Pressure-Transient Characteristics of Hydraulically Fractured Horizontal Wells in Shale-Gas Reservoirs With Natural- and Rejuvenated-Fracture Networks

Abstract

Summary During the past few years, several studies have analyzed the pressure-transient responses of hydraulically fractured horizontal wells in shale-gas reservoirs. However, that research included simplified models that reflected natural and hydraulic fractures -only, unlike real shale reservoirs. To develop an accurate shale-gas model, this study considers the effects of rejuvenated fractures as well as natural and hydraulic fractures. Rejuvenated fractures, regarded as an important specificity in this paper, are revitalized natural fractures created by hydraulic fracturing. To analyze the pressure-transient characteristics and productivity of fractured horizontal wells in shale reservoirs, extensive numerical simulations have been conducted. This model considers the effects of natural- and rejuvenated-fracture permeability, matrix permeability, parameters of hydraulic fractures (e.g., width, height, and half-length), and the range of stimulated reservoir volume. Results show a clear distinction between existing models and the proposed model. In the proposed model, the boundary induced by the rejuvenated fractures generates pseudoboundary-dominated flow. This work expands our insight into the pressure-transient characteristics of a hydraulically fractured horizontal well in a shale-gas system.