manikanta report final

8/10/2019 Manikanta Report Final

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Training report on

Industry academia interaction trainingprogram

For Petroleum Engineering Students

Dated from

16-06-2014 --- 01-07-2014

Venue: University Senate Hall, JNTUK

Submitted

By

Manikanta

.P


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Department

Of

Petroleum Engineering & Petrochemical Engineering

University College of Engineering (Autonomous)

Jawaharlal Nehru Technological University Kakinada

ACKNOWLEDGEMENT

I would like to acknowledge my sincere gratitude towards Prof.K.V.RAO

sir, in organizing 16 day workshop for the benefit of students and

bringing all the way, Industry people for this interaction programme.

Without the support and help from industries, this programme

wouldnt have been realized, I would be obliged to ASHOK VARMA-

Director-Onshore (ONGC)for his continuous support and affinitytowards our University.

I would like to extend my gratitude to Mr. Soma sekhargaru, for taking

initiation in allocating resourceful speakers for each and every lecture

of this programme.

The structure of this programme wouldnt be fleshed without the guest

speakers from ONGC, Aker solutions, Reliance Industries, Expro Gulf,

OIL Limited. I thank every speaker for sharing their precious experience

with us.

My sincere thanks to SPE Kakinada sectionfor accepting and

supporting this event.


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I would like to thank all the University officialsfor providing excellent

ambience for this workshop and their support in guiding us towards

excellence in carriers.


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Lectures in 16 day workshop:

1.

1.Seismic data acquisition ------Mr. Ashcharya chaubhey

2.

Seismic data processing -------Mr. V. Sasibusan sharma

3.

Open hole logging -------Mr. Raj bob

4. Cased hole logging -------Mr. Chandrasekhar

5.

Offshore installations -------Mr. Pavan kumar

6. Cement volume calculations -------Mr. Kodhandapani

7.

Well completions -------Mr. Swarna raju

8.

Well testing -------Mr. Somasekar

9. Deep water field development -------Mr. Narhari

10.

KG basin reservoirs -------Mr. Raghu ram

11.Flow assurance -------Mr. Kishan rao

12.

Subsea installations --------Mr. Tormond amlien

13.Water injection systems --------Mr. Gopal Rao

14.

Work over operations --------Mr. P.V.N. Rao

15.Artificial lift --------Mr. Bhaskar rao

16.

Enhanced oil recovery techniques --------Mr. Dilip kumar

17.

Subsea maintenance and operations -------Mr. Alan doughlas

18.

Well services --------Mr. Y.R.L Rao

19.

Offshore oil exploration and safety --------Mr. Prasad20.New exploration licensing policy --------Mr. Sasibushan sharma

21.

Produced water treatment and project management

-----Mr. Ramakotaiah

22. Production decline analysis, Offshore platforms, Natural gas reserves,

Overview of Indian gas sector, LNG, liquefaction and maintenance process,

Prevention And Control of cross country Pipelines, Nodal Analysis, Significant

gas fields In World --- Prof. K. V. Rao


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Day 1: SEISMIC DATA ACQUISITION

--- MR. Ashcharya chaubey (ONGC,

Rajahmundry)

In this lecture MR.CHAUBEY has explained data acquisition methods starting right

from need for seismic study and how are they generated.

I have listed out some key points delivered in his lecture and concepts I benefitted

from this lecture.

Characterization of seismic waves:

P -waves love waves

Swaves Rayleigh waves

Body waves are crucial in building subsurface strata image. Hence properties are

summarized:

S -waves doesnt pass through (l)&(g) as they cannot regain change in

volume

Pwaves are first arrivals since they travel in all phases parallel to direction

of propagation

SEISMIC SOURCES:

Land

1. Dynamite2. Vibrosis

Water

1.

Air gun

Depending on location we choose source. Locations where top layers

are unconsolidated it is preferable to use vibrosis otherwise much of

seisimic waves

Body waves surface waves


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2.

Folding of different time intervals in same layer from different rays

eliminate multiple reflections and ground roll.

3.

Slicing of 3D data is helpful in identifying the changes in heterogeneity of

reservoir (faults).

4.

Even the costs of 3D survey is accounted to be high the probability ofsuccess ratio in identifying prospect is high with high resolution and

accuracy.

Day 1: DATA PROCESSING AND INTERPRETATION

----Mr. V. Sasibusan sharma

After acquiring the data, processing is essential in order to remove ground roll,

ghost waves, reverberations, diffraction effects.

In this following lecture, procedure has been discussed by MR. V. Sashibushan

Sharma in a sequential steps to process the data.

wavelet processing

normal move out correction

stacking

DE convolution

Migration

Interpretation

WAVELET PROCESSING:

Our primary aim is to convert to wavelets into zero phase which enables to

improve resolution and polarity detection.

NORMAL MOVEOUT:

Since all the subsurface strata is dipping rather than horizontal as assumed,

it is preferable to plot all the data on horizontal by taking dip as zero andzero offset time.

VERTICAL STACKING:

It reduces random noises by summing up wavelet amplitudes at same

location.


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DECONVOLUTION:

Here much of Ground Roll and ghost waves are detected and filtered by

compressing the frequency and amplitude so that resolution is increased.

MIGRATION:

With case of dipping beds migration helps in correcting dipping reflections

into proper spatial relationship.

It also helps in diminishing diffraction effects especially at faults.

DATA INTERPRETATION:

Slicing of 3D data is done to identify heterogeneous reservoir

characteristics.

We generate data to time depth conversion thus a 2D seismogram isgenerated.

