Location

Rolla, Missouri

Session Dates

11 Jun 1999 - 17 Jun 1999

Keywords and Phrases

Abandoned Coal Mine; Golden Eagle; Coalbed Methane; Gas Production; Coal Mine Methane; Numerical Modeling; Overburden Relaxation; Gas Migration

Abstract

The abandoned Golden Eagle underground coal mine in Colorado contains gassy coals from which Stroud Oil Properties, Inc. (Stroud) has been recovering gas since 1996. The mine closed permanently in 1996, and during its operation drained methane from gob and ventilation boreholes. Stroud currently produces about 1.8 million cubic feet of near pipeline quality gas per day from six of these boreholes. Although the project has proven successful, gas recovery has been challenging because of low bottom hole pressure and variable borehole performance. Wellhead compressors are required to boost gas pressure for delivery to the main plant. Connecting additional boreholes to the gathering system often decreases production from existing production boreholes. Increasing gas removal has resulted in air leaks that lower gas quality. Stroud monitors the gas quality and blends any below-spec gas with its above-spec gas to ensure that the resulting product meets pipeline standards. This gas is then compressed for sale into a nearby pipeline. Overburden relaxation and finite difference modeling indicate that overlying coal seams and the coal remaining at the margins of the mined out workings contribute a significant amount of gas to the current production.

Department(s)

Mining Engineering

Meeting Name

8th U.S. Mine Ventilation Symposium

Publisher

University of Missouri--Rolla

Document Version

Final Version

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Jun 11th, 12:00 AM Jun 17th, 12:00 AM

Recovery of Methane from the Abandoned Golden Eagle Mine Property

Rolla, Missouri

The abandoned Golden Eagle underground coal mine in Colorado contains gassy coals from which Stroud Oil Properties, Inc. (Stroud) has been recovering gas since 1996. The mine closed permanently in 1996, and during its operation drained methane from gob and ventilation boreholes. Stroud currently produces about 1.8 million cubic feet of near pipeline quality gas per day from six of these boreholes. Although the project has proven successful, gas recovery has been challenging because of low bottom hole pressure and variable borehole performance. Wellhead compressors are required to boost gas pressure for delivery to the main plant. Connecting additional boreholes to the gathering system often decreases production from existing production boreholes. Increasing gas removal has resulted in air leaks that lower gas quality. Stroud monitors the gas quality and blends any below-spec gas with its above-spec gas to ensure that the resulting product meets pipeline standards. This gas is then compressed for sale into a nearby pipeline. Overburden relaxation and finite difference modeling indicate that overlying coal seams and the coal remaining at the margins of the mined out workings contribute a significant amount of gas to the current production.