OVERVIEW OF MOBILITY CONTROL IN MICELLAR - POLYMER ENHANCED OIL-RECOVERY PROCESSES

Enhanced oil recovery processes require mobility control for proper displacement of oil and water from porous media. In some processes, concentrated or dilute surfactant systems can be used to recover oil following waterflood operations. These surfactant systems are, in turn, displaced by dilute aqueous polymer solutions. To minimize “fingering” of one chemical system into another, the mobility of the displacing fluid must be no greater than the mobility of the fluid being displaced. Therefore, rheological properties of materials used for enhanced oil recovery are important. Potentially useful surfactant formulations consist of water, salt, cosurfactant, and sometimes oil in addition to the major surfactant. The concentration and/or type of each component can alter the rheological behavior of these surfactant systems. Two types of water soluble polymers are available for mobility control in field application. Again, polymer type, polymer concentration, and salt concentration affect flow behavior. Data are presented to show the effects chemical composition and shear rate have on the rheological properties of chemical formulations useful in enhanced oil recovery operations. © 1979, The Society of Rheology. All rights reserved.