Self-assembled microspheres feasibility study for conformance control in high temperature and high salinity reservoirs

Abstract

This paper investigated the micro-structure and swelling and heat tolerance of DCA (divinylbenzene-co-acrylamide) microsphere and its self-assembly ability at high temperature, high salinity, oil-water system. Heterogeneous cores have been used in displacement experiment to evaluate the conformance control effectiveness of DCA microsphere. The result suggested that DCA microsphere has a hollow structure and many oligomer chain segment on the microsphere surface extending into the aqueous solution. The particle size of microsphere has strong stability. DCA microsphere can tolerate temperature up to 260 °C and still self-assemble in an oil-water system at high temperature and high salinity condition; DCA microsphere can self-assemble in the core into microspherical clusters used for conformance control of injected water, resulted in subsequent water flooding pressure increase of tenfolds and oil recovery enhancement of 9.53%; DCA microsphere exhibit effective conformance control of CO2 and control well CO2 channeling. CO2 displacement with conformance control using DCA microspheres has 15.8% higher oil recovery than direct CO2 displacement. DCA self-assembled microsphere can improve development of high–temperature, high-salinity heterogeneous reservoir and provide an aid for enhanced oil recovery.