ABSTRACT
I. Scope ..................................................................................................................... 326 A. Primary Recovery...................................................................................... 326 B. Secondary Recovery.................................................................................. 326 C. Tertiary Oil Recovery................................................................................ 326
II. Introduction ........................................................................................................... 327 A. Enhanced Oil Recovery............................................................................. 327 B. Chemical Flooding .................................................................................... 327
1. Development of Chemical Flooding ......................................... 327 C. Chemical Surfactant .................................................................................. 329
1. Surfactants.................................................................................. 329 2. Cation Exchange ........................................................................ 332 3. Stability ...................................................................................... 332
D. Surfactant Flooding ................................................................................... 332 1. Mechanism of Surfactant at Reservoir Rocks........................... 333
E. Surfactant Mixture..................................................................................... 333 1. Ideal Mixtures ............................................................................ 334 2. Application of Ideal Mixing ...................................................... 334 3. Nonideal Mixtures ..................................................................... 334
F. Polymer Flooding...................................................................................... 335 G. Alkaline Water Flooding ........................................................................... 336 H. Traditional Surfactant/Polymer Flooding ................................................. 336 I. Surfactant-Polymer Interaction in Solution .............................................. 337 J. Relation between the Interfacial Tension and Residual Oil Saturation ... 338 K. Phase Behavior in EOR ............................................................................ 339 L. Application of Surfactants in Enhanced Oil Recovery ............................ 339
1. Interaction between Surfactant and Polymer at Reservoir Rock ........................................................................................... 340
2. Displacement of Oil by Spontaneous Imbibition of Aqueous Surfactant Solution..................................................................... 340
3. Adsorption of Different Surfactants on Kaolinite..................... 341 4. Acidified Oil/Surfactant Enhanced Alkaline System ................ 341 5. Dual Surfactants-System for Enhanced Oil Recovery
at High Salinity .......................................................................... 341 6. Ultralow IFT Using Neutralized Oxidized Hydrocarbon
Surfactant ................................................................................... 342 7. Mixed Micelles .......................................................................... 342 8. Biosurfactants as New Surfactant.............................................. 342
Acknowledgments........................................................................................................... 342 References ....................................................................................................................... 343
I. SCOPE
A. Primary Recovery A traditional step for increasing oil recovery is to inject gas or water into an oil reservoir for the purpose of delaying the pressure decline during oil production; a technique called pressure maintenance. A well-executed pressure maintenance program can substantially increase the amount of economically recoverable oil over that to be expected with no pressure maintenance. Without either fluid injection or an active natural water drive, oil recovery falls to where further production is no longer economically feasible. In the early days of the petroleum industry, reservoirs were allowed to produce naturally until a certain stage of depletion had been reached, generally when the production rates had become uneconomic. This was known as the primary production phase.
