Inclusion of Fracture Skin in Duong’s Model of Rate-Decline Analysis for Fracture-Dominated Shale Reservoirs

Production forecast plays an important role in helping us make rational decisions in face of large uncertainties. Unconventional oil and gas production has followed an accelerated growth trajectory in the US oil and gas industry. Unconventional reservoirs vary significantly in their reservoir characteristics and production methodologies when compared to conventional reservoirs. The differences between conventional and unconventional reservoirs lead to significant duration of transient flow regimes for the unconventional reservoirs and this calls for using new methodologies for reserves forecast. Work by Valko and Lee (SPE 134231), and Duong (SPE 137748) are some of the most popular methods of decline curve analysis for unconventional reservoirs. This thesis presents a critique of Duong’s Method for rate decline analysis for fracture-dominated shale reservoir and proposes a more rigorous method for reserve forecast by including fracture skin in Duong’s model. The proposed new method can be used for unconventional oil and gas reservoirs.