Geohydrologic feasibility study of the Northern and Central Appalachian basin areas for the potential application of a production process patented by Jack W. McIntyre

摘要

Geraghty & Miller, Inc. of Midland, Texas conducted geologic and hydrologic feasibility studies of the potential applicability of a patented (US Patent Office No. 4,766,957) process developed by Jack W. McIntyre for the recovery of natural gas from coalbed/sand formations in the Northern and Central Appalachian basin areas. General research, based on a review of published literature from both public and private sources, indicates that the generally thin, but numerous coalbeds found in the greater Appalachian Basin area do exhibit some potential for the application of this patented process. Estimates of total gas reserves in-place (Gas Research Institute, July 1991) for coalbeds in the Central and Northern Appalachian Basin areas are 5 trillion cubic feet (TCF) and 61 TCF respectively. Produced waters associated with coal deposits in the greater Appalachian Basin area can be characterized on the basis of established but limited production of coalbed methane. Central Appalachian coals generally produce small quantities of water (less than 50 barrels of water per day for the average producing well) which is high in total dissolved solids (TDS), greater than 30,000 parts per million (ppM). The chemical quality of water produced from these coal seams represents a significant disposal challenge to the operators of methane-producing wells in the Central Appalachian Basin. By contrast, water associated with the production of coalbed methane in the Northern Appalachian Basin is generally fair to good quality, and daily production volumes are low. However, the relatively slow desorption of methane gas from Northern Appalachian coals may result in a greater net volume of produced water over the economic life of the well. The well operator must respond to long-term disposal needs.