PREPARED BY:

ABDUALGHAFFAR.E.BEZAN AHMED.I .ABUFARWA MOHAMED.M.ELNECA’A

UNIVERSITY OF TRIPOLIFACULTY OF ENGINEERINGPETROLEUM DEPARTMENT

10/7/19

SUPERVISED BY: D r. MOHSEN MOHAMED KHAZAM

Contents

1. Comparison and Assessment of PVT Data

2. Selection of Representative Amal Fluid Sample

Data preparation

Recommendations

Conclusions

Modeling

Data Preparation

Objectives

Introduction

1. Phase Behavior and EOS Tuning of The Selected PVT Sample.

2. Relative Permeability.

3. Slim Tube Modeling.

Modeling

2

Introduction

• Amal Field Location

• Reservoir Fluid Type

• Laboratory Analysis of Reservoir Fluids

• EOS Overview

• Miscibility Concept

3

Amal Field Location Map

Black oilLow-shrinkage crude oil

Naphthenic

Introduction

Oil gravity=34.7° API

GOR = 410 SCF/STB

Bo = 1.356 rbbl/STB

Pi = 4690 psig

Pcurrent = 2719 psig

Pb=1852 psig

Tres= 229° F

Kw=12.15

• Amal Field Location

• Reservoir Fluid Type

• Laboratory Analysis of Reservoir Fluids

• EOS Overview

• Miscibility Concept

B1

B2

B3

B4 B7

B11

B12

B14

B46

B17

E1

N1

N11

R10.847

0.849

0.851

0.853

0.855

0.857

0.859

0.861

0.863

0.865

220 240 260 280 300 320

SP.G

r C7

+

Mw C7+

Watson Factor (Kw)

0

500

1000

1500

2000

2500

0 200 400 600 800 1000 1200

Pres

sure

psig

Temperature °F

Phase DiagramAmal Fluid Specifications

Comp. MOL %

CO2 0.5

N2 1.35

C1 25.62

C2 6.67

C3 6.8

I-C4 1.44

n-C4 4.65

I-C5 1.81

n-C5 2.61

C6 4.62

C7+ 43.93

Critical Point

4

.well name

?

?

14 wells

ObjectivesThe main objective of this study is to dynamically validate the Amal phase behavior model using CO2as injection solvent for EOR applications.q PVT Screening and Assessment

ü Collect all the Amal available PVT data (14 samples).ü Analyze and assess the PVT properties arealy and vertically.ü Select the most representative PVT sample to model.

q Phase Behavior Modellingü Select and adjust the most commonly used EOS’s (PR3 and SRK3) to model the Amal fluid behavior.ü Use conventional and special PVT data for tuning purpose.ü Examine the extended and lumped compositional models using the splitting and lumping techniques.

adopted in the industry (e.g. Whitson approach).

q Slim Tube Modellingü Build and characterize a slim tube model using 1D E300 model with optimum number of grids.ü Use measured data to back calculate the base relative permeability curves (BL & JR techniques).ü Conduct sensitivity analyses to evaluate and minimize any other dynamic flow effects.ü Simulate CO2 injection at different pressures with the concept of interfacial forces (IFT change) and its

impact on relative permeability shapes.ü CO2 MMP determination.

5

Comparison and Assessment of PVT Data

6

0

5

10

15

20

25

30

35

40

45

50

Co2 N2 C1 C2 C3 iC4 nC4 iC5 nC5 C6 C7+

Z %

Compositional graph

B27 B1 B2 B3 B4 B7 B51

Comparison and Assessment of PVT Data

1.05

1.1

1.15

1.2

1.25

1.3

1.35

1.4

1.45

0 1000 2000 3000 4000 5000

Bo S

TB/b

bl.

Pressure PSIG

Formation Volume Factor At 229° F

B1-12 B2-12B4-12 B7-12B51-12 B3-12

0

100

200

300

400

500

0 1000 2000 3000 4000 5000

Rs S

CF/S

TB

Pressure PSIG

Solution Gas Oil Ratio At 229° F

B2-12

B4-12

B7-12

B3-12

B1-12

?

0.75

1.25

1.75

2.25

2.75

0 1000 2000 3000 4000 5000

Visc

osity

CP

Pressure PSIG

Viscosity At 229° FB1-12 B2-12B4-12 B7-12B51-12 B3-12

B1

B2

B4

B7

B51

B3

9900

10000

10100

10200

10300

10400

10500

10600

1000 1500 2000

Tota

l dep

th ft

.

Saturation Pressure PSIG

Saturation Pressure Variation With Depth

B1

B2

B4

B7

B51

B3

B1

B2

B4

B7

B51

B3

9900

10000

10100

10200

10300

10400

10500

10600

0 10 20 30 40 50

Tota

l dep

th ft

.

