Study on the Plugging Performance of Bilayer-Coating Microspheres for In-Depth Conformance Control: Experimental Study and Mathematical Modeling

Microparticles covered with double-layered coatings are developed for in-depth conformance control to enhance oil recovery within heterogeneous reservoirs. The proposed bilayer-coating microspheres (BCMS) can transport deeply into a porous media, owing to the rigid outer layer designed for protecting the adhesive inner coating. The objective of the present work is to characterize the adhesion property and the plugging behavior of BCMS at reservoir temperature and fluid salinity. A series of static and coreflood tests are conducted. BCMS exhibits resistance to high temperature and high salinity and shows a great ability of deep transport into porous media. A mathematical model for the deep-bed filtration of BCMS in porous media is developed, accounting for the limited retention concentration and the velocity difference between the suspended particles and the carrier fluid. Modeling results match the measured pressure drop histories in coreflood tests with high accuracy, which validates the proposed analytical model. BCMS shows promising potential for application in production enhancement in hydrocarbon reservoirs.