From the pages of
Sublette Examiner
Volume 2, Number 45 - February 6, 2003
brought to you online by Pinedale Online

EIS: 210 coalbed methane wells in South Piney

by Cat Urbigkit

The Bureau of Land Management is beginning the process of preparing an environmental impact statement for the South Piney Natural Gas Development Project.

The EIS will analyze the impact of a proposal to drill by Infinity Oil and Gas of Wyoming, Inc., and Williams Production to drill from 100 to 210 coalbed methane wells in the South Piney area.

The BLM supplied the following background information: In July 2002, the companies submitted to the BLM a proposal to develop natural gas resources in the South Piney area. The total project area includes approximately 31,230 acres, of which approximately 15,440 acres are comprised of federal surface and mineral estate managed by BLM; 1,760 acres of State of Wyoming surface and minerals; and 14,030 acres of private surface ownership. Of the 14,030 acres of private surface ownership, 11,413 acres are "split estate'' (private surface/federal minerals) lands, with the remaining 2,617 acres of mineral estate in private ownership. Drilling is proposed in Townships 29 and 30 North, Range 114 West, 6th Principal Meridian. Access to the project area is from U.S. Highway 189, Wyoming Highway 350, Sublette County Road No. 23-142, and existing roads and two-track trails in the overall project area.

The companies propose to drill a minimum of 100 to a maximum of 210 natural gas wells within the overall project area. Infinity intends to drill wells to a maximum depth of approximately 5,000 feet to recover coalbed methane from the Upper Cretaceous Mesaverde Formation. Williams plans to drill wells to a maximum depth of 10,000 feet to recover natural gas from the Frontier Formation. The project area currently has five wells producing from coal seams in the Mesaverde Formation, one well currently producing from the Frontier Formation, one water disposal well, and four shut-in/temporarily abandoned deep Madison Formation gas wells. Williams drilled two additional Frontier Formation wells in Fall 2002.

The companies' proposal includes a drilling program based on a 160-acre spacing pattern (four wells per section) for both the Mesaverde and Frontier Formations. The companies have a joint interest in approximately 9,680 acres, and development in this area may result in the drilling of up to eight wells per section (four wells to the Mesaverde Formation and four wells to the Frontier Formation on a common or shared 160-acre spacing pattern). The remainder of the overall project area would see either Mesaverde or Frontier Formation development at a density of four wells per section.

The proposed gas field development would include the following associated structures and facilities:

1. Each well location would have a separator, dehydrator and produced water storage tanks. Infinity's Mesaverde Formation well locations would require a surface-pumping unit for dewatering the Mesaverde coals. Infinity anticipates the need to install up to 20 central production facilities (production pods) within the overall project area. These production facilities would collect and compress methane produced from wells in the well field, as well as collect and dispose of produced water.

2. An access road and buried gas and produced water lines would be constructed to each well location. Infinity's Mesaverde Formation wells would require a water disposal line for transmission of produced water to a central disposal facility. The produced water line would be placed in a common trench with the gas line.

3. Up to four natural gas transmission pipelines would be constructed and would tie in with an existing 4-inch diameter gas pipeline located east of the project area in Section 1, T29N, R114W.

During the projected life of the project, the existing 4-inch gas transmission line may need to be looped, or replaced, with a larger diameter line to accommodate the volume of gas produced from the area.

4. Infinity anticipates the installation of small reciprocating compressors at each of the individual Mesaverde Formation production pods within the well field for compression of methane produced from individual wells within the well field. Williams anticipates the need for one centralized compressor station for the compression of natural gas from the Frontier Formation.

5. A water disposal and injection well would be drilled at each of Infinity's centralized production pods for the subsurface disposal of water produced from the Mesaverde Formation. The produced water would be reinjected into a deep aquifer below the Mesaverde Formation.

The companies propose to drill an average of approximately 30 wells per year over a seven-year period. After consultation with U.S. Fish and Wildlife Service regarding threatened and endangered species, BLM may authorize additional delineation wells while the EIS is being prepared.

Results from additional delineation wells would assist the companies in determining the actual level of development to achieve Federal regulatory mandates of ultimate maximum recovery of federal mineral resources. Approval would be granted provided that the additional delineation wells would not result in potential significant impacts, and that BLM's final decision would not be compromised.

The BLM's notice last week of its intent to prepare an EIS begins the public participation process. The public scoping period is now open for 60 days, giving the public the opportunity identify issues, concerns and alternatives it would like to see addressed in the EIS.

In addition, a public scoping meeting will be held Monday, Feb. 24, at 6:30 p.m. in the Marbleton Firehall. The BLM will be soliciting representatives from affected interests and stakeholders to participate in the environmental analysis process.

All comments received at the public meeting or submitted in writing by mail will aid the BLM in identifying issues, developing a range of alternatives, and analyzing environmental impacts.

Comments should be submitted in writing to: Field Manager, BLM, Pinedale Field Office, 432 East Mill Street, P.O. Box 768, Pinedale, Wyo., 82941. For more information, contact Bill Lanning of the BLM at 307-367-5300.

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