Geological adaptability and optimization method of well structure for coalbed methane well: with Western Guizhou as an example

Large amount of coalbed methane (CBM) resource is distributed in Western Guizhou, and it is under conditions of coal seam groups. But the process of CBM exploration and development is lagging behind for the complex geological conditions. The used well structure is difficult to meet the need of construction in geologicaly complex area. Based on engineering practice and reservoir protection, combined with geological features and drilling difficulties, the geology adaptability of CBM well was analyzed; four stratum structure (including coal structure) conditions were also divided. Finally, four kinds of well structure design and eight working structure were put forward, and their adaptability and applicable scope were also analyzed. So the conclusion can provide a new thinking for CBM structure design in complex geological condition.