Jiyuan Oilfield Low Permeability Reservoir Water Shutoff Profile Improvement

Today in our country most of oilfields using water injection have stepped into the high-aquifer stage, therefore it is very important to deal with the deep stratum. In this thesis the matching with throat-pore and the migration characteristics of pre-gelled particles and styrene butadiene latex(SBL) are studied by using core flow models and the self-designed test equipment. "Ultimate deformation pressure" and "crush pressure" have been given to describe the material characteristics of the pre-gelled particles and evaluate the plugging characteristics, which offer a basic method to choose more appropriate particles in a certain reservoir conditions. The results of the physical simulation of pre-gelled particles show that the particles mainly plug the pore close to the entrance, and are crushed into smaller particles in the course of migration, which results that the block capability of particles in deep of reservoir is weaker than those around entrance. In the inhomogeneous stratum the pre-gelled particles have some selective plugging characteristic. In the course of migration the particles can enhance displacement efficiency to oil film and residual oil in throat-pore. The results of physical simulation of SBL indicate that its injection capability is matched with permeability of core. The SBL slug can migrate in core, and its speed in higher permeability is faster than that in lower. The selection of SBL during the injection is so poor that its plugging capability in high permeability core is stronger than that in low.