Priority Selection of Weak Gel Flooding Formula on Heterogeneous Reservoir

Abstract

Nowadays, most of the oilfields have been entered later development stage, it is difficult for reservoirs to depend on water flooding technology to improve recovery factor enormously. To satisfy deep flooding demand on heterogeneous reservoirs, the weak gel system is developed in the lab. Due to the mixture of organic chromium and HAPM, forming the organic weak gel system. HPAM concentration is from 1300mg/l to 1500mg/l and from 150mg/l to 210mg/l for cross-linking agent, the weak gel system formed stably with the high viscosity which is above 10000mp·s and moderate gelation time is from 45h to 130h.The best formula was selected with HPAM concentration 1500mg/l, and cross-linking agent concentration 210mg/l.The core displacement experiment shows the weak gel system has a well flooding effect on heterogeneous reservoirs, and its recovery rate increases 16.2%。