a

Missan University college of engineer dept. of petroleum

Determine WOC By

Different methods

By the students: 1- Hayder Abdulzahra 2- Hussein Mohammed KH 3- Karrar Riyadh MH 4- Marwa Salim SH

Supervisor ASST; Dhiaa Salman

Graduation project Department of petroleum

College of engineering Missan - 2016

b

c

© 2016 [Hussein Mohammed KH]

d

DECLARATION

I hereby declare that this project report is based on my original work except for citations and quotations which have been duly acknowledged.

Signature : _________________________

Name : ________________________________________________________

________________________________________________________

Date : _________________________

e

APPROVAL FOR SUBMISSION

I certify that this project report entitled “Determine WOC by different methods” Was prepared by: 1- Hussein Mohammed KH 2- Hayder Abdulzahra 2- Karrar Riyadh MH 4- Marwa Salim SH Has met the required standard for submission in partial fulfillment of the requirements for the award of Bachelor of Petroleum Engineering at University of Missan.

Approved by,

Signature : _________________________

Supervisor : ___ ASST; Dhiaa Salman __

Date: / / 2016

I

Table of contents

Page number Table of contents ............................................................................................................................. I

Symbols ........................................................................................................................................ III

ABSTRACT...................................................................................................................................... iii

ACKNOWLEDGEMENTS ................................................................................................................... iv

Dedication االھداء ................................................................................................................... v

INDEX OF FIGURES .......................................................................................................................... vi

INDEX OF TABLES ........................................................................................................................... vi

Chapter one .................................................................................................................................... 1

1-2 The study area ....................................................................................................................... 3

1-3 Aim of the Study..................................................................................................................... 4

CHAPTER 2...................................................................................................................................... 4

WOC derivation from log interpretation ......................................................................................... 4

2-1 INTRODUCTION .................................................................................................................. 4

2-2 Theory ............................................................................................................................... 5

2-3 Methodology...................................................................................................................... 6

2-4 The Results ........................................................................................................................ 6

2-5 Discussion ........................................................................................................................ 13

Chapter three ............................................................................................................................... 14

MDT ......................................................................................................................................... 14

3-1 defini on ......................................................................................................................... 14

3-2 MAIN COMPONENTS OF AN MDT TOOL ............................................................................... 14

3-3 MDT INTERPRETATION ...................................................................................................... 14

3-4 The calculation ................................................................................................................. 18

3-5 Discussion ........................................................................................................................ 21

Chapter four ................................................................................................................................. 22

Capillary pressure ...................................................................................................................... 22

4-1 Introduc on ..................................................................................................................... 22

4-2 The main benefit of capillary pressure ................................................................................. 22

4-3 Theory ............................................................................................................................. 23

II

4-4 Methodology.................................................................................................................... 23

4-5 The result......................................................................................................................... 24

4-6 Calcula on ....................................................................................................................... 29

4-7 Discussion ........................................................................................................................ 29

Chapter five .................................................................................................................................. 30

Conclusion and Recommendations .............................................................................................. 30

Refrences ..................................................................................................................................... 31

III

Symbols T2 = formation temperature (Fᵒ)

D = Log depth (feet)

BHT = Borehole temperature (Fᵒ)

TD = Total depth (feet)

T1 = surface temperature

Rmf = Resistivity of mud filtrate (ohm-m)

Vsh = shale volume (%)

GRlog = (Gamma ray log (API Unit)

GRmax = Gamma Ray maximum (API Unit)

∅D = Porosity from density log (%)

∅ =

=

=

=

Sxo = Water saturation in flush zone

Rxo = Water saturation in flush zone

Shr = Residual hydrocarbon saturation

Rsh = Resistivity in shale zone

= cementation constant

Rw = Water resistivity in univaded zone

Rt = True resistivity

∅Dc2 = Porosity(%), hydrocarbon fluid correction

IV

H = height of water oil contact above FWL

Pc = capillary pressure

Iw = water density

Io = oil density

=

(g) = acceleration due to gravity (9.81 m/s2)

(r) = pore radius

K = permeability (md)

∅ = (%)

= contact angle between the hydrocarbon and water

(rhow) = formation water density (in*g/cc)

(rhoh) = hydrocarbon density (in*g/cc)

iii

ABSTRACT Graduation project

OWC determination of MB21 Reservoir, Buzurgan oil field by Different methods.

