BEHAVIOR OF POLYSACCHARIDES UNDER HARSH CONDITIONS

The implementation of EOR polymers for high salinity and high temperat ure reservoirs requires a detailed knowledge of their solution behavio ur. This paper describes the results of comparative studies of the mos t commonly used polysaccharides, i.e., xanthan and scleroglucan. Impro ved laboratory techniques, such as equipment for stability tests under anaerobic conditions and high-temperature low-shear viscometer, have recently been designed to characterize their behavior under field cond itions. It has been shown that: The stability and good filterability o f improved quality polymers are maintained for several months at 90-de grees-C. The viscosity of polysaccharides is decreased only slightly b y an increase in temperature to 90-degrees-C. From flow experiments an d batch tests, adsorption levels on reservoir rocks decrease with temp erature.