深层页岩气开发工程技术进展

Progress in engineering technologies for the development of deep shale gas

深层页岩气储层埋藏深、地应力大、岩石强度高、塑性强,导致钻井速度低、周期长,压裂复杂裂缝程度低,改造体积小,极大制约了深层页岩气的经济有效开发。鉴于此,针对我国特殊的页岩储层地质条件,围绕深层页岩气的有效开发重大工程技术难题,开展了基础理论方法探索、核心工具研发、液体材料体系开发以及关键工艺技术研究等攻关,并取得了重大技术进展,初步形成了3500~4500 m深层页岩气开发工程技术体系。在四川盆地涪陵江东和平桥区块、威荣、永川、丁山等地区应用了近80口井,钻井周期缩短了29.8%,测试产量达到(10~25)×104 m3/d,基本实现了深层页岩气的经济有效开发。

The pay zone of deep shale gas usually has high strength and strong plasticity due to the large burial depth and the high level of in-situ geostress.Such geological conditions result in not only a low rate of penetration(ROP)and long drilling period for the drilling engineering,but also a low complexity of the fracture network and a small stimulated reservoir volume(SRV)from the fracturing.These greatly limit the economical and effective development of deep shale gas.Concerning the major engineering technical problems of the effective development of deep shale gas,research focusing on basic theory and methods,essential tools,liquid material system,and key techniques was carried out considering the special geological conditions of shale gas in China.Through this technical research,great technology progress has been achieved,and the engineering technical system for deep shale gas at the depth of 3500~4500 m has initially formed.These technologies were adopted for nearly eighty wells in the Fuling Jiangdong and Pingqiao blocks in the Sichuan basin,Rongwei,Yongchuan,Dingshan and other areas.The drilling time decreased by 30%,and the test production reaches(10~25)×104 m3 per day,which basically realizes the economical and effective development of deep shale gas.