and Happy New Year!

Best regards,

Evgeniy Bakulin, President of National Joint Stock Company «Naftogaz of Ukraine»

INTERNATIONAL COOPERATION

In 1959 Ruhrgas AG mixed the German natural gas with coke of own production in Dorsten to meet the peak demand. In 1960, Ruhrgas had 1.6 billion m³ of natural gas under the contract.

In 1966, the first Holland natural gas came to the Ruhrgas networks after a significant portion of local gas pipelines, as well as domestic equipment and industrial furnaces started to be reequipped for use of the natural gas. In 1968 Ruhrgas reached the sales of natural gas at the level of 11 billion m³, and next year the share of sales of the natural gas for surpassed that of the sale of the coke gas the first time.

In 1973 the first Soviet natural gas went to the Ruhrgas AG in Bavaria. The contracts with Soyuznefteksport dd. 1970, the supply of pipes by Mannesman, the equipment for compressor stations and loan agreement for DM 1.2 billion for construction of Union pipeline were important steps to mitigate the "East-West conflict."

Due to the growing demand for natural gas by the industry and the private sector, the Ruhrgas gas network and joint transit projects with the Italian company SNAM (TENP) and French Gaz de France (MEGAL) have been developing rapidly.

The imports of natural gas in the Netherlands and the Soviet Union constantly increased.

In 1977, the first imported Norwegian natural gas was delivered to the German North Sea coast, and the gas import from Denmark and the UK was started later.

In the 1990s and 2000s the acceleration of the rate of movement of natural gas to Europe was observed. The coke gas played only a minor role for some industrial customers.

This period was also marked by the increase of European integration and EU enlargement, with simultaneous changes in the regulatory framework of the energy sector, especially in the gas market. These factors, as well as increased competition, have forced all energy companies to take actions to strengthen their positions in this market. In early 2003 Ruhrgas AG became a part of the E.OH group and from July 01, 2004 it has received the name of E.OH Ruhrgas AG.

The financial and economic crisis of 2008, oversaturation of the European gas market with liquefied gas and further sharpening of the competition and market liberalization encourages the energy companies to strengthen their competitiveness even after 2015.

E.OH group has taken up this challenge at once. The cut in costs, transformation of structures into more compact and efficient ones, and therefore more powerful - all of this led to creation of a program of the group restructuring. In this regard, there also have been significant changes in E.OH Ruhrgas AG. Last year, on the basis of the Third Energy Package of the European Committee, E.OH Ruhrgas sold its gas transportation system. The remaining technical services and professionals were transferred to a subsidiary of E.OH group - E.ON New Build and Technology.

In early May the parts of E.OH group, which dealt with gas in Essen and trade in Düsseldorf, moved through the merger to the new company, E.OH Global Commodities CE, based in Düsseldorf, which since the very beginning covered the global markets of the future.

I am sure that E.OH Global Commodities CE will have a good international reputation inherited from Ruhrgas, the pioneer and the immediate creator of gas business not only in Germany but also in Europe as a whole.

E.OH team remaining in Kyiv as a representative office of E.ON Global Commodities CE continues the scientific and technical cooperation with the Naftogaz of Ukraine National Joint Stock Company and Ukr-Transgas PJSC.

Through Oil and Gas Industry of Ukraine magazine, on behalf of E.ON Ruhrgas AG management, my colleagues from Essen and team of the Kyiv office, and from myself personally, I want to thank our Ukrainian colleagues and friends for more than 20 years of hospitality, cooperation, support and many wonderful hours spent together at work and rest!

My words of sincere gratitude are addressed first of all to the gas workers in Kyiv on gas pipelines and compressor stations throughout Ukraine for their tireless work to implement the transit commitments. This also applies to the other experts from government agencies, departments, scientific and educational organizations as well as colleagues from the enterprises with which we collaborated, whose services and support played an important role in ensuring the uninterruptable work of our offices for many years and in all weather conditions!

I wish good health, professional success and family happiness to the editorial board, authors of articles and readers of Oil and Gas Industry of Ukraine scientific and practical magazine. Dear workers of oil, gas and refining industry!

I congratulate you on the New Year and Merry Christmas!

I wish you good health, good humor, inspiration, creative success and the delight from hard and dedicated work for the good of the motherland!

Let the New Year bring you hope and faith in realization of all your plans and expectations, confidence in the future, and add strength for the new professional achievements.

Let the bright holiday of Christmas fill your soul with good things and love and inspires for noble causes!

I wish you happiness, prosperity and implementation of your most cherished dreams!

Sincerely, rector of IFNTUNG

Y.I. Kryzhanivskyi

Name

Oil and Gas Industry of Ukraine

Scientific and production magazine. Published once in 2 months

Co-founders

Naftogaz of Ukraine National PKSC

Ivano-Frankivsk National Technical University of Oil and Gas

Editor-in-chief

E. M. Bakulin

6/2013

(6) November – December

Index 74332

No. of copies: 1000

Price acc. to the Catalogue of publications of Ukraine 22.63 UAH

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Publisher

The magazine is referred by University of Tulsa (USA) and VINITI RAN (Russia)

Recommended for publishing by the Scientific and Technical Board of Naftogaz of Ukraine National joint-stock company

Oil & Gas Industry of Ukraine Editor-in-chief

Ievhen Mykolayovych Bakulin - Chairman of the National Joint Stock Company "Naftogaz of Ukraine"

Deputy chief editors

Vadim Prokopovych Chuprun - Deputy Chairman of the National Joint Stock Company "Naftogaz of Ukraine"

Ievstakhiy Ivanovych Kryzhanivskyy - Doctor of Engineering Sciences, professor, corresponding member of The National Academy of Sciences of Ukraine, the Rector of Ivano-Frankivsk National Technical University of Oil and Gas

Editorial board

Oleg Maksimovych Adamenko - Doctor of Geologo-Mineralogical Sciences

Yurii Volodymyrovych Banakhevych - Doctor of Engineering Sciences

Serhii Valeriyovych Bojchenko - Doctor of Engineering Sciences

Mykhailo Mykhailovych Bratychak - Doctor of Chemical Sciences

Frants Frantsovych Butynets - Doctor of Economic Sciences

Hennadiy Borysovych Varlamov - Doctor of Engineering Sciences

Volodymyr Mykhailovych Vasyliuk - Candidate of Engineering Sciences

Yurii Oleksandrovych Venhertsev - Doctor of Philosophical Sciences, Candidate of Engineering Sciences

Serhiy Andriiovych Vyzhva - Doctor of Geological Sciences

Yaroslav Stepanovych Vytvytskyi - Doctor of Economic Sciences

Mykhailo Davydovych Hinzburh - Doctor of Engineering Sciences

Vasyl Vasylovych Hladun - Doctor of Geological Sciences

Petro Fedosiiovych Hozhyk - Doctor of Geological Sciences, member of The National Academy of Sciences of Ukraine

Liliana Tarasivna Horal - Doctor of Economic Sciences

Oleksandr Ivanovych Hrytsenko - Doctor of Engineering Sciences, corresponding member of Russian Academy of Sciences

Volodymyr Yaroslavovych Hrudz - Doctor of Engineering Sciences, professor

Mykola Oleksiiovych Danyliuk - Doctor of Economic Sciences

Tetiana Yevhenivna Dovzhok - Candidate of Geological Sciences

Volodymyr Mykhailovych Doroshenko - Doctor of Engineering Sciences

Oksana Teodorivna Drahanchuk - Doctor of Engineering Sciences

Dmytro Oleksandrovych Yeher - Doctor of Engineering Sciences, corresponding member of The National Academy of Sciences of Ukraine

Yurii Oleksandrovych Zarubin - Doctor of Engineering Sciences

Oleksandr Yuriiovych Zeikan - Candidate of Geological Sciences

Ihor Mykolaiovych Karp - Doctor of Engineering Sciences, member of The National Academy of Sciences of Ukraine

Oleh Mykhailovych Karpash - Doctor of Engineering Sciences

Oleksii Mykolaiovych Karpenko - Doctor of Geological Sciences

Ihor Stepanovych Kisil - Doctor of Engineering Sciences

Volodymyr Pavlovych Kobolev - Doctor of Geological Sciences

Yurii Petrovych Kolbushkin - Doctor of Economic Sciences

Roman Mykhailovych Kondrat - Doctor of Engineering Sciences

Mykhailo Dmytrovych Krasnozhon - Doctor of Geological Sciences

Ihor Mykolaiovych Kurovets - Candidate of Geologo-Mineralogical Sciences

Mykola Volodymyrovych Lihotskyi - Candidate of Engineering Sciences

Oleksandr Yukhymovych Lukin - Doctor of Geologo-Mineralogical Sciences, member of The National Academy of Sciences of Ukraine

Borys Yosypovych Maievskyi - Doctor of Geologo-Mineralogical Sciences

Yurii Fedorovych Makohon - Doctor of Engineering Sciences (University of Texas, USA)

Mykhailo Ivanovych Machuzhak - Candidate of Geologo-Mineralogical Sciences

Oleksandr Oleksandrovych Orlov - Doctor of Geologo-Mineralogical Sciences

Zynovii Petrovych Osinchuk - Candidate of Engineering Sciences

Myroslav Ivanovych Pavliuk - Doctor of Geologo-Mineralogical Sciences, corresponding member of The National Academy of Sciences of Ukraine

Viktor Pavlovych Petrenko - Doctor of Economic Sciences

Oleksandr Pavlovych Petrovskyi - Doctor of Geological Sciences

Viktor Mykhailovych Svitlytskyi - Doctor of Engineering Sciences

Mariia Dmytrivna Serediuk - Doctor of Engineering Sciences

Orest Yevhenovych Serediuk - Doctor of Engineering Sciences

Vitalii Ivanovych Starostenko - Doctor of Physico-mathematical Sciences,member of The National Academy of Sciences of Ukraine

Serhii Oleksandrovych Storchak - Doctor of Engineering Sciences

Leonid Mykhailovych Unihovskyi - Doctor of Engineering Sciences

Dmytro Dmytrovych Fedoryshyn - Doctor of Geological Sciences

Illia Mykhailovych Fyk - Doctor of Engineering Sciences

Pavlo Mykolaiovych Khomyk

Ihor Ivanovych Chudyk - Doctor of Engineering Sciences

Anatolii Petrovych Chukhlib - Candidate of Economic Sciences

Eduard Anatoliiovych Shvydkyi - Candidate of Economic Sciences

Oleh Anatoliiovych Shvydkyi - Director of "Naukanaftogaz"

Anatolii Stepanovych Shevchuk - Candidate of Engineering Sciences

Contributors to this issue

Management of Science and Technology Policy

National Joint Stock Company "Naftogaz of Ukraine" Department of the publication organization of scientific and practical journal

Head of Department

T.P. Umuschenko

Editor N.H. Vorona

Delivered on 01.12.2013. Published: 23.12.2013 Format 205 × 285. Paper coated. Offset printing.

CONTENTS

ECONOMY AND DEVELOPMENT PROBLEMS KOLBUSHKIN Ju. P.

Development of the gas market of Ukraine……………………………………………………………………………………………………………………………..3

WELL DRILLING HOHOL V.I., OHORODNIKOV P.I., SVITLYTSKYI V.M. Ana lysis of longitudinal, torsional and bending vib rations of drill string……………………………………………………………………………………………….5 TSAPLII M.P., YUDINA V.V., PAVLOVSKYI A.P., MISHCHUK О.О. Surface activity of fne, oxide type heterogeneous fllers during friction……………………………………………………………………………………………9 GULYAYEV V.I., GAIDAICHUK V.V., SHEVCHUK L.V. Computer simulation of drill string bit spinning vibrations in deep wells…………………………………………………………………………………………..1 4 GULYAYEV V.I., GAIDAICHUK V.V., ANDRUSENKO O.M., SHLYUN N.V. Diferential «stif-string» model for drag and torque simulationin deviated bore-hole…………………………………………………………………….1 7

OIL AND GAS PRODUCTION VELYCHKOVYCH A.S., PANEVNYK D.O.

Rationale for choosing the geometric dimensions of well hydraulic jet pump…………………………………………………………………………………….20 SVITLYTSKYI V.M., CHAICHENKO B.I. Improvement of well productivity by simultaneous action on the bottomhole formation zone with chemical agents and pulse-wave influence……………26 KACHMAR Yu.D., TSIOMKO V.V., BABII M.B. Mathematical simulation of oil well productivity…………………………………………………………………………………………………………………..28

OIL AND GAS TRANSPORTATION AND STORAGE TARAIEVSKYI O.S.

Strength assessment of ring welded joints of pipes with corrosion defects……………………………………………………………………………………….33

AUTOMATION AND INFORMATION TECHNOLOGY VLASIUK Ya.M, COMPAN A.I., VLASIUK L.Ya.

The reliability of the instrument metering for natural gas………………………………………………………………………………………………………….38 ROHACHUK M.P., TYSHCHENKO M.V., OLOMSKYI S.V., VASYLIUK Yu.A., RIABOSHAPKO S.M., ROMAN, V.I. MUKOIED N.I. Automation of seismic survey supervision………………………………………………………………………………………………………………………….41

THE HISTORY OF THE INDUSTRY HUZIICHUK I.O., TEMEKH I.T.

Establishment of the industrial oil production in the Carpathian region as a precondition for the foundation of Oil Field Museum of Galicia…………..44

INDUSTRY EXPERTS Paton B. Ye…………………………………………………………………………………………………………………………………………………………...32

INTERNATIONAL COOPERATION G. ENKE

Representation of E ON Global Commodities CE in Ukraine……………………………………………………………………………………………………….48

List of articles published in 2013……………………………………………………………………………………………………………………………………………………………………24 Information……………………………………………………………………………………………………………………………………………………………13, 23, 27, 37, 47

ECONOMY AND DEVELOPMENT PROBLEMS

Development of gas market of Ukraine

UDK 338+351.863(477)

© Ju.P. KOLBUSHKIN Doctor of Economics National Joint-Stock Company ‘Naftogaz of Ukraine’

The article brings up an issue of further development and reformation of the Ukrainian gas market and the cooperation of the National Joint-Stock Company «Naftogaz of Ukraine» with the international financial institutions and global gas companies.

Key words: Ukrainian gas market, natural gas, reforming of the National Joint-Stock Company «Naftogaz of Ukraine» energy independence, gas companies.

Natural gas market and reformation of the National Joint-Stock Company ‘Naftogaz of Ukraine’

It is known that Ukraine is one of the largest markets of natural gas in Europe consuming about 55-60 bln. m3

natural gas per year, the import is 65-70%. Taking into consideration the global challenges of the world market of power resources, as well as evaluating appropriately the prospects and the role of in the ‘gas triangle’ Russia-Ukraine-European Union, our country contributes to development, reformation and liberalization of the Ukrainian gas market. The necessity of legal changes was dictated by the Ukraine’s joining to the Treaty establishing the Energy Community requiring adaptation of the law of Ukraine to the EU norms.

Today, the main legal act defining the ‘game rules’ at the Ukrainian gas market is the Act of Ukraine ‘On grounds of functioning the market of natural gas in Ukraine’ of June 16, 2011, as continuation of the European directives and was aimed at termination of multi-year monopolist state. It may also ensure the equal access to all the market participants to gas transport systems of Ukraine.

In addition, the industrial consumers got right to select independently the gas supplier since March 1, 2012 (while de facto they have this right since April 2011); governmental organization – since January 1, 2013; heat supply companies (only those which supply heat to household) – since 2014, and household users – since 2015.

On May 7, 2012, amendments to the Act of Ukraine "On Pipeline Transport" came into force to reform the oil and gas industry. And in October of that year there was cancelled the Resolution of the Cabinet of Ministers of Ukraine dated March 5, 2008 "On the realization of imported natural gas in Ukraine", which opened the market for natural gas imports to Ukraine to other businesses. In case of proper compliance with national standards, consumer and environment protection, any company is free to trade natural gas at the domestic market of Ukraine.

Following the amendments to the legislation the fact is evident that these amendments will not be enough without reformation of the National Joint-Stock Company "Naftogaz of Ukraine" – a leading company at the market that is the main importer of natural gas and the main entity of the formation of natural gas resource for the Ukrainian consumers.

Therefore, the Cabinet of Ministers of Ukraine founded the appropriate interagency working group on development the Company reform program. Having reviewed the rules of applicable Ukrainian legislation regulating the activities of the gas industry, on June 13, 2012 the Cabinet of Ministers of Ukraine issued the decree "On the reorganization of subsidiaries of the National Joint-Stock Company "Naftogaz of Ukraine".

According to this resolution there was taken the decision to reorganize the SE “Ukrtransgas” and there was approved the proposal of the Ministry of Energy and Coal Industry of Ukraine on reorganization of subsidiary “Ukrgasvydobuvannya”. Due to this resolution the Cabinet of Ministers charges to transform the subsidiaries

“Ukrtransgas” and “Ukrgasvydobuvannya” in public joint-stock companies. Meanwhile, National Joint-Stock Company "Naftogaz of Ukraine" administers the corporate rights of these joint-stock companies by agreement of the Ministry of Energy and Coal Industry of Ukraine under the current law. The state registration of PJSC “Ukrtransgas” and PJSC “Ukrgasvydobuvannya” was completed on December 27, 2012.

The National Joint-Stock Company "Naftogaz of Ukraine" signed the contract with the well-known company ‘Ernst & Young’ for accomplishment of scientific research work ‘Development of program of reformation of the National Joint-Stock Company "Naftogaz of Ukraine". The work will result in proposals on the most optimum variants of the Company restructuring in the Company and its subsidiaries main activities (mining, transport, storage, oil and gas realization).

Now, it is under negotiation of the approval of the Terms of Reference on preparation of the Program of the reformation of the National Joint-Stock Company "Naftogaz of Ukraine" within the trust fund of the European Commission. It is expected that the reorganization will be carried out in accordance with the commitments undertaken by Ukraine's joining to the Energy Community Treaty, which will provide independent operator of the gas transportation system with all the powers prescribed by EU legislation.

Besides, on April 26, 2013, the Verkhovna Rada of Ukraine registered the Draft Act of Ukraine "On Amendments to Certain Legislative Acts of Ukraine to reform the National Joint Stock Company "Naftogaz of Ukraine". Passing this bill will help to make a company reform aimed at improving the economic efficiency of oil and gas industry. On the other hand, all items of the new law comply with EU law and will contribute to energy independence of Ukraine.

We would like to emphasize that the improvement of legislation and reform of the National Joint Stock Company "Naftogaz of Ukraine" means a certain part of the work aimed at the liberalization and development of the gas market in Ukraine. The company does not cease to work to achieve the energy independence paying a particular attention to increasing the gas production onshore and offshore, the development of unconventional gas, increased technical equipment production and diversification of energy supplies. And in this regard we rely on the support of the European Union, in particular, the fact that Ukraine will be given the equal compared to other market law (especially, in relation to Slovak direction).

Cooperation with international financial organizations and gas companies

National Joint Stock Company "Naftogaz of Ukraine" pays special attention to cooperation with international leading companies in the gas industry. Undoubtedly, its biggest partner in the gas issues was and remains "Gazprom" - the main supplier of natural gas to Ukraine and the EU.

The relationship between the National Joint Stock Company "Naftogaz of Ukraine" and Gazprom are realized under the terms of the bilateral agreements, existing long-term contracts and significantly affect the balance of power on the gas map of Europe.

Despite the fact that the company has repeatedly declared about unfair and unequal contractual conditions it continues to implement all the commitments. Thus, Ukraine both at the government level and at the level of business entities conducts with Russia talks on changing the conditions of long-term contracts. For two years the National Joint Stock Company "Naftogaz of Ukraine" has been taking all the possible measures to optimize the conditions for long-term contracts with Gazprom. During this time a number of joint consultations and workshops have been conducted, the appropriate statement was repeatedly sent to reduce natural gas prices and annual volume of imported gas, obtain guarantees from the Russian side on supply of natural gas volumes for transit through Ukraine to Europe. Unfortunately, by this time, the desired results have failed to be reached.

Considering the importance and wide range of gas issues, large capacity and complexity of the Ukrainian market, the need for significant investment and application of new technologies, the National Joint Stock Company "Naftogaz of Ukraine" cooperates with other leading gas companies, including Shell, Eni, RVE, Ferrostal, Totale, E ON – Ruhrgas, ExxonMobil, Chevron, Halliburton etc..

Conclusion

Thus, it is evident that the Ukrainian gas market is on the verge of radical changes aimed to bring it closer to the European standards and open to foreign investors. Clearly, the reform way will be long and difficult; it will require considerable efforts and patience from all stakeholders. Certainly, we understand the reforms mean the only way for market liberalization, legislation harmonization to open profitable prospects for Ukrainian gas industry and bring our country closer to energy independence.

It should be emphasized that the National Joint Stock Company "Naftogaz of Ukraine" always fulfils all its obligations before the international and the national partners, as evidenced by its well-deserved reputation as a reliable

company. The company is interested in cooperation in various fields, open to further discussions and negotiations mutually beneficial for dialog participants.

