Hydraulic Fracture Growth in Transversely Isotropic Rocks
Brice Lecampion
École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
ABSTRACT: Anisotropic rocks are found everywhere in nature. In particular, at metric to decametric scales, sedimentary rocks exhibit a transverse isotropy associated with beddings. Lecampion discusses the impact of such type of anisotropy on the growth of fluid-driven fractures in the case of normal and strike-slip in-situ stress regimes where the fractures grow vertically, perpendicular to the horizontal layering. Lecampion also highlights important gaps in our knowledge of fracture properties in anisotropic rock, especially how the evolution of fracture energy between the so-called divider and arrester directions impact the ultimate shape of hydraulic fractures. Typical transverse isotropy encountered in practice leads to significant horizontal elongation and, thus, is an intrinsic mechanism for height containment of hydraulic fractures in the absence of in-situ stress contrast, and a possible explanation for why stronger height containment is observed compared to the predictions of isotropic models in practice.
