Study On Depth Profile Control Technology By Core-shell Polymeric Microspheres

The characteristic of the core-shell polymeric microspheres and its water shutoff technology is studied in this paper.By means of theories analysis and laboratory experiment, we awarenessed that the core-shell polymeric microspheres expanding when they met mith water and mingling with each other. Findings of research showed that the core of the polymeric microspheres expanding faster than the shell of the polymeric microspheres in water, then electron-positron microspheres were created. The microspheres with bipolarity can be adsorbed to pore wall of the formation. Under certain condition,the positive and negative charge drawed on mutually, the microspheres with bipolarity gradually became larger material structure by the string or the regiment so that this structure can decrease the porous channel cross-section area. If the adsorptive blocking happened at pore throat, then fluid diverted locally, subsequent fluid flowed into other infiltration passages. Utilizing the viscosity behavior of water soluble polymeric substance displacing oil and elastic behavior of the sphere, this article designed water shutoff technology making use of polymeric microspheres. The field experiment using polymeric microspheres to profile control and displace oil which began at Xinlicun oilfield in 2005 has already obtained success. This experiment indicated that using core-shell polymeric microspheres to control water and increase oil is an effective method .