Coal bed methane extraction
Work on to tap clean energy
Indian company launches feasibility study
FAISAL MAHMUD
Mining Associates Private Limited (MAPL), an Indian consulting company for the state-run Bangladesh Oil, Gas and Mineral Corporation (Petrobangla), has launched a feasibility study on extraction of coal bed methane (CBM) at Jamalganj coalfield in north Bangladesh.
CBM, a source of clean energy, can be found almost in any place where there is coal. It has the potential to help replace other diminishing hydrocarbon reserves, and recent developments in technology are playing a large part to harness this resource.
The general manager of Petrobangla, Md Akhtaruzzaman, told The Independent that the feasibility study will provide necessary information on CBM and the potential to generate power from it.
In July 2014, Petrobangla had floated an international tender to appoint a consultant. As per the tender, Petrobangla planned to initiate a feasibility study for the extraction of CBM in Jamalganj by engaging an internationally-reputed consulting firm.
Under the project, the intention was to drill three core wells. Laboratory testing of coal samples for a feasibility study of CBM at Jamalganj was also intended.
Nine foreign companies submitted proposals for the job, and six were approved at the 455th board meeting of Petrobangla. Finally this June, the Cabinet committee on purchase approved a proposal from the energy division to award the contract to the West Bengal-based MAPL. The company will receive Tk. 19.13 crore to carry out the job.
Sources said MAPL has mobilised its consultants for Petrobangla and is reviewing the existing documents and information on the coalfield.
The firm has delineated three sites in Joypurhat district in northern Bangladesh for drilling wells at the Jamalganj coalfield. The firm expects to start drilling and sampling of coal from the wells this month.
Once coal samples are obtained, drill holes will be geo-physically logged and coal samples will be analysed to find out their chemical composition and methane gas content. Also, the thickness of the coal seams, permeability, and the roof and bed conditions will be tested to assess whether the Jamalganj coalfield could offer commercial possibility for extraction of CBM.
Experts said CBM reservoirs are different from conventional reservoirs in many ways, but the basic differences relate to water production and gas storage mechanism. Hydrocarbon storage capacity in most oil and gas reservoirs is related to porosity because gas is trapped and stored in the pore systems of the matrix. Coal has moderate intrinsic porosity, but it can store up to six times more gas as compared to an equal volume of sandstone at similar pressure. The gas storage capacity is determined primarily by the coals rank.
The Jamalganj coalfield was discovered by a UN-Pakistan mineral survey team between 1962 and 1965 during a geological and geophysical survey in the Jamalganj-Jaipurhat area. With an estimated reserve of about 1.053 billion tonnes of coal, it is the deepest and largest coalfield in Bangladesh.
It has seven coal seams in depths ranging between 600 metres and 1,100 metres. The coal layer is assumed to be 40 metres wide. Compared to other coalfields in Bangladesh, the Jamalganj coalfield is considered to be too deep to be exploited by conventional underground or open pit mining as the coal is found at a depth of 150-500 metres.
