特低渗透油藏新型高效驱油剂的研究与应用——以延长油区杏子川油田王214试验区为例

The research and application of new effective oil displacement agent for ultra-low permeability reservoir-case study of Wang214 field in Xingzichuan oilfield of Yanchang

为解决特低渗透油藏油井产能低、含水上升快、产量递减快、采收率低的问题,通过室内实验对22种驱油剂进行了筛选,优化了适用于延长油区特低渗透油藏的高效驱油剂,其由11号非离子表面活性剂和15号生物表面活性剂按照体积比为1∶1复配而成。对该新型驱油剂进行了界面张力实验、抗盐与抗钙性能实验和岩心驱替实验,结果表明,其具有脱油效率高、界面张力低、抗盐与抗钙性能强、溶解性好、驱油效率高和成本低的优点,可以改变储层岩石润湿性,降低注入压力,较大幅度地提高原油采收率,改善特低渗透油藏开发效果。在延长油区杏子川油田王214试验区开展了矿场试验,至2012年8月油井见效率为90%,可以提高原油产量40%,区块累积增产油量为13555t,水驱曲线预测提高采收率6.08%,阶段投入产出比为1∶5.06。

The Yanchang oilfield is famous for its ultra-low permeability which is the main factor leading to low productivity, water cut rising fast, high capacity diminishing and low recovery. In order to solve these problems, a new agent has been selected through 22 kinds of agent by static de-oiling experiments, and agent interfacial tension experiments, and the salt experiments and core flow experiments, and its affects has been proved in a water injection zone of Wang214 field in Xingzichuan oilfield. The effects is obvious, for the crude oil production has been improved by 40%, and the oil recovery factor has been enhanced by 6.08%, the cumulative oil is 13 555 tons, and the input-output ratio is 1∶5.06. This displacing agent has a broad prospects in ultra-low permeability reservoirs for the features of high removal efficiency of oil, low interfacial tension, calcium salt tolerance performance, good solubility, high oil displacement efficiency and low cost, which can change the reservoir rock wettability, reduce the injecting pressure, enhance oil recovery, improve the production effects, and have a high percentage of input and output.