低渗透油藏压裂水平井裂缝优化研究

Fracture optimization for horizontal wells in low permeability reservoir

姜晶 李春兰 杨敏

JIANG Jing LI Chunlan YANG Min

中海石油基地集团采油技术服务公司渤海研究院，天津　300452 中国石油大学石油天然气工程学院，北京　102249 中石化胜利工程设计咨询公司北京分院，北京　102249

Bohai Research Institute of Oilfield Technology Services Company, CNOOC Oil Base Group, Tianjin 300452, China Faculty of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Sinopec Shengli Engineering Design Consulting Company, Beijing Branch, Beijing 102249, China

针对低渗透油藏压裂水平井裂缝参数难确定的问题，在某低渗透油藏概念模型的基础上，结合裂缝性低渗透油藏的实验研究，运用油藏数值模拟方法，对压裂水平井的裂缝参数包括裂缝方位、裂缝位置、裂缝条数和非均匀裂缝长度等影响因素进行了优化研究。研究结果表明，在概念模型的基础上，考虑直井注水水平井采油的井型组合时，水平采油井走向应垂直于最大主应力方向，且裂缝方位应平行于最大主应力；裂缝最优缝数为3条，且裂缝最优间距为水平井水平段长度的0.23～0.30倍；对于非均匀裂缝长度的3条裂缝，中间缝较长两端缝较短的部署方式为最优。通过本次数值模拟研究发现，低渗透油藏压裂水平井的裂缝参数确实存在最优情况，实际油田应根据不同的模型类型考虑优化各裂缝参数。

Since it was difficult to determine the fracture parameters of fractured horizontal wells in low permeability reservoir, on the basis of the concept model and experimental study, this paper used reservoir simulation method to optimize fracture parameters, including fracture azimuth，fracture position, fracture number and non-uniform fracture length. The results show that the horizontal oil well should be perpendicular to the direction of maximum principal stress and the fracture azimuth should be parallel to it when straight well floods and horizontal well produces. The optimal fracture number is three and optimum distance is 0.23~0.30 times of horizontal section length. For three cracks with non-uniform length, the deployment way middle fracture is longer is the best. Through this simulation study, we find that there are indeed optimal parameters in fractured horizontal wells of low-permeability reservoir. Optimization of fracture parameters should be considered according to different models in actual Oilfield.