Author(s): Jin Xianglan, Xi’an Research Institute Company Limited, China Coal Technology and Engineering Group
Pages: 111-117
Year: 2015 Issue:  7
Journal: Coal Science and Technology
Keyword:  Ordos Basin; coalbed methane; free gas; resource quantity; geological significances;
Abstract: In order to study the gas content distribution features of the Jurassic low rank seam in Ordos Basin and the evaluation significances of the coal bed methane resources,a mathematical statistics and system theory method was applied to a study on the coal bed methane potential and the composition features,prediction of free gas in the coal and the calculation of the coal bed methane resource volume.The results showed that the coal bed methane potential in Ordos Basin was in middle grade of the national low rank coal bed methane potential,the desorption gas content was 0. 11 ~ 4. 33 m3/ t,the lost gas was about 20% of the total gas content,the residual gas was less than5% generally,the free gas was 11. 96% ~ 48. 16% of the total gas content,the percentage of the free gas was related to the coal porosity and preservation conditions. Based on a unit divided from the coal system as the unit of the coal bed methane evaluation,the total volume of the coal bend methane resource calculated with the volume method was 75 833. 62 × 108m3.