Effect analysis of borehole microseismic monitoring technology on shale gas fracturing in western Hubei

Abstract

Hydraulic fracturing technology is an important means of shale gas development, and microseismic monitoring is the key technology of fracturing effect evaluation. In this study, hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well (hereinafter referred to as EYY2HF well). The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System, which is the oldest stratum of horizontal shale gas wells in the world. A total of 4341 microseismic fracturing events were identified, and 23 fracturing stages of the well were defined. The fluctuation of the number of events showed a repeating “high-low” pattern, and the average energy of these events showed minimal differences. These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate. The main body of the fracture network extended from northwest to southeast, consistent with the interpretation of regional geological and seismic data. The stimulated rock volumes showed a linear increase with the increase of the fracturing stage. Some technological measures, such as quick lift displacement, quick lift sand ratio, and pump stop for secondary sand addition, were adopted during fracturing to increase the complexity of the fracture network. Microseismic fracture monitoring of the well achieved expected effects and guided real-time fracturing operations and fracturing effect evaluation.