UAE University

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UAE University Faculty of Engineering Graduation
project II
Waterflooding of Carbonate Reservoirs
Advisor
Dr. Ibrahim Kocabas.
Masoud Ahmed

Abdulla Salem
Final Presentation 10/6/2004
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Presentation Layout

• Introduction,
• Objectives,
• Types Of Reservoir Formations,
• Waterflood Design,
• Laboratory Experiments ,
• Field Design,
• Economical Decision,
• Environmental Social Impacts and
• Conclusions Recommendations.

Waterflooding of Carbonate Reservoirs
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• Oil Recovery Stages
• Primary.
• Secondary (Waterflooding) and
• EOR (Enhance Oil Recovery).
• Secondary Recovery results from the
  augmentation of natural energy present in the
  reservoir through injection of water to displace
  the oil toward production wells.

Waterflooding of Carbonate Reservoirs
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Secondary Recovery Method (Waterflooding)
Waterflooding is the most common method of the
Secondary Recovery.
Waterflooding of Carbonate Reservoirs
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Water
Is widely available and inexpensive relative to
other fluids, easy to inject and efficient in
displacing Oil.
Waterflooding of Carbonate Reservoirs
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Why Waterflood is Needed?

• Week Natural Reservoir Energy
• Under-Saturated Oil Reservoirs.
• Negligible Aquifer Support.

Low Oil Recovery
High Pressure Drop due to Production

• Low Permeability Reservoirs
• Less than 50 md.

Delayed Support from Aquifer (Edge Water)

• Large Reservoirs
• Less than 50 md.

• Heterogeneous Reservoirs
• Tar Mates, etc.
• Permeability Barriers.

Lack of Communication Between Oil and Water Zones.
Waterflooding of Carbonate Reservoirs
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Objectives

• Supplementing the natural reservoir energy by
  pressure maintenance and immiscible fluid
  displacement.

• To design a Waterflooding for fractured
  Carbonate Reservoirs.

• Environmentally safe and Economically feasible.

Waterflooding of Carbonate Reservoirs
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Types of Reservoir Formation

• Carbonate
• Sandstone
• Carbonate is the most common formation in the
  United Arab Emirates.

Waterflooding of Carbonate Reservoirs
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Waterflood Design
Relative Permeability Curve
Fractional Flow Curve
Lab Experiments
CGM Model
Field Design
Pattern Area
Craig-Geffen-Morse Correlation
Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Porosity
Vp w / ?w
A p (D2/4)
VB A x L
Where, ? Porosity, fraction. Vp Pore
Volume, cm3 VB Bulk Volume, cm3 W Weight of
sample, gram ?w water density 1.056 gm/cm3.
A cross sectional area, cm2. L length of
core sample, cm. D Diameter of cores, cm.
Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Permeability
Waterflooding Apparatus
Q Vw / t
Where, Q Flow Rate, cm3 / sec. K
Permeability, darcy. A Cross-sectional Area,
cm2. µ Water Viscosity, c.p and equals to 1.15
cp. L Length of sample, cm. dp Pressure
Drop, atm. Vw Volume of Water collected in the
Tube. t Time, seconds.
Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Core Sample REF1 (Relative Permeability Effect on
Fracture)

• Porosity (?) 24.5
• Absolute Permeability K 147 md

REF1 (half-Shape Fractured)
Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Core Sample (REF2)
Core Sample (REF3)
REF2 (T-Shape Fractured)
REF2 (T-Shape Fractured)

• Porosity (?) 13.7
• Absolute Permeability K 24 md

• Porosity (?) 21
• Absolute Permeability K 63 md

Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Relative Permeability Curve
Waterflooding of Carbonate Reservoirs
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Laboratory Experiments
Fractional Flow Curve
Waterflooding of Carbonate Reservoirs
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Field Design

• Assumptions
• Pattern Spacing Five-Spot.
• Pattern Area (alternatives) 20-acre and
  10-acre.
• Thickness 1 feet.
• Pressure Drop 500 psi.

