Application Study on Clay Plugging Large Pore Paths in High Temperature and High Salinity Reservoir

Aiming at high temperature and high salinity reservoir, clay is optimized to plug large pore paths. Particle size distribution of stabilizing Na-bentonite is characterized by laser particle analyzer and dispersity by the method of bleeding index. The results show that stabilizing Na-bentonite has good behavior of dispersity. However, it is nonuniform in size, and the adaptive permeability is in a range from 3 to 20μm², which is proved by injectivity test. Plugging ability and plugging mechanism of clay plugging system are studied, including clay dispersion system, curing system of clay and super-fine cement, flocculation system of clay-AM-AMPS and clay-phenolicresin gel. Curing system of stabilizing Na-bentonite and super-fine cement was successfully applied to two wells in Gudao oilfield in 2009 and achieved good effects.