肇源南油田直井缝网压裂技术政策论证

致密油藏主要开发方式为缝网压裂,缝网压裂与常规压裂相比,其可行性和施工规模等都有很大的不同;因此缝网压裂技术政策的论证迫在眉睫。从岩石矿物成分、脆性指数、天然裂缝发育程度、压裂液及施工工艺等角度分析肇源南油田缝网压裂的可行性,通过Lord Kelvin点源函数分析直井底压力分布函数,进行直井与压裂井有效驱替系统论证。通过与启动压力梯度对比,确定了直井、压裂井的极限井距。论证肇源南直井缝网压裂规模,确定肇源南油田直井缝网横向波及宽度在60 m左右,单段施工规模必须大于1 500 m~3才能获得较好的改造效果。研究结果为缝网压裂在肇源南油田大面积推广提供了技术指导。

Vertical Well Network Fracturing Technique Policy Argument in ZhaoYuanNan Oilfield

Network fracturing is a key development scheme for low or ultra-low permeability reservoirs, which is different from conventional fracturing in feasibility analysis and fracturing scale optimization. So it is not effective to use conventional method to constitute network fracturing technique policy. In this paper, analyzed feasibility of network fracturing in ZhaoYuanNan oilfield from the rock mineral composition, the brittleness index, the natural fracture development degree and fracturing scale optimization. In addition, vertical well bottom pressure distribution function were established by Lord Kelvin point-source function, and the effectively demonstrate displacement system between vertical wells and fracturing Wells has been built. Compared with start-up pressure gradient, determined the limit of vertical well spacing is 45 m and the limit of the fractured well spacing is 120 m. Finely the study argued the vertical well fracturing scale in ZhaoYuanNan oil field, also made sure that the Lateral spread width is around 60 m, and that only when single segment construction scale is greater than 1500 m3, it could effect. The study results provided a new approach for fracturing optimization in low permeability reservoir.