Waterflooding of Carbonate Reservoirs
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Field Design
20-acre Pattern Spacing
Wi (bbl) Wi / Wibt EA (fraction) Qi Sw2 (fraction) fo2 Sw5 av NP (PV)
12422.71 1 0.76 0.43 0.63 0.22 0.730 0.327
21125.21 1.70 0.80 0.72 0.643 0.18 0.740 0.352
29827.71 2.40 0.83 0.99 0.656 0.14 0.750 0.374
38530.21 3.10 0.95 1.23 0.669 0.1 0.770 0.447
47232.71 3.80 1.00 1.46 0.682 0.06 0.780 0.480
79835.33 6.43 1.00 2.320 0.695 0.02 0.783 0.483
112437.95 9.05 1.00 3.177 0.708 0.01 0.787 0.487
145040.57 11.68 1.00 4.035 0.721 0.006 0.790 0.490
177643.19 14.30 1.00 4.893 0.734 0.002 0.794 0.494
Waterflooding of Carbonate Reservoirs
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Field Design
20-acre Pattern Spacing
Qi (PV) NP (Mbbl) Fwo (bbl/bbl) q (bbl/day) Mobility R Conductance Ratio Time (yrs)
0.33 12.42 1.29 15.06 0.2 0.38 2.26
0.56 13.38 2.19 14.27 0.2 0.36 4.06
0.78 14.20 3.18 13.87 0.21 0.35 5.89
1.01 16.97 4.55 11.89 0.23 0.3 8.88
1.24 18.25 15.67 9.51 0.24 0.24 13.60
2.10 18.38 49.00 9.51 0.24 0.24 22.99
2.96 18.50 99.00 9.91 0.25 0.25 31.09
3.82 18.63 165.67 10.31 0.26 0.26 38.56
4.67 18.76 499.00 10.70 0.27 0.27 45.48
Waterflooding of Carbonate Reservoirs
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Field Design
20-acre Pattern Spacing
Waterflooding of Carbonate Reservoirs
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Field Design
10-acre Pattern Spacing
Wi (bbl) Wi / Wibt EA (fraction) Qi Sw2 (fraction) fo2 Sw5 av NP (PV)
6211.35 1 0.76 0.43 0.63 0.22 0.730 0.327
14913.85 2.40 0.80 1.00 0.643 0.18 0.740 0.352
23616.35 3.80 0.85 1.54 0.656 0.14 0.750 0.383
32318.85 5.20 0.93 2.03 0.669 0.1 0.770 0.437
41021.35 6.60 1.00 2.49 0.682 0.06 0.780 0.480
73623.97 11.85 1.00 4.207 0.695 0.02 0.783 0.483
106226.59 17.10 1.00 5.922 0.708 0.01 0.787 0.487
138829.21 22.35 1.00 7.637 0.721 0.006 0.790 0.490
171431.83 27.60 1.00 9.353 0.734 0.002 0.794 0.494
Waterflooding of Carbonate Reservoirs
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Field Design
10-acre Pattern Spacing
NP (PV) Qi (PV) NP (Mbbl) Fwo (bbl/bbl) q (bbl/day) Mobility R Conductance Ratio Time (days)
0.327 0.33 6.21 1.29 15.90 0.2 0.38 1.07
0.352 0.78 6.69 2.64 15.06 0.2 0.36 2.71
0.383 1.24 7.27 3.94 14.65 0.21 0.35 4.42
0.437 1.70 8.31 5.76 12.55 0.23 0.3 7.05
0.480 2.16 9.12 15.67 10.04 0.24 0.24 11.19
0.483 3.87 9.19 49.00 10.04 0.24 0.24 20.09
0.487 5.59 9.25 99.00 10.46 0.25 0.25 27.82
0.490 7.30 9.32 165.67 10.88 0.26 0.26 34.96
0.494 9.02 9.38 499.00 11.30 0.27 0.27 41.57
Waterflooding of Carbonate Reservoirs
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Field Design
10-acre Pattern Spacing
Waterflooding of Carbonate Reservoirs
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Economical, Environmental andSocial Impacts

• Economical Impact

• (Benefit of the Project)
• Increase the production
• Primary Recovery 15 - 25
• Secondary Recovery (Waterflooding) other 15
  20 of production.
• Total is 30 - 45 Oil Production.

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Economical Decision
Area 10 Acres Time of Project 1.1 years
Area 20 Acres Time of Project 2.3 years

• Cost
• Pipelines and other auxiliaries 0.25 MM/well
• Well Cost 1 MM X 4 wells MM 4
• Cost MM 4 (0.25 MM/well X 4 wells) MM 5

• Cost
• Pipelines and other auxiliaries 0.25 MM/well
  
• Well Cost MM 1 X 4 wells MM 4
• Cost MM 4 (MM 0.25 X 4 wells ) MM 5

• RevenueNp(Mbbl) X Oil Price(/bbl)

• RevenueNp(Mbbl) X Oil Price(/bbl)

Np (Oil Produced) 0.912 MMbbl Oil Price 25
/bbl
Np (Oil Produced) 0.457 MMbbl Oil Price 25
/bbl

• Revenue 0.457 MMbbl X 25 (/bbl)
• MM 11.4

• Revenue 0.912 MMbbl X 25 (/bbl)
• MM 22.8

• Profit Revenue - Cost
• 22.8 5 MM 17.8

• Profit Revenue - Cost
• 11.4 5 MM 6.4

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Economical, Environmental andSocial Impacts

• Environmental Impact

• Disposal Water.

• Social Impact

• Additional revenues.

Waterflooding of Carbonate Reservoirs
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Conclusions

• Waterflooding is a proven oil recovery process.
  It is not always successful and economically
  profitable, but there is a sound basis for
  engineering waterflood projects.
• Waterflooding is the most common method of the
  Secondary Recovery.

Recommendations

1. Back Pressure application displacing missing.
2. Constant Rate Pumping is missing and
3. Amott tube equipment is missing.

We Would be able to explore imbibition's process
much better.
Waterflooding of Carbonate Reservoirs
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30 minutes
Thank you for your Attention
Any Questions?