Author Kolbushkin Juiriy Petrovych Director of Economic Planning and Budget calculations of the National Joint Stock Company "Naftogaz of Ukraine", Doctor of Economic Sciences. He graduated from the Kyiv Institute of National Economy, specialty - finance and credit. Interests: analysis of the effectiveness of material and financial flows of oil and gas complex.

WELL DRILLING

Analysis of longitudinal, torsional and bending vibrations of drill string HOHOL V.I. OHORODNIKOV P.I. Doctor of engineering science International Scientific Technical Institute SVITLYTSKYI V.M. Doctor of engineering science PJSC ‘Ukrgasvydobuvannya’

UDK 622.24.053

The paper considers longitudinal, torsional and bending vibrations of the drill string that occur during the bottom-hole deepening. The equations are presented that show the possibility of applying vibration velocity to evaluate the strength and reliability of the string pipes in case of vibrations.

Key words: drill string, oscillations, vibration velocity, tension.

Longitudinal vibrations of the drill string occur during RIH operations (SPO), works of roller-cutter bit during drilling, when pumping the drilling fluid and the rotation of the column. Torsional vibrations occur by interaction of the elements of (BHA) and the bit with the well walls and the work of roller-cutter bit at wave-type bottom [1].

Let’s consider the influence of longitudinal oscillation of roller-cutter bit on the drill string during bottom deepening.

The perturbation strength in the axial direction resulted from the interaction of the bit face is transmitted to the drill string and the pipes. The axial bit displacement is accompanied by the increase of potential energy in the column pipe with the bit movement downward, the potential energy become kinetic one used for rock failure. The elastic waves associated with rolling cutters from tooth to tooth. The alternating half-waves of compression - tension cause the change of potential energy of heavy bottom, which leads to the increase of the axial load on the drill and bottom failure [2].

The efforts in cross section tubes differ from the efforts resulted from the static calculations. The elastic vibrations that occur in the drill string during the bit interaction with the bottom, both directly and indirectly, affect additionally the value of the internal force factors. For the mathematical description of the mechanical system – the drill string in the process of deepening the bottom to determine its internal security and reliability factors it is needed to record not only the equations of the model of oscillatory processes, but also to clarify the relationship of the model of wells deepening.

Having modelled the drill string in the form of a rod with distributed parameters and appropriate boundary conditions, we constructed the diagram represented in the figure. Thus, the weight drill pipes (WDP) are taken as concentrated mass, damping mass is ignored.

Given that the drill string is linear deformed system, the total weight factors can be defined in its cross-sections through the deformation under the known formulas of the elementary theory of materials strength:

where E – module of longitudinal elasticity, Fk – surface of cross section of column, G – rigidity modulus, Ip – polar moment of inertia of surface of cross section of column, u(x,t) – longitudinal elastic displacement of cross-section, ϕ – angle of twist in the considered section.

Given the static modes drilling resulted in internal static load, general efforts are equal to the static and dynamic components:

Meanwhile, this dynamic components of these forces are determined through the inertial forces by means of formulas:

The equation of elastic vibrations of the drill string can be obtained from the equation (1) and by their differentiation them by x, find expressions that bind the components of beam deformation with external distributed loads, and then enter the appropriate distributed inertial forces

Let’s describe the external load as:

where qa(x,t) – external linear load (interaction of columns and walls of the well with drilling fluid).

Thus, we get the equation of longitudinal and torsional vibrations of the drill string:

where qx(x,t) і qкp(x,t) – linear function of the external load (weight, fluid friction).

Taking the first approximation that the linear functions of the external unit load approaches to zero, after transformations and provided designations

we have the differential equations of longitudinal and torsional free elastic vibrations of the drill string as the core system:

As the drill string during drilling takes the form of a spatial spiral and the hole axis is curved, the stiffness axis of the column does not coincide with the axis of the centers of gravity of the cross sections. Bending vibrations are accompanied by torsional vibrations relatively to the stiffness axis and vice versa. The set of specified oscillations is explained by the presence of inertial oscillations among them, which are proportional to the distance between the stiffness axes and centers of gravity. The equations of bending oscillations of drill string are considered below.

The oscillations of the drill string caused by the work of the bit at the bottom, are forced [3]. The form of these oscillations varies depending on the BHA, as well as geological and technical conditions and drilling modes.

Let’s analyze small longitudinal and torsional oscillations of the drill string described by the equations (7).

The first equation of the system (7) relates to longitudinal oscillations of the drill string and the limit conditions are as follows: at X = 0

where C0 – stiffness of drilling line system;

at X = H + L (H – length of steel drill string (SDS), L – length of casing)

where Rв – bottom reaction.

Considering the process of bottom deepening is quasistatic one and on the basis of the above mentioned conclusions in the first approximation we take

where vM – instantaneous mechanical velocity of deepening the bottom during drilling.

Having differentiated by the time the first system equation (7) and designated ди(х,t)/дt=V we write it as follows

Appropriately, the expressions (8) and (9) are represented at X = 0

at X = H + L

The solution of equation (11) may be represented as the product of two functions, one of which depends on the time and the other - on the location of sections:

or

If we consider the longitudinal oscillations of the drill string as the thin rod at a specific moment of time t = t1, the first multiplier T is constant:

As the number of proper oscillations of frequencies w1, w2, w3 ... for such construction is unlimited, each value w

has partial solution that is similar to the equation (15). In the first approximation we consider that during deepening the bottom there harmonic oscillations of drill string resulted from bit-rock interaction during roller-bit transfer along wave-type bottom:

Adding this solution to the equation (11), we have

The general solution of the equation (18) we write as follows:

The resulting expression determines the shape of the elastic line of the drill string during its oscillations.

The Constants C and D are defined considering (12) and (13):

Having added the constants C and D to the equation (19) we have:

For practical application of this result it is important that it is possible to determine the stress state of the drill string in the form of the elastic line. These solutions are realized with the longitudinal oscillations under the influence of external disturbances. The frequencies of the resonant oscillations are determined by the natural oscillations that meet certain own forms.

The solutions (19) and (21) are valid for columns of considerable length with low bending rigidity, especially for the column stretched part. To calculate the oscillations of the drill string while drilling the inclined holes aimed a spatial trajectory it is necessary to use the analog as a curved rod with non-stretched axis, which is a system with variable parameters by length. The results of the use of such models give better initial parameters on calculations of reliability of the drill string.

The oscillations of the drill string and its elements can be considered random, and their parameters should be calculated using the apparatus of the theory of possible fluctuations. At this stage of research, we assume that the reaction of the drill string as a mechanical system at narrow-band random oscillation will be equivalent to the effect of harmonic oscillation, and the response system for broadband oscillation – reaction to the action of polyharmonic drilling. Thus, in the first approximation we assume that the drill string has harmonic oscillations.

The failure of drill string elements are associated with the action of many geological and technical factors, if stress or strain in its elements exceed the permissible value and the element is destroyed or has any partial deformation resulting in the rejection of element (e.g., bit ) during the further work. In this case, the criterion is excessive tensions.

The majority of the fatigue damage in the drill string occurs when tension during oscillation is not very high, but the destruction is caused by a large number of cycles of stress. The criterion of failure in this case will be to reach the material endurance.

Fig. 1. Modeling scheme of drill string: С0 – stiffness of drilling line system which are changed during the

deepening the bottom; Н – length of drill string; L – length of casing; Е – module of elasticity; Fk – surface of cross section of pipes; G – module of displacement; Іp – polar moment of inertia of string; М – weight of casing; I – casing inertia moment; Сп, Ск – respectively longitudinal and torsional stiffness of buffer; U0(x,t), φ0(x,t) – longitudinal and torsional displacement of sections of drill string; U(t), φ(t) – longitudinal and torsional displacement of bit; Rв – bottom reaction

The presence of stress concentrators reduces the longevity of the drilling tool. In this regard, there are used various principles of reducing oscillation stresses. Recently, many countries use vibration velocity as indicator of reliability of structures in case of vibrations [4]. Mean square value of vibration velocity is linear related to the root-mean-square stress and does not depend on constructive features of drill string. Then, we use maximum stress for evaluation of stiffness

where vмакс – maximum amplitude of related vibration velocity of element, A* - factor considering the distribution of stresses and related amplitudes of vibration speeds according to the volume of drill string.

Below, under [5], it is provided the value of factor A* for rods:

Longitudinal oscillations of rods - 1,00;

torsional oscillations of circular rods - 0,75;

bending oscillations of freely overhanging beams - 2,00;

bending oscillations of thin wall rods fixed from both sides, under such tones: basic - 1,73, higher - 2,00.

The possibilities of the practical use of the obtained criterion are proved by its use in turbine construction and for calculation vibration stress of internal combustion engines [6].

Let’s consider the simplified equations of elastic vibrations of the drill string as rod with variable cross section along the length, for which we use the equations (2) and (3). We differentiate by x the longitudinal force, the torsional moment will enable to find expressions related to deformation of system with external parameters and loads. It is necessary to repeat calculations for longitudinal and torsional oscillations. It will be resulted in differential equation of bending oscillations of drill string in surface x, у:

The function may be represented as the sum y(x,t)=y1(x,t)+y2(x,t), where the first element describes the free longitudinal oscillations of construction, the second element – forced oscillations. Respectively, the homogenous differential equation will be:

Let’s consider the oscillations of linear drill string in case of hinge support. If we do not take into consideration of displacement, the form of elastic line of string which we module by elastic rod is sinusoid:

where Y0 – amplitude of oscillations at any point of linear link, i – number of oscillations form, L – length of linear link of drill string.

Then, we use the works results [5, 6]. Bending moment:

Maximum stress in the link of drill string:

where W – resistance moment.

Let’s calculate the frequency of free oscillations of this string link

We write the expressions for the length of semi-wave

We re-write the expression (27) as follows:

Thus, the maximum stress of bend is proportional to maximum vibration velocity of the elements of the drill string and for acceptable conditions of fixation does not depend on their constructions and dimensions.

The definition of vibration velocity by means of found equations (23) and (24) enables to define theoretically the maximum stress in string points avoiding complex experimental records.

Having introduced the notion of factors of dynamism η and form stress k, we define the safe vibration velocity for drill string generated by the bit (kinetic drilling) [5]:

where

this is the formless form of oscillations and movable coordinate.

Due to this equation, we define the vertical vibration velocity of roller-bit resulting in any possible fatigue fracture of over-bit elements of BHA.

WELL DRILLING

Surface activity of fine heterogeneous fillers oxide nature during friction

УДК 621.891, 620.194 М.P. Tsapliy V.V. Yudina

cand. of Engineering sciences А.P. Pavlovskiy О.О. Mischuk cand.of Physical and Mathematical Sciences Ukrainian Scientific Research Institute of Oil Refining Industry «МАSМА»

The analysis of regularities of formation and properties of abrasive-resistant microstructures of steel friction surfaces arising under the influence of lubricating agents with fine-dyspersated titanium dioxide and mineral hydrosilicate was carried out in stationary and specific for drilling operations dynamic conditions of friction. Key words: friction, surface, abrasive-resistant film, oxide type fillers.

It is known that during the machinery operations in the surface layers of friction pairs due to deformation and thermal processes occurring intensive changes in physical and chemical properties of the metal, affecting the service life [1, 2]. In a sufficiently broad range of destruction energy of the original structure of the metal the uneven unsteady processes cause different types of solid-phase transformations of the surface layer under conditions of friction [3, 4].

A specific influence way to the evolution of surface microstructure of the metal in the friction zone is the introduction to the lubricant of heterogeneous colloidal fillers [5-7 ]. Such fillers are expanding range of chemicals designed to drill oil and gas equipment. [8] In recent decades, in practice, are often used fillers made of powdered rock minerals (betonies, serpentine rocks, magnetite , etc.) [ 7]. These minerals as impurities in a very large quantity belongs to the nature of bituminous materials that may play a significant role during drilling [9 ]. Most of these minerals belong to the natural hydro silicate, which can easily break up in the contact friction area and due to relatively low temperature dehydration convert into oxide fillers that influence the friction synergistically with oxides of transition metals [6 ]. The study of the formation mechanisms of abrasive -resistant surface microstructure of the metal under the influence of said filler is problematic because of trends ( risk) of coagulation their particles in the lubricant environment and, in general, long-term micro abrasive action in the initial period of friction.

The aim of the study was to explore and describe both as under stationary or dynamic conditions of friction the special abrasion-resistant friction microstructure occurring in the contact zone of high-strength steel friction pair under the influence of lubricants with specific fillers oxide type - surface modified natural asbestos and transition metal oxides.

Table 1 Average and projected cationic composition of the MF filler

Structure cation(Kt)

Concentration, atm %

Elemets

Na K Ca C Fe Cr Mg Al Si

cations

Kt + 0,2 1, 0 – ? * – – – – – 1,2Kt 2+ – – 1, 0 – 0,7 0,7 18, – – 21,2Kt 3+ – – – 8,9 – – 6,6 – 15, 5Kt 4+ – – – – – – – – 62, 62,1

Total 0,2 1, 0 1, 0 – 9,6 0,7 18, 6,6 62, 100

* Specifications of analyzer did not allow to study a carbon

Table 2 Load influence on anti-wear properties of lubricating compositions with mixtures, estimated according to GOST 9490

The diameter of the wear track DЗ, mmLubricant 196 Н 392 Н 588 Н 784 Н

МС20 0 52 0 70 3 10 *МС20+0 1 % мас МФ – 0 67 1 09 2 50МС20+0 2 % мас МФ 0 48 0 62 0 84 1 15МС20+0,6 % MoS2 – – 1,00 –

Li-lubricant+2 % lubr.

ТіО2

– 0,86 – –

Li-lubricant+10 % lubr.

ТіО2

– 0,98 – –

* Intensive adhesion of a friction pair

* coagulation conditions of microparticles TiO2 and microabrasion effecet of coagulants

Objects and methods of research

During the work was studied the influence of typical oxide-type fillers:

Fig. 1. The microstructure of the friction surfaces of stationary balls of 4-balls pair for cases: Base Oil МС20 (а); МС20+0,1 % lubr. МФ (б); МС20+0,2 % lubr. МФ (в, д); Li-lubricant with 2 and 10 % lubr. ТіО2 accordingly (г, е). Arrows indicate the direction of rotation of the moving ball. Load: 390 Н (г, е); 590 Н (а, б, в); 780 Н (д). Speed of rotation 1200 min. Friction duration 1 h.

MF sample - mineral powder of the asbestos group, modified by zinc dialkyldithiophosphate DTP Zn;

ТіО2 sample - unmodified microdispersed titanium dioxide powder.

As a comparison under the same conditions was assessed the influence of classical filler - molybdenum disulfide MoS2.

Powder fillers at various concentrations was added to the base lubricants: oil MS20, Li-acidic grease (КЧ = 1 mgKON /g), similar under elemental composition to Litol-24, rosin oil КАВС -45. Samples of balls with a diameter of 12.7mm hardness HRC 62-64, made from steel ШХ15, tested in the test lubricant compositions on 4-balls friction devices of type Falex-6 and Shell.

Chemical composition of powdered fillers and properties of friction surfaces was studied by means of metallography, scanning electronic microscopy, Auge-electronic spectroscopy and stepped spraying of the surface metal layers by ions of argon, energy dispersive X-ray microanalysis.

To study the structural features of the wear-resistant steel surface in the friction zone was investigated its density characteristic [2, 6]:

Characteristic

where S(h) - the total intensity of the Auge-lines of chemical elements, normalized to the relative sensitivity factors of elements at depth h - layer arrangement; S0 ~ const - average value of S (h) in the metal volume.

In addition to standard methods using a four-ball pair and friction device Falex-6 was used a specially developed methodology of tribological studies in the range of typical for rapid drilling machines 100-4000 min-1 (vibration frequency 1-63 s-1), which provided a modes of controlled-variable inequality friction conditions and the predicted microstructural reorganization of the surface steel ШХ15 [10].

Results and discussion

To clearly identify of the filler MF was made electron probe microanalysis of its sample and made conclusion according its cation composition (Table. 1).

On completion of testing was concluded the based on mineral sample MF is quite common mineral crocidolite asbestos (amphibole group of asbestos). This is a complex hydrsilicate of iron and magnesium with cations admixtures К+, С+, Сr2+, Са2+, Al3+:

(Na, K, C+)2(Fe2+, Cr2+, Mg, Са)3(Fe3+, Al)2[Si8O22](OH)2.

Table 3 Average diameter of D wear scar of fixed balls and the average coefficient of friction f of 4-balls pair after the initial breaking-in stage: breaking-in time is 20 min, load

588H, rate of turn-over 1200 min 1

Lubricant D, mm fМС20 0,42 0,049

МС20+0,1 % lubr. МF 0,44 0,054

МС20+0,2 % lubr. МF 0,44 0,053

Table 4 Average diameter of the D wear scar of fixed 4-balls pair after the rate of turn-over growth in the range 100-3800 min-1

Lubricant Load, Н D, mm

МС20 390 0,54

МС20+0,1 % lubr. МF 390 0,43

МС20+0,2 % lubr. МF 390 0,43

КАВС+5 % lubr. ТіО2 490 0,92

Zinc, phosphorus and sulfur content (surface-active elements of the modifier DTF Zn) were very low and registered only within an error of the electron probe microanalysis.

The ultimate composition of the sample ТіО2 was confirmed by Auge-spectral studies. Also found that in the normal state the powder particles of this hydrated have a dioxide surface.

Study of tribological characteristics of lubricating compositions within given in GOST 9490 testing duration (1 hour) was found some antiwear and antiscuff significant efficiency of the MF filler even in comparison with the classic filler MoS2 (Table 2).

Trends of the initial friction period is illustrated in Table. 3. Analysis of the received variables indicates that the processes of a friction pair setting in the case of base oil MC20 (Table 2, 588 W) and the final formation of abrasion-resistant surface metal microstructure under the influence of filler MF (Fig. 1, b) develops not at the early break-in period of a friction pair, and later, between the 20 and 60 min of friction.

In Fig. 1 is shown the microstructure of wear scar of fixed 4-balls pair (diameter values are given in Table 2.) for different lubricant compositions. The comparison reveals certain similarities of the influence of powdered natural hydro silicate and transition metal oxides, relatively shifted under concentrations scales fillers and loads on the friction pair. For the case of base oil MC20 was formed microstructure of wear scar surface (Fig. 1, a) is the result of a series of sequential micro and macroprocesses flow activated by prior setting of surface friction pair.

Fig. 2. The dependence of the friction coefficient f of n braking –in of 4-balls friction pair for the case of: oil МС20 (1); МС20+0,1 % lubr. МФ (2); МС20+0,2 % мас. МФ (3); lubr КАВС+5 % lubr. ТіО2 (4). Load: 390 Н (1–3); 490 Н (4). Step-up of n with average speed 75 min-1

Fig. 3. The microstructure of the friction surfaces of fixed balls of 4- balls pair provided the growth in the range 100-3800 min.for the cases: oil МС20 (а); МС20+0,1 % lubr. МФ (б); МС20+0,2 % lubr. МФ (в); lubr. КАВС+5 % lubr. ТіО2 (г). Load: 390 Н (а, б, в); 490 Н (г)

Fillers in lubricating compositions prevent setting of surfaces, but cause the microabrazive influence on metal (Fig. 1б, г). Increase of their concentrations in relation to surface-active components in an oil composition leads to the

local formation of structures, which are particularly resistant to microabrazive wear (Fig. 1, в, line in the vicinity of microstrip line A), reducing the wear surfaces (Table 2), but also enhance their apparent their heterogeneity (Fig. 1, в, д, е).

Let us assume that indicated structure results from buckling of friction mode and corresponding adjustment of the surface layer . In the following studies, we apply variable test conditions [10 ]. Dependence of friction coefficient on the rate of turnover (Fig. 2), registered for the studied oil compositions show regular oscillation coefficient of friction. Their amplitude is the smallest in the case of filler MF (curves 2 and 3), indicating the effective inhibition under the influence of its micro particles of specific critical transformation of the steel microstructure [10].

Fig. 4. Concentration profiles of Сі elements (а) and density (Equation (1)) of segments (б) in a wear-resistant surface structure investigated within the microstrip line А (see. Fig. 1, г) of the surface friction of fixed steel ball of the 4-balls pair. Oil МС20 with addition of 0,2 % lubr. МФ

Estimated value of fixed balls of the 4-balls pair wearing (see Table. 4) showed significant anti-wear performance of mineral hydrosilicate МФ during almost the same study duration, as in the case of GOST 9490 (Table 1). The effective value of volumetric balls wear, which is proportional to the cube of the average diameter of the wear strap decreased twice in the presence of filler МФ: (0,54)3/ (0,43)3= 2.

