The Numerical Simulation of Hydraulic Transmission in the Process of Coalbed Methane (CBM) Wells Drainage in the South Block of Shizhuang

Abstract

Based on the data of CBM vertical well’s exploration and development in the south block of Shizhuang. This paper applies the method of comparison and adopts the software Visual Modflow4.2. The software simulated the 8th well whose original permeability and modified permeability is both poor and the groups of wells when draining for the rule of hydrostatic transmission. Results show that the relationship between original permeability and modified permeability determine the track of hydraulic transmission. When single well is draining, the hydraulic transmission can be seen as several concentric circles whose center is wellbore, but when the groups of wells are draining, regularity is the change of water level is not obvious because of the heterogeneity of coal reservoir. After draining for a long time, the water level difference between drained area and not drained area has appeared. The potential energy of underground water has a trend that overall downward, but did not form effective interference between the wells. Therefore, the original permeability and modified permeability become the key factor whether a region has high yield or not.