8/3/2019 82-16

http://slidepdf.com/reader/full/82-16 1/2

83

Sep. 2011. No.82/Exploration & Production

Ashoori, S. Petroleum University of Technology (PUT)

Khaksar Manshad, A. Persian Gulf University

Tabatabaie, s.h. Islamic Azad University- Omidiyeh

Masumi, M. Islamic Azad University- Omidiyeh

Application of Scaling Equation withFunction of Pressure to Predict Onset of Asphaltene Precipitation of Crude Oil

Abstarct

In this study, the amount of asphaltene precipitation by introducing a simple and applicable scaling equation can be determined as a

function of pressure, dilution ratio and molecular weight of solvent at a constant temperature. At pressures above the bubble point,

increasing the pressure of crude oil decreases the amount of asphaltene precipitation but below the bubble point, it increases. The

 parameters of this scaling equation have been determined by using reservoir pressure and genetic algorithm optimizing models. The

most important application of this equation is to predict the onset and calculate the amount of asphaltene precipitation at different

conditions.

Keywords

Keywords: Asphaltene, Precipitation, Onset, Scaling Equation, Genetic Algorithm, Bubble Point Pressure, Solvent

Paper AbstractsPreparebly: Mehdi shahhoseini Parvaneh Taherinia

Analysis the Effects of Important Parameterson Water Flooding in Oil Reservoirs UsingStreamline Simulation Technique

Homayoon Afshar, F. Amirkabir University of technology

Ameri, O. Sepanir Company

Parvin Entezari Maleki, P. Islamic Azad University -Tehran

Vatanparast, H., Bazdar, H. Deputy for planning

and Supervision on Hydrocarbon Resource, petroleum

ministry

Experimental Investigation of Factors Affectingthe Original Wettability of Carbonate Rocks andWettability Alteration as a Method of EOR 

Abstarct

Altering the wettability of the carbonate reservoir rocks from oil-wet to water-wet has been figured prominently as one of the enhanced oil

recovery methods in recent years. Putting the idea into practice requires a basic understanding of the wettability and the controlling factors.

In this study, the influence of the factors such as presence of polar components, electrical surface charges and the initial aqueous phase on

formation of oil-wet carbonate surfaces have been investigated by measuring the contact angles in n-hexane (or n-decane)/aqueous phase/calcite

systems at different compositional conditions. The results show that cleaned carbonate surface is strongly water-wet and the original wetting

state of the surfaces altered to strongly oil-wet due to adsorption of polar components or deposition of organic matter onto the surface. The

negatively charged components of the crude oil have a higher affinity to calcite surfaces and hence they are more effective in changing the initialwetting state of the rock. Furthermore, the effect of the cationic surfactant C12TAB and the sulfate ion concentration on wettability alteration

of oil-wet carbonate rocks toward water-wet condition as a method of EOR have been studied in this paper. The results show that the cationic

surfactants are able to change the wetting state towards water-wetness and the potential of altering wettability increases with concentration.

Study of the sulfate ion concentration in water on wetting characteristics of carbonate surfaces at two different temperatures, 20 and 80°C,

demonstrated that the sulfate ions could improve the wettability towards water wetness at higher temperature, and the contact angle would

further decrease by increasing the concentration.

Keywords

Wettability, Carbonate, Contact Angle, Surfactant

Abstarct

Simulation through the streamline makes it possible to monitor the fluid motion process in any time, which results in the better 

management of the reservoir and prevent spending extra charges. Simulation of water flooding using streamline simulator is the best

use of this technique and helpful tool for engineering purposes. In this technique, injected fluid motion can be studied and the most

ideal state can be fulfilled.

In this paper, it has been tried to show some cases that are necessary to investigate at real project (industrial project scale), by

studying the effective parameters on flooding. Not to care about these parameters may cause many adverse consequences.

Doing sensitivity analysis using streamline simulation is optimum and more efficient method in flooding study, particularly water 

flooding, while this method is very much less time-consuming compared with the other commercial dynamic simulator using

conventional method, as the simulation time is very important issue during the sensitivity analysis for common simulator.

