Pseudo-steady state analysis in fractured tight oil reservoirs

The log-log plots of normalized rate versus material balance time of two fractured horizontal wells completed in the Cardium and Bakken formations show three distinct regions of quarter, half and unit slopes. The first two regions can be interpreted by the existing semi-analytical models for bi-linear and linear transient flow. This study develops a pseudo-steady state (PSS) model for linear dual porosity reservoirs that describes the third region (unit slope). The application of this PSS model on field production data from two tight oil wells yields reasonable estimates of hydraulic fracture half-length and average matrix permeability. Also, this paper demonstrates how the proposed PSS analysis complements the transient linear analysis commonly used in industry.