Research on Optimization of Horizontal Well Fracturing Parameters Based on Numerical Simulation

The deep coalbed methane in the SSL block is characterized by strong in situ stresses, elevated thermal conditions, and over-pressured reservoirs. These conditions lead to poor adaptability of vertical-well fracturing technology for CBM extraction. Due to the high investment cost of staged fracturing of horizontal wells, it is necessary to optimize the well type and fracturing process parameters before the experiment, in order to find the optimal horizontal section length and fracturing process parameters. On the basis of in-depth analysis of the characteristics of deep coalbed methane reservoirs, numerical simulation technology was used to carry out optimization research on segmented fracturing horizontal well technology from the aspects of horizontal section length, number of fracturing fractures, fracturing conductivity, fracturing length, and fracturing pattern. Research has shown that segmented fracturing of horizontal wells can communicate the coal seam cleavage fracture system, with a large drainage area and good pressure reduction and gas production effects. The optimal wellbore structure parameters for segmented fracturing of horizontal wells are a horizontal section length of 1000–1200 m, divided into 4–6 sections for fracturing, with a spacing of 120–150 m and uniform distribution of fractures. This well type has been applied in adjacent blocks and has shown good development benefits.