Production Data Analysis of Tight Hydrocarbon Reservoirs

Abstract

Tight reservoirs stimulated by multistage hydraulic fracturing are commonly described by a dual porosity model. This work hypothesizes that the production data of some fractured horizontal wells (which contain reactivated natural fractures) may also be described by a triple porosity model. We test this hypothesis by extending the existing triple porosity models to develop an analytical procedure for determining the reservoir parameters. We derive the simplified equations for different regions of the rate-time plot including linear and bilinear flow regions. The second part of this work focuses on analyzing production data of tight oil reservoirs. We plot rate-normalized pressure (RNP) versus material balance time (MBT) of two wells drilled in Cardium and Bakken formations. We observe a half-slope followed by a unit-slope in both cases. We hypothesize that the unit slope reflects the linear pseudosteady state (PSS) flow and develop a new model to analyze this boundary- dominated flow.