Eng. Rashid Sher Mohd, M.Sc
INTRODUCING OF ENHANCED OIL RECOVERY
Lecture Contents Introduction Reservoir Engineering Aspects in IOR and EOR Immiscible Flooding (Waterflooding)
Miscible Flooding Chemical Flooding Thermal Injection Microbial Enhanced Oil Recovery (MEOR) Guidelines for Selecting IOR and EOR Methods Design and Implementation of EOR Method DK - 2 -
Lecture Evaluation Attending
= 10 %
Home Works
= 10 %
Presentation
= 05 %
Mid Test
= 25 %
Final Test
= 50 %
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References
-
Latil M, Bardon C, Burger J, Soureau P., “Enhanced Oil Recovery”, Graham Trotman Ltd, London, 1980.
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Van Poolen,H.K., ”Fundamentals of Enhanced Oil Recovery, Penn Well Books Division of Publishing Company, Tulsa, Oklahoma, 1980.
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National Institute for Petroleum and Energy Research, (NIPER) “Enhanced Oil Recovery Information”.
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Eng. Rashid Sher Mohd, M.Sc
INTRODUCTION
HOW IF THE OIL PRODUCTION FROM THE WELL OR FIELD WAS DECREASES ?
The definition of EOR
•
A method that use to recover the oil content when the general oil production method no longer efficient
OIL RECOVERY PHASES Primary Recovery
NATURAL FLOW ARTIFICIAL LIFT
WATER DRIVE
DEPLETION DRIVE
GAS CAP DRIVE
GRAVITY DRIVE
COMBINATION DRIVE
SECONDARY RECOVERY
WATER FLOODING
PRESSURE MAINTENANCE
IMMISCIBLE GAS FLOOD
FLOODING
GAS LIFT
PUMP
TERTIARY RECOVERY
MISCIBLE GAS FLOOD
-CO2 FLOOD - N2 FLOOD - INERT GAS - RICH GAS
CHEMICAL FLOODING
- ALKALINE - SURFACTANT - POLYMER - MICELLAR POLYMER - ASP
THERMAL INJECTION
MICROBIAL EOR
- HOT WATER - STEAM FLOOD - INSITU COMBUSTION
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Natural or Primary Recovery Drives Solution gas drive Gas cap drive Water drive Gravity drainage Combination drive
Gas Oil Water
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Secondary Recovery Waterfloods and Immiscible gas floods No compositional or temperature changes take place in the reservoir except pressure and displacement Suitable for light oil, low viscosity oil and low pressure reservoirs
Injector
Producer
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Enhanced Oil Recovery
Cause physical, chemical, compositional and thermal changes in the reservoir rock and fluids Improve recovery beyond secondary level
Injector
Appropriate selection and design are important Producer
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Typical Recovery Factors Natural or Primary Methods Heavy oil
5 - 15 %
Light oil: solution gas drive
10 - 25%
water drive, gas cap
20 - 40%
gravity drainage
30 - 45%
Secondary Methods Waterflood
20 - 45 %
Immiscible Gas flood
15 - 40 %
Tertiary or EOR Methods Laboratory tests
70 - 90 %
Field applications
45 - 75 % DK - 13 -
Incremental Recovery Factor
Incremental Secondary Recovery
Qo, BOPD
Extrapolated primary
Primary phase
Secondary phase
Incremental Tertiary / EOR Extrapolated secondary
EOR phase
Time or Cum. Production DK - 14 -
ENHANCED OIL RECOVERY (EOR) The main objective of EOR is to recover as much as possible oil in reservoir / well Aim at increasing the oil recovery over its primary and secondary potential.
EOR methods involve injection of substances which cause changes in compositions, temperature and rock-fluid interactions in the reservoir. In some cases, EOR Methods could be applied after Primary or even at discovery. Sometimes called Tertiary Recovery Methods. This does not mean that EOR Methods have to be applied after Secondary Recovery. DK - 15 -
IOR AND EOR MECHANISMS
Waterflood
Maintains reservoir pressure & physically displaces oil with water moving through the reservoir from injector to producer.
Thermal
Reduces Sorw by steam distillation and reduces oil viscosity.
Chemical
Reduces Sorw by lowering water-oil interfacial tension, and increases volumetric sweep efficiency by reducing the water-oil mobility ratio.
Miscible Gas
Reduces Sorw by developing miscibility with the oil through a vaporizing or condensing gas drive process.
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FACTOR AFFECTING EOR Reservoir Depth. Reservoir Heterogeneity. Remaining Reserves (RR). Rock Properties. Fluid Properties. Reservoir Drive Mechanisms.
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IOR AND EOR MAIN OBJECTIVES Goal of IOR and EOR processes is to mobilize remaining oil reserves Achieved by enhancing oil displacement and volumetric sweep efficiencies - Oil displacement efficiency is improved by reducing oil viscosity (e.g., thermal floods) or by reducing capillary forces or interfacial tension (e.g., miscible floods)
- Volumetric sweep efficiency is improved by developing more favorable mobility ratio between injectant and remaining oil reserves (e.g., chemical floods, WAG processes)
Important to identify remaining oil reserves and mechanisms necessary to improve recovery before implementing IOR and EOR
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EOR IMPLEMENTATION STEPS RESERVOIR
GEOLOGY DATA
Type of Rock Migration Direction Bulk Volume (Vb)
RESERVOIR DATA
Rock Properties
Porosity Permeability Saturation Wettability Capillary Pressure
PRODUCTION DATA
Fluid Properties
Reservoir Condition
Oil Properties Water Properties
Res. Pressure Res. Temperature
Reservoir Drive Mechanism
Oil Cut Water Cut Remaining Reserve
Screening Criteria
Selecting EOR Methods
Laboratory Study Evaluation
Simulation Study Pilot Project
Monitoring and Evaluation
Full Scale
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