Unconventional resources such as coalbed methane will become progressively more important worldwide as population continues to grow at an unprecedented – and possibly unsustainable – rate.
As a result, coalbed methane and other unconventional resources undoubtedly will play an important role in supplying energy needs to both economically developed and emerging nations worldwide in the foreseeable future.
Preliminary worldwide coalbed methane resources are estimated to range between 5,800 and 24,215 Tcf (164 to 686 Tm3).
The largest potential resources, which also have the largest degree of uncertainty, are in the Former Soviet Union with 4,000 to 16,116 Tcf (113 to 456Tm3). North America ranges between 951 to 4,383 Tcf (27 to 124 Tm3), whereas South America and Europe range from 15 to 32 Tcf (42 to 91 Bm3) and 161 to 269 Tcf (4.6 to 7.6 Tm3), respectively. Africa ranges between 27 to 55 Tcf (760 to 1,557 Bm3), and the Middle East has no coalbed methane resources. The Asia Pacific region, which includes China, ranges from 646 to 3,360 Tcf (18 to 95 Tm3).
The rate of coalbed methane resource development within individual countries will be highly variable due to local economic factors and government energy priorities and policies.
The United States remains the world leader in coalbed gas exploration, booked reserves and production, although coalbed methane production is expanding internationally – particularly in Canada and Australia, and commercial production from India will undoubtedly accelerate in the near future.
In North America, there is commercial coalbed gas production or exploration in approximately 12 U.S. and several Canadian basins. Coalbed methane now represents 9 percent of 2006 dry-gas production and 9 percent of proved dry-gas reserves in the United States, with the major producing areas located in the San Juan, Powder River, Black Warrior, Raton, Central Appalachian and Uinta (Ferron and Book Cliffs) basins.
Other U.S. areas with significant exploration or production are the Cherokee, Arkoma, Illinois, Hanna, Gulf Coast and Greater Green River basins.
Annual coalbed methane production in the United States continues to increase, but not as rapidly as in previous years. The annual 2006 coalbed methane production was up slightly (1,758 Bcf; 49.8 Bm3) from 2005 coalbed methane production, which was 1,732 Bcf (49.0 Bm3) from an estimated 54,000 wells (figure 1).
Coalbed methane reserves decreased slightly from 19.892 Tcf (563.3 Bm3) in 2004 to 19.620 Tcf (555.6 Bm3) in 2006, representing a decrease of only 72 Bcf (7.7 Bm3) (figure 2).
There are two important facts to remember:
- Demand for natural gas in the United States is expected to increase 50 percent over the next 20 years as additional co-generation power plants and natural gas electric power generation facilities are constructed.
- The global demand for energy will continue to increase regardless of the current economic downturn as the middle classes of emerging economies such as China and India continue to expand.
Therefore, development of unconventional resources such as coalbed methane and gas shales worldwide is critical for economic stability and continued growth.
Enhanced coalbed methane recovery using sequestered greenhouse gases (carbon dioxide) and microbial conversion of the coal and sorbed gases into methane may represent a solution to solving energy and environmental objectives simultaneously and development of these technologies is accelerating to meet global demand.