Multi-Stage Fracturing Technology of Normally Pressured Shale Gas in Horizontal Wells in the Wulong Block

In-situ horizontal stress differences within shale gas reservoirs in the Wulong Block, southeast Chongqing are large.It is difficult to create complex volumetric fractures for high-angle and bedding fractures, to open low-angle fractures, and to change the fracture extention orientation.In addition, in-situ stress differences make economic development of normal pressure gas reservoir very difficult.Based on the analysis of technical difficulties of normal pressure shale gas in the Wulong Block, it is planned to increase the complexity of the fractures and so as to increase stimulated reservoir volume under high stress difference taking slick water as the fracturing fluid and perforation cluster spacing, perforation cluster length optimization as well as inter-cluster temporary plugging.To improve fractures conductivity and ensure that the fractures extend sufficiently in shale gas reservoirs, a multi-stage fracturing technology suitable for normal pressure shale gas in horizontal well of the Wulong Block has been developed by using continuous gravel filling and optimizing fracturing scale.The technology was successfully applied in Well Longye 2HF and it resulted in gas production of 9.4×10⁴ m³/d.Based on the fracturing data analysis of Well Longye 2HF, the application of this technology can improve fracture complexity, form network fractures, and increase individual-well production of normal pressure shale gas well, and realize economic development in normal pressure shale gas.