Similarly synthetic seismogram is generated from sonic log data and

both Graphs are correlated to check the degree of accuracy.

Things learnt apart from literature:

Upon generating the data and plotting the contour upto reservoir

boundaries, it is job of geophysicist to identify sweet spots in interval so

that maximum data is acquired in building reservoir model with

stipulated number of wells.

DAY 2: OPEN HOLE LOGGING

---Mr. Raj bob, ONGC--

In this lecture we have gone through series of open hole log tools and their

principles discussed by MR. Raj bob. Later based on the data obtained from logs

formation physical characteristics are evaluated.

WORKING PRINCIPLES

Resistivity

1. Normal configuration

2. Lateral


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3.Latero

Normal configuration: in here two measuring electrodes, one at bottom

hole and other at surface measure the potential diff. across formation.

Since electrodes are much apart vertical resolution is low and thin beds

cannot be detected.Hence well go for lateral configuration were two measuring electrodes are

placed in borehole.

LATERAL CONFIGUATION: in this case the pit fall is side by defect

were much current chooses least resistive path to reach receivers.

Hence only thick resistive beds are detected

LATERO CONFIGURATION: two same potential electrodes are placed

so that current is focused linearly into formation beds.

DENSITY

1. Gama-Gama2. LDT

Here the principle is Gama rays generated are emitted into formation

resulting in number of release of electrons and scattering of photons

Spacing the detectors is key in obtaining the data, both number of

rays flashed and litho log.

NEUTRON --- here both the epithermal, thermal neutrons and Gama rays

are crucial in getting density of formation.

SONIC --- here acoustic wave is transmitted into formation and the travel

time corresponds to density of formation. Back drop of tool is this wavedoesnt travel in free porous path

EPT --- it measures the dielectric permittivity of water in formation by

propagation of electromagnetic waves.

NMR --- here external magnetic field is applied in turn decay time of proton

to realign back is measured. HC OOIP can be corrected by immobile residual

Kerogen.

RFT, SP, G-RAY, Dip meter are some fundamental tools which have been

discussed.

FORMATION EVALUATION:

Determine litho log and estimate shale content from SP or G-RAY

Determining Rw of formation from resistivity.


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Determining Sw in Formation from resistivity

Estimation of porosity of data from sonic, density, neutron and

averaging to get improved value.

Evaluating net HCPV by N/G vol, Sw


Cross plots of neutron and density is extremely reliable in identifying tight

gas zones and M and N plots for mineral identification

Chlorine log is best suited for determining resistivity of Fresh water and

identification of interfaces but with EPT there is no necessity of running

neutron sources.

Utilization of dielectric permittivity of water to check out for water channel

filled porosity.

Sonic wave path behavior differs along formation and corrected with helpof check shot surveys.

Day 2: CASED HOLE LOGGING

----Mr. Chandrasekhar. ONGC

In this session, cased hole logs followed by production logging tools and auxiliary

jobs done in a well were discussed by MR. Rajshekhar.

CEMENTBOND EVALUATION LOG:

--Based on arrival times of acoustic waves and spacing of receiver and source

combinations helps us in evaluation of cement bond behind borehole and

casing with CBL and behind formation and casing using VDL.

--If the bond is good CBL amplitude is small & VDL gives a wiggly plot.

--Similarly USIT tool also images cement bond quality around formation.

--The quality of bond is easy to find as acoustic impedance plot is dark shaded

indicating good cement bond.

CASED HOLE FORMATION RESISTIVITY: It impedes current (milliamps) into

formation giving formation conductivity. With the advent of this log it

enables to identify zones left behind and zones saturated with water


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AUXILLARY JOBS: These include identifying pipe stuck up point using free

point indicator tool, removing casing debris using junk basket and fish jobs

Production logging is carried out when the well is put in production and

measurements include flow rate, fluid density, down hole temperature and

down hole pressure


Micro debanding topic relatively gives us idea whether presence of any gas

channeling is taking place while cement is setting.

In order to check out the presence of micro annulus pressure is applied on

borehole and log is run again. If the micro annulus still persists then we can

infer channeling has been taking place

Design of flow meter is made to cover entire radius of well bore, so that wecan measure velocity of fluid at boundary as well as at midpoint of point

Temperature allows us to easily identify channeling behind casing, casing

leaks, gas channeling as there is temperature drop due to expansion and

identification of thief zones.

Day 3: Offshore installations

---V. Pavan Kumar (ExproGulf)

This session about offshore installations, equips us with a practical knowledge in

offshore environment. I feel it a virtual tour rather than a seminar hall session. It

gives us a bird view of installations in offshore structures and related

components, which was not at all in our academic curriculum.

He gave us some practical challenges faced by them during their experience. At

the end, sir advised us in our carriers with some specialized courses. We call off

the session with a few doubts from our students.


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Day 4: Deep water well integrity management

Siva sankhar busam (Reliance industries)

This class started with an introduction of the reliance industries and their

activities in E&P sector. He explained their operation strategies in KG D6 field.

KGD6 consists of D1D3 and MA fields presently.

D1, D3 - Gas field

MA - Oil field.

D1, D3 Gas fields:

Total of 18 wells with horizontal Xmas tree(5 / 7 10000psi)

2 are cased hole frac pack completion.

16 are Open hole gravel pack completion.

MA Oil field:

Total of 7 wells with horizontal Xmas tree(5 10000psi)

5 wells are horizontal completions and 2 wells are vertical.

Well integrity:Application of technical, operational and organizational solutions

to reduce risk of uncontrolled release of formation fluids throughout the life cycle

of a well.

