Skip to main content

Fracture Propagation Driven by Fluid Outflow from a Low-Permeability Aquifer

Author(s): Gor, Gennady Yu; Stone, Howard A; Prévost, Jean H

To refer to this page use:
Abstract: Deep saline aquifers are promising geological reservoirs for CO2 sequestration if they do not leak. The absence of leakage is provided by the caprock integrity. However, CO2 injection operations may change the geomechanical stresses and cause fracturing of the caprock. We present a model for the propagation of a fracture in the caprock driven by the outflow of fluid from a low-permeability aquifer. We show that to describe the fracture propagation, it is necessary to solve the pressure diffusion problem in the aquifer. We solve the problem numerically for the two-dimensional domain and show that, after a relatively short time, the solution is close to that of one-dimensional problem, which can be solved analytically. We use the relations derived in the hydraulic fracture literature to relate the width of the fracture to its length and the flux into it, which allows us to obtain an analytical expression for the fracture length as a function of time. Using these results we predict the propagation of a hypothetical fracture at the In Salah CO2 injection site to be as fast as a typical hydraulic fracture. We also show that the hydrostatic and geostatic effects cause the increase of the driving force for the fracture propagation and, therefore, our solution serves as an estimate from below. Numerical estimates show that if a fracture appears, it is likely that it will become a pathway for CO2 leakage.
Publication Date: Oct-2013
Electronic Publication Date: 2-Aug-2013
Citation: Gor, Gennady Yu, Stone, Howard A, Prévost, Jean H. (2013). Fracture Propagation Driven by Fluid Outflow from a Low-Permeability Aquifer. Transport in Porous Media, 100 (1), 69 - 82. doi:10.1007/s11242-013-0205-3
DOI: doi:10.1007/s11242-013-0205-3
ISSN: 0169-3913
EISSN: 1573-1634
Pages: 69 - 82
Type of Material: Journal Article
Journal/Proceeding Title: Transport in Porous Media
Version: Author's manuscript

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.