Method of treating a high temperature formation to permit the use therein of temperature sensitive hydrophilic, viscosity increasing polymers

摘要

Polymer flooding is an effective means of increasing the sweep efficiency of a displacement process for recovering petroleum from a subterranean, petroleum containing formation; however, most polymers suitable for use in flooding operations hydrolyze or otherwise decompose at temperatures above about 150 DEG F to 200 DEG F, and the temperature of many subterranean petroleum-containing formations is in excess of 150 DEG F-200 DEG F. Polymers may be employed in tertiary recovery in formations whose temperatures are greater than the temperature stability limit of the polymer if the formation temperature is first reduced by introducing an aqueous fluid such as water at a temperature substantially below the temperature limit of the polymer into the formation for a period of time sufficient to reduce the formation temperature to a value at or below the temperature tolerance level of the polymer.