Integrity of a well should be necessary from initial designing of a well, until

abandoning it.

Threat groups identified for subsea wells are:

1. Designing, fabrication and installation

2.

Corrosion and erosion

3.

Valve failures

4. Control monitoring failures

5. Structural failures

6.

Natural hazards

Well integrity and RAM analysis: (Reliability, Availability and Maintainability)


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Quantifying risks and their impacts of their consequences

Well Integrity Management

Inspection

Operational Surveillance

Operational Assurance

Testing

Maintenance

Well Integrity Management Resources

Organization

Subsea Services

Surveillance equipment

Processes / Procedures

Audits / Reviews

Later, the role of instrumentation was discussed in well operations such as choke

upstream pressure, choke downstream pressure, annulus pressure transmitter

and presence of acoustic sand detector, followed by the role of valves in well

operations, such as production wing valves, master valves, annulus access valves

etc. along with purpose and function of XMT valves.

Moving on to the next topic, a few more safety equipments were discussed

briefly,

Downhole pressure and temperature gauge (Two numbers).

Crown plugs (2)

SCSSV


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Packer

Well IntegrityLoss Response:

CMTEMT

Crisis/Emergency management processes, Competent and

experienced leadership, Drill to confirm readiness

MOU among Operators

Emergency cooperative agreement

Things learnt apart from literature

Well design should include sufficient surveillance equipment to ensure best

available management of the risks during the operational phase

Well design and completion should include consideration of the full life

cycle of the well.

Subsea well integrity management during the operational phase of the well

will include resources that are not easily available ad-hocincremental

OPEX costs are to be expected

The relative risk between risk to safety and risk to production can change

significantly throughout the life of a well.

The test program for active barriers should be commensurate with the level

of risk the well presents throughout its life, the test program should be

adaptive with consideration of the changing risk profile that is presented by

the well.

Production systems can be designed to aid in response to well integrity

loss.

Day 4: Cement volume calculations

Kodhandapani garu (OIL LTD)


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During the lecture, I came to know the importance of cementation, how

cementation protects the casing. The process of making cement slurry with

different cement additives was explained.

There exists three types of cementation.

1) Primary cementation

2)

Repair cementation

3)

Special cement jobs

Repair cementation includes cement squeeze jobs and shoe strengthening

jobs. I came to know how these jobs are done. Squeeze cementation is

done using hesitation method and cement block method

Special purpose jobs include Abandonment plugs, Side-track plugs, Loss

prevention plug jobs, In-situ combustion wells, Tested zone isolation jobs.Plug cementation is used to isolate mud loss zones and tested intervals .I came to

know how the well depth and temperature governs the cementation design.

Thus wells in the low pressure or sub-hydrostatic pressure are cemented either

with the slurry containing high strength microspheres or foam slurries

Apart from our literature, I learned that,

Dispersants/ Friction Reducers -These are chemicals added to cement slurries to

improve flow properties. Dispersed slurries have lower viscosity and can bepumped in turbulent flow at lower pump rates, thereby minimizing the

horsepower required and lessening the chance of lost circulation and premature

dehydration.

Fluid-loss Additives - These are used primarily to maintain a constant water to

solid ratio in cement slurry, thereby improve primary cement jobs.

(Synthetic polymers, cellulose derivatives etc.)

0-200 cc/30 min Good control

200-500 cc/30 min Moderate control

500-1000 cc/30 min Fair control

Over 1000 cc/30 min No control


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SPECIAL CASES The wells with high pressure gas zones not only need

Heavy slurries, but need additional special additives like gas Check, gas blocks

Control mechanisms for fluid loss mechanism are formation of miscells, improving

particle size, and increasing viscosity of interstitial water and cement slurry tosome extent and also addition of heavy weight materials such as Sand, Barite,

Hematite, Limonite etc.

I learnt the functions of top plug, bottom plug, floating collar, centralizer, spacers,

displacers and their role in cementation. How the volume of cement slurry is

calculated was depicted clearly along with displacement mud volume calculations.

A few doubts regarding this session for me was the stage cementing design, which

was clarified by him during the session. I feel this session as very practical in

nature and very much informative.

The lecture was winded up by discussing some practical problems that were faced

by their company during cementation in extreme conditions of high temperature

and gas channeling and a few case studies.

Subsea Systems

--- S. Swarna Raju, SE (P), EOA ---

This lecture of Swarna Raju sir gives a basic understanding of subsea technology,

such as,

Subsea Field Developments

Subsea Production Systems

Subsea Control Systems

He briefly explained about different types of offshore structures and land rigsalong with their limitations.

The main areas in subsea production systems are:

The structures

Work over and completion systems


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Tie-in and connection systems

Production control system

He explained various operations involved in a subsea field development and the

challenges that are facing due to geographical conditions. Weather conditions of

the major oceans are,

North seaRough seas

Gulf of Mexicoperiodic hurricanes

Africacalmer sea

Asia--typhoons

Arcticrough with ice and frost

Then, he explained the basic units of a production system, permanently installed

equipments, and their installing tools

Types of subsea structures

Cluster layout

--long distance between wells

--rig relocation may be required

Template system

--wells will be closer

--No rig relocation required after installation--Large size flow lines

Sir clearly differentiates horizontal and vertical XMTs

In Vertical XMT, tubing hanger is located in the wellhead.

In Horizontal XMT systems, the tubing hanger is located in the horizontal

XMT.

Subsea control module: a retrievable component used to control chokes, valves

and monitor pressure, temperature, and position sensing devices, that ismounted on the tree of the manifold. It is the brain of the control system.

