Coalbed Methane Production Analysis – The Integration of Conventional and Unconventional Techniques for this Non-Conventional Reservoir

Boyer II, Charles M., S. Dana Weida, And Lawrence J. Pekot
Schlumberger Data and Consulting Services, Pittsburgh, PA

The commercial development of gas-charged coal seam reservoirs as sources of natural gas is a recent milestone in the world hydrocarbon industry – beginning initially in the United States, but growing rapidly in Canada, Australia, and in other countries around the world. Two key factors that led to the commercial development of coalbed methane were 1) the early recognition and understanding of coal’s unique reservoir properties; and 2) the development of completion and production practices specific to this unusual reservoir. Coupled with the development of this industry was the parallel development of specialized analytical and simulation–based tools – for the field, laboratory, and office – employed in understanding this different reservoir. Important to the continued development of this industry is the understanding of a well’s (or production field’s) past performance. Through this understanding, improved exploration, drilling, completion, and production performance can be achieved. However, the high production variability commonly exhibited by these naturally fractured reservoirs often necessitates the use of statistical and probabilistic methods, in addition to the more simplistic and conventional methods. The coupling of these analytical methods with higher-quality reservoir data results in a more definitive understanding of performance and provides for a means of assessing the technical and commercial success of a well or well field. This often leads to improved resource recovery, increased recoverable reserves, and enhanced commercial success for the operator. This presentation will address the tools and integration methods currently used in coalbed methane production analysis. In addition to the discussion of the analytical methods, case studies of using this process in coalbed methane plays around the world will be presented.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004