Mining Publication: Methane Drainage Study in the Sunnyside Coalbed, Utah
The Bureau of Mines is conducting research to determine the effectiveness of long holes in degasifying an area of the upper split of the lower Sunnyside coalbed at Kaiser SteelCompany Sunnyside No. 1 mine. These holes were drilled from the two outside entries of a section that was closed to mining because of excessive methane emissions. Two holes drilled to 430 and 450 feet produced initial gas flows of 160,000 and 127,000 cfd, respectively. Sixteen days after the completion of the second hole, the total gas production declined to just over 144,000 cfd. In 9 months of degasification, over 35 MMCF of commercial-quality gas has been removed from the coalbed. The combined gas flows declined to 106,000 cfd in the 9- month period. The two holes have reduced face emissions by about 40 pct.