摘要
针对裂缝性低渗油藏多发育微裂缝、非均质性严重、水窜严重，常规调驱技术难以发挥有效作用的难题，以丙烯酰胺、2-丙烯酰胺-2甲基丙磺酸钠为共聚单体，以过硫酸铵引发剂，N，N-亚甲基双丙烯酰胺为化学交联剂，锂皂石为物理交联剂， Span80和Tween80为复合乳化剂，环己烷为油相，采用反相乳液聚合合成了一种耐温耐盐耐剪切的超细聚合物微球，并对其静态性能、封堵性能和提高采收率性能进行了评价。结果表明：超细聚合物微球为圆度很好的球形微米颗粒，初始平均粒径为8.5μm，膨胀性能良好，在20℃的模拟地层水中吸水48h后粒径能达到初始粒径的8倍左右。该微球具有较好的耐温、耐盐和耐剪切性能，平均封堵率为88.39%，平均提高采收率21.37%。长庆油田H392区块S井的矿场试验表明：调驱后注水井注入压力升高，井组含水率由93.5%下降至74.2%，产油量增加125%。图8表5参12
Abstract
The fractured low-permeability reservoirs are characteristic of numerous microcracks, serious heterogeneity and water channeling and the conventional flooding technology is difficult to play an effective role in the reservoir. In the paper, the superfine polymer microspheres were synthesized by inverse microemulsion polymerization, using Span80 and Tween80 as the emulsifiers, cyclohexane as the oil phase, ammonium persulfate as initiator, acrylamide and dimethyl acrylamide 2 sodium sulfonate as comonomers, N, N-methacrylamide as the chemical crosslinker and hectorite as the inorganic crosslinker. The static performance, plugging property and oil displacement efficiency were evaluated. The results showed that superfine polymer microspheres were a kind of spherical micron particles and the initial average particle size was 8.5μm. The superfine polymer microspheres had good swelling property and the particle size could reach 8 times of the initial size after 48 hours under the condition of simulated formation water at the temperature of 20℃. The superfine polymer microspheres also had good temperature-resistant, salt-resistant and shear-resistant properties. The plugging ratio was up to 88.39% and the enhancement of oil recovery reached up to 21.37%.The field experiments of the well S in Changqing Oilfeild H392 block indicated that the injection pressure rose after profile control and flooding, at the same time, the water content of well group fell from 93.5% to 74.2%, and daily fluid production rate increases by 125%.
论文详情