Optimization of well pattern in the development of coalbed methane through vertical wells

Optimization of well pattern in coalbed methane reservoir has very critical effect on its effective development through vertical wells.At present, in the form of areal development of several coalbed methane (CBM) reservoirs in China, the selection of vertical well pattern should be further investigated.For effective development and higher recovery, it is essential to optimize well pattern for coalbed methane reservoirs with different formation properties. In this work, for coalbed methane reservoirs with different face cleat permeability and heterogeneity coefficients, reservoir simulation is used to simulate the production with three well patterns including square, rectangle and rhombus, the reasonable range of face cleat permeability and heterogeneity coefficient is obtained for each well pattern.The simulation results indicate that square well pattern is not applicable to the development of coalbed methane reservoir, rectangle well pattern is appropriate to the development of coalbed methane reservoirs with medium, low or ultralow permeability, rhombus well pattern is suitable to the development of coalbed methane reservoirs with medium or high permeability.