Sensitivity analysis of modeling parameters that affect the dual peaking behaviour in coalbed methane reservoirs
Abstract
Coalbed methane reservoir (CBM) performance is controlled by a complex set of
reservoir, geologic, completion and operational parameters and the inter-relationships
between those parameters. Therefore in order to understand and analyze CBM prospects,
it is necessary to understand the following; (1) the relative importance of each parameter,
(2) how they change under different constraints, and (3) what they mean as input
parameters to the simulator. CBM exhibits a number of obvious differences from
conventional gas reservoirs, one of which is in its modeling.
This thesis includes a sensitivity study that provides a fuller understanding of the
parameters involved in coalbed methane production, how coalbed methane reservoirs are
modeled and the effects of the various modeling parameters on its reservoir performance.
A dual porosity coalbed methane simulator is used to model primary production from a
single well coal seam, for a variety of coal properties for this work. Varying different
coal properties such as desorption time ( ÃÂ), initial gas adsorbed (Vi), fracture and matrix
permabilities (kf and km), fracture and matrix porosity ( ÃÂf
and ÃÂm), initial fracture and
matrix pressure (to enable modeling of saturated and undersaturated reservoirs), we have
approximated different types of coals. As part of the work, I will also investigate the modeling parameters that affect the dual
peaking behavior observed during production from coalbed methane reservoirs.
Generalized correlations, for a 2-D dimensional single well model are developed. The
predictive equations can be used to predict the magnitude and time of peak gas rate.
Subject
Coalbed MethaneCitation
Okeke, Amarachukwu Ngozi (2005). Sensitivity analysis of modeling parameters that affect the dual peaking behaviour in coalbed methane reservoirs. Master's thesis, Texas A&M University. Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /4196.