超低渗透致密油藏水平井五点井网平面优化调整  

Plane optimization adjustment of horizontal-well＇s five-spot pattern in ultra-low permeability tight oil reservoirs

作　　者：杨承伟[1,2] 张建伍[1,2] 孙栋[1,2] 陈振波[1,2] 张英[1,2] 李书恒[1,2] 

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,710018 [2]低渗透油气田勘探开发国家工程实验室

出　　处：《低渗透油气田》2017年第1期63-68,83,共7页

摘　　要：鄂尔多斯盆地开发实践表明，五点水平井井网注水开发投产后初期递减大．有效驱替难以建立。通过数值模拟、流线模拟方法对目前纺锤形布缝五点水平井井网渗流场、饱和度场和压力场进行了评价。提出了水平段过长、中缝剩余油无法动用是影响开发效果主要因素。为此以水平井最小注采单元五点井网为基础，通过加密布缝矿场试验、势的叠加原理和启动压力梯度相结合的方法对井网和裂缝参数进行了优化，提出了新的调整方案。新方案增加了井网注采比。在水平段长度不变的情况下将原先的纺锤形布缝五点井网变为哑铃型布缝七点井网，同时将缝间距由70—80m优化调整到60m。新调整方案平衡了裂缝间单缝产量对比．实现了水平井裂缝与注水的合理匹配，降低了开发递减。The development practice in the Ordos Basin shows that after waterflooding in horizontal-well five-spot pattern is put into production in commission, the initial decline rate is relatively high and the effective displacement system is hard to be established. Numerical simulation and streamline simulation were applied to evaluate percolation field, saturation fieht and pressure field of present horizontal-well five-spot pattern with fusiform fissures arrangement. The evaluation results show that the overlong horizontal interval and cannot-be-used of the remaining oil in the middle fractures are the main factors affecting the development effect. On the basis of five-spot pattern of minimum injection-production unit in horizontal wells, by fiehl test of increasing the density of fractures arranged, and combining the principle of superposition of potentials and starting pressure gradient, the well pattern and fracture parameters were optimized, and a new adjustment plan was proposed. The new plan increases injection-production ratio of tile well pattern, changes the previous fusiform fissures- arrangement five- spot pattern into dumbbell- shaped fissures- arrangement seven- spot pattern, and decreases the fissure spacing from 70-80 m to optimized 60 m. This new adjustment plan balances individual-fissure＇ s production contrast, realizes the reasonable matching between fissures and waterflooding in horizontal wells, and reduces the decline rate.

关 键 词：致密油藏 水平井 五点井网 渗流场 流线模拟 最小注采单元 

分 类 号：TE243[石油与天然气工程—油气井工程]