Missan University College Of Engineering

Dept. Of Petroleum

Supervisor: Asst; Dhiaa Salman

In Petroleum reservoir study and management, an accurate description and estimation of the OWC is very important in quantifying the resources (OIIP) and therefore selection of production techniques, rates and overall management of the reservoir. The main goal of this project is to determine the OWC of MB21 reservoir/Buzurgan oil field through the integration and comparison of results from well logging, MDT and special core analysis data. A total of three wells from Buzurgan oil field were evaluated (BU-51, BU52 and BU-53) using interactive petrophysics software IP v3.5. The predicted depth of MB21 OWC obtained by well logging interpretations was estimated to be at -3874.06 mssl and this is approximately matching the depth of the field geological study (3875 mssl) taking into consideration the rise of the oil water contact due to prolonged production date on the other hand the result obtained by capillary pressure data was predicted to be at -3870.86 mssl. however, due to the Inadequate available MDT data which by investigating the data obtained by all the MDT jobs in the field, revealed that the pressure test points were conducted by the operator company only in the MB21 oil pay zone and no pressure test points were taken from the below water zone therefore the MDT interpretation results was impossible to predict the free water level and as a result FWL was estimated from logs interpretations. However literature review of the mentioned method and the interpretation procedure were mentioned for the future modification in this project in case of the availability of the proper MDT data.

iv

ACKNOWLEDGEMENTS First we thanks Allah very much, and we would like to thank our project supervisor

Mr. Dhiaa Salman for his many suggestions and constant support during this

project work, and all thanks to Eng. Abass section head of well logging

interpretations from E&D department CNOOC-MOC partnership companies for his

technical advices. Thanks for all the doctors and assists in Missan university, college

of engineering, dept. of petroleum, especially DR. Hanon, Dr. Ahmed AL_Sharaa,

Dr. Raed AL-Saidy , Dr. Salam AL-Rubaiaui and Asst ALI NOORULDEEN.

Without your efforts this work would never have come into existence (literally).

Missan 2015- 2016

v

Dedication االھداء

ابطال الجیش العراقي والحشد الشعبي ،الذین بفضل دمائھم وتضحیاتھم تستمر الى الحیاة .

الغوالي ، الى ابائنا االعزاءامھاتنا الى

االخوة واالخوات ،االقارب واالصدقاء نھدیكم ثمرة جھدنا ونتیجة مسیرتنا الدراسیة .فقط النكم اصحاب ھذا االنجاز ، فھو بجھودكم وبفضل تشجیعكم ،باكملھا لیس لشيء

االمھات واالباء شكرا لكم من صمیم القلب، شكرا لتضحیاتكم .فخورون نحن بكم جداعلى ما جدا . واقصى امانینا ھو أن ترضوا عنا .شكرا لكم وجزاكم هللا افضل الجزاء

بذلتموه من اجلنا فھو الذي یجزي االحسان احسانا .

كل االساتذة والتدریسیین الذین تناوبوا على تعلیمنا من المرحلة االبتدائیة حتى والى .شكرا لكم المرحلة االخیرة من دراستنا الجامعیة

والى التي ادعوا هللا أن یرزقني ایاھا ، الى حبیبتي رقیة اھدي الیك كل ما املك على

أمل أن نتصفح ھذا االوراق معا في قادم االیام أن شاء هللا .

حسین محمد خلیف -1

حیدر عبد الزھرة رحیمھ-2

كرار ریاض میحان-3

مروه سلیم شویل-4

جامعة میسان

كلیة الھندسة قسم ھندسة النفط

2015 -2016

vi

INDEX OF FIGURES.

Figure no Page 1-1 1 1-2 2 1-3 3 2-1 6 2-2 7 2-3 7 2-4 8 2-5 9 2-6 10 2-7 11 3-1 15 3-2 16 3-3 17 3-4 18 3-5 19 3-6 20 4-1 25 4-2 26 4-3 27 4-4 28

-

INDEX OF TABLES

Table Page 1-1 3 2-1 12 2-2 12 2-3 12 3-1 19 3-2 20

1

Chapter one 1-1 Introduction Missan oilfields are located in the Missan province in southeastern Iraq and close to

the Iraq-Iran border. It is about 175km north to the Basra city and about 350km

southeast to Baghdad (Figure1-1).

