Research and application of DCA microspheres as deep profile control agent in low permeability reservoir

Abstract

Many chemical profile agents have been widely adopted to control water content. Polymer microsphere is a new potential profile control technology developed rapidly in recent years. According to the diameter of reservoir rock throat, the polymer microspheres matching the throat diameter are prepared by nano-micron material synthesis method. The mechanism of profile control is that the microspheres can move freely in the porous media after entering the reservoir with injected water. The polymer microspheres accumulate in the throat to block up and cause resistance to the flow, so that the subsequent flow will turn around and flow around. Because the microspheres have the certain degree of viscoelasticity, the microspheres will be elastic deformation as the plugging pressure difference increases to a certain extent. Then the polymer microspheres continue to migrate deeply through the throat, so as to achieve step-by-step deep profile control and flooding.

In this article, divinylbenzene-co-acrylamide microspheres (DCAMs) with different particle size were firstly prepared by using dispersion polymerization. Then their physical properties such as chemical structure, micromorphology, particle size and size distribution, swelling property and stability were reseached. The core displacement experiment under the simulated reservoir conditions was designed to analyze the recovery and profile modification performance of DCAMs.