Characteristics of CBM welll production and small geological structure controls in southern Yanchuan Block

According to the production data of 81 coalbed methane( CBM) production wells of southern Yanchuan CBM Block,the gas production characteristicof differ ent CBM wells were studied and the controlling factors of gas production were disscussed in the paper. The statistical results showed that there were 3 types wells divided into on the CBM well water production,which were high water production well, normal water production well and low water production well. Meanwhile ,the gas production of the last two CBM water production wells was ltter higher than the first type CBM well for single gas production well. The results also showed that the gas production of CB M well was influenced obviously by the small geological structure. Generaly,the gas production of CBM wells was higher when wells located far from the small fault with wa ter flowing or nearly to the small fold with well permeability. Otherwise,the gas production was limited. Thus,it was necessary to further research the small geological struct ure of the CBM block to find out the favorable target with higher gas production for the large scale exploitation.