Conclusions & References (Coalbed Methane)

Conclusions

COALBED_METHANE_221.jpg

Alaska has a significant portion of the coal resources in North America, and coal is by far the most abundant domestic energy resource available in the United States. Nevertheless, the occurrence of coal in an Alaskan sedimentary basin does not necessarily mean that subsurface coalbed gas can be economically produced. Subsurface coals need appropriate geologic and hydrologic characteristics to be CBM prospects. Lack of data on the geology, hydrology, subsurface water quality, coal quality, coal permeability, and gas content in most coal basins impedes assessing the coalbed methane potential in much of rural Alaska. However, there are areas that contain significant potential and could be explored and developed if the right incentives were available and plans developed. Detailed geologic field work and surface outcrop sampling is required in most areas before proceeding to the step of drill testing for gas content. The cost of obtaining coal gas content by drill coring is expensive, as much as $1 million per shallow drill hole as noted in the Fort Yukon experience. Additionally, the Fort Yukon project confirmed that the low-rank lignite coals present in a number of basins are not viable options for producing methane gas.

It is crucial that a proper assessment of all requisite geologic parameters be completed by qualified personnel before development decisions are made. A poorly conceived and executed CBM exploration program in rural Alaska could raise false expectations of the existence of a profitable resource where it is not geologically reasonable. Similarly, a poorly executed study could condemn a resource not properly assessed or evaluated for test sites. Like all energy resources, coalbed methane can be an excellent source of heat and power, but unique geologic conditions must be present, and rigorous scientific and economic evaluations need be performed before development can occur.


References

American Society of Testing Materials (ASTM), 1983, Standard classification of coal by rank: ASTM designation D388-82 in gaseous fuels, coal and coke, Philadelphia, 1983 Book of Standards, v. 5.05.

Ayers, W.B. 2002, Coalbed gas systems, resources, and production and a review of contrasting cases from the San Juan and Powder River Basins. AAPG Bulletin, V.86, No.11, PP.1853-1890.

Bustin, R.M., and Clarkson, C.R., 1998, Geological controls on coalbed methane reservoir capacity and gas content, International Journal of Coal Geology, Volume 38, Issues 1-2, Pages 3-26.

Merritt, R.D., and Hawley, C.C., 1986, Map of Alaska's coal resources: Alaska Division of Geological & Geophysical Surveys Special Report 37, 1 sheet, scale 1:2,500,000

Rural Alaska Coal bed Methane: Application of New Technologies to Explore and Produce Energy, Final Report, 2006, Work Performed for grant DE-FC26-01-NT41248 for the National Energy Technology Laboratory, Arctic Energy Office, US Department of Energy, 123 pages.

Saulsberry, J.L., Schafer, P.S. and Schraufnagel, R.A., eds., 1996, A Guide to Coalbed Methane Reservoir Engineering, Gas Research Institute Report GRI-94/0397, Chicago, Illinois, 342 pages.

Schraufnagel, R.A. 1993, Coal bed methane production, in B.E. Law and D.D. Rice, eds., Hydrocarbons from coal: AAPG studies in Geology 38, 341-359.

Scott, A. R., 1995, Application of burial history and coalification to coalbed methane producibility: in Geology and Hydrology of Coalbed Methane Producibility in the United States: Analogs for the World, (W.R. Kaiser, A.R. Scott, and R. Tyler eds.), InterGas ’95, The University of Alabama Continuing Education Workshop, pages 127-136.

Stach, E. Mackowsky, M-Th., Teichmuller, M. Taylor, G.H., Chandra, D., and Teischmuuler R., 1975, Stach’s textbook for coal petrology (2nd Ed.): Gebruder Borntraeger, Berlin, Stuttgart, 428 pages.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License