DefinePK

Abstract

An appropriate characterization of such unconventional resources as shale formations requires the availability of practical and accurate tools. Wells drilled in shale formations have to be hydraulically fractured for commercial production since the permeability is very low to ultralow reaching values in the order of nanodarcies. If these formations are tested by keeping constant the flow rate, then, there is a need of providing a pressure-transient interpretation technique which in this research follows the TDS philosophy. Contrary to transient-rate analysis where a third flow regime is observed during the transition period between linear and pseudosteady state which allows for the model identification, in transient-pressure analysis that period does not exist so identification of the permeability model cannot be obtained. Therefore, the developed equations for permeability, half-fracture length, skin factor and reservoir length are used without considering the model. The equations were successfully tested with synthetic examples.