The microstructure of the balls friction surfaces (Fig. 3) also significantly varied under the influence of admixtures. In the case of oxide filler TiO2 in rosin oil КАВС (Fig. 3, г) typical critical transformations of the steel microstructure are interrupted, probably under the influence microabrazive action of the filler (Fig. 2, curve 4).

Under the influence of lubricating compositions with filler MФ on the surface friction we witnessed a presence of, fine wear-resistant and, obviously, abrasion-resistant surface film that is best seen in Fig. 3 г. Decrease of the concentration of MФ filler causes deterioration of the homogeneity of this film (Fig. 3, б).

The results of Auger analysis of the surface, resistant to wear microabrazive wear (Fig. 1, г , microstrip line A) for the case of lubricating compositions with filler MФ

we witnessed its complex thin-film structure. Analysis of the profile (Fig. 4a) shows that the modifier ДТФ Zn acts synergistically with hydrosilicate of iron and magnesium, which promotes the formation of a new structure of steel surface [11].

Study of density characteristics of silicon-containing surface (Fig. 4, a) in equation (1) showed the presence of condensed steel ШХ15of surface oxide structure type compared to the volume (Fig. 4b). Investigated surface (Fig. 4) does not reach the volume of steel, as evidenced by the relatively low values of the iron concentration in it. Between the compacted surface and the volume of steel is seen also the transition layer with "disperse" structure.

Abrasive resistant surface microstructure created in friction conditions under the influence of oxide filler ТіО2 were thoroughly investigated in [6]. We found that the microstructure of the surface formed by carboxy ща iron and titanium and have also relative increased volume density relative to the volume of steel ШХ15 (density characteristic in equation (1) reaches to 0,4-0,5).

The similarity of the generated surface microstructures for both studied fillers (ТіО2 and МФ) under different loads of friction pair raises questions about the role of the processes of dehydration of МФ filler in conditions of transient friction.

Conclusions

We witnessed an analogy between surface microstructure of steel, created in conditions of friction as a result of such fine heterogeneous oxide fillers such as hydro and natural oxides of transition metals. Under the influence of fillers on the friction surface of steel ШХ15 may form a surface film, resistant to microabrazive wear. The results of the study proved that its formation occurs in certain modes of friction (close to setting or dynamically change of the wear mechanisms) due to the simultaneous transformation of the microstructure of the critical surface layer and the influence of microparticle filler. Abrasive resistant film is a complex surface microstructure of the oxide type, which has a higher density compared to the bulk steel structure.

By the method of periodic changes of moving balls turnover rate of 4-balls friction pair were made conditions of nonequilibrium mechanical and chemical activation of the steel surface, specific to the dynamic characteristic of the drilling of oil and gas wells in which the effects of formation of abrasive-resistant microstructures are shown the most effective way. The latter, in particular, makes the possibility of on-line diagnostics and research.

Authors Tsapliy Maksym Petrovych Research Engineer, post-graduate UkrNDINP "MAСMA." Fields of research - friction and wear of metals under the influence of lubricant.

Yudina Vita Vasylivna Senior Researcher of UkrNDINP «МАСМА», candidate of Technical Sciences, Fields of research - development of production technologies and study the properties of lubricants.

Pavlovskiy Anatoliy Petrovych post-graduate UkrNDINP "MAСMA». Fields of research - friction and wear of metals, production technologies of lubricants.

Mishuk Oleg Oleksandrovych Senior Research Engineer UkrNDINP "MACMA" candidate. Sci. sciences. Fields of research - spectroscopy, physics and chemistry of solids surface, friction and wear of metals.

News New search well on the Romanian shelf Petroseltic International PLC, a subsidiary of Melrose Resources Romania BV, began drilling of search wells in

promising areas of Cobalcescu South, located on the Black Sea at the distance of 170 km to the southwest of Constanta. The well has a complex trajectory, its purpose is to open promising horizons of the Miocene. The company has a 40% shares in the concession areas of the Est Cobalcescu and Muridava. In the first area its partners are the Beach Petroleum SRL and the Petromar Resources SA, each of which owns 30 % of shares.

Conducted by Petroseltic set of studies has shown promising areas as of high gas and of oil. After drilling of search wells in this area , the company plans to drill exploration drill hole in the nearby area of Muridava

Romania: Petroceltic group spuds Black Sea

wildcut. Oil & Gas Journal/16.10. 2013

WELL DRILLING

Computer simulation of drill string bit spinning vibrations in deep wells

УДК 539.413+622.243

© Gulyayev V.I., D-r of Tech.Sciencies National Transport University Gaidaichuk V.V., D-r of Tech.Sciencies Kyiv National University of Engineering and Architecture Shevchuk L.V. National Transport University

The paper studies the problem of whirl vibrations of a rotating drill string bit under conditions of its friction interaction with the bore-hole bottom surface at the wandering contact point. The mechanism of the bit spinning and rolling without sliding on the rigid surface has been analyzed. To study the whirl vibrations the methods of theoretical mechanics are used. The kinematic in du ce m e n t of the ro ta t ing bi t mo t i on witho ut slid in g is sh ow n to be t he ma i n c a u se of it s sta b ili t y loss. T h e d etailed st ud y o f th e b it whirling revealed three types of its motion associated with direct and inverse rolling as well as pure spinning. Key words: drill string, swirling, well, bit, movement trajectory, simulation.

Due to the depletion of accessible hydrocarbon resources in recent years significant amounts of oil and gas extracted from a deep underground reservoirs. However, in these cases, oil and gas production related to technological difficulties of deep wells drilling, including the possible emergence of abnormal situations caused by critical states of quasi-static equilibrium and vibrations of the drill string (DS ) [1 , 2]. These include friction weldings of boring columns and their critical bending protrusion and vibration, which can include axial, torsional and bending vibrational motion [3–5].

However, the most complex mechanism with bottom bending vibrations of the DS caused by action on the bit of variables over time normal and junction forces of a contact and frictional interaction of the bit with the wall. In this case, the geometric center of the bit begins to move around the center line of the hole ahead of or behind the rotary motion of the column. In mechanics they are called precession oscillations. In works is [ 6, 7] noted that the above-mentioned motion of the center bit has a different nature and for its definition is used the term «whirling», translated into Ukrainian - «кружляння». It was studied on simplified physical and mathematical models with one or two degrees of freedom for different friction laws interaction with the wall and the bit of the hole. These models are far from the real system and poorly reflect the actual dynamic processes.

Experiments and observations have proven that, in some modes of spinning oscillations the bit starts to hit the skids of the bottom hole, and its center moves quite complex trajectories that remind of polypetalous plate forming on the surface of the borehole wall troughs which are invalid for specifications for drilling. It is possible the realization of two types of motion bits. In one of them the bit bearing happens with slip, and between the surface and down hole appears a force of friction directed along the tangent to the trajectory of the point of contact. In the second type of motion the rotating bit rolls without slipping on the surface of the bottom hole, satisfying the conditions of kinematic elm. To study the oscillations of such system can only by methods of theoretical mechanics and mechanics of elastic rods.

The article deals with the computer simulation and vibrations problem of the second type.

Methods of computer simulation

Since the bit surface (Fig. 1) and the withdrawing of well may have different shapes, the drilling process under different perturbations are possible motion transitions of bits from pure rotation (full-time drilling process) to its additional rolling movement from the vertical point of contact with the bit with withdrawing of the well and distortion of the axis of the drill string. To investigate these phenomena is necessary to put the problem of elastic transverse vibrations of the drill string, in which a kinematic ties are boundary conditions for the equations its motion.

Fig. 1. Geometric shapes

Oscillations of whirling bits that rotates with angular velocity co, usually accompanied by involvement in the vibration process of lower parts of the columns, which are located between the centering devices and act as additional support. Therefore, when analyzing the mechanism of oscillations excitation of spin whirling bits under the influence on the upper part of DS we will ignore and denote its fragments AB and BC with lengths l and e. (Fig. 2).

Fig. 2. Diagram of the drill string

Selected tubular portion of DS prestressing by the the bit torque Mz and longitudinal compressive force T, which is equal to supporting reaction of the bit to the withdrawing of well. The dynamics of this area we will

simulate based on the theory of short twisted rotating rods. To that effect, we introduce a fixed coordinate system OX YZ and coordinate system Oxyz, which rotates with DS, with the general O on the resistance A. For quantitative analysis of kinematic excited spin fluctuations is necessary to compose a dynamic equation of the whole rotating selected for review 2-stringer ABC, which is prestressed by torque Mz = -Mfr and longitudinal compressive force T =-R. These equations are given in [1, 2].

We will introduce also a system of coordinates O1x1y1z1 to describe the elastic rotation of the bit rotating, axis Ox1, Oy 1 which are parallel to the axes Ox, Oy respectively, and the beginning of O1 is on the axis Oz and in the source position coincides with the center of mass C of the bit. Will connect with a bit a system Cx2y2z2, which axis Cx2, Cy2 in the initial position are parallel to the axes Cx 1, Cy 1, and in the case of elastic deformation of the columns returned to the corners-v'|C and u'|C u' with a bit.

We assume that the bit has a shape of an rotating ellipsoid and rolls along the surface well, which is the acreage (Fig.3).

Fig. 3. Scheme of the contact interaction of ellipsoidal bit with a rough acreage

Developing the kinematic propulsion of bits, we assume that the elastic rotation angles of the system Cx2y2z2 are relatively small. Then you can enter a vectorof complete rotation angle:

Will connect with a bit the system of axis Cx3 y3 z3 axis Cz3 which is a continuation of the elastic axis of the column, axis Cy3 is collinear to the vector θ, and the axis Cx3 completes this system to the right three vectors (see Fig. 3). These axes coincide with the principal central axes of inertia ellipsoid. To determine the point of contact G of the bit with withdrawing of well will write the equation of the ellipse obtained by cross-sectional surface of the bit by the acreage x3Cz3:

In the same acreage, we will introduce axis Cx4 and Cz4 (see Fig. 3). Transition from the system x3Cx3 x4Cx4 conduct by using the formula:

Fig. 4. Motion Trajectory of the point of contact of the bit with withdrawing of well

Rolling conditions without sliding ellipsoidal bodies on rough surface are given by:

They link the movement velocity of the bit center and its rotational with displacements u, ν, so are the kinematic boundary conditions for the core of the drill string. These are added with conditions of bits dynamics that allow to examine the dynamics problem as fully defined system. To construct these equations will use the principle of conservation of angular momentum of change of the bit according to the point G:

where KG – is a principle of conservation of angular momentum of the bit according to the point G, MG – moment of toughness force, acting on the bit recorded in the same system.

On the basis of the correlations (1) - (5) set up three point boundary problem of the dynamics of the lower span of the drill string with a bit. It is added by the initial conditions that define the initial system excitation. Numerical solution of the problem is carried out by using a finite difference implicit scheme at time t.

Stable and unstable bits movements on withdrawing of well

By the developed procedure were studied oscillations of spherical and ellipsoidal bits for different values of the geometric parameters and the angular velocity w. Fig. 4 shows the trajectory of the contact point G on withdrawing of well in the fixed coordinate system. Positions а– в in Fig. 4 corresponds to the case of spherical bit with a radius a = 0,12 m. You can see that by value of a radius of withdrawing of well surface R = 0,592 m (see Fig. 4a) a point G moves along a closed path trajectory. When R = 0,15 m , w = 10 rad /sec point G moves along a spiral curve that tapers. This regime is stable and more favorable because the bit trying to take regular (on the axis of the column ) position after after it is taken from the working class. When R = 0,15 m , w = 10 rad /sec point G moves along a spiral curve that extends. This drilling mode is unstable.

For a bit of ellipsoidal shape the movement trajectory of the contact point G grow increasingly complex. Fig. 4, г–е shows the selected loop-shaped curves that are expanding, of unstable regimes, which are realized for elongated (and <b) and flattened (a> b) ellipsoids.

Conclusion

Finally, note that considering problem of self-excitation oscillation is a multivariable because these modes depend on the form of bits, withdrawing of well surface geometry and angular velocity of column. However, as shown by our However, as shown by our calculations, mode stability is determined by the bending instability of the lower span of the column between its centralizer. As this rigidity with decreasing of cross-sectional area of the column and increasing of torque and axial compressive strength decreases, so is necessary to select the values of these quantities to prevent the self-oscillation of a system.

WELL DRILLING

Differential «stiff-string» model for drag and torque simulation in deviated bore-holes

УДК 539.413+622.243

© V.I.Gulyayev Dr.Sc. National Transport University V.V. Gaidaichuk Dr.Sc. Kiev National University of Building and Architecture O.M. Andrusenko N.V. Shlyun National Transport University

The problem of computer simulation behavior of drill strings in hyper deep vertical, inclined and horizontal wells is stated with the aim of forecasting the possible initiation of emergency situations during drilling operations. The questions of stability and post-critical non-linear deforming of the drill strings are considered. It is shown that all of them are singularly perturbed from the mathematical point of view and because of this, they are poorly amenable to theoretical analysis. The algorithms allowing surmounting these difficulties are proposed. The software for study of these phenomena is elaborated. The elaborated software permits one to construct its trajectory securing the smallest values of resistance forces and to choose the least energy-consuming and safe regimes of drilling.

Key words: deviated bore-hole, “soft-str ing” model, “stiff-st ring” model, geometr ical distor tions, spiral imperfections, safe regimes, computer simulation.

One of the most important technological components of hydrocarbon production is drilling of deep vertical and inclined wells. But their dr ivage is f raught with great tech nological dif fcul-ties caused by permanent balance change of the forces of gravity, resistance (friction), inertia, and elasticity acting on the drill string and its bit as well of the moments of thees forces [1, 2]. Therefore, in drilling curvilinear bore-holes the percentage of emergency situations and casualties continues to remain high. The above-listed factors make the problem of computer simulation of the processes of movement and elastic bending of drill strings in the channels of curvilinear bore-holes to be notably urgent.

Early in the development of techniques for deep curvilinear bore-hole drilling, as a rule, the bore-holes of the simplest con-fgurations with small distortions of axial lines were consi-dered. In these bore-holes, the bending strains of drill strings are not essential and they can be neglected. In these cases the DS was simulated by an absolutely fexible thread and an approach called the minimum curvature method («soft-string» model) was ad-opted [3, 4].

With advances in techniques of the curvilinear bore-hole drilling, they became to acquire more complicated geometry, their depths enlarged, and their horizontal distances from vertical began to exceed 12 km. It is reasonable that the process of the well drilling, the energy consumption related to it, and the emergency situations attendant on it turn out to be by far most sensitive to the mistakes allowed at the stage of the well design and inevitable in its drivage [5].

In the studies [6, 7], a new approach based on the use of the theory of fexible curvilinear rods («stiff-string» model) was proposed for simulation of these processes. It was demonstrated that the resistance forces could be essentially reduced and even the sticking effects could be avoided through combination of the axial and rotary movements of the DS during performance of the raising-lowering operations.

In this paper, the problem of creation of techniques for computer simulation of technological means minimizing ener-gy consumption in movement of a DS in a curvilinear bore-hole with geometrical imperfections is stated. It can be used at the stage ofthe well geometry design and prescription of requirements on its accuracy, in the design of regimes of the DS drivage and their realization, as well as in the execution of the operation of the DS ridding of the sticking.

«Stiff- string» drag/torque model

To simulate the mechanical phenomena attending the drilling process and to select its most favorable characteristics, use the mathematical model based on the theory of curvilinear flexible rods [6, 7]. Assume that the DS axially moves with velocity w and rotates with angular velocity со in a bore-hole channel with known geometry. In the Oxyz coordinate system its axial line T is prescribed in the form

ρ= ρ (s), (1)

where ρ is the vector function ρ = xi+ yj+ zk describing the axial line of the bore-hole; i, j, k are the unit vectors; s is the parameter measured by the length of the axial line of the DS.

Consider that the axial lines of the DS and bore-hole coincide. Then, it is possible to determine all geometrical characteristics of the bent DS including the curvature radius R, curvature kR, and torsion kT:

With the use of correlations (1), (2), t he equalities are deduced which determine the components of the gravity force vector

and components of contact force between the D S and the bore-hole

Here Fz and Mz are the internal axial force and torque; A is the bending stiffness of the DS.

Assume that the DS is being dragged with velocity ώ and rotates with angular velocity ω simultaneously. Then, the conditions of the Coulombic friction are realized between the surfaces of the DS and bore-hole.

As a consequence, the stress-strain state of the DS in its axial movement with the ώ velocity and simultaneous rotation with angular velocity ω can be described by two frst order differential equations

where the functions k R, ƒ gr τ are known and the required friction functions ƒ gr

τ , m fr , and Fn can be determined with the help of Eqs. (3)-(5).

Solution of Eqs. (5) under given initial conditions allows one to construct functions Fτ(s), Mτ(s) and to fnd the values of axial force Fτ(Si ) and torque Mτ(Si) which should be applied at the point of the DS suspension for performance of the required technologic regime for chosen ratio η between the velocities of rotary (ωr) and axial (ω ) motions. As our theoretical results demonstrated, in doing so, the value of parameter η infuenced essentially

on the possibility to perform the designed operation [6, 7]. Thus, enlargement of the η value entails increase of Mτ(Si ) and decrease of Fτ(Si ) and vice versa, it is possible to enlarge Fτ(Si ) reducing η.

The marked opportunity of change Fτ(S), Mτ(S) and control over technological process through the η parameter varying at its every step permits not only to predict and avoid emergency situations and failures, but also to select the least energy consuming regimes of the drilling processes. Indeed, assume that the real geometry and admitted imperfections measured through the use of logging sonde are known. Then the work dW performed in the elementary segment ds can be represented in the form

After solving system (5) under different η with allowance made for the measured geometrical imperfections, choose the η i value providing minimal value dWi for the considered regime and length Si. At this case, the ωi value is selected issuing from the technical data and possibilities of the engine device of the drilling rig.

Notice that the proposed approach can be used both at the stage of the well design and its drilling. In the frst case, the hypothetical parameters of the bore-hole trajectory and imperfections can be varied in wide limits reasoning from the technological possibilities of their realization. In the second case, the real magnitudes of these parameters are prescribed, which are found in the result of electrical logging analysis.

Energy saving regime of raising a drill string in a well with spiral imperfections

Let the well trajectory be originally designed as a part of an ideal hyperbolic curve, as shown in Fig. 1, a. But in reality, it is not possible to ensure exactly the conceived outline of the bore-hole axis and usually some distortions are introduced into its geometry. The localized 3D spiral is one of the common shapes met in practice. Its pitch λ = 2π/k is determined by the wave number k and is considered to be constant (Fig. 1, b), its radius h(s) has maximal value hc at the point s = sc.

Th rough the use of the elaborated approach the energy sa-ving operation of a DS raising in a well with localized spiral imperfections is considered.

In design of a bore-hole geometry and techniques of its drivage, one is forced to take into account a great variety of determining factors including the horizontal distance from the vertical (exceeding 12 km), depth (down to 4 km), well outline (in our case, hyperbola), and possible occurrence of geometrical imperfections. Below, the case is t reated when the desig n hy perbole is preset in the domain 3p/2< S < 2p and determined by the parameters H = 4000m, L = 10000m, and ε= 3. The set of spiral imperfections of amplitude hc = 2m and pitch λ = 109m is superimposed on the hyperbola trajectory. Its center is assumed to be located at Sc = 3S/8. Here S is the well length.

It should be pointed out that these imperfections are not discernible at the real scale shown in Fig.1. So, their images are presented at larger scale in this figure.

In our analysis, the following typical factors were chosen: r = 0,08415m, thickness of the drill string tube δ= 0,01m, E = 2,11011Pa, γt = 7850kg/m3, γl = 1500kg/m3, friction coeffcient μ = 0,2.

Firstly, consider the infuence of the taken imperfections on the functions of axial force Fτ(s) (Fig. 2, a) and torque Mτ(s) (Fig. 2, b) at r| = 1. In Fig. 2, the functions Fτ(s) and Mτ(s) are represented. Curves 1 in these diagrams correspond to the design well with ideal geometry, curves 2 represent the case when the bore-hole is distorted.

On the basis of the prescribed geometry, the problem for Eqs. (5) is solved for the chosen length Si and different values of the ratio η= ωr/ ώ between the velocities of the rotary (ωr) and axial (ώ) motions. Then, the value ηi is selected which minimizes the elementary work (6). To minimize energy consumption during execution of the raising operation the item-by-item simulation method was used at every stage of the optimization analysis. In order for this modeling to be made, the drill string length S was divided into ten equal segments ∆Si = S/10 (i =1, 2,…, 10) which were detached one after another from the drill string length, imitating the drill string raising operation. In Fig. 3, the diagram of the ηi value change is shown.

It issues from this illustration, that the smallest resistance to the motion of the full length drill string is achieved when η≈ 2,033. But while the drill string is raising, the necessity to rotate the system decreases and when the well segment with imperfections is passed, it becomes possible to raise the drill string without rotation, because ηi ≈0.

It is necessary to note also that the proposed software allows one to perform computer monitoring of tehnological operations of drilling.

