聚合物微球在延长油田特低渗油藏的研究与应用

Research and application of polymer microspheres in ultra-low permeability reservoirs of Yanchang oilfield

延长油田储层属于特低渗低孔、且部分裂缝发育,含水上升快,开采难度大。为此,通过实验搅拌法制备不同浓度的聚合物微球,从搅拌速度、反应温度、交联剂浓度、水解度等几个方面进行微球影响因素分析,并在此基础上开展封堵性能及驱油性能评价实验研究。实验结果表明,注入微球浓度为3 000 mg/L,注入倍数0.5 PV时,残余阻力系数和封堵率均较高,封堵能力较好,含水率最大下降幅度为28.8%,采收率提高22.7%。矿场试验应用表明,投入产出比1.00∶1.21,具有较好的调驱效果,对类似油藏开发提供了一定的借鉴意义。

Reservoir in Yanchang oilfield belongs to ultra-low permeability and low porosity reservoirs, and some fractures are well developed, the water cut rises quickly and there exists difficulty in exploitation. Therefore, by means of experimental agitation, polymer microspheres with different concentrations were prepared by experimental stirring method, the influencing factors of microspheres were analyzed from the aspects of stirring speed, reaction temperature, concentration of crosslinking agent and degree of hydrolysis. On this basis, the experimental study of plugging and flooding performance evaluation was carried out. The experimental results show that when the injected microsphere concentration is 3 000 mg/L and the injection multiple is 0.5 PV, the residual resistance coefficient and plugging rate are both high, and the plugging ability is good. The maximum reduction range of water content is 28.8%, and the recovery rate is increased by 22.7%. The field test application show that the input-output ratio is 1.00∶1.21, which has good profile modification and oil displacement and can be used for reference for similar reservoir development.