Coalbed Methane Symposium and Field Trip

Title: Coalbed Methane Symposium and Field Trip

Author: Ed Coalson and Jim Mullarkey

Publication: The Outcrop, August 2000, p. 1, 8

Over 460 participants from cities across the U.S. attended the 2000 Coalbed Methane (CBM) Seminar and Field Trip on June 20-21, offered jointly by the RMAG, GRI, and PTTC. Participants traveled from as far away as Pennsylvanian, and British Columbia. Speakers talked about current CBM projects, environmental and production issues, new technologies, and new plays. Interestingly, most speakers used computer-generated presentations rather than 35 mm slides.

The technical program consisted of nineteen half-hour oral presentations, including a keynote luncheon talk by John Curtis. Several papers detailed ongoing development efforts in established Rocky Mountain CBM projects and plays, including the Ferron play in Utah, the Raton coals, and the San Juan Basin play. Some fairly high-tech aspects of evaluating and exploiting established CBM deposits were discussed, including enhanced recovery, chemical stimulation, digital simulation, and other topics.

Dave Hill and co-authors Charles Nelson and Chuck Brandenburg (GRI) recapped the changing industry perception of CBM resources. While some had thought that the removal of tax credits for CBM production would cause the CBM industry to collapse, the opposite has happened. Operators are finding commercial production from coals previously thought to be too low in gas content to be commercial, e.g., Drunkard’s Wash Field and the Powder River Basin Fort Union play. The potential contribution of secondarily migrated (as opposed to purely adsorbed) gas is now fully appreciated. The San Juan Basin model of commercial CBM production is no longer the only one. Production from CBM completions is at an all-time high of 1.3 TCF per year from 8,000 wells (6,000 of them in the Rockies). This provides 6.5% of U. S. natural-gas production.
Marc Bustin ( University of British Columbia) pointed out that coal matrix porosities can be as high as 12%. Free gas in this porosity normally is lost during coring. Yet there are several instances where coals overproduce sorbed-gas volumetrics.

Interestingly, no entirely “new” Rocky Mountain plays were discussed. Yet companies are drilling and testing prospects across the Rockies, including the Hanna (Fort Union-equivalent) and Greater Green River (Williams Fork, Adaville) basins, as well as lesser-known areas. Apparently, early results on these plays still are considered proprietary.
Unlike last year’s symposium, which focused on Rocky Mountain CBM, this year’s symposium addressed play areas outside the Rockies. Symposium organizers Bruce Kelso, Keith Murray, Mark Choury, Ray Gorka, John Horne, Fred Mark, Rick Obernolte, and Steve Perlman invited speakers who discussed CBM in Oklahoma, Canada, the Illinois Basin, and the Gulf Coast. Rob Downey (Energy Ingenuity Company) discussed the new Tyonek play in the northern Cook Inlet, a play with apparent marketing limitations.

Three talks touched on litigation and environmental aspects of CBM. Tony Gorody showed inexpensive methods to establish pre-development baseline data. Tony indicated several reasons that litigation should be expected to follow CBM development. Paul Oldaker presented interesting data linking increased gas seep activity to increased precipitation or snowmelt in the outcrop area of the Fruitland coals near the Colorado New Mexico border. Rick Obernolte, with co-authors Kathy Wilkerson and Kathy Russell (Greystone), had an unusual presentation, speaking briefly on regulatory issues (permitting, environmental), then opening the floor to questions. A very lively discussion ensued, suggesting that this remains one of the more important aspects of CBM development. For illustration, the Wyoming BLM received almost 2500 APD’s for CBM wells in the first six months of 2000.

The field trip to the Raton Basin that followed the seminar filled up early. Chuck Pillmore (USGS) and Tom Hemborg (CGS) led 57 people to see exposures of the Trinidad, Vermejo, and Raton formations as well as operations in the Spanish Peak, Lorencito, and Long Canyon fields.

At the seminar, the RMAG offered for sale CD’s of the out-of-print 1988
and 1991 CBM guidebooks. A few copies remain. Call the RMAG office.

Companies sponsoring the event were Oso Energy Resources, Pennaco, Pense Brothers Drilling, Subsurface Consultants and Associates, Texaco E&P, Barrett Resources, Bearpaw Energy, Tom Brown Inc., Energy Laboratories, and Greystone Environmental. Rosemary Bauer and Sandi Pellissier handled logistics. Fourteen exhibitors also helped to make the event possible. John Horne and Kim Sandefeur helped with AV and CD­ROM equipment.

The content of the seminar suggests that geological evaluations of CBM plays “ahead of the bit” are only half of the story; successful through-­pipe testing also is necessary before a play can be demonstrated. The current approach seems to be to find an area with theoretically adequate gross coal thickness and gas content (and perhaps conventional trapping potential), then drill a pilot program of at least five wells in order to produce them long enough to demonstrate coal permeability, actual (not theoretical) gas-in-place, and dewatering potential.

Yet the seminar showed a continued strong interest in exploiting CBM resources, even in the face of uncertainty about the geological controls on production. Despite problems with water production, environmental regulations, and delayed initial production, the resource appears to be large, and the interest sustained. CBM wells in Wyoming alone were producing more than 150 MMCFD by the end of 1999. Kelso thinks that production from coalbed methane plays will continue to grow. We just don’t know to what level.”

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