Conclusions

1. The problem of an elastic drill string bending inside a curvilinear channel of a bore-hole is stated for evaluating the elastic, contact, and friction forces attending the drivage operations.

2. It is shown through the use of the elaborated software that the resistance forces impeding the drill string dragging inside the well can be regulated through the combination of its axial and rotary movements. The method for minimization of the energy consumption by the choice of a special ratio between the velocities of these movements is proposed.

References

1.Gulyayev V.I. Free vibrations of drill strings in hyper deep vertical bore-wells / V.I. Gulyayev, O.I. Borshch // J. Petr. Sci. Eng. – 2011. – V. 78. – P. 759–764.

2.Gulyayev V.I. The buckling of elongated rotating drill strings / V.I. Gulyayev, V.V. Gaidaichuk, I.L. Solovjov, I.V. Gorbunovich // J. Petr. Sci. Eng. -2009. - V. 67. - P. 140–148.

3.Brett J.F. Uses and limitations of drillstring tension and torque models for monitoring hole conditions / J.F. Brett, A.D. Beckett, C.A. Holt, D.L. Smith // SPE Drill. Eng. - 1989. -V. 4. - P. 223–229.

4.Sawaryn S.J. A compendium of directional calculations based on the minimum curvature method / S.J. Sawaryn, J.L. Thorogood // SPE Drill. Complet. - 2005. - P. 24. - 36 March.

5.Mitchell R.F. How good is the torque / drag model? / R.F. Mitchell, R. Samuel // SPE Drilling & Completion. - 2009. - P. 62. – 71 March.

6.Gulyayev V.I. The computer simulation of drill column dragging in inclined bore-holes with geometrical imperfections / V.I. Gulyayev, S.N. Hudoly, L.V. Glovach // Intern. J. of Solids and Structures. - 2011. -V. 48. – P. 110–118.

7.Gulyayev V.I. Sensitivity of resistance forces to localized geometrical imperfections in movement of drill strings in inclined bore-holes / V.I. Gulyayev, S.N. Khudoliy, E.N. Andrusenko // Interact.Multiscale Mech. - 2011. - V. 4 (1). - P. 1–16.

OIL AND GAS PRODUCTION Rationale for choosing the geometric dimensions of well hydraulic jet

pump

УДК 622.24+621.694.2 © Velychkovych A.S.,

cand. of Engineering sciences Panevnyk D.O IFNTUNG

Barlow’s equation written for a thick-walled cylindrical shell a relationship was found between the stress that occurs in the material of the above-bit unit body and the flow of flush fluid for different designs of the borehole pump-circulation system and the jet pump flowing section. The study made it possible to determine the minimum allowable wall thickness for the above-bit ejection system, which facilitates its fault-free operation.

Key words: well pump, above-bit device, ejector technologies, Barlow’s equation, formation fluid, hudro-elevator, washing fluid.

The high efficiency of ejection technology has led to a wide range of their application in the drilling, development and operation of wells during the implementation of intensification methods of oil and gas production in collection systems and preparation of reservoir fluid. Complications of reservoir fluid extraction conditions require the creation of new methods of development of hydrocarbon deposits, and therefore improving of ejection technologies of oil and gas production is an urgent task.

Despite considerable experience in designing, design engineering of well hydraulic jet pumps is limited by justification of geometrical dimensions [1-4] and production material [5] of the elements of the flow part.

At present, there is no methodology for determining of the required well hydraulic jet pump. The special feature of the downhole equipment is a significant difference in the pressure of the column of pipes and channels of annulars space due to hydrostatic pressure and hydraulic losses in the pump cell - circulating system. The situation is complicated by the possibility of occurrence of cavitation in certain areas of the circulation system, when the magnitude of the hydrostatic and hydrodynamic pressure drops to zero. After a difficult operating conditions of ejection systems for case details of a jet pump is used thick membrane, thereby increasing the metal equipment and limited possibilities for its use.

The aim of research, the results of which are presented in this work is a theoretical justification of the selection method of the wall thickness of ejection system with external placement of the jet pump.

Asubject of research shown in Fig. 1 а, implements a combined washing of near withdrawing area [6] and can be classified as a jet gun of bit version with parallel connection of hydraulically linked to at-bit area of the jet pump and center inlet of workflow.

Determination of wall thickness of at-bit jet pump provides pressure calculation and analysis of the nature of the flow distribution in the pump cell-circulating system of wells.

The flow of drilling fluid flow Qн moving the central channel of the drill string and enters the cavity formed by the cylindrical shell of the case 1 of at-bit device (Fig. 1b). At point "в" occurs a distribution of main stream, one part of the flow Qр is aimed at working nozzle 2 of the jet pump and the other with a flow Q д continued downward movement passes through the jetting bit nozzle 3 and after cleaning of the withdrawing goes to at-bit area and hydraulic annular channel space. Pressure difference acting on the cylindrical portion of the housing 1, determine the level of the horizontal dotted line a- a (see Fig. 1, б) carried out through the output section of the working nozzle jet pump 2. At point "к" we determine the pressure Pк that matches the internal pressure in the cavity of the housing 1 of the jet pump, and at point "з" - the pressure P з that for cylindrical shell casing is external. Pressure difference ∆P = Pк – P з create tension in the material cylindrical shell and is the main factor that determines the wall thickness of the housing of the at-bit unit.

The output pressure of the working nozzle jet pump changes from hydrostatic (in case of zero productivity of jet pump Qн and labor losses Qр) to the value of saturated vapor pressure P нп of flushing solution when ejection system operates in cavitation mode [7 ]. In this case, at point "з" (Fig. 1 б) formed cavitation area that directly borders the outer cylindrical surface of the case of at-bit device, and the value of pressure in the annulus area takes the value of P з = P нп.. The pressure value of vapor compared with the value of the hydrostatic pressure P г is small : Pнп= (0,0005 - 0,001) P г, so when determining pressures in case of at-bit device can take as Pк= 0 and ∆P = Pк. The most difficult conditions of jet pump using - during its exploitation in cavitation mode, so that particular case is necessary to take into account when elaborating the methodology of calculation of wall thickness of the device.

Fig. 1. Design (a) and hydraulic circuit (б) of ejection system for drilling: 1 – case of unit; 2 – operating nozzle of jet pump; 3 – bit

Modern methods of pressure calculating in a cylindrical shell include [8] the using of formula Lame and Barlow. Note that the recommendations for the use of the formula Barlow well represented in the standard American Society of Mechanical Engineers (ASME) [9]. Given that the calculations for the Lame theory allow 5% greater of pressure values than formula Barlow, just the last will use to determine the wall thickness δ of at-bit hydraulic elevator:

where d - inner diameter of the casing hydraulic elevator; [σ] - allowable normal pressure.

For elevator as part of the drill string that works during drilling, was obtained a similar formula for determining the wall thickness of its case using momentless shell theory [10], neglecting the influence of axial pressure from the weight of the drill string and shear ressures from its torsion, compared with influence of ring pressure caused by pressure Pк.. It is clear that, in this case, is necessary to take adequate assumptions for safety factor value.

Thus, the strength design of the at-bit unit case reduced to determining the hydraulic resistance pump-circulation system elements of the well and pressure Pк. In the simulation process of the drilling fluid movement we suppose that the diameter of the drill string and the well throughout its length does not change, and the hydraulic losses in socket joint are minor.

Given the peculiarities of determining hydraulic losses in cell-circulating pump systems [11], the formula of pressure P determination is:

where ρ-is density of drilling fluid; g - acceleration of gravity, Нн and Нс - the depth of the jet pump placement and the well, λк, λз - the coefficients of the linear hydraulic resistance according to the channel of the drill string and annulus; μд - nozzle flow coefficient of the bit; N - number of bit nozzles, dд - the diameter of the bit nozzles; D - diameter of the hole (bit) dв, dз, - the inner and outer diameters of the drill string.

The first component of formula ( 2) determines the amount of hydraulic pressure at the level of jet pump Нн placement. The second component , which determines the linear hydraulic losses in the drill string at the site of jet pump placement to bits, calculated under the formula Darcy - Veysbah [12 ] after replacing the velocity of the stream flow rate Vк on Q д. etc. The third component of the formula (2 ) defines the hydraulic losses in local stands formed by flushing system of the bit. The final component of the formula (2) defines the hydraulic losses in the annulus space above the location of the jet pump.

Fig. 2. Absolute (a) and relative (б) value of the wall thickness of the at-bit unit depending on its internal diameter and productivity of mud pump: 1 – d=0,0714 m; 2 – d=0,0904 m; 3 – d=0,1 m

Determination of the coefficients of the linear hydraulic resistance λк and λз provides a standard procedure of calculating the velocity of the drilling fluid, actual and transition Reynolds numbers. After setting the fluid mode movement and determination of the area of the hydraulic friction the coefficients of the linear hydraulic resistance λз, λк are calculated by formulas of Stokes Blasius and Altshul. [12].

The solution of equation (2 ) requires a prior calculation of flow rate losses of drilling fluid in the circulation system of the well. Pump- circulating systems of withdrawing area forms a closed path in the form of two parallel hydraulic channels. The first channel consists of a hydraulic nozzle of jet pump is and the other - from the area of the drill string between the jet pump and bit, the rinsing bit system and annulus area below the location of the working nozzle. From the calculation theory of complex pipelines is known that the combination of two parallel hydraulic channels ending by nodes: input (point "в" ) and output (point "з" ). Between nodal points are two simple pipelines with relevant local factors and linear resistance. By branching (node "в") through the central hydraulic channel moves a drilling fluid with the flow Qн and pressure Нз, and from node " з" moves the same amount of liquid, but with less pressure. Thus, the pressure losses in each of the hydraulic channels will be identical and are determined as the difference between pressure (or pressures) at the nodal points. Alignment of resistance losses in hydraulic channels of the withdrawing area is due to the redistribution of corresponding losses Qp and Qд in separate parts of the closed circuit.

Given the Darcy-Weisbach to determine linear and local hydraulic losses note equation of equal pressure in a closed circuit of parallel links:

where μp – discharge coefficient of working jet pump nozzle; n – number of jet pumps in the ejection system; dp – diameters of the jet pump nozzle.

The components of formula (3) are determined discharge coefficient of working jet pump nozzle, drill string, drilling bit system and annulus.

After substitution the last expression can be reduced to the quadratic equation

coefficients of which is determined by the formula

If used the at-bit device (Hс = H н) the equation (4) is much-simplified.

Distribution of losses in the ejection system is defined by the component equations (4) - (7). In particular, if the number of jet pumps in at-bit ejection system is n = 4 [6], and the number of nozzles jetting bits N = 3, then if the conditions Hс = H н; Цp = \хд; d р = dд the flows losses in withdrawing area of the wells are Qд = 0,43Q н;Q р = 0,57Qн.

Taking into account the equality of pressure losses in the parallel links of closed circuit, the second and third term in equation (2) can be replaced by a component that determines the hydraulic losses in the working nozzle jet pump. However, simplification estimated equation reduces its information content regarding the design of drilling bits, as in this case does not contain the component that determines the flow resistance.

Using equation (1 ), (2 ), (4 ) - (7 ) will determine the wall thickness of the hydraulic elevator at-bit for such conditions : ρ = 1000 kg/m3 ; H c = 4000m, μд = 0.95 , dд = 0, 01m ; d з = 0,216m; = 0.127m, [ a] = 100 MPa (Fig. 2). The value of the inner diameter of the unit housing are taken (Fig. 2a) based on weighted geometric sizes of drill pipes wich usually used in manufacturing bases of service support UBR for manufacturing of drilling equipment. Analysis of the dependence indicates that the considered conditions prevailing effect on the value of pressures that occur in basic parts of hydraulic elevator under internal pressure. It should also be noted that the relative wall thickness of the case δ = δ/d does not depend on its internal diameter (Fig. 2b). For any values of the internal diameter of the unit case the value of its relative thickness is described by a single graphical dependence. In view of these results, basic parts of hydraulic elevator, given the generally accepted classification can be attributed to thick shells.

Conclusion

A developed pressure designe technology arising in cylindrical shell of the at-bit hydraulic elevator as a result of internal pressure makes it possible to determine allowable ratio under these conditions of wall thickness and internal diameter of the casing. The studies can be used at the design stage and exploitation eof jection systems, they help to increase the effectiveness of well construction in difficult geological conditions. The aim of further research is experimental verification of the proposed methodology for determining the wall thickness of the at-bit hydraulic elevator with external placement of the jet pump.

Authors

Velychkovych Andriy Semenovych Candidate of Techn.Sciencies, reader of Structural Mechanics of the Ivano-Frankivsk National Technical University of Oil and Gas. Research interests include the development and calculation of elastic shell elements.

Panevnyk Денис Олександрович

Student of the Institute of Mechanical Engineering of the Ivano-Frankivsk National Technical University of Oil and Gas, branch - oil and gas business. Research interests - modeling of hydraulic elements of pump circulation systems of Oil and Gas Complex.

NEWS

Branch Line of South Stream

Russian company "Gazprom" and the Bulgarian company «Plinacro» held talks on the construction of 100 km of the branch line from the future gas pipeline "South Stream" to feed gas to Croatia. This section of the pipeline will have an annual output of 2.7 billion м3, the cost is estimated at 79.9 million USD. It is expected that the pipeline will be commissioned in December 2016..

Deputy Chairman of Gazprom O. Medvedev and the President of the Republic of Srpska M. Dodik signed implementation roadmap of energy projects in Serbia under the project "South Stream". Roadmap foresees the necessity to sign an intergovernmental agreement on cooperation between, Russia and Bosnia and Herzegovina, when implemented projects for the construction of the above branch pipeline and power plants that use natural gas as a fuel.

Pipeline & Gas Journal/August 2013, р. 16

LIST OF ARTICLES PUBLISHED IN 2013

ECONOMY AND DEVELOPMENT PROBLEMS KOLBUSHKIN Ju.P. Development of the gas market of Ukraine……………………………………………………№ 6 MARCHENKO A.I., STUKALENKO І.О. International natural gas markets: problems and possible ways of solving…………………....№ 3 OIL AND GAS GEOLOGY VLADYKA V.M., NESTERENKO M.Yu., BALATSKYI R.S. Research technique and testexperiments for the analysis of petrophysical properties of weak-consolidated and friable rocks…………………………………………………………………№ 2 VLADYKA V.M., PUSH A.O., NESTERENKO M.Yu., BALATSKYI R.S. Trends of changing reservoir properties of Sarmatian stage rocks of the northwestern part of Bilche-Volytske area under different facial conditions of sedimentation (in English)………..№ 5 YEVDOSHCHUK M.I., BARTASHCHUK L.O. Prediction of non-structural hydrocarbon traps in Upper Visean stratum on the slopes of near-axial troughs of DDD………………………………………………………………………….№ 5 YEVDOSHCHUK M.I., HALKO T.M., SEDLEROVA O.V., VOLKOV A.V., YAKUBENKO G.M. Prospects for oil and gas bearing capacity in Ukrainian sector of the Sea of Azov by a comprehensive assessment of GPS study data…………………………………………………№ 1 ZIUZKEVYCH M.P. On some problematic issues of the current efficiency of oil exploration work (in English)…………№ 5 IVANYSHYN V.A., KOPCHALIUK A.Y. Paleotectonics of Yaroshivska area…………………………………………………………………...№ 5 KYCHKA O.A., KOVAL A.M., TYSHCHENKO A.P., DOVZHOK T.Ye., KOROVNYCHENKO Ye.Ye. Concerning the problem of development of methane hydrate potential of the Black Sea……………№ 5 KOVAL Ya.M. Improvement of geophysical well logging data interpretation by constructing rock distribution patterns according to the cement type (in English)……………………………………………………......................................................№ 5 KUKHTINA-HOLODKO L.М., HOLODKO B.I. Oil and gas prospects for Vietnamese continental slope and adjacent shelf of the South China Sea……………………………………………………………………………………………..№ 3 MACHUZHAK М.І., LYZANETS А.V. Discovery potential of important deposits deeply buried in the Dnipro-Donets basi…………№ 3 MACHUZHAK M.I., LYZANETS A.V., TYKHOMYROV A.S. New areas of focus for finding large deposits of hydrocarbons in DDD………………………№ 5 ORLIUK M.I., DRUKARENKO V.V. Analysis of the physical parameters of the sedimentary cover rocks of the northwestern part of DDD in connection with its oil and gas bearing capacity……………………………………...№ 2 POLUKHTOVYCH B.M., HALKO T.M., KRYSHTAL A.M., YAKUBENKO H.M. Oil and gas bearing capacity of Paleocene carbonate formations of the southern oil and gas bearing region………………………………………………………………………………….№ 2 PROKOPIV V.Y., PITONIA V.A., PRYDACHYNA O.M. Express method for determining the areas of residual oil reserves at a late stage of Development…………………………………………………………………………………...№ 4 TUMANOV V.R., CHEBAN V.D The application of the thermal imaging generalization method for hydrocarbon accumulation evaluation in the Western Desert of Egypt…………………………………………………….№ 3

KHARCHENKO М.V., POPOVA Т.L., PONOMARENKO L.S. Priorities for the development of hydrocarbon resources of the Hlinsk-Solohivskyi oil and gas region of the Dnipro-Donets basin…………………………………………………………….№ 3 WELL DRILLING VOIEVIDKO І.V. Specifi city drilling of the sidetracks in well casing…………………………………………...№ 2 HOHOL V.I., OHORODNIKOV P.I., SVITLYTSKYI V.M. Analysis of longitudinal, torsional and bending vibrations of drill string……………………..№ 6 GULYAYEV V.I., GAIDAICHUK V.V., ANDRUSENKO O.M., SHLYUN N.V. Differential «stiff-string» model for drag and torque simulation in deviated bore-hole (in English)…№ 6 GULYAYEV V.I., GAIDAICHUK V.V., SHEVCHUK L.V. Computer simulation of drill string bit spinning vibrations in deep wells…………………….№ 6 KUNTSIAK Ya.V., LUBAN Yu.V., LUBAN S.V., KULYK Ya.I. Concerning the issue of mudding permeable beds when using clayless drilling fluids……….№ 4 KUSTUROVA O.V., SHEVCHENKO R.O., ZHUHAN O.A., LIAMENKOV S.V. Lubricating additives in drilling and methods of their research……………………………….№ 4 LUBAN Yu.V., LUBAN S.V., DUDZYCH V.V., BOYKO A.H., SEMENIUK V.H. Application of clayless drilling fl uids under conditions of high reservoir pressures and temperatures……………………………………………………………………………………№ 2 OHORODNIKOV P.I., SVITLYTSKYI V.M., HOHOL V.I. Analysis of drill string vibration strength using the theory of random vibrations…………….№ 2 OHORODNIKOV P.І., SVITLYTSKYI V.М., HOHL V.І. Wearing capacity of some elements of the drill string during boring………………………….№ 3 OHORODNIKOV P.I., SVITLYTSKYI V.M., HOHOL V.I. Some aspects of operational reliability of the drill string and its components in well construction process………………………………………………………………………………………….№ 1 TSAPLII M.P., YUDINA V.V., PAVLOVSKYI A.P., MISHCHUK О.О. Surface activity of fine, oxide type heterogeneous fillers during friction……………………..№ 6 OIL AND GAS PRODUCTION VELYCHKOVYCH A.S., PANEVNYK D.O. Rationale for choosing the geometric dimensions of well hydraulic jet pump………………..№ 6 VOITENKO Yu.I. The effectiveness of strong methods of stimulation of oil and gas production and the prospects of their use for unconventional reservoirs…………………………………………..№ 5 HOSHOVSKYI S.V., VOITENKO Yu.I., SOROKIN P.O. Effectiveness of the state-of-the-art technologies of secondary penetration of productive horizons and ways to improve it………………………………………………………………№ 4 DOROSHENKO V.M., ZARUBIN Yu.O., HRYSHANENKO V.P., PROKOPIV V.Y., SHVYDKYI O.A. Main directions for improving field development systems and potential for buildup of oil production in Ukraine…………………………………………………………………………№ 2 DOROSHENKO V.М., PROKOPIV V.Y., RUDYI М.І., SHCHERBIY R.B. Prior to the introduction of polymer watering in oil fields of Ukraine………………………...№ 3 KACHMAR Yu.D., TSIOMKO V.V., BABII M.B. Mathematical simulation of oil well productivity……………………………………………..№ 6 KOPEI V.B., KOPEI B.V., YEVCHUK O.V., STEFANYSHYN O.I. Impact of oil on the vibration behavior of the pumping unit gear…………………………….№ 1 MYSLIUK M.A., PETRUNIAK V.Ya. Concerning the use of statistical estimates of productive bed parameters using pressure recovery curves………………………………………………………………………………………….№ 4

