Tedesco, Steven1, Trent W. Green2, Stephen R. Wolfe2
(1) Atoka Coal Labs, Englewood, CO
(2) Pinnacle Technologies, Englewood, CO
ABSTRACT: Pilot Tests In The Illinois And Western Interior Basins To Determine Commercial Productivity From Pennsylvanian Aged Coals
Coalbed methane production is viewed as an attractive source for the growing US natural gas demand. Undeveloped resources of coalbed methane in the United States have been estimated at 60 Tcf. A majority of the coal in the USA is accessible at shallow depths, making well drilling and completion inexpensive. Finding costs are also low since methane occurs in coal deposits, and the location of the Nation’s coal resources are well known.
Millions of acres of potential coalbed methane gas production identified in the Illinois and Western Interior Basins and depths vary from 300 to 2,800 feet in depth, vary from 0,3 to 2 meters, are High Volatile C to Medium Volatile in rank and are of Middle to Upper Pennsylvanian in Age. The coal seams have gas contents varying from 5 to 325 scf per ton. Permeability measurements range from >0.1 mD to as high as 250 mD.
The primary purpose of a pilot test program is to determine gas deliverability potential and initial water production. Well spacing, time to dewater, and ultimately time to reach maximum gas production is crucial to overall project development economics. Secondarily, the pilot programs are designed to confirm gas contents and permeability estimates obtained from initial data wells.
The pilot wells are placed in such a way to maximize well-to-well interference during a reasonably short production test period (4 to 6 months). This paper presents the initial results of several ongoing pilot projects in both basins. Parameters such as full-field well spacing, water disposal requirements and facilities, artificial lift, gas deliverability, and ultimate recoveries can be estimated and asset development economics determined.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.