Coal Bed Methane
Coal bed methane is a form of natural gas that is trapped inside the coal matrix. Methane and water also line the fractures in the coal, called the cleats. The coal bed must be dewatered before the gas will flow. CBM is a significant part of Federal energy system in the USA, where the CBM development reached 1.3 trillion cubic feet annually.
CBM is produced by drilling wells into a coal seam. The coal bed is dewatered by pumping out the ground water. Gas follows the water and is separated at the top of the well.
Old Type – vertical CBM well
New horizontal and multi-lateral completion technology can dramatically boost recovery rates and reduce surface footprints. In all cases, this technology eliminates hundreds of thousands of vertical wells. Two primary technology needs now exist: improved under-balanced horizontal and multi-lateral drilling methods and more cost effective methods of drilling and guidance of horizontal wells. Today’s horizontal and multi-lateral drilling capability can offer much for CBM development. The anisotropic cleat permeability in most coals limit production from seams with low to average permeability, even though permeability is often low in only one orientation. Efficiently under-balanced drilled multi-laterals can open the marginal permeability plays with minimal to no formation damage.
LeMar offers full CBM project development in partnership with Core Laboratories (coal research and CBM process development), Scientific Drilling (horizontal multilayer drilling technology and equipment), and Gardes Energy (CBM project management).
LeMar and partners signed a joint venture with KazTransGas, to extract around 2 billion cubic meters of CBM annually on a 412-km2 territory at Karaganda Basin in Kazakhstan.
Wells typically produce gas for 7-10 years.
Although CBM can be cleaned and put into a natural gas pipeline, most coal deposits are not in close proximity to one. However, the developed gas can be processed at the deposit site by turning it into syngas and electricity, and, with further syngas processing, into fuels: naphtha and diesel.
Once CBM is removed from coal bed, the same equipment and wells can be used for coal gasification (UCG) to obtain syngas underground and then process it into fuels and electricity.