Energy Sources Part A-recovery Utilization and Environmental Effects, Vol.40, No.16, 1897-1909, 2018
Coalbed methane-produced water characteristics and insights from the Jharia coalfield in India
Coalbed methane (CBM) has emerged as one of India's important unconventional natural gas sources in the past decade. A number of environmental questions flank the commercial development of CBM and its holistic success, one of which is coproduced water management. Present work aims at assessing the geochemistry of co-produced water samples collected from CBM wells in Jharia coalfield, India. It is found that pH is within accepted limits and the bacterial contamination is minimal. The major ions present in the water samples are sodium and bicarbonate. It is observed that the produced water is generally influenced by a mix of evaporite dissolution and silicate weathering and the samples are oversaturated with respect to calcite and dolomite. Subsequently, an assessment of the energy requirements of membrane-based technologies (such as reverse osmosis and nanofiltration) has been performed. The estimated energy consumption is 0.45-1.40 kWh per cubic meter of water, for differing levels of sodium desired in treated water. Membrane-based methods seem to be effective for treatment of CBM co-produced water, and the selection of membranes can be based on the geochemistry and also the level of treatment desired.