利用特殊结构井提高小断块边底水油藏采收率

江苏油田安丰、宋家垛等复杂小断块边底水砂岩油藏的油藏规模小、含油带窄、含水上升快、停关井多、吨油操作成本高,使用常规井进行调整经济效益差。主控断层断面附近井网难以控制的构造高部位、井间地带及隔夹层遮挡下水驱难以波及到的地带,是小断块边底水砂岩油藏开发后期剩余油富集的主要区域。在精细油藏描述的基础上进行剩余油分布研究,根据剩余油分布部位与规模的不同,有针对性地采取侧钻井、水平井、多目标高精度定向井等特殊结构井,充分挖掘各类剩余油潜力,大大改善了油藏开发效果。利用特殊结构井进行调整挖潜,仅以19口常规井的投资达到了34口井的效果,实现了边际油藏的高效开发。图4表1参11

Enhancing oil recovery of edge and bottom water reservoirs in the small fault blocks by using special wells

The Anfeng and Songjiaduo Oilfield in the Jiangsu Oilfield consists of small complex fault block reservoirs with edge and bottom water, and the reservoirs are characterized by small reserve volume , narrow oil bearing area , rapid water - cutrise, many closed wells and high cost. The remaining oil mainly locates in the top of the structure along the trace of fault which is not controlled completely by well pattern, zone among wells, zone sheltered by interlayers. The develop'ment efficiency is improved by tapping the remaining oil with special wells such as side tracked wells, horizontal wells, and high accuracy directional wells with multi-targets. The cost for 19 common wells could have the effect of 34 wells and the marginal reservoirs are developed efficiently.