Fig(1-1) Location of Missan Oil Fields The fields consist of three producing oilfields, namely Abu Ghirab, Buzurgan and Fauqi oilfields. Structurally, Buzurgan oilfield ranges about 40km X 7km with two

domes in the north and south respectively, the south dome is shallower and covers

bigger area(Figure1-2). The well locates in the W of BU-9, whose distance is about

0.6Km Buzurgan oilfield has two sets of reservoir, Tertiary Asmari and Cretaceous

Mishrif. 7 pay zones are divided in the Mishrif reservoir which is MA, MB11,

MB12, MB21, MB22, MC1 and MC2. The main pay zone is distributed in lower

part of Mishrif reservoir. The main pay zone MB21 of Mishrif oil reservoir in

Buzurgan oilfield has an oil-water system and is an edge water structure

stratigraphic reservoir with wide oil-water transition zone. The pay zones of MC1

2

are also an edge water structure stratigraphic reservoir. The natural energy in

Mishrif oil reservoir of the oilfield is weaker than that in Asmari reservoir of Abu

Ghirab oilfield and Asmari reservoir of Fauqi oilfield, but is stronger than that in

Mishrif reservoir of Fauqi oilfield.

. Buzurgan oilfield was put into production in November 1976 and are produced

from the Mishrif reservoir with regular well pattern and large well spacing (＞

800m). The production rate reached 40kbbls/d before it was shut down for more

than ten years during 1980~1998 due to the war. After the oilfield resumes

production in 1998, it has maintained the production level at about 35kbbls/d.

Pay zone MB21 contribute 95% oil production of Buzurgan oilfield with the

cumulative production of 172.96mmbbl.

During the Rehabilitation Period, About 44 new wells are proposed to be drilled in Buzurgan field.

. Fig(1-2) Oil-bearing map of Mb21 pay zone in the north dome of Buzurgan

oilfield with new wells.

3

1-2 The study area The Buzurgan field is located south of Iraq in Missan province Buzurgan is situated near the

Iraq-I ran border, about 300 km Southeast of Baghdad and 40 km Northeast of Amara City. In

this study, three boreholes in Buzurgan field-North dome (BU-51, BU52 and BU-53) and

one well in south dome BU-3 have been studied The geographic coordinates of

Buzurgan field are.

Table (1-1) the geographic coordinates of Buzurgan field

Fig (1-3) Location map of the study area

Eastern

Northern

700 000

3572 100

708 000

3582 000

740 000

3550 O00

732 200

3543 OOO

4

1-3 Aim of the Study Determine the oil water contact of MB21 Reservoir/Buzurgan oil field using

log analysis, MDT and capillary pressure methods.

Compare the obtained results with the past field geological study. Identify the challenges in these methods used for estimating the MB21 OWC.

Recommend the best possible and reliable estimation method.

CHAPTER 2 WOC derivation from log interpretation 2-1 INTRODUCTION Oil-water contacts in a development well are determined from water

saturations derived from resistivity logs, either by detailed formation

evaluation or by some quick look technique. In the absence of resistivity

logs, thermal neutron decay time logs are useful in areas having saline

formation water. To determine the O/W contact for a development field, a

tentative level is established on the basis of log analysis and testing results

of exploratory wells and also from information obtained from nearby wells.

Sometimes, in the areas to be discussed, open hole logs are not available

because of bad hole conditions, high inclination of the well, or logging

equipment malfunction. Cased hole neutron logs are not useful due to their

limitations. Variations in the O/W contact are common from well to well

due to changing porosity and permeability.

5

2-2 Theory: Log analysis technique has been used to find the answers to the fundamental questions:

What kind of rock is present?*

If Reservoir rock exists?*

*Are any hydrocarbon present?

Type of hydrocarbon present ?*

How much hydrocarbon is there ?*

There are several equations that using in Log Analysis method:

T2=( )+ T1 ………………..……………….………1

Rmf2 = Rmf1 * ( . )( . )

………....…………2

Vsh =

…………………….……3

∅D =

………………………………4

Sxo = ( / ) ∅

………………….5

Rw = ∗ ∗ ……….…………..………. 6

……..……….. 7 Sw = ( / ) ∗

Sh = 1 - Sw ……………..…………..…………….. 8

…for water and hydrocarbon zones……10 ∅ = ∅ ∅

………. ……for gas zones……10 ∅ = ∅ ∅

6

2-3 Methodology 1-collect las file for BU51, BU52 and BU53.

