Decline Curve Analysis for HP/HT Gas Wells: Theory and Applications

Abstract This work formalizes the Arps' D and b -parameters using a semi-analytical flow relation for a well produced at a constant bottomhole pressure in an HP/HT reservoir. The semi-analytical formulation is given in rate-time and rate-cumulative forms, and the definitions of the D and b-parameters are derived directly from the semi-analytical form. The rationale for this work is the over-dependence that many analysts place on the Arps' D and b-formulations (i.e., the original hyperbolic rate-time model), tuned to specific (i.e., constant) values of the D and b-parameters. The purpose of this paper is to establish guidelines for reserve estimations and for production extrapolations in general. The relations developed in this work can be applied to a number of different HP/HT tight gas and shale gas field cases in this work we validate our proposed procedure with a simulated example and we apply the methodology to a fractured gas well in an HP/HT reservoir. A comprehensive workflow is provided, as well as the relevant details/formulations of the analytical flow solution for HP/HT gas cases. We also provide decline curve plots/plotting functions to yield reserve estimates and production extrapolations.

Decline Curve Analysis for HP/HT Gas Wells: Theory and Applications Conference Paper