Permeability model of fractured rock with consideration of elastic‐plastic deformation

Abstract The evolution of rock permeability has been studied exhaustively, and a broad array of permeability models has been proposed. These models are normally derived under the assumption of elastic deformation when subjected to external stress. Under this assumption, these models define fracture permeability as a function of either gas pressure or effective stress. However, experimental observations indicate that rock fracture may experience unrecoverable deformation during the loading process. The goal of this study is to resolve this contradiction. In this study, derivation of fracture permeability correlation for elastoplastic contact of rough surfaces is presented. The proposed method for describing permeability evolution not only considers the topography of fracture surfaces but also and, more importantly, integrates the plastic deformation of rock fracture. Subsequently, the deformation and permeability change of shale sample containing a single rough‐walled fracture is experimentally investigated. The results show that the permeabilities obtained during the loading process are larger than the permeabilities obtained during the unloading process under the same stress conditions and that the fracture deformation cannot be fully recovered during the unloading process. At last, the proposed permeability model is applied to the experimental results and it is shown that the proposed model can predict the laboratory permeability data.

Abstract licence: CC BY

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.