NAHORNYI V.P., DENYSIUK І.І., LIKHVAN V.М., SHVEIKINA Т.А. Acoustic wave scattering by gas bubbles in reservoirs………………………………………..№ 3 RUDYI S.M., KACHMAR Yu.D., RUDYI M.I. Interaction of silicate rock with acid-cut clay muds under pt conditions in the reservoir. Part 1. Pressure effect on rock solubility………………………………………………………………№ 1 RUDYI S.M., KACHMAR Yu.D., RUDYI M.I. Interaction of silicate rocks with acid-cut clay muds under pt conditions in the reservoir. Part 2. The mechanism of formation component dissolution………………………………………….№ 4 SVITLYTSKYI V.M., CHAICHENKO B.I. Improvement of well productivity by simultaneous action on the bottomhole formation zone with chemical agents and pulse-wave influence…………………………………………………….№ 6 STRIUKOV E.H. Simulation of filter gravel pack in-wash in a well with a significant deviation from a vertical or in horizontal well………………………………………………………………………………№ 1 OIL AND GAS TRANSPORTATION AND STORAGE BILOBRAN B.S., DZIUBYK A.R., YANOVSKYI S.R. Influence of the installation elastic bending on the stress-strain state of the pipeline aboveground passages in the mountains………………………………………………………………………………………№ 4 BILYAVSKYI M.L., FLIUNT O.R. Improving the reliability of rotating machinery of oil and gas industry……………………….№ 1 DATSIUK A.V., OSINCHUK Z.P. Underground gas storage facilities as an important factor of providing consumers in Ukraine with gas in emergency situations (in English)…………………………………………………№ 4 LOKHMAN I.V. Ukrainian gas transmission system renovation project: reliability and efficiency of gas transit to Europe (in English)…………………………………………………………………………№ 2 NIKOLAIEV V.V. Corrosion and mechanical testing of pipe steel for predicting oil product pipeline life………№ 1 PIANYLO Ya.D., VAVRYCHUK P.H. Diffusion of gases in porous media taking into account the convective component………….№ 5 PRYTULA N.M., HRYNIV O.D., VECHERIK R.L., BOIKO R.V. Replacement of buffer gas by nitrogen in gas storage reservoirs (models, methods, numerical experiments) …………………………………………………………………………………...№ 4 PRYTULA N.M., PRYTULA M.H., SHYMKO R.Ya., HLADUN S.V. Calculation of work modes of Bilche-Volytsia-Uhersko underground gas storage facility (program complex)……………………………………………………………………………..№ 3 STORCHAK S.O., ZAYETS V.O., SAVKIV B.P. About the concept of underground gas storage in Ukraine…………………………………….№ 4 TARAIEVSKYI O.S. Strength assessment of ring welded joints of pipes with corrosion defects……………………№ 6 OIL AND GAS PROCESSING BRATYCHAK M.M. From gasoline plants of Precarpathians to the modern petroleum refining industry of Ukraine…………………………………………………………………………………………№ 2 SHKILNYUK I., BOYCHENKO S. Methodically organizatonal principles of biologial stability providing of aviation fuels (in English)………………………………………………………………………………………...№ 1

AUTOMATION AND INFORMATION TECHNOLOGY VLASIUK Ya.M, COMPAN A.I., VLASIUK L.Ya. The reliability of the instrument metering for natural gas……………………………………..№ 6 ROHACHUK M.P., TYSHCHENKO M.V., OLOMSKYI S.V., VASYLIUK Yu.A., RIABOSHAPKO S.M., ROMAN, V.I. MUKOIED N.I. Automation of seismic survey supervision…………………………………………………….№ 6 UNCONVENTIONAL TECHNOLOGIES AND ENERGY EFFICIENCY KASIANCHUK S.V., MELNYK L.P., KONDRAT O.R. Peculiarities of the development of unconventional gas deposits……………………………..№ 2 KOMPAN А.І., REDKO А.О., AHELEST S.B. Co-generation recovery scheme of secondary resources using in the gas processing Plant……………………………………………………………………………………………№ 3 MYSLIUK M.A., KHOMYNETS Z.D., SALYZHYN Yu.M., BOHOSLAVETS V.V., VOLOSHYN Yu.D. Some ways to improve construction technologies for shale gas wells………………………...№ 1 PANEVNYK О.В. Limiting conditions determination of using the hydrocarbon utilization system jet apparatus..№ 3 REDKO A.O., REDKO O.F., KOMPAN A.I. Gas turbine exhaust-gas heat utilization of main gas pipeline gas-compressor units…………№ 4 LABOR AND ENVIRONMENT PROTECTION PAVLIUKH L.I. Improvement of oily wastewater sorption treatment technology………………………………№ 1 DRYHULYCH P.H., PUKISH A.V. The problems of urban areas in developing oil and gas fields on the example of Boryslav…№ 2 THE HISTORY OF THE INDUSTRY HUZIICHUK I.O., TEMEKH I.T. Establishment of the industrial oil production in the Carpathian region as a precondition for the foundation of Oil Field Museum of Galicia……………………………………………………№ 6 AT THE BRANCH ENTERPRISES SHVYDKYI O.A., DOVZHOK T.Ye., HRYSHANENKO V.P., KHOMYK P.M. SE «Naukanaftogaz»: 10 years path from regional research to discovery of oil and gas fields.№ 4 INTERNATIONAL COOPERATION ENKE G. Representation of E.ON Global Commodities CE in Ukraine………………………………...№ 6 INDUSTRY EXPERTS KOZAK F.V. …………………………………………………………………………………№ 5 MARUKHNIAK M.Y. ………………………………………………………………………..№ 5 MATSIALKO M.V……………………………………………………………………………№ 2 PATON B.Ye………………………………………………………………………………….№ 6 PYLYPETS І.А. ………………………………………………………………………………№ 3 SKLIAR V.T. ………………………………………………………………………………….№ 4 STIOPKIN V.I. ………………………………………………………………………………..№ 1

OIL AND GAS PRODUCTION Well productivity increase by simultaneous application of action

of chemical reagents and pulse-wave action to the bottomhole formation zone

UDC 622.244.6

© V.M. Svitlytskyi

Doctor of Technical Sciences B.I. Chaychenko Ukrgazvydobuvannia PJSC

The pa per presents a method of increasing the productivity of wells through a combination of influence of chemical agents with cyclic hydrodynamic pulses.

Key words: well, productivity, chemical reagents, pulsator valve type, cyclic hydrodynamic pulses.

The bottomhole formation zone (BFZ) is subjected to the most intense action of various physical, mechanical, hydrodynamic, chemical, physical and chemical factors caused by the extraction of liquids and gases from the formation or their buildup in the deposit in the course of its development. The BFZ condition- predetermines to a significant extent the total oil and gas production, debit of the mining and reception capability of injection wells. The permeability of reservoir rocks is deteriorated significantly compared to the natural permeability. This is due to the formation of sediments made of clay particles, asphaltenes, resins, waxes, salts etc. in BFZ pore space. The result is the sharp increase in liquid and gas filtering resistance, well flow rate reduction etc. In the fields with paraffin base oil the formation of monolithic surface layers of sediments can lead to a significant reduction in flow rate and even complete clogging of BFZ pore space [1].

To clean BFZ from sediments generated in the pore space, a number of methods is used, which can be subdivided into three main groups: chemical, mechanical and thermal [1]. Recently, the new methods of effect on the bottom zone of the reservoir are widely used. The researchers' attention is increasingly attracted by methods creating the cyclical effects reservoirs, i.e. thermal, acoustic, hydrodynamic [1, 2].

The research has established that the creation of cyclic hydrodynamic and thermal fields qualitatively affects the increase of gas and oil yield and intensification of the deposit development rate with low reservoir permeability, in particular its bottomhole zone [3-5].

To create the cyclic hydrodynamic pressure pulses the valve type pulsator (VTP) was designed, the scheme of which is shown in the figure.

Fig. Valve type pulsator: 1 - body, 2 - spring; 3 - rod, 4 - finger, 5 - cap 6 - piston, 7 - fitting; 8 - connector, 9 - ball 10 – adapter, 11 - bushings, 12 – compaction rings, 13 - saddle

The principle of its action is as follows. The valve type pulsator is immersed directly into the well in the range where the bottomhole zone must be cleaned from sediments. The device is attached to the tubing or a column of flexible long tubes (Coiled Tubing) via the connector. The chemical reagents required to perform the process are fed from the measuring cylinder via a plunger pump under the pressure into the valve type pulsator via the tubing through the connector 8. Passing through the adapter 10, the fluid compresses the ball 9, pressed to the adapter with a spring 2. Under the pressure of the fluid the ball moves down compressing the spring, the hole is opened and the liquid begins to fill the piston chamber, passing through the holes in the choke 7. When the liquid fills the piston chamber and is compressed until the pressure above the piston 6 is not less than the pressure beneath it, the piston begins to rise up, thus closing the inlet through the action of a finger on the ball and opening the outlet. The fluid starts leaving out of the piston chamber through the nozzle 5 with a high speed. The pressure in the chamber drops down, and the compressed spring instantly straightens and, acting through finger 4 on piston 3, move it down, closing the outlet. Then the whole process repeats again.

It follows from the above that the outlet closure rate depends on the stiffness of the spring and its compression degree. However, you should consider that the increased reverse piston speed will increase the piston impact strength on the outlet, which may contribute to do the destruction of the walls. The significant spring stiffness also influences the ball displacement. Therefore, you need to choose the most optimal value of the spring stiffness.

Overall, the complete pulsator operation cycle can be conventionally subdivided into four stages:

the ball, under the pressure of the fluid created by the pump, falls down, opening the hole for the flow of fluid into the piston cavity;

keeping the ball in the final position and its filling with the piston chamber fluid;

under the influence of the fluid pressure difference arising due to the difference of cross section planes affecting the piston, piston movement and simultaneous movement of the ball with a spring to its original position and their overlapping of the hole for fluid supply to the piston chamber;

return of the piston under the action of the spring to its original provisions due to lowering of the pressures under the piston.

Finally, it is necessary to add that the valve type pulsator operation can be adjusted by change of the pressure or fluid consumption by the pumping unit. Meanwhile the change of the amount of fluid fed at the pulsator outlet does not affect the pressure, but changes the operation frequency.

Conclusion

Thus, the proposed method of removing the mud sediments from the pore space of the BFZ using the valve type pulsator will help to improve the efficiency of the well productivity recovery process, which will primarily allow increasing the flow rates of production well and reception of injection wells significantly.

List of References 1. Handbook of Petroleum Business / ed. by Doctors of Technical Sciences, V.S. Boyko, R.M. Kondrat, R.S. Yaremiychuk. - Kyiv, Lviv, 1996. - 620 p. 2. Surguchev M.L. Secondary and Tertiary Methods of the Layer Oil Production Increase / M.L. Surguchev. - Moscow: Nedra, 1985. - 308 p. 3. Yaremiychuk R.S. Increase of the well productivity upon development and operation of paraffin base oil deposits / R.S. Yaremiychuk, V.M. Svetlitskiy, G.P. Savyuk. - Kyiv: State Scientific Research and Design Institute of Oil Industry, 1993. - 226 p. 4. Kachmar Y.D. Intensification of the influx of hydrocarbons into the well / Y.D. Kachmar, V.M. Svitlytskyi, B.B. Syniuk, R.S. Yaremiychuk. – Lviv, Centre of Europe, 2004. - 352 p. - Vol. I. 5. Kachmar Y.D. Intensification of the influx of hydrocarbons into the well / Y.D. Kachmar, V.M. Svitlytskyi, B.B. Syniuk, R.S. Yaremiychuk. – Lviv, Centre of Europe, 2004. - 414 p. - Vol. II.

NEWS

European Shale Gas May Add 1 Million Jobs The shale gas production in Europe may add 1 million jobs, make the industry more competitive and reduce the regional

dependence on the imported energy resources. This is stated in the study of the International Association of Oil and Gas Producers (IGP). This study performed by independent consultants also stresses that the shale gas production during 2020-2050 could provide the economy with extra EUR 1.7 to 3.8 trillion.

"The shale gas production will provide significant economic benefits, said Ronald Festor, Director of the IGP European Branch. - Each cubic meter of the produced shale gas means a reduction of its imports, which will increase the number of jobs, revenue, and improve the energy security. Therefore, we should encourage the shale gas exploration."

The study models the impact of the shale gas production on the economy of 28 EU countries according to three scenarios differing by the production levels. According to the studies, the shale gas operations may create 400 to 800 thousand extra jobs by 2035 and 600 to 1100 thousand extra jobs by 2050, and most of them will be created in the areas most affected by the economic crisis. The own production may reduce the dependence on gas imports by 62 to 78%. The less Europe will spend on energy imports, the more it will be able to invest in its economy. During 2020 to 2050 the investment in the EU countries may increase by EUR 191 billion. The own gas production can also reduce the energy prices compared with the scenario where shale gas programs will not be implemented. The relatively low prices will increase the income of individuals and reduce the cost of products thus making them more competitive in international markets.

http ://www. ogj/articles/2013/ll/eu-shale-gas-production

OIL AND GAS PRODUCTION

Mathematical Modeling of Oil Wells Productivity

UDC 622.276.2.001.57

© Y.D. Kachmar

Candidate of Technical Science V. V. Tsiomko Candidate of Technical Science M.B. Babiy National Research and Design Institute of Ukrnafta PJSC

The paper describes a mathematical model of determining the potential productivity of oil wells and their current skin effect for most fields in Ukraine. Current skin effect is determined by comparing current productivity with potential productivity of the well. After application of stimulation methods the prospects for production increase and the amount of additional oil production are estimated. The correlation of prospected by the developed method additional oil production and actual production is an evidence of the effectiveness of the proposed model. Key words: well, productivity, skin effect, flow capacity, intensification.

In order to make an informed decision on the expediency of applying the methods of intensification of the reservoir fluid inflow to the well, one must first identify the potential performance of layers and the mudding status of the bottomhole zone and only then assess the opportunities and prospects of increasing the production rate by inflow intensification methods.

To solve this problem, the methods of determining the potential productivity and well skin effect, as well as assessing the prospects of the bottomhole zone processing (BZP) were developed [1]. Based on this method, the National Research and Design Institute of Ukrnafta developed WProduct software.

The mathematical model of the well potential productivity is based on determination of the water permeability of each productive layer in the well cross-section in particular and all layers in general for layer conditions of deposits of the Precarpathian and Dnieper-Donets depression (DDD). Consequently, the productivity of the well with unmudded bottomhole zone and its flow rate is calculated when the skin effect is zero. Then the current skin effect and the possibility of increasing the flow rate by means of intensification is estimated.

The sequence of determination of the potential well productivity, feasibility and expected efficiency of application of the reinforcement means is as follows:

determine the capacitive power parameter (CPP) of the well, which is the product of the conditional rock capacity and pressure gradient formation;

determine the water permeability factor for each layer, all or selected layers; calculate the coefficient of potential productivity of each layer, all or selected layers; calculate the coefficient of actual productivity and the skin effect according to research at steady filtration; calculate the expected efficiency of the BZP application method in the selected range by skin effect

reduction. Let’s consider the nature of the calculations at each of the aforesaid stages. First, based on the input data on

the well the CPP of each productive layer is calculated as a product of the effective layer thickness, porosity determined according to geophysical studies, and layer pressure gradient [2], i.e.:

where Ej is a capacitive energy parameter m·m3/m3 (MPa/m); hj is the effective layer thickness, m; m0 is the mean porosity, m3/m3; PPL is the layer pressure, MPa, HPLj is the average layer perforation depth, m.

CES of all productive layers is determined similarly, taking into account the total effective thickness of all layers and the mean porosity for this thickness.

The threshold CES value is one of the empirical criteria for assessment of the feasibility of applying the methods of intensification of the influx through the BZP, which varies depending on the flow rate required for intensification cost recovery and the expected value of the additional oil recovery. CES threshold is not constant, but depends on the BZP cost prime cost and price of one ton of oil.

The most difficult thing is to determine the reservoir permeability in situ. First, the absolute rock permeability of each reservoir is determined and then recalculated into permeability for oil based on the residual rock water saturation, and in the end It is adjusted by the rock pressure effect on the rock permeability via the compressibility coefficient.

Fig. 1. Dependence of absolute permeability on reservoir porosity and lithotype for Precarpathians (a) and DDD (b) fields

Table 1 Codes and types of collectors in Precarpathians fields

Collector code types Particle class and size of

clastic grains Cement

contents,% Quartz

sandstones Quartz

siltstones Max 5 ZS1 - 5 - 10 ZS2 -

Medium and coarse

sandstones (0.25 - 0.5 - 1.0 mm) 10 - 20 ZS3 -

5 ZD2 - 5 - 10 ZD3 -

Fine sandstones (0.1 - 0.25 mm)

15 - 20 ZD4 - Siltstones (0.01 - 0.1 mm) Max 10 - ZA

The absolute permeability is determined depending on the lithographic types of collectors allocated based on the fractional composition of grains and cement content. Table 1 and 2 provides information on the types of lithological reservoirs of Precarpathians and DDD by grain size and content of clay and carbonate cement.

The correlation dependencies of absolute permeability from open porosity for each allocated lithotype of Precarpathians and DDD rocks was developed, which became the basis of graphic dependences depicted in Fig. 1.

Then the permeability kn for reservoir oil filtration at residual water saturation of rock (to approximate the filtration to reservoir conditions for all types of collectors) from absolute permeability kand is calculated based on experimental data, based on which the graphic dependences n k = f (k a) shown in Fig. 2 were built.

The impact of vertical rock pressure increase on the permeability of rocks for oil in situ is calculated through the compressibility factor knp:

where kn is permeability, m2•10-3; αGA is the rock compressibility factor. To assess the influence of the rock compression stress effect on permeability, first it is required to determine the rock compression stress as the difference of the vertical mining and reservoir pressure, MPa:

where Hпл is the average depth of layers, m The adjustment to reflect the impact of the mining and reservoir pressure on the compressibility of rocks is

made based on empirical dependencies shown in Fig. 3, which are constructed using the results of research performed by F. Kotyahov and T. Dahkylgov [3]. The impact of porosity, cement content and tension in the rock, which depends on the difference between vertical mining and reservoir pressure, is taken into account.

Using the graphs shown in Fig. 3, the rock compressibility factor is determined depending on the well depth at the stress corresponding to the reservoir pressure equal to 50, 75 and 100% of the hydrostatic pressure and via the collector type based on the grain size, porosity and its clayness.

The coefficient of permeability of all oil saturated or selected layers shall be determined as the mean by layer thickness [4]:

where kjнp is the coefficient of permeability of the j-th layer, m2. The water conductivity of each oil saturated layer εj taking into account the permeability, effective thickness

of reservoirs and oil viscosity at reservoir conditions shall be determined by the well-known formula:

where μj is the oil viscosity in reservoir conditions, mPa·s. The water conductivity of all oil saturated or selected layers is determined as the sum of water permeability.

The well flow rate and productivity shall be determined based on the classical model of radial planar flow to the well of a single-phase Newtonian fluid (oil) according to the Darcy law. On the basis of this law, the flow rate can be calculated as follows:

where Q is the liquid flow rate, m3/day; k is the averaged permeability coefficient, m2; h is the thickness of layer, m; Pвб is the acking pressure, MPa; μ is the oil viscosity in situ, mPa.s; b is the volume ratio of oil; Rk is the feeding circuit radius, m; rc is the well radius, m; S is the skin effect, which takes into account all the additional resistance (pressure loss) in the well bottomhole zone in a generalized manner.

To calculate the potential values of well productivity and flow rate, i.e. the hydrodynamically perfect well, the skin effect equal to zero (S=0) is taken, and the water conductivity value is determined above, so formula (6) will acquire the following form:

Table 1 2 Codes and types of collectors at DDD deposits

Collector type codes Particle class and size

of clastic grains Cement

content,% Quartz sandstones

Oligomictic sandstones

Polimictic sandstones

Quartz siltstones

5 - OSR2 PS R4 - Medium and coarse sandstones 5 - 10 KSR1 OSR3 PSR5 -

10 - 15 KSR2 OSR4 PSR6 - (0.25 - 0.5 - 1.0 mm) 15 - 20 KSR3 OSR5 PSR7 -

5 KD1 OD3 PD5 - Fine-

grained sandstones 5 - 10 KD2 OD4 PD6 -

(0.1 - 0.25 mm) 10 - 15 KD3 OD5 PD7 -

15 - 20 KD4 OD6 PD8 - Large and various-grained siltstones

5 - - - KA4

5 - 10 - - - KA5 (0.01 - 0.1 mm) 10 - 15 - - - -

If the reservoir developed the dissolved gas mode, i.e. the reservoir pressure is lower than the saturation

pressure Pнас, it is stipulated to take into account the phase permeability reduction for oil through a part of the depression moving the aerated oil in the reservoir. To take into account the impact of oil degassing subject to reservoir pressure reduction on its influx to the well the industrial analog of Khrystianovych functions (H), suggested by I.D. Amelin, was used, which is best determined from the industrial data by the formula ∆ Н = А·∆Р, where ΔH is the depression on the layer expressed in terms of the Khrystianovych function, MPa; A is a coefficient which depends on the pressure drop degree in the reservoir vs. the saturation pressure; ΔP is a complete depression on the layer, MPa.

