CoalBed Methane (CBM) Prospect in Tebulan Block, Sarawak- Malaysia

CoalBed Methane (CBM) is categorize as an unconventional hydrocarbon produced from coal seams. Before the mining of the coal, the combustible gas, “methane” needs to be produced entirely. Therefore, the methane production of the coal mine is to protect the coal mine from explosion. CBM is a clean burning fuel that helps to reduce air pollution. It also helps to reduce the need for conventional fossil fuel. This project focuses on the potential of Coal Bed Methane (CBM) in Tebulan Block coalfield, Sarawak - Malaysia. A block in the Balingian area is picked as the preliminary assessment area. The Liang formation (Balingian Coal) is lignite coal with a mean vitrinite reflectance of 0.32%, coal seam thickness of 0.33 to 29.69 ft. According to Geoscience and Mineral Department Malaysia, moisture content is between 12.9% to 18.7%, volatile matter ranges from 37.8% to 43.4% with fixed carbon ranges from 40.3% to 43.4%. The coal contains a very low ash content of 2.7% and a sulphur content of less than 1%. Four different core samples were used with porosity and permeability values from 1.58% to 5.12% and 0.15mD to 46.15mD. The gas storage capacity at different pressures was determined from an isothermal adsorption test based on the modified Boyle’s law. The result of the adsorption isotherm test showed that the maximum adsorbed methane in the coal is 374.62scf/ton at the maximum pressure of 1219.58 psia. The linear regression of Langmuir Volume and Langmuir pressure showed 714.29scf/ton and 1024.5psia respectively. The value of the maximum absorbed methane used in the calculation of the gas-in-place yields 15.207 Bscf over an area of 6.094km2. The result is compared to other similar coal mines showed a very good prospect to produce first CBM in Malaysia.