2- Using IP V3.5 program and import the LAS file for each well.

3-calculating Vsh from gamma ray & neutron density porosity cross plot.

4-idendtify the lithology from the neutron-density cross plot

5- Calculate water saturation using Archi's equation model.

4- Adjust Pickett plot parameters with reference to water zone.

5- Detect WOC depended on SW values.

6- Using IP to make correlation between the wells.

2-4 The Results The following figures shows the results for the log interpretations.

Fig(2-1) pickett plot for BU51

7

Fig(2-2) pickett plot for BU52

Fig(2-3) pickett plot for BU53

8

figure (2-4) CPI result for BU51 from IP program

9

' figure (2-5) CPI result for BU52 from IP program

10

figure (2-6) CPI result for BU53 from IP program

11

figure (2-7) correlation between the wells by using IP program

12

the following tables shows the result values for the sample wells

BU51

WOC at wireline logging depth (m)

RTKB (m) WOC at MSL (m)

3915 38,2 3876.8

Table (2-1) the result value for BU51

BU52

WOC at wireline logging depth (m)

RTKB (m) WOC at MSL (m)

3926.5 41.6 3884.9

Table (2-2) the result value for BU52

BU53

WOC at wireline logging depth (m)

RTKB (m) WOC at MSL (m)

3888.5 28 3860.5

Table (2-3) the result value for BU53

The main pay zone MB21 of Mishrif oil reservoir in Buzurgan oilfield has an oil-water system which has an OWC from logging of around -3874.06 m SSTVD .

13

2-5 Discussion The computer processed interpretation using IP v3.5 was performed to predict the OWC of MB21 Buzurgan oil field derived from log interpretations for the wells (BU-51, BU52 and BU-53). Las files for the three wells were collected and data quality check reviewed and it was basically that volume of shale was calculated from the two indicators (Gamma ray & neutron-density cross plot) and the minimum values of Vsh were used in calculating the effective porosity. The formation lithology of the Mishrif reservoir is limestone as it provided by the field geological reports and as well as the interpretations of neutron-density cross plot shows best agree with geological data. Porosity model of neutron-density was used except in wash out zones where density log would give erroneous measurements therefore sonic log was used to calculate the formation porosity instead of the neutron density porosity cross plot. RW and formation temperature gradient (Rw=0.02 at 95 c, TG=2.4 c/100 m) were obtained from geological reports and Archie equation model has been used to predict the formation water saturation and pickett plot parameters has been adjusted for the three wells ( a=1, n=2, m=1.95-2), there values were carefully chosen as these may drastically alter the estimated porosity. The predicated oil water contact for the three wells (BU51 3876.8 , BU52 3884.9 , BU53 3860.5 ) m ssl showed some variance and this this bring us to a point that more wells need to be studied to give more accurate predication of the oil water contact.

14

Chapter three: MDT 3-1 definition Modular Dynamic Formation Tester is the tool through which we can test the formation and measure the formation pressure, temperature and get the pure reservoir fluid and water samples.

3-2 MAIN COMPONENTS OF AN MDT TOOL :- Formation Pressure Gauges Formation Resistivity Gauges Pump Out Live Fluid Analyzer Sample Chamber. 3-3 MDT INTERPRETATION:- Interpretation of MDT data is very interesting. For interpretation you have to make a graph between the formation pressure and depth. When you plot the formation pressure against the depth you will get the density gradient, values of which are given as under: Oil, Gas and Water has different gradients. 1-Gas = 0.55 g/cc 2-Oil = 0.88 g/cc 3-Water = 1.0 g/cc

• These are density gradients of different fluids. Where your gradient changes you can mark the Gas-Oil

15

contact, Gas-Water contact, Oil-Water contact. • The deeper pressure points should have higher value of pressure. If this is not

following then its means the data is not correctly recorded. • During plotting the data some points will fall away from normal behavior

these points called “Super Charge” points due to low permeable formations like Shale.

• MDT gas/oil sample is very suitable for PVT analysis and other lab analysis. Through this sample we can calculate the compressibility factor and gas components.

• Calculate the salinity of formation water in laboratory through MDT water sample is very excellent use of formation water sample. Through this salinity we can calculate the formation water resistivity (Rw), which is the most essential parameter in log interpretation.

