Hydraulic Fracturing in Petroleum and Geothermal Reservoirs with Reference to the Utah FORGE Stimulation

Abstract

In this paper, we present some fundamental aspects of hydraulic fracture height growth in unconventional petroleum and geothermal reservoirs and describe the likely shape of the hydraulic fracture or the stimulated reservoir volume (SRV) resulting from the Stage 3 stimulation in the Utah FORGE. We use a 3D poroelastic DD method which considers planar and non-planar fracture propagation and interactions with natural fractures. We show that asymmetric height growth is to be expected in the stress regimes encountered in EGS and that height growth can be hindered by the rock mass discontinuities such as preexisting fractures, rock anisotropy, and lithological boundaries. In the case of Stage 3 in Utah FORGE, the data seems to suggest upward growth and interaction with natural fractures, leading to a moderately complex SRV consisting of a HF/NF network.