四川地区水驱气藏开发探讨

A Discussion on Development of Water-drive Gas Reservoirs in Sichuan Province

通过收集前人水驱气藏开发的研究成果,对水驱气藏储层宏观和微观水侵机理进行分析,总结出了无水采气、带水自喷和排水采气三个阶段水驱气藏的不同开采措施。结合川西地区合兴场须家河组气藏和新场气田须二气藏实例,提出无水采气期取决于气井配产和裂缝角度,配产高或裂缝角度高,无水采气期短;对于裂缝-孔隙型水驱气藏开发,通过判断来水的大小和方向、控制气藏采气速度小于2%以及排水采气等方法提高最终采收率。

By collecting previous research results of water-drive gas reservoirs and analyzing their macro and micro mechanisms of water encroachment,different development measures are designed respectively for their three development periods of water-free gas recovery,gas flowing with water and water-discharge gas recovery.In combination with the examples of Xujiahe Formation reservoir in Hexingchang and Xu-2 reservoir in Xinchang field,the western Sichuan,it is proposed that the period of water-free gas recovery is dependent on allocation of gas well rates and fracture dips,and that the higher the allocation or the dip,the shorter the period of water-free gas recovery.For the fracture-porosity type of water-drive gas reservoirs,their final recovery efficiency can be increased by predicting water volume and direction,keeping gas production rate lower than 2% and using the method of water-discharge gas production.