Preparation of micrometer cross-linked polymer particles and study of its plugging property

In order to improve the oil-displacement effect of microspheres, larger particles of cross-linked polymer were synthesized by inverse emulsion polymerization to match cores with biggish duct. Before hydration, particle sizes of microspheres are a few hundred nanometers, the particle sizes can increase by about 10 times after hydration, which shows that cross-link polymer microspheres have well expanding properties. The plugging property under high temperature is exhibited well in low-pressure millipore filter experiments, and the core flooding test showed that for the heterogeneous core with a high permeability of 4.5μm², flooding pressure was raised high enough to present stepped deep plugging by crosslinked polymer microspheres.