Composition Variation With Depth

C1 C7+

Areal Analysis Vertical Analysis

7

0.7

0.72

0.74

0.76

0.78

0.8

0.82

0 1000 2000 3000 4000 5000

Oil

Dens

ityGm

s/Cc

Pressure psig

Density At 229° FB1B2B4B51B7B3

Phase Behavior and EOS Modeling

PR3 EOS was applied to simulate Amal

phase behavior using:

ü Conventional PVT tests

üConstant-composition expansion.

üDifferential liberation.

üSeparator tests.

üViscosity tests

üSpecial PVT tests

üSwelling test.

üSlim tube experiments-MMP.

• C7+ Characterization/splitting using • Whitson Gamma-Distribution Model.• Three pseudo-components.

• Critical Properties and Acentric Factors• Kesler-Lee Correlation• Edmister Correlation

• Regression Techniques• Careful selection of weight factors for

different experiments• Regression variables within acceptable limits

•Grouping technique• Mole Fraction

• Regression Technique• Critical properties (Pcrit, Tcrit )• Critical Volume (Vcrit)• Binary interaction coefficient (BIC)

PVTi Package Splitting & Regression Grouping & Regressing

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1

95 295 495 695

SP.G

R

Mw

Katz and F iroozabadi

pseudo-component

Comp. mol % MWCO2 0.5N2 1.35C1 25.62C2 6.67C3 6.8IC4 1.44NC4 4.65IC5 4.62NC5 2.61C6 1.81

FRC1 16.927 119.59FRC2 19.721 266.82FRC3 7.2816 580

Comp. Z% MwCO2 0.5 0.1629

N2C1 26.97 16.642

C2 6.67 1.4847

C3C4 12.89 50.724

C5C6 9.04 74.523

FRC1 16.927 119.59

FRC2 19.721 266.82

FRC3 7.2816 580

8

• Regression variables• Tcrit, Pcrit, Sshift, BIC• Vcrit

Simulation of Conventional PVT Tests – Lumped ModelCCE: Relative Vol. DL: Gas-Oil Ratio DL: Gas gravity

DL: Liquid density DL: Oil rel vol Oil viscosity

Simulation of Special PVT Test – Lumped Model

SWELL: Sat Pressure SWELL: Relative Vol.

Base Relative Permeability Curves

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.05 0.1 0.15

SG

1/Qi

Sg avg

Sg2

Sor = 1-0.54 = 0.46

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.5 1 1.5 2

SG

1/QI

Sg 2

Sg avg

Sor = 1-0.54 = 0.46

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Kro

krg

Sg

Smoothed relative permeability curves

Bardon and Longeron Method Jones and Roszelle Method

KrO = ΔpOfO

Δp − t d Δpdt

Krg = Δpgfg

Δp − t d Δpdt

KrO = ⁄µOfO2 µe2 Krg = ⁄µgfg2 µe2

Bardon and Longeron Method

Jones and Roszelle Method

11

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Kro

Krg

Sg

BL & JR comparison

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Kro

krg

Sg

Smoothed relative permeability curves

Applying lab data from the immiscible experiment At 2000 Psia (IFT = 5 Dyne/Cm)

Analytical correlations can be applied to calculate the base relative perm (using simulation model with trail & error) if no enough measured data are available to back calculate the base relative perm.

• Corey correlation (1954) oil-gas system

Relative Permeability – Using Analytical Correlations

12

krg = krgmaxSg − Sgc

1 − Swc − Sgc − S𝑜𝑟Ng

kro = kromax1 − Swc − Sor − Sg1 − Swc − Sgc − S𝑜𝑟

No

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Kro

Krg

Sg

Corey Correlation

krg

kro

0.1

1

10

100

0 0.2 0.4 0.6 0.8 1

Krg/

Kro

Sg

Krg/Kro

Krg/Kro Corey

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.2 0.4 0.6 0.8 1

Kro

Krg

Sg

Corey vs BL method

Krgmax = 0.46 Sgc = 0 Ng = 0.98

Kromax = 1 (Sor) = 0.46 No= 2.363

1215 cm (40 ft.)

DY = 0.4136 cm

Dx = 6.075 cm

ɸ = 35.3%K = 4600 md

Soi = 100%

200 cells

Pore Volume = 73.37 cc

Injector Producer

Qi = 7.104 cc/hr.

2250 F23 hr..DZ = 0.4136 cm

• The Slim Tube horizontal model was built using Eclipse E300• 3PR EOS • Rel.Perm curves

Slim Tube Experiments - Simulation Model

Exp. Pressure Psia

1st 2000

2nd 3000

3th 3600

4th 4000

Reservoir Temperature

13

C = 3.4E-6 psi-1

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr..)