Well Completion- Tubing string and well head Assembly:

In this session, sir deals with the components of tubing string and well head

assembly and their selection criteria.


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Starting with the basic function of a tubings, sir had defined a few parameters

that are used in selection criteria such as materials, load conditions, operation

conditions etc.

Tubing requirements: API/ISO specification, Quantity, size designation, weight,

grade, Length, API grades-chemical content, manufacture processes, and heat

treatments.

Sour wells (wells with H2S content greater than 0.05 psi partial pressure)-

specific sour service required.

In detail, sir explained tubing load analysis with burst load, collapse strength,

tension load

Then, sir had brushed our concepts in completions and packers

Retrievable Hydraulic type packers

bidirectional slip system

Set by hydraulic actuation

no tubing manipulation

shear-release to unset

highly deviated wells

A few components of completion string, such as scsssv, bridge plug, sliding sleeve,blast joint etc.

SCSSSV: ---Flapper type valve,

---tubing-retrievable and wire line-retrievable

Sliding sleeves: Establishing communication between the tubing and annulus for

fluid circulation

Multi zone production- packer isolation with sliding sleeves.

Methods of operating sliding sleeves include:

By wire line jarring up/down to open/close.

By pressure, to open and close

By pressure to open, wire line to close


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Applications of sliding sleeves are:

Displacing fluids, Selective testing, treating or production in multiple

completion, killing by circulation, Pressure equalizing, using the tubing to kick-

off the second string in a dual completion, Install valve or choke, flow

regulation.

Bridge plug:Set in the casing to prevent the flow in the casing. It provide

additional safety while the Christmas tree is being nipple up or nipple down.

Permanent or retrievable.

To isolate the zones

Set either mechanically or by wire line

Blast joint: Blast joints are used in the tubing string opposite the perforation

in producing zone, where the jetting action of the fluid can erode the outside

of the tubing.

Abrasion resistant, steel or normal steel that is coated with, plastic, rubber,

tungsten carbide, or ceramic.

Flowing coupleis used to delay erosional failure at points inside a completion

string, where a turbulent flow is expected to occur.

Landing nipple is short section of thick walled tubular that are machined

internally to provide a locking profile and at least one packing bore.

The purpose is to provide a profile at specific point in the completion string to

locate, lock and seal subsurface flow controls, either through wire line or pump

down methods. It can be used at virtually any point in the completion string

Moving on to the next, sir explained few components of well head assembly, such

as tubing head, tubing hanger, and extra facilities in subsea well head and subsea

XMT.

The session was winded up with a few doubts from students..


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SESSION: WELL TESTING OPERATIONS

--Mr. Somsekhar (ONGC, EOA)--

In this session of Somsekhar garu, He has gone through fundamentals of testingoperations, necessity to carry out testing at regular intervals to understand the

productivity of reservoir through wire line at well site and shutting well headers at

GGS and errors incurred when measured at well header node.

He has gone through

Types of tests.

Test Design and equipment

Interpretation.

He has explained on objectives of well testing in detail. Different type of tests like

DST, Mini DST and RFT are explained.

He also dealt about sequence of well testing later he moved to temperature and

pressure gradient survey methods.

Later he explained about PI, Open flow potential. He clearly explained about the

methods in reservoir studies of a gas well. Different type of tests like Isochronal

test, Fall off test, Modified Isochronal test, Build up and draw down test was

explained. He also explained the equipments like well head, X-mas tree, Wireline

winches, Pressure Gauges.

We call off the session with a few doubts from students.

An introduction to deep water field

developmentNara Hari (ONGC, EOA)

Mr. Narahari lecture consists of 2 phases. First, what should a under graduate

student should know about the deep water field. Secondly, the present

technologies of deep water field.


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Being a resident of Kakinada, Sir make us to have the advantage of getting known

to information of offshore technologies. Also, the fields of Kakinada are not only

deep water fields. These fields are different from other in this following ways,

Steep gradient of depth

High pressure and high temperature(HPHT) conditions

Presence of high sulphur content

Deep water fields

Small pockets of hydrocarbons

ONGC had drilled a well in west Godavari at temperature of 427 Celsius. Its

the only well with such a temperature present in the world up till now. The fields

of Kakinada made the operating companies to invest in R & D field for new

material technology to sustain the disastrous conditions of HPHT. Apart frommaterial technology, it is also investing in cement technologies to coup up with

the problems in cementing operations at such conditions.

We, the students of JNTU Kakinada are a step ahead of students from other

colleges by having knowledge about these fields which are having tough

conditions.

Mr. Narahari explained the latest highly advanced technologies in subsea such as

subsea compressions of hydrocarbon streams, subsea processing and subsea

pumping. At present, Aasgard field in Norway compression facilities on the

seabed itself. Recently explored fields of East and West Africa needs subsea

processing and pumping technology. Research activities had already started in Eor

activities in deep water fields such as subsea injection of water, gas, polymer and

surfactants.

The second phase of his lecture consists of different types of offshore structures.

Challenges in deep water and subsea technologies.

Major challenges faced in deep water fields are

Harsh environment

-Wind, Water currents, Weather

High Temperature Gradient

-hydrate formation, Wax formation, pour point


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Riser Design

-flexible risers, dynamic forces

Well Intervention difficulties

-deep, wet tree, floaters

Maintenance Issues

-deep, ROVs

Cost and Risk Factors

-Development, Logistics, small pools

Comparison of different offshore structures along with their advantages and

disadvantages were shown.

SESSION: KG-BASIN GEOLOGY.

