Calculation of abroad coalbed methane recoverable resources

In order to improve the precision in coalbed methane (CBM) exploration, geological analogy has been employed to evaluate CBM recoverable resources. Combining the basic parameters concerning CBM accumulation and reservoir formation and the relative statistics of CBM basins that could be acquired, the paper chooses 10 geological parameters controlling CBM recoverability as index of similarity in index block and forecast blocks, further, these geological parameters were quantified through the quantitative binary status approach. The recoverable coefficient in index block was calculated by adsorption isothermal curves, in view of practical situation of CBM development, the variation range of the CBM recoverable coefficients in forecast blocks was calculated by method of Monte-carlo. The results of the recoverable resources calculation in 10 CBM basins in North America, Russia-Ukraine-Kazakhstan and Australia, as the result of an evaluation from recoverable coefficient and geological reserves, indicated that Bowen Basin in Australia is higher in recoverable coefficient and larger in recoverable resources, showing good conditions for exploration and development.