ABSTRACT
This chapter discusses the key concepts of longwall gas prediction and proposes a preliminary prediction model for US mining conditions. Methane flow from the mined coalbed can be easily measured using periodic ventilation surveys. Gas emitted from mined coal being transported from the working areas is considered important only for the time that it contributes gas to the longwall panel area. The authors realize that the construction of this model was predicated on information contained in the 1iterature and from ongoing US Bureau of Mines’ field studies. A methane drainage system consisting of a gob borehole and underground cross-measure boreholes were used to supplement mine ventilation. A preliminary model of gas emissions for mining operations the Eastern United States has been developed. It is based upon methodology developed in Europe and incorporates a component of US subsidence theory.