---Raghu Ram (ONGC, Rajahmundry asset)---

Mr. Raghu ram garu, during this session, detailed the geology of KG basin. Being a

resident of Kakinada, we should know the characteristics of KG basin. Sir helped our

brains in this aspect.OUTCROP OF KG BASIN

Ages of geologic time scale and distinguished lecturer has explained the

strike trends of present KG & PG basin with comparison to Pangea.

Detailed coverage on several areas of exploration like Cauvery Basin, Krishna-

Godavari Basin.

Mainly concentrated on explaining the features of KG-PG basin like slope,

sedimentary thickness, age of formation, strike. Mentioned about the discoveries of oil and gas fields in KG basin.

Dealt with the principles of seismic survey and 2D, 3D survey.

Explained how seismic data is interpreted and observed.

Explained about how to identify different strata like Dudukkuru sandstone,

Raghavapuram shale, Bommuru sandstone...


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Many of the doubts posed by our friends on kg basin reservoir heterogeneity

and formation of hydrates on shallow continental slope has made this basin quite

challenging.

SESSION: FLOW ASSURANCE

----MR. Kishan Rao (ONGC, Rajahmundry asset) -

--

In this session, MR.KISHAN RAO garu has presented this topic FLOW

ASSURANCE which deals with wax control during production operations in

wells.

He has initially gone SARA analysis of crude from which we can estimate

fractions of saturates present in crude. The speaker mainly explained about

the problems faced by the working team in each segment of the pipeline

starting from the production tube to the trunk line.

Mainly, the problems in pipeline are due to wax precipitation, asphaltene

formation, paraffin formation, scaling, corrosion etc. he was mainlyconcerned about the need of flow assurance and also about challenges of

flow assurance in sub-sea. Also explained about the impact of flow assurance

technologies.

He explained in-detail and interestingly about wax precipitation and also

about wax crystallization. He also explained the type of fluid flows that are

generally encountered in vertical flow like bubble flow, churn flow, slug flow

and annular flow. Also explained how a crude oil is generally classified.


Through this lecture Ive came to know the importance in estimating fractions

of paraffins, aromatics to analyze crude behavior in wax formation.


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Paraffin waxes behave as Newtonian fluids above wax appearance temperature

Shifting of zones from hydrate risk zone to hydrate free zone.

Subsea installations in deep water fields

---Tormod Amlien (Aker solutions)----

Mr. Tormod Amlien started with the introduction of their company Aker

solutions, and their tie ups with Reliance Industries in KG D6 field. It was the first

deep water field project in India with an investment of 9 billion dollars. He did a

touch up about their branches at various countries and their contractors across

the globe, describing in which locations, different parts of subsea installations are

manufactured. They were at Finland, Kaulalampur, Perth, Houston, Tokyo etc.

Then he started explaining different parts in subsea installation floor and their

functions such as

Jumper installations,

XMT installations with LTRT and TRT,

Manifold installation,

Suction anchor installations, Umbilical installation,

Installation and retrieval of flow control modules (FCM), along with the

presentation of their installation videos.

He then moved on to next part,

Umbilical lay vessel and construction vessel. He explained their role in deep

sea installations.

In my view,

Doubts regarding this session are, how the tidal wave movements will

be compensated during the careful installation of XMTs and FCMs. Also, the

particular shape of jumpers, which were to prevent errors in meteorology

calculations.


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At a glance, I feel this session as a virtual tour of subsea installations rather than a

classroom lecture.

SESSION: WATER INJECTION SYSTEMS

---MR. Gopal Rao (ONGC, Rajahmundry)--

This lecture has been presented by Mr. Gopal rao one of the alumnus of our

college. He has been working as electrical engineer at Mumbai high.

He has discussed series of injection patterns followed by advantages and

operating costs and water treatment costs after an injection project is

implemented.

When the well flows naturally then it is called as primary recovery method. When

the methods like water or gas injection is used then it is called secondary recovery

methods. The use of different types of flooding does can be called as tertiary

recovery methods. On this session we are concentrating only on water injection

method, one of the secondary recovery methods. The purpose of this type

injection is:

Maintaining or improving reservoir pressure.

Most economical method for reservoir management.

Helps to move the oil in place.

Void-age compensation.

Injection wells, always may not be new ones, which are drilled and cased. These

may be the wells, which are once in production.


How the patterns of water injection wells are selected in between the oil

and gas production wells. What selection criteria are should be taken intoaccount in designing pattern, evaluation of the parameters in their

designing etc. which were actually not covered in our literature were

explained in detail through this presentation.


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Work over operations

---P. V. N. Rao (DGM (P)-ONGC-EOA)

This lecture by P. V. N. Rao garu consists of two sessions. In which, first session

deals with his presentation about work over operations, and in his second session,

he explained a few problems facing by the industry, and challenges he had

encountered during his experience, with a few photographs taken during his

experience.

During the first session, he explained what a work over operation is..? And what

jobs are under well servicing and intervention..?

- Work-over is any operation performed on a well to restore or increase its

production or even to safely abandon a well once it is found no more fit for

production

- Work-over operations are carried out by a drilling rig, light/ work-over rig,

Hydraulic rig or platform rig, modular rig, jack-up rig, barge rig

- Operations commence with subduing the well, removal of the X-mas tree from

the wellhead and replaced by blow out preventer (BOP) equipment.

Well servicing consists of:

- Servicing of Self flow wells, SRP wells, Gas lift wells, Screw pump wells, Detection

and repair of channeling behind casing, Testing and transfer to other objects,

Fishing, milling and stuck-up removal and re-completion, Detection and repair of

casing damage, Water /gas shut off, etc.