Keywords

Streamline simulation, Water flooding, Breakthrough time

8/3/2019 82-16

http://slidepdf.com/reader/full/82-16 2/2

Paper Abstracts

84

Mahmoudan,H. Pars Oil and Gas CompanyDetermining the Appropriate Time toReplace Worn-Out Bit Using Real Data

To Reduce Drilling TimeAbstarct

Drilling operation is one of the most expensive parts in oil and gas fields’ development projects especially in offshore. A lot of 

attempts are done by drilling engineering to reduce the cost of drilling time. A lot of factors are considered in modification of 

drilling time such as selecting suitable drilling rig, preparing a good drilling program, designing proper BHA, etc. one of these

factors is to determine suitable time for changing a used drilling bit to minimize bit change trips and reduce in bit and rig costs.

In this study calculation of bit performance based on economical consideration and its advantage is explained and then a real

case is reviewed. This case study shows that usual method for evaluating bit performance based on ROP. In some cases results

show changing a used bit and as a result increasing drilling time and wasting money, and on the other hand, using engineering

calculation can help drilling supervisors to make faster actions and more accurate decision for determining bit change time. In

the case reviewed in this study, not using economical calculations results in almost thirty hours delay in making a decision for 

changing the bit. So it shows that in each well of the project with length around 4000 m that usually uses ten bit, more attention

to bit performance can lead up to some days reduction in drilling time which in turn cases thousands of dollar reduction in cost.

Keywords

Drilling operation, Drilling bit, ROP, Bit performance, Changing used bit, Economical consideration

Lower Paleozoic Petroleum System Modelingin South Zagros and Persian Gulf 

Cementation Factor- Porosity Relationship from CoreAnalysis Results Comparison with Shell and BoraiEquations at Dolomitic Reservoir in the Zagros, Iran

Abstarct

Water saturation (Sw) is one of the most important parameter in hydrocarbon reservoir evaluation which is commonly computed

from Archie equation. The cementation factor (m) has a vital character in this formula, so that small changes in m lead to significant

differences in Sw. The m value is a highly variable and depends on the porosity (Ø), pore type, permeability, rock fabric, formation

water salinity and so on. Therefore insert a constant value (i.e.2) in Archie formula will cause an incorrect Sw. In this study in order 

to investigate the m-Ø relationship, a total number of 27 samples were selected from one of dolomitic reservoir in two different

fields in South West of Iran (Zagros Basin). The data was classified into 3 groups based on porosity-permeability as proposed by

Lucia. The F and Ø values were plotted on a log-log scale to obtain mean value of m. Also, trends of Ø vs. m compared for actual

data and calculated one from Shell and Borai equations. The trends show an increase of m with increase of Ø in actual data and

Borai equation, whereas Shell equation shows an opposite behavior, especially in low porosity range (Ø<%10). As a result, based

on obtained regressions formulae provided by m-Ø plots, a new equation is presented. Applying computed m value from this new

equation in similar cases will minimize the error in Sw calculation.

Keywords

Cementation factor, Archie equation , Porosity, pore type, Zagros Basin

Rostami, A. Exploration Directorate, NIOC

Hasani Give, M. Exploration Directorate, NIOC

Salehi Rad, S. Islamic Azad University -Tehran

Sherkati, S. Exploration Directorate, NIOC

Abstarct

The Paleozoic Sediments are noteworthy for many of probers to research in Arabian Plate during last decades. Significant values of 

Oil and Gas in this area were generated from Silurian Organic rich shale. The petroleum system was modeled by common softwares

(like PetroMod and Genex) in Saudi Arabia and determined maturity proportion of source rock in various locations. We used

Geological data of three Wells drilled in Persian Gulf for modeling by PetroMod-1D software the petroleum system of paleozoic,

and need to notify, just one of these wells was penetrated to Silurian Shale (Sarchahan Formation). Results of this study show

Silurian Shale increases in maturity trend from Saudi Arabia to Iran. Gas window maturity in Persian Gulf and over-mature in some

 parts of Zagros Basin are recognized for this shale. In Persian Gulf basin, presences of paleohighs, in basement caused different

 burial depth for source rock, which influenced its maturity compare to the general trend of the region.

Keywords

Paleozoic, Petroleum System Modeling, Persian Gulf, Zagros, Sarchahan Shale, Silurian, Source Rock Maturity, Paleohigh