低渗透油藏自适应弱凝胶辅助氮气泡沫复合调驱体系

Composite profile control of self-adaption weak gel assisted nitrogen foam in low permeability reservoir

针对陕北裂缝性低渗透油藏物性差、非均质性严重及传统调剖效果差问题,研究自适应弱凝胶辅助氮气泡沫复合调驱技术中弱凝胶和氮气泡沫的配伍性,优化复合调驱体系的注入参数,评价复合调驱体系的驱油性能.结果表明:复合体系具较好复配性,室内优化凝胶段塞大小最优注入体积为0.3PV,泡沫最优注入体积为0.6PV,在设备允许的条件下尽量用小段塞、多轮次注入泡沫液;水驱高含水率后,优先注入凝胶段塞,再注入泡沫,调堵效果最好,复合调驱体系双管岩心驱替相对提高采收率幅度达43.69%;矿场试验井组含水率由80%下降至62%,单井日产油量由0.27m3增至0.70m3.复合调驱技术在GY油田具有较强适应性,大幅度提高油田采收率,可为同类油藏增油控水提供借鉴.

Aimed at characteristics of poor physical properties,serious heterogeneity and poor effect of traditional profile control in fractured low permeability reservoirs in northern Shanxi,research adaptive weak gel auxiliary nitrogen foam composite profile technology.The compatibility of weak gel with nitrogen foam was researched,injection parameters of composite profile system were optimized,and the flooding performance of composite profile system was also evaluated through in-door experiment.The results of in-door experiment showed that composite system has good complex effect,in-door experiment optimized the size of the gel slug optimal injection volume 0.3PV,foam optimal injection volume 0.6PV,under the conditions of the device allows,try to be short slug,multiple rounds injection the foam liquid.At high water cut stage,inject gel slug first,and then inject foam,plugging the best results.Double-barreled core displacement with composite profile system can relatively increase oil recovery rate of 43.69%.The water content of the field test well group decreased from 80%to 62%,the daily oil production increased from 0.27m3 to 0.70m3.The composite flooding technology has strong suitability for GY oil field and oil recovery can be greatly enhanced.This has a certain reference function of stabilizing oil output and controlling water content for similar reservoirs.