Research On Large-scale Shale Gas Fracturing Technology

Deep shale gas reservoirs have high in-situ stress,large horizontal principal stress large difference,high reservoir temperature,complex bedding and natural fracture distribution,and strong rock plasticity,which leads to difficulty in fracture initiation and expansion of hydraulic fractures,degree of fracture complexity and transformation volume.Low,small fracture width,low conductivity and rapid decline greatly limit the economic and effective development of deep shale gas.The paper takes Weiyuan block and Yongchuan block as the research object,and analyzes the deep shale gas net fracturing of Weiyuan and Yongchuan Longmaxi Formation from the aspects of structural location,preservation conditions,reservoir properties,rock mechanics and in-situ stress characteristics.Through the series of deep shale gas hydraulic fracturing optimization design,such as fracturing optimization,perforation parameters,fracture parameters,well material,fracturing process parameters,etc.,the deep shale gas optimization design principle was established and the shale gas optimization design method was formed.Based on the fracability and fracturing optimization design of the reservoir,deep shale gas composite fracturing technical measures such as the multi-cluster perforation stress interference technology,the temporary plugging and fracturing technology and temporary plugging process technology are studied to improve the fracture complexity and fully transform the horizontal section into the overall goal.The research results have been applied in many wells in the block and achieved good results.