Reservoir Engineering Courses – K. Madaoui - 2004
145
Reservoir Engineering Courses – K. Madaoui - 2004
ENHANCED OIL RECOVERY PROCESSES
CONTENTS
-1-INTRODUCTION
EOR world potential-
-2-THERMAL PROCESSES
-Steam injection –Air injection
-3-CHEMICAL METHODS
-Polymers and Surfactants
-4-GAS INJECTION as a promising EOR process
-Specificities,Mechanisms,Efficiencies,Selection criteria,Ratios,Methodology to
conduct a GI project
-5-CONCLUSIONS: EOR vs R&D
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Reservoir Engineering Courses – K. Madaoui - 2004
Typical Oil Field Performances
Time Years
Field Oil Rate
Aband.
Rate
WATER-CUT
NATURAL
DEPLETION
(30%)
WATER
INJ.
(+ 15%)
NP
DNP
Diagnosis
3rdTYPE
EOR
(+ 10%)
IRM (+ 5%)
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Reservoir Engineering Courses – K. Madaoui - 2004
Ultimate Reserves and Recovery mechanism sequence
Npu =N1+N2+N3 at economical abandonment conditions
=N1+(Ni-N1)[EdxEvol]water+(Ni-N1-N2)[EdxEvol]gas
How to optimise Npu?How to combine N1,N2,N3?
Main parameters?
N1(nat.depl.) :identification-limitations-duration
N2(water inj.) :limitations-implementation-duration
N3 (EOR) :process selection-implementation
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Reservoir Engineering Courses – K. Madaoui - 2004
Tertiary Recovery Objectives
PRODUCE-ECONOMICALLY- PART OF OIL LEFT BY
CONVENTIONAL RECOVERY METHODS
–Improvement of displacement efficiency
decreasing Sorw
miscible or near miscible gas injection
chemical flood-surfactants
increasing gravity forces
oil vaporization
–Improvement of volumetric sweep efficiency
lowering mobility ratio by increasing mw
chemical flood - polymers
reducing mo
thermal flood