致密油藏体积压裂水平井产能评价

Analysis of the Hydraulic Fracturing Horizontal Well Productivity in Tght Oil Reservoir

致密油藏储层中天然裂缝发育,表现出双重介质特性。通过体积压裂产生的人工压裂缝,可以有效改变水平井筒附近的地应力分布,同时通过水力压裂缝为桥梁,来增强天然裂缝与水力裂缝、以及水平井筒之间的联系,从而改善致密油藏内的流体渗流。本文通过将致密油藏划分为水力压裂缝控制外区域、水力压裂缝控制区域、裂缝内区域等一共三个渗流区域,并假设线性流为主要流动特征,对体积压裂水平井的初始产能进行了分析。研究表明,随着水力压裂缝条数的增加,水平井的初始产能增加。考虑钻完井成本、油价及财税影响,水力压裂缝的条数具有最优值。

Natural fractures existed in tight oil reservoir which belonged to dual porosity reservoir.Artificial fractures were made by hydraulic fracturing which could effectively change the distribution of the terrestrial stress near the wellbore.These artificial fractures could also increase the linkage among natural fractures,the artificial fractures and horizontal wellbore to enhance the fluid flow in the tight oil reservoir.The paper divided the tight oil reservoir into three area which could be described as area outside of the control of the hydraulic fracture,area in the control of the control of the hydraulic fracture and area in the hydraulic fracture itself.The flowing character in the three areas was assumed as linear flow based on the actual production.The initial production of the hydraulic fracturing horizontal well was analyzed based on the foregoing research.The initial production of the hydraulic fracturing horizontal well increased with the increasing of the number of the artificial fractures.Especially,there existed a optimal number of the artificial fractures considering the drilling and completion cost,the oil price and the finance policy.