封闭油藏不同含水期的井网方案优化

Optimization of well pattern design at different water-cut stage of closed reservoir

吴浩 姜汉桥 乔岩 孟凡乐 陈文滨 孟艳

中国石油大学（北京）油气资源与探测国家重点实验室，北京 102249

State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China

合理的井网设计对油藏开发具有重要意义。文中结合典型地质数据，建立了机理模型，对某封闭油藏不同含水期的合理开发方案进行论证。结果表明：开发初期，弹性开采和反九点开采的合理运用可延长无水采油期并减缓含水上升速度；中含水期，五点法井网含水率上升慢，采出程度比排状井网高2.9百分点；高含水期，将低潜力油井由五点井网加密为斜五点井网效果最佳；特高含水期，相对于直井，水平井更有利于开采边界剩余油，将边界附近的老井侧钻为水平井成本最低，采收率为62.92%，近似等于新钻水平井采收率；同时对水平段长度进行优化，得出合理水平段长度在230 m左右。

Reasonable well pattern design is of great significance to reservoir development. Based on the typical geological data, this paper establishes the mechanism model, and theoretically demonstrates the reasonable development scheme of a closed reservoir at each stage. The analysis shows that the reasonable use of elastic recovery and reverse nine point recovery can extend the period of anhydrous recovery and slow down the rising speed of water cut. In the middle water-cut oil production period, the water-cut of five-point well pattern increases slowly, and the recovery degree is 2.9 percentage points higher than that of the row well network. In the high water cut period, and the low potential oil wells should be adjusted from five-point pattern to an inclined five-point pattern. In the super high water cut period, the horizontal well is more favorable to the remaining oil at the production boundary than the vertical well. In terms of economic benefits, lateral drilling of old wells near the boundary is the lowest cost and the recovery rate is 62.92%, which is approximately equal to the recovery rate of new horizontal wells. At the same time, the length of the horizontal section is optimized, and the length of the reasonable horizontal section is around 230 m.

10.6056/dkyqt201903015