Analysis on main controlling factors and comprehensive evaluation of coalbed methane production capacity of Junlian Block

In order to accurately evaluate the coalbed methane production capacity in southern Sichuan region where is abundant of coalbed methane resources, r ain controlling factors of capacity were analyzed based onstable production period data from 65 producing wells in Julian Block. Coalbed methane comprehensive evalu ation system was established formed by seven subordinate indicators and two first grade indicators which include geological factor and fracturing effect. Weight factors of indicators were calculated by analogy method and grey correction analysis. Fuzzy optimization method based on two grades weight factors was applied for gas well C omprehensive evaluation. Evaluation results which had good agreement with actual productivities were verified by 110 stable producing wells. Wells with scores greater than85 were divided as high production wells, wells with scores between 75 and 85 were divided as middle yield wells, wells with scoresless than 75 had poor productio n effect.The comprehensive evaluation method also can be used for productivity prediction, favorable target area optimization, post evaluation of coalbed methane expl oitation and technology policy adjustment.