• The formation water analysis is also very useful for well completion equipment. Density = specific weight =

Specific weight = density * g

Pressure gradient =

Fig (3-1) pressure gradient pattern for multi liquids

16

In a reservoir that is hydrostatic the pressures in the continuous phases vary by

depth based on the density of the fluid in the continuous phase. In an oil reservoir,

oil density is primarily a function of the gravity of the oil, the amount of dissolved

gas and the pressure.

Gas are common over large areas and in very thick reservoirs. Nonetheless, it is

more common to have an approximately constant pressure gradient over the

Thickness of an oil reservoir among all wells that are hydraulically continuous.

Similarly, water gradients are usually even more constant. Except for very heavy

oils (whose density approaches that of water) it is usually possible to distinguish oil

and water bearing formations by obtaining multiple formation pressures at different

depths in the reservoir. If there is no clear oil/water contact in a wellbore, the use of

these gradients can often identify an oil/water contact depth. Natural gas gradients

are typically much less than liquid gradients and can serve a similar purpose. In

thick reservoirs the density of oil usually varies with changing depth. This is quite

common and it is possible to detect varying density (compositional grading) from a

depth vs. pressure plot using FT data.

Fig (3-2) pressure gradient pattern for the reservoir

17

Fig (3-3) Pressure vs Depth The geology of the reservoir is very important when considering gradient analysis, prior knowledge of its structure can serve as lead indicators to what the gradient trends will look like and is demonstrated by the diagram of the single well producing multiple zones from the same field but not necessarily the same HC deposit or communicating reservoirs. A discontinuity in the pressures obtained from formation tests can be used to identify probable hydraulic isolation among reservoirs due to layering, faulting or other geological heterogeneity.

18

Fig (3-4) pressure gradient pattern for petroleum and water

3-4 The calculation :

due to the Inadequate available MDT data which by investigating the data obtained by all the MDT jobs in the field, revealed that the pressure test points were conducted by the operator company only in the MB21 oil pay zone and no pressure test points were taken from the below water zone therefore the MDT interpretation results was impossible to predict the free water level. However the MDT data of BU52 and BU51 are plotted on pressure-depth cartizen graph and interpreted to

19

shows that there is proplem in the measumrment of the data which are useless in determination of FWL. The data and the interpretation results are below: BU52

NO. MD（m）

Mud

pressure

before

measured（

psi）

Formation

pressure（

psi）

Mud pressure

after

measured（psi

）

Temp of

Formation

（℃）

Pressure style

6 3861.0 7292.43 5375.97 7292.40 101.28 V 7 3863.0 7296.14 5378.42 7296.00 101.05 V 8 3872.0 7313.33 5516.85 7313.28 101.66 9 3894.0 7354.83 5553.91 7354.62 101.89 10 3906.0 7377.72 5581.82 7377.46 102.23 11 3916.0 7396.23 5595.10 7396.20 102.52 12 3919.0 7402.02 5598.58 7401.84 102.66

Table (3-1) BU52 MDT data measurments

Fig (3-5) BU52 MDT interpretation From the interpretations it seems to be that the first two points on the graph are valid pressure tests and shows an oil zone with 0.86 gm/cc density but the others points on the graph are not valid due to the error in the tool itself or due to supercharge.

3850

3860

3870

3880

3890

3900

3910

3920

3930

5350 5400 5450 5500 5550 5600 5650

BU52 MDT interpretatuion

20

BU51

No MD m formation pressure

5 3862 5785.22

6 3872

7 3876 5797.6

X 3888.5 5816

8 3900.5 5829.5

9 3902 5830.4

X 3904

10 3905 5834.52

11 3908 5837.2

12 3910 5839.97

13 3914 5843.66

Fig (3-2) BU51 MDT data measurments

Fig (3-6) BU51 MDT data interpretation

3860

3870

3880

3890

3900

3910

3920

5780 5800 5820 5840

BU51 MDT data interpretation

21

From the interpretations it seems to be that the pressure tests points fall on a line with best regression of 0.85 gm/cc oil density density more points needed to pass through the water zone below 3920 m KB to be able o predicating the MB21 FWL.

3-5 Discussion two wells ( BU51 and BU52) have been interpreted; BU52 has some anomaly in the

data either due to the MDT tool itself or due to the super charge of the formation

which may indicate low permeable zone so the interpretation of the two valid points

for this well can’t predict the FWL and they give a trend of 0.86 gm/cc oil density

BU51 well have good pressure readings and gives a trend of 0.85 gm/cc oil density

but FWL can’t be predicated because no test points were conducted in the water

zone for MB21 mishrif reservoir.

