DefinePK

Abstract

It is well known that hydraulic fracturing can efficiently be applied to develop both low permeability and unconventional gas reservoir. Sometimes, the formations cannot be fully fractured and, then, the resulting fracture does not end up with infinite conductivity. Besides, for either tight or unconventional gas reservoir, a fracture network will be developed around the well during the fracturing process. This paper presents a semi-analytical model governing fluid flow in porous material for a finite-conductivity-fractured well in a composite gas reservoir, considering the fractures as either partially or fully penetrated. By nature, a fracture-network system around the well is always induced in tight gas formations, then, a composite model with inner dual-porosity to describe stimulated reservoir volume is established. Solutions for both constant-production rate and constant-bottom hole pressure are obtained by using the point-source function and the Laplace transformation techniques which are used along with the Stehfest algorithm to obtain the numerical inversion of the pressure and rate variables. The pressure-time and rate-time behaviors are then analyzed by careful observation to both transient-pressure and the rate-decline type curves. The models and type curves introduced in this work possess both theoretical and practical valuable application in the field of well test interpretation for the system under consideration.