Abstract: Liaohe basin is one of domestic basins with coal, oil and gas resources. Its eastern sag contains coal bed that has characteristics of wide distribution, big thickness, low metamorphic grade and deep buried depth. It is significant to appraise the selected areas of coalbed methane in this sag for optimizing the exploratory areas and developing the conventional oil-gas and non-conventional coalbed methane resources. This paper chooses the coalbed cumulative thickness, gas content, gas saturation, reserves abundance of coalbed methane, coalbed continuity and cap rock condition as factors for assessment to develop a fuzzy comprehensive appraisement model adaptable to the studied area. The assessment result indicates that Rehetai-Sanjiepao area and Oulituozi area in the eastern sag are more favorable, the former is of big thickness, good continuity and shallow buried depth of coal bed, being as the most favorable area for coalbed methane exploration in this sag.

Key words: Liaohe basin, coalbed methane, exploration, evaluation, assessment