Unfortuentaly no offset data from other wells in the field have proper MDT data so

it was impossible to predic the FWL using MDT data interpretations.

22

Chapter four Capillary pressure 4-1 Introduction:

Defined capillary pressure as the difference in pressure across the interface between two phases. Similarly, it has been defined as the pressure differential between two immiscible fluid phases occupying the same pores caused by interfacial tension between the two phases that must be overcome to initiate flow.

Capillary pressures are generated where interfaces between two immiscible fluids exist in the pores (capillaries) of the reservoir rock. It is usual to consider one phase as a wetting phase and the other as a non-wetting phase. However, intermediate cases occur which can greatly complicate the picture. The drainage case, i.e. a non-wetting phase displacing a wetting phase applies to hydrocarbon migrating into a previously brine saturated rock. Imbibition data is the opposite to drainage, i.e. the displacement of a non-wetting phase by a wetting phase. Thus, the drainage data can usually be used to predict non-wetting fluid saturation at various points in a reservoir, and the imbibition data can be useful in assessing the relative contributions of capillary and viscous forces in dynamic systems. 4-2 The main benefit of capillary pressure is :

• Determine initial water saturation in the reservoir.

• Determine fluid distribution in the reservoir.

• Determine residual oil saturation for water flooding applications

• Determine pore size distribution index.

• May help in identifying zones or rock types.

• Input for reservoir simulation calculation.

23

4-3 Theory

The height of WOC above FWL for each site is calculated using the equation (Archer 1986).

H = ( ) = ( ) .

WOC = FWL – H

The capillary force per unit area P is given by :

P = .

Jfunction=( ∗√∅

( ))

Pc =(rhow – rhoh)*h*3.281*0.433

4-4 Methodology

Data of special core analysis from two wells (BU-3 , BU-4) have been collected and the pc lap data have been converted to reservoir conditions then J function has been calculated to normalize the variation in the petrophysical core properties (K&phi) then J and the corresponded Sw have been plotted on Cartesian graph for each core on same plot with different depth in MB21 reservoir. A universal J function has been derived to give best fit to j curves then J curve has been converted to PC and the latter one has been converted to depth against saturation.

24

4-5 The result

The results for BU3 are below

CORE1 depth (ft) depth (m) k md Φ %

12559 3827.983 5.1 17.6 PClap PCres sw Bar Psi psi J

98.6 0.025 0.362594 0.130937 0.002711 97.5 0.05 0.725189 0.261874 0.005422

95 0.1 1.45038 0.523748 0.010844 89.4 0.2 2.90075 1.047493 0.021687 81.4 0.3 4.35113 1.571241 0.032531 70.5 0.4 5.80151 2.09499 0.043375

60 0.6 8.70226 3.142483 0.065062 50.6 1 14.5038 5.237483 0.108437 39.2 2 29.0075 10.47493 0.216874 33.9 3 43.5113 15.71241 0.325311

28 5 72.5189 26.18738 0.542185

CORE2 depth (ft) depth (m) k md Φ %

12564 3829.507 12.2 18.1 PClap PCres sw Bar psi psi J

99.3 0.025 0.362594 0.130937 0.004135 98.6 0.05 0.725189 0.261874 0.008269 97.8 0.1 1.45038 0.523748 0.016538 94.9 0.2 2.90075 1.047493 0.033076 89.7 0.3 4.35113 1.571241 0.049615 80.7 0.4 5.80151 2.09499 0.066153

64 0.6 8.70226 3.142483 0.099229 54.4 1 14.5038 5.237483 0.165383 42.5 2 29.0075 10.47493 0.330764 35.4 3 43.5113 15.71241 0.496147 28.7 5 72.5189 26.18738 0.826912

25

Fig (4-1) J function with Sw for all cores

00.10.20.30.40.50.60.70.80.9

11.11.21.31.41.51.61.71.81.9

22.12.22.32.42.52.62.72.82.9

33.13.23.33.43.53.63.73.8

0 10 20 30 40 50 60 70 80 90 100 110

J,FU

NCT

ION

SW

CORE1

CORE2

CORE3

CORE4

CORE5

CORE6

CORE7

CORE8

CORE9

CORE10

CORE11

CORE12

CORE13

CORE14

CORE15

CORE16

CORE17

CORE18

CORE19

CORE20

26

Fig (4-2) the optimum J function with Sw

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 10 20 30 40 50 60 70 80 90 100 110

