Determination methods of well pattern and spacing for coalbed methane reservoir considering hydraulic fractures

Hydraulic fracturing is usually necessary in low permeability area for vertical CBM well, this means the well spacing is dependent on the fracture parameter.By comparing the production and recovery in different fracture length and conductivity, the effect of fracture on gas production is analyzed and the law is revealed.Based on evaluation of the well spacing in which the gas recovery is up to 50% for 15years, the relation of fracture and well spacing is studied.It shows that the well spacing can be enlarged as the length and conductivity of fracture become larger, especially in low permeability coal seam.Thus, the well spacing along fracture direction can be increased, rectangular or diamond patterns are good choice.Take a CBM reservoir in China for example, rectangular pattern 350m×300m or diamond pattern 700m×400m are recommended.