Fig. 2. Dependence of permeability through the water saturated rock from absolute permeability

In terms of Precarpathians deposits the phase permeability reduction was established through a part of the depression which drives the aerated oil in the reservoir by R.V. Mysiovych and V.P. Klyarovskyi who built the graphical dependence A=f(Pпл /Pнас) to determine A coefficient. To assess the impact of reduced reservoir pressure versus saturation pressure Pнас on the oil influx to the well we [5] found the correlation as follows:

Table 3

Comparison of predicted productivity and flow rate indicators after BFZ vs. the actual indicators

Productivity coefficient m3 /(d · MPa)

Liquid flow rate, m3 /day

Productivity coefficient m3 /(d · MPa)

Liquid flow rate, m3 /day

Productivity coefficient m3 /(d · MPa)

Liquid flow rate, m3 /day

Productivity coefficient m3 /(d · MPa)

Liquid flow rate, m3 /day

Well

before BZP potential predicted after BZP 1600 – Boryslav 0.57 2.7 1.9 9.5 1.15 5 0.8 4.5 1700 - Boryslav 0.8 3.2 3.9 15 1.8 8 1.14 5.3 73 – Staryi Sambir 0.69 5.7 1.5 14.5 1.35 12, 5 1.34 12, 5 12 - Mr - Bytkiv 0.36 1.7 0.9 4.9 0.8 4.5 0.45 2.5 188 – North Dolyna 0.4 2.6 3.2 23 2.9 15 3.38 23.6 214 - Kachanivka 0.68 2.4 2.2 8.9 1.6 6 1.9 8.2

81 - eshetnyany R 0.51 0.2 2.9 20 1.67 8 2.5 12, 5 On the

average per well 0.57 2.64 2.5 13.7 1.46 8.5 1.64 9.7

To take account the gas-saturated oil movement, i.e. when the saturation pressure is greater than the reservoir

pressure, formula (7) shall be supplemented with A factor. The remaining parameters should be added to Dupoi formula is the form corresponding to the saturation pressure, and its expression will appear as follows:

Next, the potential productivity of wells shall be determined:

The potential productivity ratio of all layers is the sum of the determined productivity coefficients of individual layers, similarly to the water conductivity. The potential production rate shall be calculated according to the formula (7) or (9).

The actual productivity for the known current values of the reservoir and bottomhole pressures and the fluid flow rate shall be calculated using the following formula (11). For comparison, you can set some of such values obtained from the studies and measurements at the well during its operation.

To determine the current skin effect of the wells, the ratio of ВП productivities shall be established first:

The magnitude of the S skin effect for each measurement of the well productivity based on Rк and rс values

and the found ВП value shall be calculated by the formula:

The calculations of BZP efficiency shall be performed depending on changes in the skin effect and the

magnitude of the depression on the reservoir. The expected performance and flow rate after BZP sha;; be calculated by the formula (6) for the skin effect set by the user taking into account the experience of using a particular BZP method. For example, after the acid fracturing (KGRP) the achieved skin effect S=2...-1 is lower than after the application of strong fracturing (PHRP), which is the strongest of the known methods of intensification and depending on the size and conductivity of the crack it provides a reduced skin effect to S=-1...-3.

1 - The first group of collector codes: ZS1, ZD2 (Precarpathians), KSR1, OSR2, OSR3 (PPD); 2 - The second group of collector codes: ZS 2, ZD 3 (Precarpathians), KSR 2, KSR 3, KD 1, OSR 4, OSR 5, OD 3 (DDD); 3 - The third group of collector codes: ZS 3, Z A (Precarpathians), KD 2, KD 3, KD 4, OD 4, OD 5, PSR 4, PSR 5, PD 5 (PPD); 4 - The fourth group of collector codes: ZD 4 (Precarpathians), OD 6, PSR 6, PSR 7, PD 6, PD 7, PD 8, KA 4, KA 5 (PPD).

Fig. 3. Dependence of the rock compressibility ratio on its occurrence depth

The described mathematical model for determination of wells productivity is the basis of WProduct [6]

application, which is used for oil wells of the deposits of UkrNafta PJSC on the stage of selecting objects for the purpose of carrying out PGRP and KGRP.

Table 3 provides the projected flow rate and productivity values prior to the application of intensification measures determined using the software and the actual data on wells operation after PGRP and KGRP, for comparison.

From the data in the above Table 3 it can be seen that: The current productivity rate of all wells was significantly (almost four times) lower than the potential, i.e.

there were good prerequisites for the use of hydrocarbon influx intensification methods; The projected rates of productivity and flow rate after the planned BZP is lower than the potential, since the

intensification methods were planned only for a part of the reservoir wells; The average productivity factor of seven wells after BZP differs from the predicted factor by less than 15%. The developed techniques is used for annual modeling of the potential productivity and the

expected additional oil production in about 100 wells of UkrNafta PJSC fields on the stage of selecting sites for EMG. The average additional production coincides with the expected one, indicating the effectiveness of the proposed technique.

Conclusion Therefore, the mathematical model of determining the potential productivity of oil wells, which are used

effectively to support the expediency of well BZP in the fields of UkrNafta PJSC was developed. References

1. Pat. 20599 Ukraine, E 21V 49/00. Method of determining the potential productivity of the oil saturated layers disclosed by wells [Text]/Y.D. Kachmar, S.S. Buchkovskyi, F.M. Burmych, V.M. Distryanov, Published on February 27, 1998. – Bulletin #1. 2. Kachmar Y.D. On filtration of fluids at a later stage of deposit development [Text]/Y.D. Kachmar, V.V. Tsiomko/Oil and gas industry. - 2000. – No. 6. - P. 26-29.

3. Kotyakhov F.I. Physics of oil and gas collectors [Text]/F.I. Kotyakhov. - Moscow: Nedra, 1977. - 287 p. 4. Kachmar Y.D. Simulation of oil well performance [Text]/Y.D. Kachmar, V.M. Distryanov/Oil and gas industry. - 2001. – No. 3. - P. 29-31. 5. Kachmar Y.D. On the reasons for reduction of flow rate from the wells of Precarpathians fields [Text]/Y.D. Kachmar, E.A. Malytskyi/Oil and gas industry. - 2000. – No. 5. - P. 31-35. 6. Certificate of registration of the copyright in work No. 40522 dd. October 19, 2011. Software for simulation of well productivity, WProduct [Text]/Y.D. Kachmar, V.V. Tsiomko, I.F. Klymovych, S.Y. Aseyev, O.B. Zalokotskyi.

INDUSTRY PROFESSIONALS

Dear Borys Yevgeniovych

The employees of oil and gas industry of Ukraine know and appreciate you as an outstanding scientist, talented organizer, state and public figure.

The fate bestowed you with active, rich and interesting life. Your inherent hard-working and talent, coupled with a sincere son’s love for your native land and the great desire of doing good to people have become the key to success in life.

You have created strong scientific schools in the field of welding, metallurgy and metal technology with global recognition and their legacy is a significant component of scientific and technical progress in the economy of our state. We are pleased to note the special attention that you paid and do pay to solving problems of oil and gas complex, including the pipeline transport. For six decades no significant main gas transportation project, starting from Dashava-Kyiv gas pipeline, has passed by your attention. The contribution to improvement of the technology of production and control of the oil and gas pipes, creation of metal for their production with high strength properties, as well development of technology and high-tech equipment for welding header pipelines are extremely important. You still lead the intergovernmental program of Highly Reliable Pipeline Transportation. For more than a half of a century you as a constant president of the National Academy of Sciences of Ukraine, have been putting the Herculean efforts so that it has achieved recognition and deserved respect in the world. On the occasion of the 95th anniversary of the establishment of the NAS of Ukraine and your birthday, please, accept our sincere wishes of good health, happiness, energy and enthusiasm in all your good deeds. Let fate remain favorable to you, giving you the joy of life, good luck, loyal and trusted friends.

Chairman of Naftogaz of Ukraine National Joint Stock Company

Y. Bakulin

OIL AND GAS TRANSPORTATION AND STORAGE Evaluation of the strong performance of the circular welded pipe

connections with corrosion defects

UDC 622.692.4 © O. S. Tarayevskyi

Candidate of Technical Sciences IFNTUNG

The paper shows the results of experimental studies and the analysis of the impact of long service life of the main gas pipelines, as well as of natural concentrators of stresses on the physical and mechanical p roperties of welded joints of steel 17G1S. A methodology was developed and patterns of gas pipeline welded joint material failure at static and low-frequency loads were established, as well as impact of stress concentrators during prolonged use. Some aspects of the mechanism of pipeline welded joint failure are considered.

Key words: corrosion, damage, pipes, welding joint, working pressure, hydraulics tests.

The problem of provision of high operational reliability of the header pipelines (HP) is of great value to the

national economy of Ukraine, since their major part has been in operation for a long time and has exhausted its regulatory resources. Stable operation and high cost effectiveness of HP primarily depends on its technical condition. During the technical evaluation of the pipeline the reliable measurement of the stress-strain state (SSS) of its linear part as one of the main factors affecting the level of the structure operational reliability plays an important role. Otherwise the pipelines may be found in an emergency.

From the analysis of the causes of HP accidents it was established that their failures are associated with metal ruptures on the whole or on the metal rings in butt joints.

More than 50% structures are destroyed due to the corrosion damage, 37% accidents are caused by poor quality metal, its lack of ductility, impact strength, poor fusion lines, factory seams etc. The detailed analysis of the causes of accidents in many cases helped to establish a direct link of the source of destruction origin with any, though hardly noticeable, defect of the metallurgical, manufacturing, construction and assembly or operational nature. This defect is the hub of stress on internal and external surfaces of the pipe. The factory defects are manifested in the form of defects of the pipe metal, non-metallic inclusions in the form of sulphide bands, shells, incomplete removal of residual local stresses of the welding seams, defects of mechanical damage of the inner surface of the pipe. During installation of pipelines and transportation of pipes to the destination point the mechanical damage in the form of dents, pockets, scratches, and defects in the transverse junction seams, including the lack of penetration etc.

To identify the impact of the working corrosion environment on the degree of strength and durability of steel pipes, it is necessary to characterize the corrosive environment. The interaction of the environment and the metal will depend on:

chemical composition and its individual components; plastic and elastic deformation; surface condition. It is necessary to distinguish between three possible cases of the metal hydrogenation leakage: hydrogenation of the metal with unstrained lattice; hydrogenation of the metal with deformed lattice (cold metal deformation processes); hydrogenation in the course of the metal deformation. The structural condition of steel and its deformation significantly affect both the electrochemical corrosion

processes and the diffusion processes, and the more unstable the phases are, the higher is its sensitivity to corrosion.

Improving the efficiency of GTS is an important issue that needs to be addressed. The process of designing and operation of such GTSs has some specific features. The imbalance in volumes of gas supply and its consumption leads to non-stationary gas flows, which in combination with a complex technological scheme of gas pipelines and rugged profile of the track makes it difficult to predict the operation modes and their management. The science-based definition of targets in terms of gas supply in non-stationary conditions it that you need to have reliable information on the daily, seasonal and other unevenness of gas consumption.

Table 1 Objects of tests and their main characteristics

Pipe No. Dn×δ , mm steel make Useful life

before elimination, years

Cause of elimination by defect type

Dimensions of the maximum defect, mm

The maximum pressure (MPa),

the nature of damage

1 1220 × 12 17 G 1 C 13 corrosion by VTD 1100 × 520 × 2,8 9.2, the state of fluidity

2 1220 × 14,5, 17 G 1 C 13 corrosion by VTD 3000 × 3,5 12.0, viscous 3 1220 × 12 17 G 1 C 17 accident KRN general corrosion 800 × 0,5 9, 8, viscous 4 1220 × 12, 17 PSU 6 corrosion by VTD general corrosion 800 × 4,4 11.0, viscous 5 1020 × 9, 17 G 1

C thermally reinforced

18 corrosion by VTD peptic corrosion 900 × 4,4 8.0, viscous

6 1020 × 9, 17 G 1 C thermally reinforced

18 corrosion by VTD peptic corrosion 300 × 3,0 10.5, viscous

7 1220 × 10,5; 17 G 2 SF, thermally reinforced

23 accident, structural defects in metal

cavity with depth up to 2.5 11, 3, viscous

8 1220 × 12,5, 17 GS 30 MG section which emerged in the swamp

corrugations, indentations 1220 × 800 × 109, ulcers up to 2.0

11.0, viscous

To date, there are two major emerging trends of forecasting: • perspective (determination of uneven gas consumption in the design problems and development of gas

supply systems); • operational (construction and analysis of consumption graphs for mode control in real systems of gas

transportation). It is believed that industrial gas consumers consume gas evenly throughout the day. This statement is not

always true, as the number of gas consumed as fuel in industry depends on many factors, such as uneven receipt of raw materials, process requirements to the quality of products etc. Therefore, for the industrial gas consumers there is also the daily non-uniformity of gas consumption, which may differ significantly from the non-uniformity of gas consumption by households, which is mainly determined by lifestyle and the related nature of power consumption. The buffer consumers can use different fuels (including the natural gas), and their use in the region leads to smoothing of uneven gas consumption.

The fluctuations of operating pressure in GTS pipelines during the day depend on the nature of the consumption of a particular region, which has a number of gas consumers. The number and nature of gas consumption by them during the days determine the fluctuations of consumption in the gas transportation system, which in turn causes pressure fluctuations. The nature of gas consumption by consumers is subdivided into three groups, i.e. industrial gas consumers, households and buffer consumers. However, this subdivision is quite arbitrary. For efficient supervisory control the record of fluctuations in gas consumption during the day is of primary importance. For such studies it is important to establish the cause of the non-stationary processes, which in most cases determines the nature of its flow. All causes of occurrence of the non-stationary processes can be subdivided into permanent and pulsed.

In addition, a sharp increase or reduction of gas intake by the consumers leads to instability of its flow in the pipeline, and unsteady processes resulting from changes in the density of gas can last for hours or even days. The similar consequences are brought about by the increase or reduction of the gas swap, the sudden switching on or off of the compressor stations, opening or closing of valves etc. Therefore, the overall process of pressure monitoring in the pipeline is characterized by the range of frequencies.

Problem Status The underground gas mains, despite the comprehensive protection against corrosion, including the passive

protection with anti-corrosion coatings and active electric chemical protection, yet are often exposed to various degrees of corrosive damage. However, to date the regularities of strength behavior of the corrosion defects are not studies in full.

Thus, the existing regulatory requirements for safe and failure-free operation of gas mains quite clearly regulate the immediate removal of substandard corrosion damage. Among other things, the development of corrosion defect in underground pipes is latent in nature and usually occurs suddenly in the form of emergency failures of varying complexity. In this situation, the methods allowing to estimate the rate of exhaustion of the strength resource of the gas pipe leading to the development of corrosion defects remain incomplete. On the other side, the modern ways of intra-pipe defectoscopy with direct measurement within one-cycle inspection help to identify the vast majority of corrosion defects. Meanwhile we see the picture of plurality of corrosion damage, the removal of which requires scientific justification of temporary priorities, since the instant elimination of defects, as required by the applicable regulations, is not possible for technical reasons.

To clarify these gaps in research and industrial stand, the large-scale hydraulic tests of corrosion damaged pipe found defective in the operated gas pipelines was performed.

The following classification group analyzes the results of tests of eight facilities (Table 1) prone to corrosion damage with the depth of more than 10% of the wall thickness.

It should be noted that the corrosion defects are found only on the outer surface of the pipe in the sites of through or closed injuries of insulation coating. Obviously, the corrosion thinning of the pipe wall cause the local increase of the stress-strain state and weakening of the pipe. Intuitively, this can be illustrated by comparing the deformation of defect-free and defective areas during tests of the pipe seams 12 and 13. The measurement results are presented in table. 2.

Fig. 1. Comparison of designed and actual reserve ratios Table 2

Results of tube deformation in the transverse direction from action of the internal pressure Tensimeter installation site Increase of tensimeter indications with changing pressure,

MPa The average deformation subject to

pressure change by 1 MPa

0 ÷ 1 1 ÷ 2 2 ÷ 3 3 ÷ 4 4 ÷ 5 5 ÷ 6 Tensimeter graduation Relative%x102

Welded pipe seam 12 Vast corrosion zone with the depth up to 4.4 mm -1 32 29 28 22

24 27 6.75

Short defect with the depth up to 4 mm 13 14 13 13 10

12 12, 5 3.13

Vast corrosion zone with the depth up to 4.1 mm 56 27 20 17 15

15 18, 8 4.70

Short defect with the depth up to 5.2 mm 16 14 6 8 8

11 10.5 2.63

Short defect with the depth up to 4.5 mm 34 20 16 17 13

12 14.4 3.60

Long defect with the depth up to 3.5 mm 19 12 9 10 7 9 9.4 2.35 Welded pipe seam 13 Vast corrosion zone with the depth up to 1 mm 53 17 18 14 13 10 14.4 3.60 Vast corrosion zone with the depth up to 3 mm 80 29 26 18 17

13 20.6 5.15

Vast corrosion zone with the depth up to 2.5mm 63 28 22 16 5

22 18.6 4.65 Undamaged pipe 10 9 14 11 10

10 10.7 2.68

From Table 2 we can see that the actual deformation of the pipe in the undamaged area is comparable to the

calculated value determined according to the generalized Hooke's law for plane stressed state, i.e. the obtained results, excluding the clearly abnormal indications of some tensimeters observed at the first stage of the load, should reflect the ongoing processes clearly enough.

Then, returning to the obtained results, we can state that tensimeters 2, 4 and 6, usually installed in the area of non-extensional defects, fixed the deformation comparable to the deformation of the undamaged pipe, i.e. such defects did not cause a marked strength reduction.

Still, the areas of the major corrosion defects (tensimeters 1, 3, 8 and 9) have been subject to deformation to a much greater extent than with defect-free pipe, i.e. these areas had higher stress. As the subsequent load showed, the break of seam 12 happened in the area of installation of tensimeter 1, where the greatest deformation was fixed that exceeded the undamaged zone deformation 2.52 times. As for pipe 13, in the course of tests it was subjected to artificial defects, which became the center of destruction.

In addition to the above, the real integral estimate of availability and value of weakening of the defective pipe still can be determined only after its destruction, as it was done in the final stages of testing of pipe seams 2, 3, 9, 13, 18 and 19.

The test and calculation results of the considered pipe seams are presented in Table 3. Hence we see that the five tested joints (1, 2, 9, 12 and 13) have the corrosion defects which, pursuant to the

applicable statutory documents, are classified as inadmissible. The presence of such damages required the repairs to eliminate them or reduce the operating pressure down to

safe values (by 4.3 to 30% of the designed pressure).

Table 3

The results of tests and calculation of the welded pipe seams with corrosion damage Parameter Number of the tested pipe welding seam

1 2 3 9 12 13 18 19

Diameter and nominal thickness of the pipe wall, mm

1220 × 12, 0

1220 × 14,5

1220 × 12,0

1220 × 12,0

1020 × 9,0

1020 × 9,0

1220 × 10,5

1220 × 12,0

Steel make 17G1 S 17G1S 17G1S 17G1SU 17G1S 17G1S 17G2SF 17GSStatutory mechanical characteristics,

MPa Tensile strength, σ in 520 520 520 520 600 600 550 520

Corrosion defect Yield point, σ t 360 360 360 360 420 420 380 350

Short (s) Long (l)

l l l l l l s l

Maximum defect depth

mm 2.8 3.5 0.5 4.4 4.4 3.0 2.5 2

% 23.3 24, 1 4.2 36.7 48.9 33.3 23.8 16.0

Allowed defect depth,% 21.2 21.7 21.2 21, 2 28, 1 August 2, 1

70.0 22.2

Pressure of the welded seam rupture, MPa 9.2 12 0 9.8 11 0 8.0 10.5 11, 3 11 0

Coefficient of the designed strength reserve, Kτ av

1.8 2, 15 1.8 1, 8 1.71 1.71 1, 8 1.8

Coefficient of the designed reserve outside the yield point, Kd

1.05 1.26 1.05 1, 05 1.0 1.0 1.05 1.05

The actual rate of strength reserve, Kpr 1.48 2.22 1.81 2.04 1.48 1.94 2.09 2.04

Index of strength reliability Kd / KAve 1, 41 1.03 1,006 1.13 0.87 1.13 1.16 1.13

Permissible operating pressure

5, 17, 5.15 5.4 4.27 3.78 4.94 5.4 5.4

Permissible operating pressure

4.14 4.22 5, 17, 3.42 2.76 3.6 4, 11 4.54

Having assessed the damage, the defects in the welded pipe 18 can be classified as requiring

repair. Meanwhile the level of operating pressure reduction at all tested facilities (in case of failure of repair) becomes even more significant (by 4.3 to 27.1%) compared to the original version.

