SCHATZEL, STEVEN J., FRED GARCIA, and FRANK E. McCALL, U.S. Bureau of Mines, Pittsburgh Research Center, Pittsburgh, PA
ABSTRACT: Methane Sources and Emissions on Two Longwall Panels of a Virginia Coal Mine
Methane gas emission monitoring was conducted on two longwall panels at a coal mine in the Central Appalachian basin. Monitoring was conducted to assess underground emissions from face, rib, and gob areas and at gob gas ventilation holes on the surface. The gob gas holes accounted for 71% of the total measured gas on panel 1 and 74% on panel 2. Panel 2 was adjacent to panel l and 13% larger in area. Panel 2 produced 69% more gas than panel 1.
Empirical modelling of methane emissions is suggested for gas source discrimination and as a predictive tool for the design of reliable gas removal systems. The U. S. Bureau of Mines developed an emissions model in the Northern Appalachian basin. None of the models performed adequately on the study panels. Efforts to improve modelling in domestic longwall mines should address the lateral gas movement, an expanded data base for model design, and more specific characteristics of methane drainage systems (i.e., completion techniques). The 69% increase in methane emissions on study panel 2 was probably due to: (1) differing gob gas borehole completion techniques, (2) differing rates of mining, (3) the additional gob gas borehole on panel 2, (4) the increase in panel dimensions and/or (5) nconsistent breakage characteristics of sandstone units in the Pocahontas coal group.
AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.