J,Fun

ctio

n

SW

J,Function VS SW For BU-3

J,Function VS SW

27

Fig (4-3) Pc with Sw

0123456789

1011121314151617181920212223242526272829303132333435363738394041424344454647484950515253

0 20 40 60 80 100 120

Pc

Sw

PC vs SW For BU-3

PC vs SW

28

Fig (4-4) Sw with Depth

05

101520253035404550556065707580859095

100105110115120125130135140145150155160165170175180185190

0 20 40 60 80 100 120

Dept

h

SW

SW VS Depth For BU-3

SW VS Depth

FWL WOC

29

4-6 Calculation Pc =(rhow – rhoh)*h*3.281*0.433

1.48 = (1 – 0.8) * 3.281 * 0.433

H = 5.21 m

WOC = FWL – H

WOC = 3876.06 – 5.21

WOC = 3870.85 m

4-7 Discussion From the capillary pressure analysis the displacement pressure is 1.48 psi and by converting this pressure to depth and subtract the assumed FWL from well logging 3876 m ssl therefore the predicted OWC from capillary pressure is 3870.86 m ssl. The special core data used in the project was obtained from wells belongs to south dome of the field due to the difficulty of getting Scal data from the same dome where log interpretation where conducted. However special core data from north dome and more accurate FWL value would lead to more convenient result.

30

Chapter five Conclusion and Recommendations The well logs, MDT and capillary pressure methods are independent ways

to estimate fluid hydrocarbon contacts. Since the basic assumptions for each

method are different therefore the estimated OWC by three methods might

lead to significant differences among estimates .OWC predication from

well logs interpretations showed some variance in the predicted OWC and

this is due to the many uncertainties in the data obtained by well logs which

usually might be effected by the wellbore hole conditions and the tools

themselves. This leads to conclusion that more wells are needed to be

analyzed to acquire clearer picture for the predicted OWC. The MDT data

were unable to predict the FWL due to the improper pressure measurements

where all the pressure tests were conducts only in the oil zone therefore the

FWL were predicted using well logs interpretations and combining the

capillary pressure special core data analysis, the OWC were estimated and

acceptable match were obtained from the different methods.In conclusion,

the best method for OWC prediction is the combination of MDT and

capillary pressure because the data obtained are more reliable than well logs

that may have many uncertainties and the measured data usually effected by

the wellbore conditions. However the better method to be practically used is

the well logs which are more economic compared to special core analysis

and MDT methods. The outcomes of this project can be further investigated

by incorporating more wells to be analyzed and obtaining proper MDT data

along sufficient Scal data. This project also can be further developed to

investigate the OWC movement over time which would lead to good

monitoring and control of the reservoir.

31

Refrences :

1. Ahmed, Tarek - Reservoir Engineering Handbook

2. http://petrowiki.org/

3. https://www.onepetro.org/

4. [Frank_Jahn,_Mark_Cook,_Mark_Graham]_Hydrocarbon_E(BookZZ

.org)

5. http://blogs.bakerhughes.com/reservoir/2011/04/09/formation-testing-

part-ii-of-iii/

6. (1989). Open hole well logging Interpretation. Texas: Schlumberger

Wireline & Testing.

7. Serra, O. (1984). Fundamentals of well log interpretation.

Amsterdam: Elsevier.

8. Archie II: Electrical conduction in hydrocarbon bearing zone. (n.d.).

In Rock Physics (Vol. 36).

9. Abdulin, F (1985): Production of oil and Gas. MOSCOW Mir

Publishers, 8 – 10.

10. Aguilera R, 2000, Comparison of water saturation values determined

from capillary pressure measurements and old logs, JCPT PETSOC-

00-09-02.

