高含水复杂断块油田加密井井位智能优选方法及其应用

Well location intelligent optimization method and its application for infill wells in high water cut complex fault-block oilfields

高含水复杂断块油田地下剩余油高度分散、多层叠置、犬牙交错,对老油田二次开发新钻高效加密井的井位优选提出了苛刻的要求。通过研究复杂断块油藏剩余油分布特点,分析了井位优选的主要影响因素。利用复杂断块油田三维地质模型和油藏数值模拟后的多种三维场数据,以剩余可动油量为目标函数,以油井控制半径、经济极限井距和经济极限剩余可动油量为约束条件,建立了剩余可动油量计算模型,并给出了复杂断块油田单井控制范围和主要参数的计算方法,实现了直井、斜井井位的单因素智能优选。采用模糊综合评判方法综合考虑影响井位优化的多种因素,建立了多因素井位优选方法。通过编制相应的计算机软件,实现了复杂断块油田加密井井位智能优选的精细化和定量化。该方法应用于大港港西油田二区二次开发工程中,优选出的井位符合油藏动、静态认识,钻井实施后取得了良好的开发效果,为高含水复杂断块油田持续效益开发提供了技术支撑。

In the high water cut complex fault-block oilfields, the subsurface remaining oil is highly dispersed, and multi layers are superimposition and interlocked. Thus, it is very important for the well location optimization of new infill wells in mature oilfield redevelopment. The remaining oil distribution characteristics of complex fault-block reservoirs were illustrated and the main influence factors of well location optimization were analyzed. The calculation model of remaining movable oil volumes was established by fully using 3D geological model and multiple 3D field data of reservoir numerical simulation for complex fault-block oil wells, when taking the remaining movable oil volume as an objective function and the control radius of oil wells, economic limit well spacing and econom- ic limit remaining movable oil volumes as constraint conditions. Meanwhile, the calculation methods of single well control area and main parameters were given for complex fault-block oil wells, thus achieving the intelligent well location optimization for vertical wells and inclined wells. The method of multi-factor well location optimization were established using the fuzzy comprehensive evalu- ation method and comprehensively considering the multiple influencing factors of well location optimization. Based on these models and methods, computer program modules were developed to realize the fine and quantitative well location optimization of infill wells in complex fault-block oilfields. This method has been applied for mature oilfield redevelopment project in Block 2 of Dagang Gangxi oilfield to achieve the optimization of well locations consistent with dynamic and static understandings for reservoirs and good development results after well drilling, providing technical support for the redevelopment of high water cut complex fault-block oilfields.