methane drainage

Methane drainage will be effected via 50 vertical wells to be drilled from the surface.

A gassy pit with a methane drainage system, but important producer of coking coal for the iron and steel industry, particularly Ravenscraig.

Such a licence is called a Methane Drainage Licence (MDL).

In addition, methane drainage is employed in Romania through in-mine wells drilled into the sealed gob (goaf) areas.

Proposed uses for the device included drilling shallow holes for mineral exploration, construction, underground gasification of coal, water and methane drainage.

Methane drainage will continue at this level for the next three to five years, but is expected to increase thereafter as mine geology deteriorates and face output rises.

Increasing the capacity of the methane drainage system at Mine B may be a prudent investment from an overall operations standpoint as well as from a safety perspective.

Methane Drainage -In addition to the methane generated by agricultural pursuits, methane is also emitted from coal mines and municipal waste dumps.

Unlike the gas produced in a more conventional mine methane drainage system, the gas produced by a virgin-coal demethanation system generally contains 95% or more methane.

The systems and infrastructure needed to produce coal safely ‘had not been completed’, whilst ventilation and methane drainage systems were unable to ‘cope with everything the company was trying to do’.

Methane extraction during this period is best effected by combining the use of wells sunk from the surface for methane drainage before mining begins with that of underground boreholes.

The Code of Practice (http://www.ilo.org/public/english/dialogue/sector/techmeet/meshcm06/code.pdf) is not a regulatory document, but rather a guidance document on best practices covering the full range of mining activities including methane drainage.

Under the right conditions, CMM recovery and use projects can be profitable, and accrued savings from avoided mine accidents could support additional capital expenditures for improved methane drainage and use.

The case studies will serve as a foundation for the development of best practices to improve mine safety through more effective methane drainage while also encouraging increased coal mine methane (CMM) utilization.

Australia and the Russian Federation commented that the case studies should include a business plan because it is necessary to make a business or economic case for methane drainage, and participants agreed with this position.

Appendix D of that report: "Methane Drainage from Coal Seams: Prospectivity of the Vasse Shelf, Southern Perth Basin" can be downloaded here in pdf format (1.4MB).

In an effort to improve longwall productivity, and address current safety issues associated with methane drainage, the CMTE has been investigating the applicability of high pressure waterjet drilling for gas drainage in underground mines.

Underground seam degassing is very inefficient in very deep workings with low permeability (conditions that are especially common in the Vorkuta deposit). That is because of the lack of time for methane drainage and the impossibility of boosting permeability by acting on the rock in the vicinity of workings.