At the same time the comparison of the actual K d and designed K av of the strength reserve ratios and their ratio Kd /KAve , the graphic images of which are given in Fig. 1 and 2, shows that only in one case (welded pipe seam 12) the required pipe reliability is not provided.

According to [5, 6], if it is impossible to carry out the repair works here, it is necessary to reduce the operating pressure to 3.78 MPa, which is 70% of the designed pressure.

Incidentally, the results of hydraulic test of this welded seam show that the designed reserve factor is ensured by the operating pressure, equal to p = 8/1, 71 = 4.68 MPa (86.7% of the designed pressure), i.e. by 23.8% more than its value.

For other welded pipe seams, save for facility 1, wherein the tube has been led to the metal fluidity only, the actual strength reserve vs. the designed one is 0.6 to 16% (see Fig. 2), i.e. the actually required pipe reliability is provided even in the case when the applicable regulations require the repair or technological measures to reduce the operating pressure (welded seams 2, 9 and 13).

Fig. 2. Indicators of strength reliability for the tested welded pipe seams

Conclusion So, as a result of hydraulic testing of welded pipe seams with inside pressure it was found that subject to availability of

the corrosion damage in excess of the regulatory value, the current level of strength resource of gas pipes turns out to be ambiguous: it may remain sufficient to secure the further operation (welded pipe seams 9, 13, 18 and 19), be critical or equal

(welded pipe seams 2 and 3) not defined for evaluation (welded pipe seam 1) or actually dangerous (welded pipe seam 12). Each of these states requires individual control of the operational reliability level of the gas transportation facility. In the first case, is an integral monitoring, in the second it is regular maintenance, in the third it is designing of detailed studies, and in the fourth it is urgent repairs etc. This control should be based on the system of criteria priorities for assessment of the current efficiency of gas pipes prone to corrosion. The tests show that the calculation of allowable stresses arising inside the gas pipe and resulting from uneven gas consumption in irrigating environments should be carried out in view of ркс coefficient, which will allow increasing them, and thus increasing the throughput capacity of the mains by increasing the pressure. The presented method allows making the right and reasonable choice of the magnitude of allowable stresses and the required number of loading cycles in the course of operation of the working environment. The fatigue processes in steel are probabilistic in nature. This, together with non-destructive control methods and the use of risk analysis within the framework of the existing security concept ("implement and correct"), allows to maintain the pipeline in the working condition. However, indisputable is the fact that in these operating conditions (I underline the joint action of variable loads and environment) and during the long-term operation the pipe material accumulates the defects that eventually lead to their destruction. The specific hazards is posed by remote places (it is impossible to eliminate the risk in due time) or difficult operating conditions (e.g., the pipeline found itself in the shear zone). Here it is necessary to apply a new concept of risk analysis, i.e. "anticipate and prevent."

References 1. Karpenko G.V. Steel strength in corrosion environment/G.V. Karpenko. - M.: Mashgiz, 1963. - 188 p. 2. Pokhmurskyi V.I. Corrosion mechanical destruction of welded structures/V.I. Pokhmurskyi, R.K. Melekhov. - K.: Scientific opinion, 1990. - 347 p. 3. Pokhmurskyi V.I. Corrosion fatigue of metals/V.I. Pokhmurskyi. - M.: Metallurgy, 1985. - 207 p. 4. Kryzhanivskyi E.I. Influence of hydrogenation on corrosion and mechanical properties of welded seams of pipelines/E.I. Kryzhanivsky, O.S. Tarayevskyi, D. Y. Petrina // Exploration and development of oil and gas deposits. - 2005. – No. 1 (14). - p. 25 - 29. 5. Kryzhanivskyi E.I. Influence of uneven gas consumption on the pipe stressful condition/E.I. Kryzhanivskyi,

O.S. Tarayevskyi // Exploration and development of oil and gas deposits. - 2004. – No. 3 (12). - p. 31 - 34. 6. Tsyrulnyk O.T. Sensitivity of the welded junction of steel 17G1S of the mains to hydrogen embrittlement / O.T. Tsyrulnyk, E.I. Kryzhanivskyi, O.S. Tarayevsky [et al.]. // Physical and chemical mechanics of materials. - 2004. – No. 6. - p. 111 - 114.

Article Author Tarayevskyi Oleg Stepanovych

Candidate of Technical Sciences, assistant professor of oil and gas transportation and storage department of Ivano-Frankivsk National Technical University of Oil and Gas. Scientific research interests: provision of trouble-free operation of pipelines in difficult conditions.

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AUTOMATION AND INFORMATION TECHNOLOGY

Reliability of instrumental recording of the natural gas

UDC 681,121 Y. M. Vlasiuk Candidate of Technical Sciences Naftogaz of Ukraine National Joint Stock Company A.I. Kompan Regional Gas Company LLC L.Y. Vlasyuk Ukrmetrteststandard SE The comparison of industrial natural gas flow meters, functioning of which is based on different metering methods usage, was made, recommendations on the optimization of choice of the meter's type in accordance with operation conditions were given.

Key words: gas flow, meters, natural gas accounting, meter inaccuracy, metrology.

In the 90s’ of the last century Ukraine inherited the Soviet all-national calibration scheme for means of measuring the volumetric flow of gas according to the requirements of GOST 8.143-75. This calibration scheme made it possible to use the flow meters and gas meters with relative permissible error max ± 5%.

Since January 01, 1997 Ukraine, in accordance with DSTU 3383, implemented the state calibration scheme for volume and volumetric gas flow measuring tools, which allows using the working means of measuring the volumetric gas flow with relative permissible error max ± 4 %. For natural gas, according to the requirements of the Rules of Measuring the Natural Gas During Its Transportation by the Gas Distribution Networks, Supply and Demand, approved by the order of the Ministry of Energy dd. December 27, 2005 No. 618, this figure reaches ± 3 (2.5)%. The operation of the majority significant natural gas consumption metering units (GMU) operated in the former Soviet Union is based on the use of the method of alternating pressure drop (using the diaphragm). In the course of certification of such GMUs the procedures for obtaining the consumption unit from the reference standards is unavailable, i.e. this method is indirect and associated with subjectivity of estimates. This leads to many conflict situations evaluated with much greater amounts of money than the cost of advanced metering. In addition, the accuracy of measurement with this method is affected significantly by the diaphragm pollution [1].

Table 1 Characteristics of the natural gas consumption measuring appliances based on various measurement methods

Gas

consumption measurement method

Error in The main range (%)

Ability to understate the readings during operation

Excessive pressure (kgf/cm2 )

Loss of pressure(kgf/cm2 )

Optimal diameter (mm)

Q min /Q max

DependenceFrom gas density

Advantages Disadvantages The maximum sensitivity of Q max

/Q sensitivity

Method of alternating pressure difference

0.8 - 1.5

+ 1 - 100 0.3 200 - 700

1/3 (6) + simplicity underestimationimpressions small range costs

50

Using the turbine meter

0.5 - 1.0

in case of damage

1 - 100 0.3 150 - 600

1/50 - high accuracy

filter (compulsory) Small consumption rang e

150

Using the rotary meter

0.5 - 1.0

in case of damage

3 - 100 0.3 32 - 100

1/250 - high accuracy

filter (compulsory)

1000

Using the vortex meter

1.0 - 0 - 10 0 8 - 100

0.2 150 - 400

1/10 + insensitivity to contamination

small consumption range

15

Using the ultrasonic meter

0.5 - 1.0

- 0 - 10 0 0.2 50 - 1400

1/1501/250 - insensitivity to contamination, high accuracy

- 1000

Using the averaged tube

1.0 - - 0.05 300 - 1400

1/3 (6) + simplicity low accuracy 30

Table 2

Parameter / Year 1997 2005 2011 2015

CONSUMPTION Working standards, the m thod of etransfer (meter + air / gas or? P + ρ)

0.5 ÷ 0.7 1.5

0.3 ÷ 0.7 1.0

0.3 ÷ 0.7

0.6 ÷ 1.0

0.15 ÷

0.5 0.2 ÷

0.5 TEMPERATURE 1 0.5 0.2 0.1

PRESSURE 1 0.5 0.1 ÷ 0.25 0.05 ÷ 0.15 CALCULATION

(reduction to standard conditions) > 2 (manually) > 1 (manually, some

computer) 0.05 (corrector) 0.02 (corrector)

TOTAL > 5 3 1.5 0.5 ÷ 0.9

Table 3 The cost of verification (calibration) of FTA for natural gas consumption (production environment - natural gas) in Europe

Conventional diameter of consumption metering appliances, mm Number of gas of consumption metering

appliances in Ukraine European price for verification (calibration) per unit, EUR thousand

Total cost of verification, EUR thousand

Ukrtransgas PJSC, Ukrgazvydobuvannia PJSC, Chornomornaftogaz PJSC, Ukrnafta PJSC ≥ 700 > 50 18x1.4* 1,300 400, 500 > 100 10x1.4 * 1,400 200, 300 > 200 4x1.4* 1,100 150 > 1000 3x1.4* 4,200 TOTAL, items 1 to 4 > 1300 - 8,000

Consumers 500, 700 > 50 12x1.4* 800 300, 400 > 150 6x1.4* 1,200 200 > 1,000 3x1.4* 4,200 150 > 2,000 2.2x1.4* 8,400 100 > 2,000 2x1.4* 5,600 TOTAL, items 5 to 9 > 5,200 - 22,200 TOTAL > 6,500 - 30,200 * VAT and customs fees

Due to the advanced international experience, the experts of Naftogaz of Ukraine National Joint Stock Company developed a concept of creation of the unified system of natural gas accounting, which was approved by the Cabinet of Ministers of Ukraine dated August 21, 2001 No. 1089. The main goal is the creation of systems for gas, ensuring the high reliability of measurement of the gas volume.

Today the advanced foreign and domestic firms developed the modern natural gas meters, the error of which is less than 0.5% (Table 1). Their introduction in Ukraine is constrained primarily due to the lack of the required metrological support.

The analysis of the former error of the natural gas metering instrument is still recorded and its expected status after implementation of the major provisions on the Concept of a Unified System for Natural Gas Metering in Ukraine is presented in Table. 2.

Table 2 shows the following points. Through the introduction of modern electronic correctors a significant reduction of the natural gas appliances

error is marked.

The error of polynomials embedded in the currently known methods of measurements using the variable pressure drop (using the diaphragm), in the best optimal ranges of consumption, pipeline diameters and module values is 0.6-0.8%. In addition, in the course of measurement using this method in the operating conditions there is an error of the primary converter of pressure drop and error in gas density determination.

The commensurate error is observed upon measurement of natural gas consumption by meters calibrated (verified) at stands existing in Ukraine, the working environment is which is air (stand error is 0.3%, the error due to a mismatch between the working environment and pressure is about 0.6%).

The noticeable error reduction is possible when using the methods proven in the world's best practice, namely the introduction of modern s precision meters calibrated at the stands in conditions close to the working ones, at the working pressure and with the natural gas. A very small measurement error of the related parameters (temperature, pressure, gas composition) under current conditions, which can frequently be neglected, becomes significant during the procedure of bringing to standard conditions and measuring the gas flow in the working conditions with an accuracy of about 0.5 %. That is, in view of the error of 1% when measuring the gas consumption, it is permissible to neglect the pressure measurement error of 0.25% or the temperature measurement error of 0.65ºC. For the expected condition these errors will become material. The modern measuring devices are able to provide significantly better performance accuracy, but the relevant metrological software, unfortunately, is still lagging behind.

Based on the real needs and operation conditions of specific sites, we recommend: at all GMS (both with meters of all types and diaphragm) it is required to install the effective filters without

valves between them and counter or diaphragm as a possible source of contamination); for large GMS (for example, with consumption in standard conditions above 5,000 m3 per hour) it is feasible

to use two accounting complexes with various measuring techniques connected in series; GMS using the method of variable pressure drop with unstable gas composition (if the gas density change is

fixed at 5 to 10 g per m3 in standard conditions), the flow density meters should be included; at the newly created and renovated GMS it is required to implement the complexes (counter with corrector)

implementing the functions of adjusting the additional meter errors depending on the temperature and working environment pressure change or the Reynolds number;

issue of flow meters, in which the relative error in the basic range upon manufacture completion is 0.5%, and during the operation - 1%;

continue the establishment and operation of stands for calibration and long-term testing of industrial meters at "natural gas" working environment with involvement of mobile standards of the Metrology Centre in Boyarka;

during issue and after repair the gas meters shall be calibrated at the stands with "natural gas" working environment under working pressure and checked at the stands with "air" working environment at atmospheric pressure and in the course of the next calibration at stands with "air" working environment at atmospheric pressure.

The cost of verification (calibration) of the natural gas consumption MAs in European metrological institutions accredited to perform such works at natural gas is presented in the table 3.

Conclusion Thus, according to the results of the performed analysis we can state as follows [2]: A significant error reduction of the instrument for natural gas accounting, the need for which is dictated by the

sharp increase in gas prices is possible only due to simultaneous introduction of modern measuring appliances (MA) and associated metrology software; It is possible to create a system of natural gas accounting with measurement error in the basic range less than 0.6%. The required domestic metrological software is being created already, and MAs are legalized and available;

The implementation of verification (calibration) of meters for "natural gas" operation environment shall take place in stages:

• All turbine, ultrasonic and rotary meters working at high pressure;

• All ultrasonic and rotary meters working at medium pressure. References

1. Vlasyuk Y.M. Concept of a unified system for natural gas metering in Ukraine (optimizing the implementation of industrial meters with various methods of measurement)/Y.M. Vlasyuk, M.I. Chupryn. - P. 73-75. 2. MP 412/03-2010. A method of checking the technical condition of the GMS using EK-B installation / V.I. Kartasheva, N.V. Babichenko, V.S. Bondarenko, Y.M. Vlasyuk [et al.]. - 21 p.

Article Authors Vlasyuk Yaroslav Mykhaylovych Candidate of Technical Sciences, an expert in the field of automation of production processes, accounting of natural gas and metrology. He graduated from IFING. The main directions of his scientific studies is creation of electronic fiscal means of instrumental accounting, improvement of metrological software for natural gas metering appliances, calibration (verification) of industrial meters by working pressure; checking the technical condition (metrological characteristics) of the natural gas metering units in operating environment; implementation of consumption metering complexes with regulated total measurement error, self- diagnostics of the natural gas metering units.

Compan Artem Igorovych He graduated from Kondratyuk National Technical University of Poltava with the major in Equipment for Oil and Gas Industry. His research interests are related to accounting and reasonable use of natural gas energy and savings in the industry.

Vlasyk Lilya Yaroslavivna 2nd category engineer of Ukrmetrteststandard SE. She graduated from KPI with the major in metro logy and measuring equipment, as well as linguistics. The main line of her work is verification of the nautral gas consumption measuring appliances.

AUTOMATION AND INFORMATION TECHNOLOGY

Automation of seismic surveys supervision

UDC 550.834.02 - 047.64 © M.P. Rogachuk M.V. Tyshchenko S.V. Olomskyi Y.A. Vasylyuk Naukanaftogaz SE of Naftogaz of Ukraine National Joint Stock Company S.M. Ryaboshapko GeoSeysKontrol CJSC, Moscow V.I. Roman Candidate of Technical Science N.I. Mukoyed Subbotin Institute of Geophysics of the NAS of Ukraine The paper presents algorithmic basics of software and hardware tools for automated supervisory control of seismic surveys within the adaptive seismic complexes.

Key words: seismic survey, supervision, noise, observation.

The response to the needs and demands of the modern seismic survey is the development and use of adaptive technology of seismic studies, as well as software and hardware for its implementation [1, 2]. The technical and technological possibilities of creation and the use of adaptive seismic survey facilities at the present stage of its development are based on the latest achievements of science and technology, including its electronic, computer and information industries. The organic kinematic and dynamic completeness of adaptive technology meets the current needs and trends of seismic studies motivated by an increase in the role and scope of detailing the structural objects and no less methodologically and technologically sophisticated exploration of non-structural geological formations. The controllability and manageability of adaptive seismic complexes with seismic record quality indicators enables the automated computer supervision of observation at the primary and basic level of technological cycle of seismic surveys, including the geological interpretation of the obtained results. The automatic adaptive supervision of observation registration and appropriate adjustments to achieve a given quality indicator of research is carried out in the course of working out the project value of observations and, in contrast to the current practice of supervision, do not result in violation of regularity and progressivity of the fieldwork.

The ultimate goal of seismic work supervision is compliance with design parameters of their quality stipulated by instructions to the customer requirements and geological problems of seismic surveys. The effectiveness of preventive design measures to ensure the quality of research is usually refuted by unpredictable and impossible proper taking into account of the spatial and temporal variability of deep and surface seismic conditions of work and unwanted seismic effects of environment. The situation is complicated by the high rate, performance of modern seismic surveys and large amounts of information received meanwhile. These circumstances lead to the lack of the existing practice of supervision of seismic surveys, based on a posteriori analysis of materials of performed works and repeated study of observations, the quality of which is proved to be not in accordance with the customer’s requirements. The key concept of adaptive technology of the seismic surveys and the basis of adaptive functioning of the seismic study complexes is a spectrum of signal-to-noise ratio, which is defined as an integral function of frequency, the value of which is the quotient of division of the target signal range module by the to noise spectrum module value for each value of frequency in the frequency range of research [2]. The requirements of geological research objectives are expressed in the form of the given spectra of signal-to-noise ratio, which in terms of seismicity regulate the temporal and amplitude resolution of research, and in geological terms – the spatial detail and parametric precision of section reproduction. During the observation based on the results of comparing the actual spectrum of signal-to-noise ratio and their set matches the adequacy of observation or the need for its continuation is determined. In the latter case, the probing signal parameters for further observation is determined and adjusted so that the desired values of the set spectra of signal-to-noise ratio were achieved. The comparison of

the actually received and set spectra of signal-to-noise ratio and adjustment of observations may be multistage. The criterion for observation completion is the achievement or exceeding of the actual received spectra of signal-to-noise ratio values of their set equivalents for all target signals. The subsequent examination of the volumes of seismic studies allows adjusting the use of methodological techniques in complex surface or deep seismic geological conditions.

The availability of the criterion of optimum adjustment results and effective completion of observation volume determines the ability to create the adaptive automated quality control systems of the recorded seismic data.

Since the use of the spectra of signal-to-noise ratio is comparative in nature, it is legitimate to use their subsequent energy definition as the ratio of the square modules of signals and noise.

In essence, the signal-to-noise ratio range is the spectrum of the output signal of the

optimal identifying filter of the known arbitrary input signal f(t) with spectrum F(ω) in

the noise background n(t),

where F * (ω) – is a complex related signal spectrum f(t), Bf (ω) is a spectrum of its automatic correlation function, and f(t), Bn (ω) is a spectrum of the autocorrelation function of noise n(t) [3]. The optimal detection filter, regardless of the intensity of the observed signal, provides the maximum rm of the ratio between the square of the customary amplitude signal value to noise variance.

The integrated nature of such numerical indicator provides no basis for determining which frequency range of

the noise and the extent to which it complicates the achievement of the required quality of supervision, and it does not direct the researcher towards the opposition to noise with arbitrary spectral composition with excitation of the corresponding spectral differentiated probing signals.

Such requirements are met by the signal-to-noise ratio r(ω), which, as a function of frequency, provides the spectrally differentiated adjustment of observations for the purpose of their optimization in variable seismic conditions of work, depending on the characteristics of structure and composition of the geological environment, as well as nature and intensity of noise.

The spectrum signal-to-noise ratio certainly describes the optimal Wiener’s filter of reproduction of

signal s( t ) by its realizations u(t) = s(t) + n(t). In turn, the optimum reproduction filter is a spectral factor of specialized optimum Wiener’s filter, the

generalized expression of which is defined as the correction filter G(ω) = R(ω)S-1(ω)V(ω), where S -1 (ω) is a perfect filter of signal compression s(t), V(ω) is a spectrum of filter specialization signal v(t), to which the observed realizations of signal s(t) were brought by filter G(ω) with the minimum mean square error [3]. For the reproduction filter, in particular, v(t) = s(t), V(a) = S(G>); for the compression filter v(t) = δ(t), where δ(t) is a delta function, V(ω) = 1.

Thus, the spectra of signal-to-noise ratio determine the algorithmic and technological ordering and orientation of the optimal observations. The optimization of observations provides for the controlled and managed comparison of the energy of excitation of informing seismic signals with the objectively existing negative factors influencing the quality of research in order to achieve its specified indices.

Above are the features of optimal adaptation of seismic studies in their spectral and temporal form. The spatial aspect of the issue is available in the case of simultaneous operation of seismic sources of their groups located in the area of works at the distances of their possible seismic mutual effects. The use of adaptive technology with the minimal impact on observations necessitates the implementation of simultaneous independent work of the grouped seismic sources by combining in time the sessions of their excitation of the probing signals with further allocation of the seismic charts of individual seismic sources of the group in the course of processing of the interference group seismic records.

