低幅度构造油田剩余油分布及稳油控水研究

STUDY ON REMAINING OIL DISTRIBUTION AND OIL PRODUCTION STABILIZING AND WATER CUT CONTROLLING OF OILFIELD WITH LOW RELIEF STRUCTURE

厄瓜多尔奥连特盆地中部T区块主力油田以低幅度构造为主，经过20年开发油田含水高达90％。通过油藏地质综合研究、开发动态跟踪分析和精细油藏数模研究，确定剩余油纵向主要分布在油层顶部，平面主要分布在井网稀疏区和局部构造高部位；利用水平井、加密斜井等开发技术，在剩余油开发中取得了良好效果。实践证明，水平井开发技术之所以在T块低幅度构造、高含水剩余油分布区具有非常显著的开发效果，是因为选择构造高部位，控制水平井井段轨迹尽量靠近油层顶部、远离油水界面以及采取合理采液强度等这些保证开发剩余油效果的关键技术的应用。

The main oilfields in Block T in the middle part of Oriente Basin in Ecuador have low relief as the dominant structure. Water cut is up to 90% after 20 years of development. Through comprehensive research on reservoir geology, dynamic analysis on development performance and fine numerical reservoir simulation, it is determined that remaining oil mainly distributes vertically on the top of reservoirs, and areally in sparse pattern areas and high positions of local structures. By using horizontal wells and infilling deviated wells, good effect is obtained in remaining oil development. Practice demonstrates that the causes of achievement of horizontal wells in Block T with low relief structure and high water cut and remaining oil distribution are： high structural positions are selected, horizontal section trajectories are controlled to be close to the top of reservoirs as far as possible and to be far away from oil- water contact, and reasonable fluid production intensity is used, ensuring application of key technologies for remaining oil development.