South Piney not the Powder River Basin

by Cat Urbigkit

Concerned citizens were told Monday night in Marbleton that the proposed South Piney coalbed methane development project is not comparable to CBM development in the Powder River Basin.

Bob Anderson of Anderson Environmental Consulting in Casper is the project coordinator for both Infinity Oil and Gas of Wyoming, Inc. and Williams Production RMT in the preparation of an environmental impact statement on the proposal to drill up to 210 wells in the South Piney area.

Anderson cited a recent Casper Star-Tribune article likening the South Piney development to coalbed methane development in the Powder River Basin.

"It is not," Anderson said.

One of the big issues associated with CBM development is what to do with the water that is produced during the development. According to the Bureau of Land Management's Mineral Occurrence and Development Potential Report, CBM occurs as a result of coalification - the process that turns plant material into coal. The methane generated in the coalification process can be stored in several ways: as free gas in pores and fractures of the coal; as a dissolved phase in interstitial water in the coal; or is absorbed onto the surface of the coal.

"Because most coals have abundant microfractures, or cleat, there is a large amount of surface area on which gas can be absorbed," the report stated. "This feature of gas storage allows coals to store a much higher volume of gas than conventional gas reservoirs.

"In order to extract the gas from the coal, it is necessary to lower the hydrostatic pressure in the coal," the report stated. "Lowering the pressure is accomplished by producing the water that is in the coal." This means pumping large amounts of water in the initial stages of development.

In the Powder River Basin, water is used on the surface, sometimes reportedly with detrimental effects.

Anderson noted that water produced in CBM development in the South Piney area is very high in total dissolved solids.

"The water will not be put on the ground," Anderson said. "The water cannot be put on the ground."

Instead, the water will be reinjected into deeper underground formations.

About 40 people attended Monday night's meeting, which was hosted by the BLM and took place at the Marbleton fire hall.

"This is not similar in any fashion with what's going on in the Powder River Basin," Anderson said. In South Piney, there will be only one well on a CBM well pad, and conventional drilling rigs will be used, not the water-well rigs used in the Powder River Basin, Anderson said.

Anderson also talked about the spacing pattern for the development, stating that most of the area would be subject to one well per 160 acres, or four wells per section, but in the common-interest area, there will be eight wells per section.

BLM's Bill Lanning said his agency might decide to include an alternative that would analyze 80-acre spacing as well. Two known alternatives that will be included in the EIS are the proposal set forth by the companies as well as a no-action alternative.

Anderson said, "The National Environmental Policy Act requires us to look at a reasonable range of alternatives in the document.

"This project is exploratory," Anderson said. "It remains exploratory." He said the development scenario of up to 200 wells "is based on the best expectations."

A development scenario had to be prepared for analysis, but Anderson said, "It is speculative with what's going to happen down the road."

The development potential remains unknown, company spokesmen said.

"To me, I'm an optimist, because I'm a geologist," said Williams petroleum geologist Paul Kovach of Lakewood, Colo.

Kovach said the EIS needed to cover the possibilities: "If you don't, there will be a price to be paid later, in delays."

"Is this Riley Ridge? No," Anderson said, "In a best-case scenario, it might compare to the Pinedale Anticline, I don't know."

There are currently seven CBM wells in the area, and three Frontier wells.

Company officials and Anderson explained that while Infinity owns the interest in the shallower Mesaverde formation, Williams controls the deeper Frontier formation, and Wold Oil Properties owns the deeper mineral rights, including the sour-gas Madison formation. Five sour-gas wells have been drilled in the area, have been filled with an inert gas and are waiting for the situation to improve to a point that economic recovery is viable.

"The wells should be in good shape for some definite period of time," Anderson said.

BLM Pinedale Field Manager Prill Mecham addressed how long the sour gas wells could sit without being put into production.

"The wells themselves have the capability to produce gas," Mecham said. She said the BLM requires companies to plug and abandon wells that are dry holes or that have reached the end of their production. That is not the case with the five sour gas wells, Mecham said. She said the BLM allows the company to leave the wells "in a safe, but inert state."

Members of the public identified several issues for the EIS to consider, including the possibility of underground coal fires once dewatering occurs, increased traffic in the area and protecting the natural beauty of the South Piney country.

The BLM is soliciting public comments and concerns during this initial scoping phase, but further opportunities for comment will come later as the EIS is developed. Comments should be sent by April 1 to South Piney EIS, BLM, Pinedale Field Office, P.O. Box 768, Pinedale, Wyo., 82941.