The technologically feasible method of combining the sessions of simultaneous independent work of the grouped seismic groups in time is diversification of probing signal excited by them according to the scheme of Hadamard matrix elements [4].The procedure of the used Hadamard matrix must be greater than or equal to the number of concurrently operated seismic sources, and the number of excitation sessions and observation of grouped interference seismograms must be a multiple of the matrix order. The advantage of use of Hadamard matrices compared to the other features of provision of simultaneous independent operation of seismic sources is a sufficiency of manipulation with polarity of signals excited by them. The amplitude and shape of the latter may be arbitrary, but constant for the sessions of a complete technological phase of observation.

These requirements for use of Hadamard matrices are necessary and sufficient to calculate the spectra of signal-to-noise ratio on seismograms generated by each of the simultaneously working seismic sources and appropriate adjustment of the extension of observation by each of them or its completion upon reaching of the preset parameters of research quality.

In technical terms, the automation of seismic studies supervision requires the increased computing power of seismic complexes and provision of the required amount of two-way information exchange between seismic station and each of the concurrently operated seismic sources. These requirements can be met by installation of an additional computer at the seismic station and appropriate improvement of the seismic complex control system. According to geological research objectives and methods, as well as technical equipment of field work at the time of observation, the set spectra of signal-to-noise ratio of the target signals and coding means for the probing signals of the simultaneously and independently operated seismic sources of seismic complexes (through the use of Hadamard matrices) are crucial for its implementation.

At the initial stage of observations the probing signals are excited in the frequency range provided by geological and technical problem. The initial phase is completed, if it is possible to identify the axes of target signals' in-phase operation or most intensive of them, provided that the quantitative ratios of their amplitude with the amplitude of the rest of the target signals are known. The data required to this effect for new areas can be obtained by performance of appropriate research or from the experience of testing the previous volumes in areas where the research continues.

The element of priority in processing the observed seismograms of the initial and generally any other accomplished stage of observation is allocation of seismograms generated by separate concurrently operated seismic sources and noise seismograms from grouped interferential seismic records.

Then, the actually received spectra of signal-to-noise ratios of the target signals at allocated seismograms of the concurrently operated seismic sources are computed, the calculated spectra signal-to-noise ratios is determined with their predetermined counterparts, and the spectra of spectral and energy probing signal parameters are determined based on the comparison results to continue the observation or spectral and energy indicators for its completion.

The spectrally controlled vibrating seismic sources are the most suitable for use in adaptive seismic complexes. Therefore, the subsequent presentation of the peculiarities of use of the adaptive technology for the needs of supervision of seismic surveys is carried out in terms of the vibration seismic survey.

For an unprejudiced geological analysis, the observation materials should be deprived of the technological consequences of their obtaining, just as the primary vibratory seismic seismograms are recorded in the form vibration charts and are interpreted in the form of core charts. However, the core charts are not the ultimate form of reproduction of the geological environment, not covered by the technological details, such as correlation noise. The requirements of the adaptive technology are met by the impulse seismograms obtained by deconvolution of core charts.

Despite the problems of deconvolution of noise intensification, the deconvolution positive effect is that the noises are separated with it from environmental information and can be neutralized by the corresponding spectral targeting of the probing signals excitation energy.

The calculation of the actually received spectra of signal-to-noise ratio of the target signals in accordance with an algorithm of the adaptive technology is performed after allocation of the seismograms of individual seismic sources from group seismic records in the form of vibration charts or core charts and deconvolution conversion into pulse seismograms. The deconvolution of core charts into pulse seismograms is the most complicated and burdensome link of the computing support of the adaptive technology, especially in the case of use of the super-multi-channel observation mega-systems [5]. From the point of view of the seismic signal excitement energy minimization and sparing of energy resources it is feasible to conduct the multiple adjustmentz of parameters of the probing signals during the observation subject to calculation of the actually received spectra of signal-to-noise ratio and impulse seismograms required to that effect [2]. In this regard it is important to identify the opportunities to reduce the computation volume primarily due to reduction of deconvolution transformation of core charts into the impulse seismograms, which is achieved through definition of parameters to continue the observations or the reasons for its completion only in the critical circumstances which occur for less intense target signals at seismic records complicated with the most intense noises. For the other, less critical seismic records, the following major parameters are automatically admissible. The selection of critical seismic records is carried out according to the computational and economic algorithms, which leads to the proper functioning of adaptive seismic complexes.

Conclusion Based on the results of comparing the actually received and set spectra of signal-to-noise ratio, the duration of

observation subject to achievement of the set quality of research, which for critical seismic records may not correspond to the set productivity indicators of seismic research, is projected. In this case, the issue of possibility of withdrawal of the seismic records of some channels of the observation system from further use or the feasibility to continue the observation shall be determined in accordance with the policy guidelines.

Compared to the subjective supervision practice capable to detect only gross violations of design parameters of seismic studies, the unprejudiced computer supervision can be used in the entire range of metrological capabilities of the adaptive technology of seismic surveys, determined by the limit of economic feasibility of increase of completeness and detailed study of subsoil, until there is a positive balance of the cost of work and the value of final geological results.

References 1. Zhukov A.P. Seismic surveillance with vibration sources/A.P. Zhukov, S.V. Kolesov, G.A. Schechtman, M.B. Shneerson. - Tver: Gers Publishing House LLC, 2011. - 412 p. 2. Roman V.I. Adaptive seismic surveys: seismic field registration models/V.I. Roman, G.A. Shportyuk, D.M. Grin, N.I. Mukoyed//Geophysical magazine. - 2011. – No. 6. - P. 152-156. 3. Gurvich I.I. Seismic survey: handbook for universities/I.I. Gurvich, G.N. Bohanyk. - 3rd ed., Rev. - Moscow: Nedra, 1980. - 551 p. 4. Mathematical Encyclopedia. - Moscow: Soviet encyclopedia, 1977. - Vol.1. - P. 85. 5. Cherepovskyi A.V. Seismic surveillance with singular receptacles and sources: review of the modern technologies and surveillance design/A.V. Cherepovskyo. - Tver: Gers Publishing House LLC, 2012. - 134 p.

THE HISTORY OF THE INDUSTRY

Establishment of industrial oil production in the Carpathian region as a prerequisite for the creation of the Museum of Oil

Fields of Galicia © I.O. Guziychuk I.T. Temeh Candidate of legal science Institute of History of Nadvirna Oilfield District NGO

The oil has been discussed in the Carpathian region for a long time. One of the first written mentions of the presence of

oil in the Carpathian subsoil is found in the works of Jan Dlugosz (1415 - 1480), a Polish historian, diplomat, Archbishop of Lviv, the author of the History of Poland in 12 volumes. The rocky oil (one of its former names) emerged on the face of the mountain streams, rivers and lakes. In those days it was mined in a simple primitive way, using the bundles of long grass or other well-absorbing materials, the oil was collected from the surface of water bodies and pressed into buckets. The people who collected oil in this way were called “lybaks”. In the 15th and 16th centuries the oil manifestations were observed near the Carpathian villages of Nebyliv, Kosmach Starunia, Molodkiv, Pidlyvche, Perehinske, Pryslup, Lukva, thresholds, Lyucha, Birch, Stebnyk, Bytkiv, Pasichna and others. The households used oil as a therapeutic ointment, the product to lubricate the tool carts, drying while dressing leather, and later it was used for street lighting etc.

The beginning of the industrial oil production in the region is believed the year of 1771. At that time in the village of Sloboda-Rungurska at Kolomyia district the oil was received from the well dug for the extraction of salt at the depth of 24 m. Subsequently, such wells for oil production (or oil cistern) began to appear in the other parts of the Carpathians, i.e. in the village of Ri pne (1786), in the village of Naguyevychi (1792), near Boryslav (1820's) etc. with the time passing by the oil reservoir got exhausted, so the wells were deepened. Currently their maximum depth is not established, but this method of production was dangerous to the miners. Frequently the rock falls, explosions of natural gas, and equipment falling caused injury to or even death of employees. One of these cases was described by the famous Ukrainian writer Ivan Franko in his story Boryslav Laughs.

Fig. 1. Manual oil collection

By the mid-nineteenth century, the oil demand was low because of the narrow scope of its economic use. For the same reasons the oil extraction technologies were not developed. The impetus for initiating the large-scale oil development in Galicia in particular and Europe in general was the invention of Jan Zeg and Ignatius Lukasiewicz who obtained the kerosene in the laboratory of the pharmacy "Under the gold star" when conducting experiments on the oil fractional distillation in 1853. They proposed the idea to use kerosene in a special lamp for lighting. These innovating ways of oil use led to the rapid growth in demand for oil, but the methods of its production were gradually pushed back by the innovating technologies, because they did not allow to keep pace with the increased demand. In the second half of the nineteenth century the drilling attempts were started in the Carpathian oil-bearing areas. The first oil wells in Boryslav with the depth of 250 m were drilled in 1862, with the depth of 75 m in the village of Sloboda-Rungurska in 1872, and in the village of Ripne in 1887. The important role in the development of oil and gas production industry of Galicia was played by disclosure of Skhidnytsia deposit. The beginning of oil industry in Skhidnytsya is associated with

digging of wells here in places of oil manifestation on the surface in 1859, and in 1872 the first well was drilled here. The implementation of drilling at great depths allowed discovering the new fields; the first oil-bearing well was drilled in Byktiv in 1899. Since then, the Bytkiv oil industry traces its history.

Fig. 2. General view of Bytkiv oil field

Fig. 3. Measures to increase the oil production (1970's)

First the wells were drilled by manual impact way, and later they began to use the mechanical impact drilling using the steam engines (locomobiles). The foreign methods were widely implemented in fields, gradually improving and adapting them to geological conditions of the Carpathians. For example, the Polish-Canadian drilling method appeared this way. The oil production method was changed too. For lifting of oil on to the top of the wells that have ceased to gush the bailer was used. Later this method was replaced by swabbing. Subsequently, oil was pumped. At the end of the nineteenth and the beginning of the twentieth century the application of group drives of the pumping installations (kirates) was used at oil fields, which enabled simultaneously driving several wells equipped with immersed pumps from one motor. The oil was also produced with a gas-lift method. The first attempts of its production using the compressed gas energy were made in Skhidnytsya, Galicia, in 1900.

Along with the increasing oil production volumes, the refineries were built. One of the first refineries was built in 1882 in Pechenizhyn (near Coloma), and in 1910 a part of the plant equipment was moved to Nadvirna. At the same time a large oil refining plant was built in Drohobych.

The introduction of new technologies both in drilling and in mining provided a significant increase in oil production in the early twentieth century. In 1909, Galicia ranked 3rd in the world after the U.S. and Russia by volume of oil production. Its indicator reached 2 million tons. The oil production center of those times in the Carpathian region was Boryslav.

In the early twentieth century the oil fields belonged to the most high-tech industries. Each oil field has its own smithery and mechanical workshop; the rail road was constructed to deliver the equipment to the wells. The autonomous power stations were built, such as gas power station in Bytkiv (1923).

The contemporary methods of exploitation of oil deposits, which were inherently barbaric, led to the fact that close to 40's of the twentieth century the volumes of oil production began to fall. The separate oil industries, including Sloboda-Rungurska field, ceased to exist completely. This also contributed to the fact that the new drilling and oil

extraction technologies widely used in the world at that time, including the rotary drilling, rarely found their application in Galicia.

The second high noon of the oil and gas industry in the Carpathian region occurred in the 50's of the twentieth century. At that time, all oil fields of the Carpathian region moved to Ukrnaftavydobuvannya trust. The complex of geological surveying works contributed to the discovery of many new fields; a surge of oil from the Deep Fold of Bytkiv-Babchenske field was obtained in 1951, and Dolynske, North Dolynske, Starosambirske, Gvizdetske, Pnivske, Pasichnyanske, Spasske, Strutynske, Oriv-Ulychnyanske, and Stynavske fields were developed. The widespread introduction of the new drilling methods, intensification of fluids influx and production was started.

Today the oil companies of Galicia have a positive experience of more than two centuries’ management. Still, unfortunately, we have to state that there is still no institution in the territory which would retain and compile the data about the formation and development of industrial oil and gas production here for future generations. In our opinion, such an establishment should become the new Museum of Oil Fields of Galicia. After all, its absence has already caused the irreversible loss of many documents, models of machinery (oil equipment, drilling tools, special mechanisms, and mining equipment).

Fig. 4. Installation of a new exhibit - a tripod for oil production Most of the machinery was disposed, and a small part was taken abroad, where it entered the "golden fund" of museum

collections. For example, a real treasure of the exhibition and funds of the Museum of Oil and Gas Industry named after Lukasiewicz in Bubrka (Poland) are the documents and equipment from Boryslav and Bytkiv oil fields, which are proudly exhibited as historical objects of the Polish national oil and gas production industry. Drawing the public attention to the problem of annual reduction of petroleum equipment, machinery, buildings, structures and other oil production facilities having an invaluable historical, cultural, scientific and technical information and, in general, is the heritage of all previous generations of petroleum industry employees, we realize that without proper accounting and preservation, which is one of the priorities of the current and future generations of oil industry employees, these items of the museum value may be lost forever, which is unacceptable.

Realizing the importance of research of the hydrocarbon production history, in order to preserve the historical heritage of the territory, a public organization Institute of History of Nadvirna Oilfield Area was created in 2012. It included the oil specialists of Nadvirnanaftogas OGPD, veterans and retirees of the enterprise, as well as many active citizens, including the regional ethnographers and historians. The very first and the main task of the organization is to create a museum of History of Nadvirna Oilfield Area, renamed into the Museum of Galician Oil Fields.

There are a lot of achievements during the year; a number of models of the oil equipment of the nineteenth and twentieth centuries were created, a number of scientific expeditions were conducted, many archival documents were found, and the work at the creation of the museum under the open sky is underway.

We believe that the museum will become a bridge between the past and the future of oil and gas industry and a testimony of continuity of the best traditions of all generations of the oil employees in Galicia.

Get involved in preserving the history of the oil fields of Galicia and the historical memory of the best representatives of the petroleum refining industry of Ukraine. See the detailed information on the museum web-site at http://oilmuseum.org.ua/

Article Authors

Guziychuk Igor Oleksandrovych The head of the Institute of History of Nadvira Oilfield Area NGO. He graduated from Ivano-Frankivsk National Technical University of Oil and Gas. The engineer of the department for mining and drilling of wells at Nadvirnanaftogas OGPD.

Temeh Igor Teodoziyovych Doctor of Law Philosophy, Candidate of Legal Sciences. Scientific consultant of the Museum of Oilfield of Galicia. His main research areas are the history of oil and gas industry, development of legal regulation of oil and gas business.

INFORMATION

65th Anniversary of Mains Gas Transportation

The USSR Council of Ministers by Resolution No. 969 dd. April 29, 1946 ordered the Ministry of Construction of FEnterprises of the USSR and the Council of Ministers of the USSR to build and commission the gas mains DashavKyiv with the diameter of 520 mm, a capacity of 2.5 millionm3 per day with the possibility of further increase in productivity of up to 5 million m3 per day.

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Despite the difficult post-war conditions, on November 17, 1948 due to the heroic and selfless work of designers, builders and local villagers the natural gas from Dashava field was supplied via Dashava-Kyiv gas mains to the gas distribution station of Kyiv(now the museum of Kyivtransgaz UMG). 65 years ago the blue fuel has come to serve the people of Kyiv*. This historical landmark has

become the reference point in the development of the mains transportation of natural gas to Ukraine.** To operate the gas mains, the Golovgazprom at the Council of Ministers of the USSR (No. 486 dd. September 11, 1948)

ordered to establish the Administration for Dashava-Kyiv Mains Operation (currently the Administration of Gas Mains Kyivtransgaz with five district departments located in the village of Hnizdychiv, Zhydachiv district, Drohobych oblast, in the city of Ternopil, in the city of Krasyliv, Kamyanects-Podilsk oblast, in the city of Berdychiv, Zhytomyr oblast, and in Kyiv)*. The first manager of the administration for Dashava-Kyiv gas mains has became Vasyl Semenovych.

The foundations laid during the design, construction and operation of Dashava-Kyiv has mains has become the basis for the development of the gas transportation system of Ukraine. In the project solutions of construction and operation of Dashava-Kyiv gas mains the innovating achievements of science and technology in the field of metallurgy, welding, insulation, cathodic protection, storage, and reliability of operation of the highly dangerous facilities were widely implemented***. The commissioning of the compressor stations in Ternopil, Krasyliv, Berdychiv and Boyarka with gas motor compressors by Clark allowed providing the productivity of Dashava-Kyiv gas mains up to 5 million m3 per day. The increased productivity of the gas mans contributed to a significant expansion of gas supply to the surrounding towns and villages, including the regional centers. This enabled us to introduce the new technologies, improve the production standards and living conditions of many residents of surrounding towns and villages of Ukraine.

The commissioning of Dashava-Kyiv gas mains was the impetus to development of new technologies in the fields of science and technology, especially in machine building, turbine, chemical, power generation, automation control systems and training, not only those inherited from the Soviet Union, but also the global ones.

So today, let us not forget those heroic work achievements of the industry veterans, thanks to the efforts of which the first gas mains 509.6 km long with four compressor stations and the working pressure of 55 bar has become the beginning of the creation of one of the most powerful gas transportation systems in the world.

© *Chornovol V.S. Historical data on the Kyiv Administration of Gas Mains.

** Andriyishyn M.P. The 60th anniversary of Kyivtransgaz UMG/M.P. Andriyishyn//Oil and gas industry. - 2008. – No. 4. - P. 3-4.

*** Oil & Gas Industry of Ukraine: progress and identity/ed. by Z.P. Osinchuk. - K: Logos Ukraine Publishign Center, 2013. - 328 p.

Y.S. Marchuk, M.P. Andriyishyn Candidate of Technical Science

INTERNATIONAL COOPERATION

Representative office of E.OH E.OH Global Commodities CE in Ukraine Hilmar Enne Head of the Representative Office of E.OH Global Commodities CE in Kyiv

Since Ukraine gained independence, the German gas concern E.OH Ruhrgas AG has been working closely with the

Ukrainian companies. For more than twenty years the annual programs of cooperation discussed the topics related to the natural gas transportation appliances, including its storage and management of these processes. There has been the exchange of experience, including the various innovations in the gas industry to adapt to the European standards, which helped to ensure a stable supply of Ukrainian gas via the transportation system of the Russian natural gas to the Western Europe. The interpersonal contact between E.OH Ruhrgas professionals and their Ukrainian counterparts contributed to establishment of friendly relations.

On January 9, 1993 the representative office of E.OH Ruhrgas AG was accredited by the Ministry of Foreign Economic Relations of Ukraine. It was a corner stone and the link of success of the Ukrainian-German cooperation.

Who were, in fact, the German gas workers, which have long worked with the Ukrainian colleagues? In 1926, the managers of the coal and steel industry of the Ruhr area in western Germany decided not to burn the coke

oven gas, or so-called "town gas", which is formed during the production of coke, but to collect it through the pipeline system and to provide for the needs of cities and industries. This is how the future Aktsiyenhezelshaft Ruhrgas was born, whose first clients were the companies like Bayer AG, Mannesman AG TyssenKrup AG and Henkel KHaA. Among cities of Hanno joined Sep, Essen, Remscheid, Zo-Lingen, Langenfeld, late st Cologne and Düsseldorf. After only five years after incorporation Ruhrgas AG has become the biggest gas supplier of the Weimar Republic, had the pipe network about 933 km log and 26 coke plants supplying about 800 million m³ of COG to the network.

In 1933, the supply of gas exceeded 1 billion m³ for the first time.

In 1935, Ruhrgas AG supported the demonstration trip of the bus fueled by gas from Essen to Konigsberg, i.e. about 2370 km long, thus helping to crown the success of gas as a fuel for cars.

In the late thirties in Germany after revelation of the gas field near the northern town of Bentham and construction of a 75-kilometer pipeline to the chemical plant in Hyuls, the era of the industrial use of natural gas began. The plans of the supply of the natural gas from the location to the Ruhrgas network failed, because after the onset of the Second World War there was a lack of funds and materials thereto.

After the bombing by the Anglo-American Air Forces in spring of 1945 the Ruhrgas pipeline network has suffered serious damage in about 400 locations. Only 2 of 51 coke plants were able to supply the gas. The gas supply has been stopped almost completely. Only after reconstruction of the pipeline and start of operation of the coke plants in 1949 Ruhrgas AG reached the gas sales volumes of 1938, i.e. 2.6 billion m³. Upon commissioning in 1954 of the first European gas reservoir in the aquifer and the completion of the plant construction for complete gasification of coal in Dorsten in 1955, Ruhrgas shifted from gas distribution to its supply. In the late fifties, against the backdrop of the first coal crisis and growing competition with oil industry, Ruhrgas was forced to develop a new strategy.