Preparation of crosslinked polymer microsphere and plugging performance study

Water-soluble crosslinked polymer microspheres are prepared by inverse micro-emulsion polymerization, the plugging performance of the system prepared with waste water from Gudao crude oil is evaluated by plugging agent, the effect of various concentration and core permeability is studied. Oil-displacement experiments are proceeded with various concentration. The experimental results show that the crosslinked polymers microsphere can dissolve in oilfield wastewater without coagulation. Experiment of plugging performance shows that the crosslinked polymers microsphere can go into the inner of rock-core and easy to be adsorbed, retained, aggregated and bridging plugged in the throats of the core media. Tests of oil-displacement in man-made rock-core show that the crosslinked polymers microsphere dissolved in oil-field wastewater has good effect on EOR and can enhance the recovery rate of emulating oil by 14%~15%, high concentration can only enhance the oil-displacement velocity.