AAPG Studies in Geology No. 50,
(Section Title: The Ferron Coalbed Methane Play) Chapter 19: Coalbed Gas in the Ferron
Sandstone Member of the Mancos Shale: A Major Upper Cretaceous Play in Central Utah, by Scott
L. Montgomery, David E. Tabet, and Charles E. Barker, Pages 500 - 528
from:
AAPG Studies in Geology No. 50: Regional
to Wellbore Analog for Fluvial-Deltaic Reservoir Modeling: The Ferron Sandstone of Utah,
Edited by Thomas C. Chidsey, Jr., Roy D. Adams, and Thomas H. Morris
Copyright © 2004 by The American Association of Petroleum Geologists and the
Society of Exploration Geophysicists. All rights reserved.
The Ferron Coalbed Methane Play
Chapter 19:
Coalbed Gas in the Ferron Sandstone Member of the Mancos Shale:
A Major Upper Cretaceous Play in Central Utah
Scott L. Montgomery1, David E. Tabet2,
and Charles E. Barker3
1Petroleum Consultant, Seattle, Washington
2Utah Geological Survey, Salt Lake City, Utah
3U.S. Geological Survey, Denver, Colorado
South Main Street, Huntington,
Utah, circa 1900. Photograph used by permission, Utah State Historical Society, all rights
reserved.
End_Page 500------------------------
ABSTRACT
Drilling for coalbed gas in the Upper Cretaceous Ferron Sandstone of
central Utah during the 1990s has resulted in one of the most successful plays of this
kind. Development through the year 2003 has resulted in three fields, as well as a
potential fairway 6-10 mi (10-16 km) wide and 20-60 mi (32-96 km) long, corresponding to
shallow coal occurrence at depths from 1100-3500 ft (330-1060 m) in the Ferron, a sequence
of interbedded fluvial-deltaic sandstone, shale, and coal in the lower part of the
Cretaceous Mancos Shale. The major reservoirs in this interval consist of thin to
moderately thick (3-30 ft [1-10 m]) coalbeds of relatively low rank (high-volatile B
bituminous) and variable gas content, ranging from 100 scf/ton (3.0 cm3/g) or
less in the south to as high as 500 scf/ton (15.6 cm3/g) in the north. Other
lithologies also contain gas and contribute a minor portion of the produced gas.
Productive wells have averaged over 500 mcf/day and, after several years of production,
continue to typically show increases in gas production. In the major productive area,
Drunkards Wash unit, the first 33 producers averaged 974 mcf and 85 bbl of water per day
after five years of continuous production. Estimated ultimate recoverable reserves for
individual wells in this unit average about 1.9 bcf, with one standard deviation about
that mean of plus or minus 1.5 bcf.
