临兴致密砂岩气藏直井缝网压裂可行性定量分析

The Possibility of Application of Network Fracturing in Vertical Wells for Tight Sand Gas Reservoir in Linxing Area

目前,临兴致密砂岩气藏主要采取直井压裂,但压后产量普遍达不到预期效果,对此,需要借鉴页岩气藏缝网压裂的成功经验,以探索直井缝网压裂是否可行。根据缝网形成的理论条件,对临兴致密砂岩气藏直井缝网压裂可行性进行了定量分析。分析了临兴致密砂岩气藏天然裂缝发育情况、地应力差异和岩石矿物组成等储层物理特征,认为该气藏具有实现缝网压裂的客观条件。同时,从水力压裂工艺方面,根据压裂诱导应力的计算结果,并与地层水平主应力差进行了对比,认为采取合理的缝内暂堵转向后,能够实现直井缝网压裂。上述2个方面的分析表明直井缝网压裂完全可行,这将为致密砂岩气藏的高效开发提供重要的技术支撑。

At present,vertical well fracturing is applied in tight sand gas reservoirs in Linxing Area,but the production effect is not ideal as anticipated.Therefore the successful experience of network fracturing in shale gas should be used for reference to explore the feasibility of network fracturing in vertical wells.According to the theory of network fracturing,and the reservoir physical and mechanical characteristics of Linxing dense sandstone gas reservoir,the feasibility of network fracturing is analyzed.The reservoir characteristics,such as natural fractures,stress difference and rock minerology,are analyzed quantitatively,it is considered that the gas reservoir has objective conditions for network fracturing.Meanwhile,from the technical aspect of hydraulic fracturing treatment,induced stress around fractures is calculated and compared with horizontal stress difference,it is confirmed that the network fracturing for vertical wells can be fulfilled by controlling temporary plugging diversion in fractures.From above analysis,it indicates that the network fracturing can be applied in vertical wells,and it provides important technical support for the development of Linxing gas reservoir in the future.