高含水期点坝水平井挖潜适应性界限研究

Study on the Adaptability Limits of Point Bar Potential Tapping by Horizontal Well at High Water Cut Stage

利用孤岛油田Ng4砂组地质及动态数据,对点坝内部侧积夹层进行定量化描述,建立了一系列反映点坝内部构型的三维典型精细地质模型,结合水平井经济极限产量,以不同注采条件下的点坝剩余油分布模式为基础,应用油藏工程以及数值模拟方法,对高含水期点坝水平井挖潜适应性界限进行了研究。研究结果表明,顺侧积夹层注水开发时,侧积夹层渗透率小于12 mD、倾角小于7°、延伸比例大于0.46、间距小于60 m时,适合水平井部署水平井挖潜;逆侧积夹层注水开发时,侧积夹层渗透率小于30 mD、倾角小于11°、延伸比例大于0.33、间距小于90 m时,适合水平井进行挖潜。这将为高含水期点坝储层中水平井部署提供一定的理论指导。

Combined with geological and production performance data in 4 sand group of upper Ng in Gudao Oilfield, the three- dimensional typical model reflecting reservoir architecture of point bar is set up according to quantitative description of lateral accretion interbed in point bar. Based on economic limit production of horizontal well, the methods of reservoir engineering and numerical simulation are used to analyze the adaptability limits of point bar potential tapping by horizontal well at high water cut stage on the basis of distribution modes of remaining oil under different injection-production patterns in point bar. The result shows that when the dip direction of interbed is consistent with water injection, and permeability of interbed is less than 12 mD, dip angle is lower than 7°vertical extension length / reservoir thickness more than 0.46 and horizontal spacing less than 60 m, it is time to prepare for tapping the potential of horizontal wells. When the dip direction ofinterbed is opposite to water injection, and the adaptability limits become 30 mD, 11°, 0.33 and 90 m respectively, it is time to carry out potential tapping. Such results provide a certain theoretical guidance for application of horizontal wells in point bar at high water cut stage.