底水油藏侧向调驱提高采收率工艺优化

为了解决底水油藏油水接触面较大、优势通道发育、生产井见水过快导致产量急剧下降的难题，采用底水油藏可视化物理模型及驱替实验系统，设计交联聚合物侧向调驱实验方案，以采收率增值为评价指标，对侧向调驱施工参数进行优化。研究结果表明，交联聚合物注入量为0.3 PV时，单位体积侧向驱采收率增值达到133.93%；注入时机为含水率低于50%时，交联聚合物在油水界面处展布效果好，采收率增值高达55.17%。采用水平井注/水平井采方式，交联聚合物在油水界面处形成隔板半径更大，侧向驱采收率增幅40.18%；油水厚度比从0.5增大至2.0，交联聚合物的隔板作用越显著，采收率增值从26.86%增加至49.67%。研究证实了底水油藏应用侧向调驱的技术可行性及潜力，为底水油藏高效开发提供技术支持。

Optimization of the lateral flooding EOR technique of bottom-water reservoir

Bottom-water reservoirs are faced with the problem of fast production decline due to large oil-water contact area, significant development of dominant pathways and fast water breakthrough of production wells. To sovle this problem, this paper adopted the visual physical model and displacment experimental system of bottom-water reservoir and designed the experimental scheme of lateral flooding control of crosslinked polymer. Then, the construction parameters of lateral flooding control were optimized by taking the incremental recovery factor as the evaluation index. It is shown that when the injection volume of crosslinked polymer is 0.3 PV, the recovery factor of lateral flooding per volume is increased by 133.93%; and if the injection begins when the water cut is less than 50%, the distrbution of the crosslinked polymer at the oil-water contact is good and the recovery factor is increased by 55.17%. In the mode of injection/production by horizontal well, the radius of the barrier composed of crosslinked ploymer at the oil-water contact is larger and the recovery factor of lateral flooding is increased by 40.18%. When the oil/water layer thickenss ratio is increased from 0.5 to 2.0, the barrier effect of the crosslinked polymer at the oil-water contract gets more significant and the incremental recovery factor is increased from 26.86% to 49.67%. The research results verify the technical feasibility and potential of applying the lateral flooding control in bottom-water reserovirs and provide the techical support for the efficient develpoment of bottom-water reservoirs.