Mining Publication: Investigation of Similarities Between Methane Drainage Potential of Utah's Sunnyside Coalbed and Eastern U.S. Coalbeds

• Coal mining
• Horizontal boreholes
• Methane

The Bureau of Mines has completed an investigation of the effectiveness of methane drainage in the lower Sunnyside coalbed at Kaiser Steel Corp. Sunnyside No. 1 Mine in Utah. Most of the previous attempts to drain methane gas using long horizontal holes were conducted in the eastern coal province. From the high degree of success realized in these efforts and the large body of knowledge gained from associated research, it seemed natural to extend the technology to western coalfields. Previous work had indicated that properties affecting gas drainage were variable in the sunnyside coalbed. In an attempt to characterize these properties, four degasification holes were drilled from the outside entries of an advancing section. The holes were drilled to lengths of 780, 1,680, 1,315, and 1,047 ft and produced initial flow rates of 50,000, 180,000, 340,000, and 240,000 ft3/d, respectively. A total of over 300 million ft3 of commercial-quality gas has been removed from the sunnyside coalbed. The four holes have reduced face emissions by 78 pct.