Laboratory experimental study on evaluation of plugging effect

Abstract

Abstract Aiming at the research of water-controlled fracturing and stimulation technology of high water content Wells in Chaoyanggou low-permeability oilfield, several laboratory experiments of plugging agents are carried out. The traditional plugging agent displacement experiments mostly adopt the way of filling sand tubes, but the filling sand tube is extremely difficult to clean after the curing of the Plugging Agent And takes a long time, which is not conducive to the simulation of multi-group experiments. Therefore, a new artificial core method is used to simulate the reservoir under two permeability conditions, and the performance of three kinds of plugging agents is studied from several aspects, such as plugging performance, breakthrough pressure, and distribution law of plugging agents after injection into the core. The experimental results show that Plugging Agent A (particle class) is suitable for plugging large pores, the plugging strength is high, and the breakthrough pressure gradient is more than 9 MPa/m. Plugging Agent B (gel class) is suitable for plugging small voids, and has good plugging performance, with a plugging rate of up to 99%. The pore structure characteristics of the core after plugging are determined by SEM experiments.