Abstract: Distinctive CBM generation law determines that to generate CBM by adequate desorption needs longer production time. So it is difficult to obtain productivity data in a short time, affecting reserves submission. This paper used practical production data to probe into CBM generation law and discuss the characteristics and suitable conditions of various reserves estimating methods. On this basis, it proposed the application of analogy technology, and conducted analogy analysis from geological background, reservoir control and sufficient data recording, electrical property of coal bed, thickness of coal bed producing CBM, CBM content, reservoir property, and the ratio of critical desorption pressure to coal reservoir pressure, so as to comprehensively verify reserves parameters, recovery ratio, productivity potential, and reserves estimation, and make the results more rational, scientific, and accurate. The analogy technology has been applied well in practice and achieved good results.

Key words: analogy technology, CBM, CBM generation law, proven reserves, estimation method