Also, components failures, decrease in well productivity leads to well intervention

Component failures are: Tubing failure- Packer failure

- Failure of flow control device such as SCSSV, sliding sleeve, wire-line nipple

- Xmas tree / tubing hanger failure / leakage

- Failure of gas lift valve and / or mandrel


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- Downhole pump failure

- Failure of SRP bottom assembly etc.

Reasons for well servicing:

- Improper and not compatible injection fluids

- Water / Gas conning

- Formation of precipitate / scale

- Heavy viscous formation fluids

- Emulsion / water blocks

- Perforation choking

- Loose formations and Sand production

Sirs discussion includes planning and preparations for a work over job.

All well intervention jobs doesnt need rigs to approach. Major rig components

required during these operations were explained and were shown in images in

detail.

Moving on, sir had shared a few experiences with us

Sharing of experiences encountered in KG onshore work-over operations

- Mobility of rig in village roads

- Eco-sensitive surroundings

- High pressure pockets

- High temperature zones

- Tight formations

Fishing Operations :

- Fish is something unwanted left inside the well like tubing, wire-line, WL tools,

BHA, Coil tubing, milled packers etc.- Cause of fishing could be due to humane error or equipment failure, pre-

mature cement setting, snapping of WL tools etc.

- Planning for fishing job involves details of fish & well details

- Selection of proper fishing tools & fishing string

- External catch tools like overshot, spiral & basket grapple


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- External & internal die collars, Taper tapes

- Lead Impression block, Junk baskets & magnets

- Hydraulic jars, bumper sub & safety joint

- Junk & Taper mills & Wash-overs

Modes of Work-over Operations

Stationary Work-over Rig

Mobile Work-over Rig

Rig-less Operations

Then, advantages of hydraulic rig when compared to that of a conventional rig

was shown.

Advantages of Hydraulic rig compared to a conventional rig:

- No drill line required (no slipping or cutting drill).

- Function of mast for lifting single joints of pipe and

bottom hole assemblies

- Individual component weights can be reduced to 8 tons

- Low centre of gravity.

- Unexpected pipe movement maximum 10 ft.

- Can accommodate any BOP stack configuration.

- Under-balanced operations and snubbing operations

- Small operational footprint

- Noise reduced to minimum.

A few rig less work over operations were explained such as running in and pulling

out gravel pack completions and conventional completions,

- Drilling extensions or cutting windows for laterals both in

overbalanced and underbalanced conditions

- Sand washing with fluid or foam

- Fishing lost wire-line tools and parted tubing or drill-pipe

- Washing perforations and acidizing

- Squeeze cementing or cutting a cement plug.

Advancements in work over operations such as Auto intelligent gas lifts,


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Tractor wire line tools and Mechanical plug back toolswere introduced.

We call of the session after sir had shared a few case studies about the following:

Some Case studies discussed in this session:

- Bhemanapalli #2

- Narsapur # 3

- Narsapur # 6

- Pasarlapudi # 13

Gas lift valves and their functioning

---V. Baskhar Rao (G.M, Production manager)

Mr. Bhaskar Rao garu explained his lecture as follows

Basic principles in oil production

Artificial lift technology principles

Concept of productivity index

Relationship between inflow performance curve and tubing performance

curve and their variance with GLR (gas liquid ratio).

Modes of artificial lift

Compressed gas type gas lift types are further classified as below:

Continuous gas lift

Intermittent gas lift

Plunger assisted gas lift

Artificial lift

By compressed gasBY Mechanical

means


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Chamber lift

And Mechanical Means of gas lifts are further classified as:

Sucker rod pump

Electrical submersible pump

Progressive cavity pump

Jet pump

Later, sir explained each mechanism briefly as follows

Gas lift:

History of gas lift valves type of artificial lift

1797: In Lab comp air was used to lift liq.

1864: First practical application of air lift by Cockford in Pennsylvania.

1865: First U. S. patent Oil Ejector wasissued to Mr. A. Brear.

1940: Pressure operated valve introduced.

1957: Introduction of wire line retrievable valves.

Terminology of gas lift mechanisms were explained at first,

FBHP( Gas lift well )Tubing pressure up to injection depth @TGLR (IGLR +

FGLR) + Tubing pressure below injection depth @FGLR

MAX GLRGLR beyond which tubing pressure starts increasing rather than

reducing.

Optimum GLRGLR beyond which FBHP does not reduce proportionately (

leads to almost constant production )

Optimum GLR to Max GLRGas injection quantity increases without

proportionate increase in oil production

Thumb rules for basic calculations of gas lift installations are:

Tubing Gradient0.15 psi/ft

(for 2 7/8& & 3 )

1 Kg/cm2effective injection pressure


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( inj.prTub. Head PR ) -100 ft of injection

Max possible injection depth (ft) = (Inj.PrTHP) /Gradient

Advantages of gas lifts:

Offers high degree of flexibility.

Effectively produces high & low GOR.

Initial cost is less if HP gas is available..

Low operating cost and ease in operation

Suitable for deep and deviated wells.

Limitations of gas lifts:

Requires HP gas well or Compressor.

Wet gas is subjected to freezing and hydrate formation and may require

gas dehydration unit.

Valve retrieval in highly deviated wells poses problem.

Scale, corrosive and/or paraffin problem may increase the back pressure &

reduce efficiency..

