Measurement of coalbed gas content of Indian coalfields: a statistical approach

Sixty coal samples from different Indian coal fields were collected and characterised to analyse the gas content, petrography and composition. The gas content of coal samples was directly determined using a canister desorption test and statistically correlated with various parameters using regression analyses. The newly developed correlations are based on Langmuir, Ryan, and Kim correlations and modified to fit the data best. The gas content was observed to be a strong function of the proximate parameters i.e. fixed carbon, volatile matter, moisture content, and ash content as resulted from regression analyses. Vitrinite reflectance was also found to affect the gas content of the coal seams. To check the significance of calculated results, a paired-samples t-tests have been performed for 42 coal samples. Results confirmed the validity of the New Langmuir and New Ryan correlations with good confidence, i.e., t = -2.1, p < .05.