11. Schlumbcrgcr Well Evaluation Confcrcncc, 1975, Arabia.

12. El Khatib N, 1995, Development of modified capillary pressure J-

Funtion, SPE Middle East Oil Show, Barein , SPE 29890 March..

http://petrowiki.org/https://www.onepetro.org/http://blogs.bakerhughes.com/reservoir/2011/04/09/formation-testing-part-ii-of-iii/

32

ةالخالص

دراسات إدارة المكامن النفطیھ المھمھ من ( WOC)أن دراسة منطقة أتصال النفط مع الماء

دیر اب وتق ن (WOC)وأن حس ي المكم وده ف ھ الموج نفط االبتدائی ة ال اب كمی ي حس دا" ف م ج مھ ) وكذلك في عملیات التثقیب واالكمال.(OOIPالنفطي

دف ث ان الھ اب (حی روع حس ذا المش ن ھ ي م ھ WOCاالساس ان لطبق ل البزرك ن MB21) لحق مات یر المجس ات تفس الل عملی ن خ رق اوال" م ثالث ط ة ب رف المنتج ة مش ) (Well Loggingطبق

)MDTوثانیا من خالل (

اب ل اللب ائج تحالی الل نت ن خ ا م ات (special core analysis) وثالث ع الدراس ا م ومقارنتھ . لسابقھ للتاكید من النتائجالجیولوجیھ ا

اء ( ع الم نفط م ال ال ة اتص ى منطق ول عل م الحص ث ت ھ البح الل دراس ق ) WOCخ د عم -عنھ ثالث 3874.06 ا مجموع ل م د تحلی ات بع یر المجس ھ تفس الل دراس ن خ ر م طح البح ن س ر م ار ةمت اب

ي ( ان وھ ل البزرك ن حق اب BU51,BU52,BU53م ل اللب ھ تحالی ن دراس ان ) وم (WOC)فق د عم ود عن ة - 3870.86 موج ون مقارب ات تك یر المجس ھ تفس ث ان دراس ر حی طح البح ن س ر م مت

ق د عم ون عن ي تك اء والت ع الم نفط م ال ال ة اتص ة لمنطق ائج الجیولوجی ن النت دا م ن -3875ج ر م متى بیان ول عل دم حص ك لع ا وذل ا م ھ نوع ون قریب اب تك ل الب ة تحالی ا دراس ر ام طح البح توى س ات مس

ھ ھ لمنطق م اف FWLدقیق ذلك ت اتل ة المجس الل دراس ن خ ھا م ذ (Well logging) تراض ع االخ م بنظر االعتبار ارتفاع منطقھ اتصال النفط مع الماء خالل الفتره االنتاجیھ.

ھ ( ات لطریق ھ البیان دم كفای ار ع ر االعتب ذ بنظ غط MDTواخ دل الض اب مع ركھ بحس ام الش ھ قی ) نتیجة د طبق ة MB21عن ھ لطبق ة المائی ي المنطق ط ف دل الظغ اب مع دم حس ط وع ھ فق ھ النفطی ي المنطق ف

MB21

رض م ع ك ت ع ذل ة وم ذه الطریق الل ھ ن خ اء م ع الم نفط م ال ال اب اتص تحال حس ن االس ان م وك بدون اي نتائج .) WOCاالجراءات الكاملھ لطریقھ حساب منطقھ اتصال النفط مع الماء (

عیري ط الش ة الظغ الل طریق ن خ ا م اء أیض ع الم نفط م ال ال ة اتص اب منطق م حس د ت ث أن (Pc)وق حیة ر ( (WOC)قیم اوي bu4) للبئ لة m 3870.85تس ائج المستحص ة النت ة لبقی ة مقارب ذه القیم وھ

رى . رق االخ ن الط م

1

DECLARATION

_Toc234300612 APPROVAL FOR SUBMISSION

_Toc234300613Table of contents_Toc450059512Symbols_Toc450059513ABSTRACT_Toc449897169_Toc450059514ACKNOWLEDGEMENTS_Toc450059515Dedication الاهداء_Toc450059516INDEX OF TABLES_Toc450059517_Toc450059518Chapter one_Toc4500595191-2 The study area

_Toc4500595201-3 Aim of the Study

CHAPTER 2WOC derivation from log interpretation2-1 INTRODUCTION

_Toc450059521_Toc450059522_Toc450059523_Toc450059524_Toc450059525 2-3 Methodology

_Toc450059526_Toc450059527 2-5 Discussion

_Toc450059528MDT3-1 definition

_Toc450059529_Toc450059530_Toc450059531_Toc450059532_Toc450059533_Toc450059534_Toc450059535_Toc450059536_Toc450059537_Toc450059538_Toc450059539_Toc450059540_Toc450059541_Toc450059542_Toc450059543_Toc450059544Chapter fiveConclusion and Recommendations

_Toc450059545_Toc450059546_Toc450059547