Intermittent gas lift is having lowest efficiency

Advantages of plunger lifts:

Requires No Outside Energy Source - Uses Wells Energy to Lift

Dewatering Gas Wells

Rig Not Required for Installation

Easy Maintenance

Keeps Well Cleaned of Paraffin Deposits

Low Cost Artificial Lift Method

Handles Gassy Wells


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Good in Deviated Wells

Can Produce Well to Depletion

Limitations to plunger lifts:

Specific GLRs to Drive System

Low Volume Potential (200 BPD)

Solids

Requires Surveillance to Optimize

Moving on to the next topic, Instruments used for monitoring and recording their

values were explained such as two pen recorder, echo meter along with their dos

and donts.

Later, a few problems faced by gas lift valves on surface and sub-surface were

discussed

This session was winded up by discussing some case studies

Electrical submersible pumps---V. Baskhar Rao (G.M, Production manager)

This session deals with the working mechanism of electrical submersible pumps,

their parts specifications, classifications and their types in detail.

Introduction: First unit installed in 1928

Range 20060,000 bopd

Depth up to 15000 ft

Average 3 years good operating life with some cases of 10

yrs. also.

Lifting cost for volume ($ /bbl) typically very low. Compatible with crooked or

deviated wellbore


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Parts of an ESP: (surface)

Electric motor

Seal section

Gas separator

Pump intake

Centrifugal pump

Motor extension leads

Power cables

Check valve and bleeder valve

Lower and upper pig tail

Centralizer

Surface parts:Electric motor:

nominal speed --3500 rpm on 60 Hertz cycle

--2915 rpm on 50 Hertz cycle

length :ranges from 5 ft to 100 ft depending on head and volume

requirements

Motor filled with highly refined mineral oil to provide necessary dielectric

strength and to serve as lubricant to motor bearings.

Protector or seal section:

Two Types

--labyrinth type

--balloon type

-- can be of two, four, six, or eight chamber type

--more chambers means more sealing protection

Gas Separator: Two types


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Poor Boy or Reverse flow separator: Routes well fluid 180 degrees

downwards so that gas escapes upward in to annulus and only liquid enters

through pull tube

Rotary gas separator: Works on centrifugal action. Keeps the heavier fluid

(liquid) to the periphery whereas lighter fluid(gas)flows through the center

in to annulus via a flow devoured

Poseidon gas-handling system, A separate gas handling system was explained

very briefly with their variance in efficiency

POSEDION = 70 % gvf (efficiency)

AGH = 40-45% gvf (efficiency)

Centrifugal pumps:

Two Types of Impeller Diffusers

Floating or balanced type: Impeller floats up and down axially along the

shaft depending on the designed and actual fluid production rates. Can

tolerate slight fluctuations in the production rates

Fixed Impeller type: Impeller is fixed to the shaft. Does not move up and

down. Suitable for pumping very high volumes.

Metallurgy :

--housing -seam less ,heavy walled, low carbon steel tubing

--shaft -K-Monel

--Impellers - Ni-resistant, Ryton, or Bronze

--Diffusers - Ni-resistant

Check valve:-a flapper disc type non-return valve,installed just above the pump,

keeps tubing always full prevents reverse flow of fluid, thus preventing reverse

rotation of the impeller, which sometimes may become dangerous to the motor

Blender valve: --Installed above the check valve, useful for draining out liquid

from the tubing during pulling out job otherwise oil/water may be splashing on


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the derrick floor, can be opened before ESP pullout, by dropping a heavy rod from

top.

--may warrant tubing p/o if accidentally broke open.

Lower pigtail: Required when SEABOARD or equivalent type of wellhead isused

--it is a small length of main cable, spliced with the main cable before

wellhead is installed and other end is connected with the electrical 'mini

mandrel.

After a brief explanation of various parts of ESP, sir discussed Designing and

Installation procedure of an ESP unit in a well along with an example and relevant

data tables which is very practical in nature.

We call off the session with a few doubts and a brief summary from the students..

SESSION: ENHANCED OIL RECOVERY TECHNIQUES

Topics on EOR primarily include three fundamental methods in improving tertiary

recovery of a field

Key points I have acquired from this session discussed by MR. Swain are, before

going for any EOR project to be implemented a thorough understanding of

reservoir properties and heterogeneities are crucial, for the project to be cost

effective.

1. THERMAL: applied to reservoirs with heavier viscous fluids(10000 cp) and

API


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Steam forms a miscible front and lowers the interfacial tension between

capillary pores which help in displacing oil through pores INSITU COMBUSTION

This method proves to have highest probability in success ratio

Mostly applicable for reservoirs with thin pay zones where areal sweepefficiency of generated steam zone due to combustion front

This method is not suitable for reservoirs with paraffinic based crude as the

coke is not formed to propagate combustion front2.

CHEMICAL:

Applied to recover residual oil saturation left out by either increasing

viscosity of displacing fluid or decreasing interfacial tension of fluids

SURFACTANT FLOODING

Surfactants like sulphonates added to injection water to reduce interfacial

tension of reservoir fluids. Micelles agglomerate micro size dropletsbetween pores trapped due to high interfacial tension play crucial role in

driving them.

Selection of thermally stable surfactant is crucial for the project to be

successful. POLYMER FLOODING

Suitable for large reservoirs

Generally this is applied for water injection projects where simultaneous

polymer flood is injected at periodic intervals to increase the mobility ratio

In a pattern either at periphery or a belt of injection wells at middle arelocated to sweep maximum areal extent of reservoir

ALKALI SURFACTANT POLYMER FLOODING

It is most cost effective process reducing the slug volume of surfactant

required to be injected

These process have least success ratio due to complexity in

approximation of formation interfacial tension3.

