The Development of a Coal Bed Methane Resource

The development of a Coal Bed Methane resource is incremental in nature. The boundaries between exploration and move to commerciality are less distinct than in the case of conventional oil and gas and are likely to follow a 4 stage approach.

1. Initial Geoscience: Initial Geoscience is most likely to involve reviewing existing data for a particular PEDL (Petrolium Exploration Development Licence), which may be taken from historic mining records and British Geological Survey materials. It is possible, but unlikely, that seismic activity might form part of this phase.
2. Coring Boreholes: This activity is distinct in that a company may wish to core the target coal seams and perform analysis of the gas content of the coal to satisfy themselves that sufficient gas is present to warrant investing in a Pilot Production Test. Coring boreholes will usually be designed to provide information about the characteristics of the coal i.e. gas content, coal structure, quality and permeability. The activity will also allow further mapping of an area in terms of geological structure and sequence particular to the area in which the borehole is drilled.
3. Pilot Production Cluster for test purposes: Testing the ability of a coal seam to produce commercial volumes of gas cannot be achieved with the use of one borehole. Typically a number of boreholes will be drilled across a known isolated slab of coal. These boreholes are likely to be horizontal wells (wells that are drilled horizontally through the coal seam in order to open up the surface area of the coal to improve the production process). These wells will then be pumped as a collective, the intention to have a uniform drainage affect on the coal. Commercial production will be determined by the volume of gas being produced when the volume of water that is being produced has reached a plateau. Composite Energy have achieved a number of UK CBM wellbore completion firsts; drilling up-dip multi-lateral in-seam wellbores and drilling down-dip horizontal intersection wells.
4. Success Case Development: If the initial Pilot Test is successful then the addition of wells to the initial appraisal cluster in order to scale up the production and commerciality of an area are likely to occur. Each wellbore is expected to have a useful production life of up to 20 years.