水平井非连续化学驱技术及其先导试验应用

Horizontal well discontinuous chemical flooding technology and pilot test application

为改善高含水阶段水平井的开发效果,提出在水平井中应用非连续化学驱技术,以渤海A油田为例,通过室内实验和数值模拟,分别从实施流程、非连续体系设计和注入方案设计对该技术进行了深入研究。结果表明,在水驱转化学驱时,前段塞应用降吸附剂和剖面调整剂来实现提高注入能力和改善注入剖面的作用;在主段塞注入过程中,结合动态监测手段适时转换为次段塞(剖面调整剂)或辅段塞(增注剂)来降低剖面反转的风险和保障注入量,以保证化学驱全过程的长效和高效。该技术在渤海A油田1185砂体的水平井进行了矿场应用,非连续化学驱方案提高采收率10.4个百分点,相比常规化学驱提高采收率1.7个百分点,实施后井组高峰日增油量为95 m3/d,增幅达56%,含水率下降10%。研究结果表明,非连续化学驱技术通过动态监测与注入多类型药剂的有机结合,可在常规化学驱的基础上进一步提高采收率,建议推广应用于中高含水期的水平井。

The application of discontinuous chemical flooding technology is proposed herein to improve the development efficiency of horizontal wells at high water cut stages.Taking Bohai oilfield A as an example,this technology was studied through laboratory experiments and numerical simulations,focusing on the implementation process,discontinuous system design,and injection scheme design.The results indicate that the application of adsorption reducing agents and profile control agents in the front slug during the transition from water flooding to chemical flooding can improve the injectivity and the injection profile.During the main slug injection process,dynamic monitoring methods are used to timely convert to secondary slugs(profile control agents)or auxiliary slugs(injection enhancers)to reduce the risk of profile inversion and maintain the injection volume,ensuring long-term and efficient chemical flooding throughout the entire process.This technology has been applied in the horizontal well of sand body 1185 in Bohai oilfield A.The discontinuous chemical flooding scheme increased oil recovery by 10.4 percentage points,which is 1.7 percentage points higher than that of conventional chemical flooding.After the field implementation,the peak daily oil increment of the well group was 95 m3/d,an increase of 56%,and the water cut decreased by 10%.The research results indicate that discontinuous chemical flooding technology can further improve oil recovery on the basis of conventional chemical flooding by combining dynamic monitoring with the injection of multiple types of chemical agents.It is recommended to apply it to horizontal wells at medium and high water cut stages.