C5+ Concentration

LAB

Simulat ion

0

4000

8000

12000

16000

20000

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20

GOR

RF%

Time (hr.)

RF&GOR VS TIME

RF% observationRF% SimulatedGOR Simulated

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.5 1 1.5 2 2.5

∆P a

tm

PVi

∆P VS PVi

observation

Simulated

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr.)

C02 Concentration

LAB

Simulat ion0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr.)

N2,C1 ConcentrationLAB

Simulat ion

• 1st experiment at P =2000 psia (immiscible case)

• Overall match is good with some exceptions at the late C5+ concentration after the B.T.

• Perfect simulation of CO2 concentration with time.

• Measured RF at the end of experiment is 41.5% (predicted is 42.8 %)

14

Slim Tube Model Results – Lumped Compositional Model

0

0.2

0.4

0.6

0.8

1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Krg

Sg

Relative Permeability curves vs pressure

Modeling Concept of Other Slim Tube Experiments

15

Once the good match on the immiscible experiment at

2000 psia was achieved and all the adverse flow

factors have been taking into consideration, then the

miscibility mechanism of other slim tube experiments

at higher pressures were simulated with the IFT

change with the relative permeability curves concept

using the following equation.

K<= = FK<=?@@ + 1 − F K<=@?B

K<C = FK<C?@@ + 1 − F K<C@?B

miscible IFT = 0

Base Relative CurveIFT = 5 dyen/cm

F =σσE

F

σE= 5 dyen/cmN = 0.32

Slim Tube Model Results – Extended Vs Lumped Compositional Model

16

• 2nd experiment at P =3000 psia(near miscible case)

• Overall match is quite good with some exceptions at the last few C5+ concentration measurements (likely measurement errors).

• Better simulation of the hump phenomenon with the extended compositional model .

• Measured RF at the end of experiment is 89% (predicted is 90 %)

0

5000

10000

15000

20000

25000

0

20

40

60

80

100

0 5 10 15 20

GOR

SCC/

SCC

RF %

TIME (hr.)

RF&GOR VS TIME RF Extended

RF Lab

RF Lumped

0

0.5

1

1.5

2

2.5

0 0.5 1 1.5 2 2.5

∆P a

tm

PVi

∆P VS PVi

ExtendedLabLumped

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr)

C02 concentration

LABLumpedExtended

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr)

N2,C1 concentration

LabLumpedExtended

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25

conc

entr

atio

n

TIME (hr)

C5+ concentration

Lab

Lumped

Extended

Hump phenomena

Lab MMP=3125psia

Minimum Miscibility Pressure (MMP)

• The measured lab MMP is 3125 psia

• The Predicted MMP using 1D-model is exactly aligned with the measured figure (3125 psia)

• Different runs were conducted to simulate slim tube experiments at different pressures and an “S“ shape trend was pictured which is aligned with many literature findings.

17

0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RF %

Pressure psia

RF VS Pressure

MMP=3125 psiaPres=2720 psia

RF≈78%

18

ConclusionsR Perfect match was achieved for Amal conventional and special PVT experiments using both PR3 and SRK3

with the extended and Lumped compositional models (13 and 8 components, respectively).

R Match of only the conventional PVT data will not be enough to simulate the slim tube experiments. Therefore, it is essential to match both the conventional and special tests for EOR simulation studies.

R The relative permeabilities at higher pressure experiments are sensitive to IFT values, especially at low IFT value. These were simulated by the change of relative permeability with IFT (i.e. the base relative perm curves will approach to straight lines as the IFT approaches to zero).

R The measured produced gas C5+ concentration, especially at the end of some experiments, was dramatically deviated from the predicted data raising some doubts on the measurements.

R The hump phenomena before B.T. time was better simulated with the extended compositional model compared to the lumped model. This highlights the favorability of extended compositional model in future EOR simulation studies.

R Perfect match of all slim tube experiments from immiscible to miscible conditions (2000, 3000, 3600 and 4000 psia) was achieved indicating the validity and reliability of Amal phase behavior model.

R The multiple contact MMP pressure of Amal field, using CO2 as injection solvent, is around 3125 psia based on measured and predicted results.

RecommendationsThe following areas for future researches are recommended, utilizing the Amal phase behavior model developed in this study:

v Simulate and study the EOR core flood experiments conducted on Amal field, such as:

üInvestigate and assess the impact of core heterogeneity, viscous fingering and gravity overrides on CO2 injections

üidentify optimum CO2 slug size and sweep displacement efficiencyüInvestigate and assess the optimum WAG process for Amal field

vConduct EOR sector model simulation studies

vConduct EOR pilot study on area of Amal field that is representing the average field properties.

19

SPE -182793-MS