MISCIBLE FLOODING

CO2, N2 FLOODING

Applied for light oils and high pressure wells as injected gas depends on

minimum miscible pressure parameter

Co2 is mostly used as it is highly miscible and turns the hydrocarbon in

pores to vapor thus decreasing the density of producing fluid

Corrosion problems in producer well is one of the backdrop


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LPG, WATER SLUG FLOODING

This process is much feasible in olden days where LPG costs are low and

requires large slugs of lean or rich gas to be injected into formation.

Many of fingering problems were encountered due to poor mobility ratio

and less areal sweep efficiency due to high vertical permeability This can also be accounted under secondary recovery gas injection project

as it would supplement reservoir pressure

CASE STUDIES: Apart from different process employed based on reservoir

petro physical properties sir has discussed effective recovery of various

process employed in different fields (pilot projects).

Typical behavior of various projects is discussed. In situ combustion projects take

bit of time to respond after implementation. In contrast polymer flooding shows

quick response in increasing oil volumetric flow rates. Later ASP flood can be done

after it has saturated with polymer to improve recovery or can be earlier.

Similarly a miscible gas injection project is applied in Gandhar field, were its

crude API >40.

Thus basically we can choose type of process based on crude viscosity and API.

SESSION: SUBSEA OPERATIONS AND

MAINTAINANCE

--Alan Douglas (Aker solutions) ---

MR.DOUGHLAS from AKER has explained series of cyclic operations

1.

Deep water work over & intervention operations: Isolating manifoldcontrol module of a certain well to replace the variable choke through rovs

or shut a well to cut down water protection.

2. Well integrity maintenance: Riser/umbilical protection against corrosion by

sacrificial anodic protection, anomalies inspection and debris detection, a

Tool anomaly report (TAR) on improper working of a cam on one of its arms


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of ROV has been given to us, hardware maintenance and control structure

of umbilical and SDA while processing signals from platforms.

3.

Monitoring controls: Number of controls are mentioned. Some of them

are

EDB---electronic distribution box SCM----switch control module

FODM----fiber optic distribution box

EFL----electric flying lead

PLEM/PLET ---a connecting segment between pipe/flow line

to manifold

4. Production system parameters: In addition to maintenance operations he

has also mentioned design life of subsea equipment based on working

conditions of equipment & selection of tree types (initially vertical trees

were installed but due to problems during work over operation laterhorizontal trees are designed).


Basically no much specified data available for us on subsea operations. This

session has benefitted us a lot with lot of new terminology on subsea

equipment and clear cut explanation on how the procedures were adopted

during anomaly detection and how the report is made.

The technology used in manufacturing steel rod umbilicals with carbon

fiber as an axial support to compensate compressive forces & tensilestrength. Later he moved onto processing of signal from platform through

umbilicals in which fiber optical cord transmits signal to subsequent well.

SESSION: WELL SERVICES

----Y.R.L Rao (ONGC)---

In this lecture MR. Y R L Rao has discussed series of well service operations

Before going through the above topics he added few lines on role of

production engineer, production problems, bull heading & procedure for

removal of Christmas tree.

Well completions & sand control


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He has come across types of completions, completion equipment,

and perforation methods.

Later he moved onto formation damage problems and evaluation of

damage. Depending upon the damage he has gone through rig lesswork over (sand wash, acid wash, surfactant job, re-perforation

through wire line without removal of x-mas tree and sand control

procedures).

Stimulation techniques

Most of intervention jobs include acidization and fracturing, they are selected

depending on quantitate damage to improve flow rates as explained by him

SESSION: OFFSHORE OIL EXPLORATION AND SAFETY

---Mr. A. Prasad---

This session has started with lecture given by Mr. A. Prasad on Offshore oil

exploration and safety measures.

His lecture includes Exploration activities, basic steps for exploration in offshore,

types of hazards, safety in offshore platforms, table explaining the causes, effects

and protection measures of various types of hazards, marine environmental

protection and potential impacts on environment.

He has also covered safety regulations and norms followed by offshore industry

He has presented some of the accidents which were caused due to lack of well

controlPasarlapudi blow out

SESSION: NEW EXPLORATION LICENSING POLICY.-- Mr. Vedantam Sasibhushana Sarma----

The afternoon session by Mr. Vedantam Sasibhushana Sarma on NELP (New

Exploration Licensing Policy). His lecture initially consists of explaining about NELP-1,


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NELP-2, NELP-3, NELP-4, NELP-5, NELP-6, NELP-7, NELP-8 and NELP-9. Later he explain

about:

Blocks currently in exploration

Fields currently under operation

Oil and gas discoveries

Recent discoveries

A glimpse of NELP-X.

SESSION: PRODUCED WATER TREATMENT

--Mr. Ramakotaiah (ONGC)---

This lecture by Ramakotaiah garu was divided into two sessions. First session deals

with produced water treatment and second session deals with project management

in petroleum industry.

The content of his first session was:

Introduction

Produced Water disposal standards

Primary Treatment

Secondary Treatment

Produced water is the term used in oil industry to describe water that

is produced as a by-product along with oil and gas. This process is carried out in three

phase separators and heater treaters. It is usually brine solution or brackish water. As

it contains high COD and BOD it should be treated before disposing it.

TREATMENTMETHODS:

Primary method Secondary method

PRIMARY METHOD:

Treatment equipments used in this primary are:

Corrugated Plate Interceptors.


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Parallel Plate Interceptors.

Cross flow separators.

At the end of the session, valuable carrier advices were given by Ramakotaiah

garu to our outgoing senior students for their carriers. With a few doubts from

our students, we call it off the session.

manikanta report final

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