New Mexico’s Raton Basin Coalbed Methane Play
Brian S. Brister1 and Gretchen K. Hoffman2
1 Gunn Oil Company, Wichita Falls, Texas
2 New Mexico Bureau of Geology and Mineral Resources, Socorro, New Mexico
The Upper Cretaceous and Paleocene coal-bearing sequences of the Raton and Vermejo Formations comprise a coalbed methane resource in the Raton Basin of New Mexico and Colorado. The Vermejo Formation records the final regression of the North American Western Interior Seaway from northeastern New Mexico. The overlying nonmarine Raton Formation resulted from sedimentation shed from the rising Sangre de Cristo uplift. Both formations include numerous thin (average 2 feet) coal beds interbedded with sandstone and mudstone. Some coals locally exceed 5 feet in thickness, sufficient for numerous mining operations to produce coal throughout the basin for much of the last century. Recent underground mining proved to be uneconomic, in part due to high methane concentrations in the mine. Pennzoil began exploration drilling to evaluate the coalbed methane potential in the Vermejo Park area in the late 1980s. The lack of a pipeline into the area and low natural gas prices during early 1990s led Pennzoil to abandon the play. By 1999, construction of a pipeline extension into New Mexico from Colorado made development of this area economically viable. El Paso Raton LLC acquired Pennzoil’s former holdings and began coalbed methane development in 1999. The field has continually expanded on 160 acre per well spacing and has grown to more than 400 wells producing methane from less than 2000 feet depth. The field is remarkable in many respects including its coalbed reservoir conditions and challenging operating conditions in an environmentally sensitive area. The New Mexico Bureau of Geology has developed a database and geographic information system combining data from these new wells, coal mines data, and other published records. This work provides better resolution of basin structure, coal thickness and extent of the coal and coalbed methane resources and related geology of the southern Raton Basin.