The Role of thermo-poroelastic Effects on Transverse Fractures in the Utah FORGE Well 16-A

Abstract

Borehole image logs of the Utah FORGE Well 16A(78)-32 reveal several zones of closely spaced fractures transverse to the wellbore. In places they occur alongside the usual axial drilling-induced tensile fractures. In this study, a 3D fully coupled thermo-poroelastic model is used to investigate the origin of these fractures. The model uses the thermo-poroelastic fictitious stress boundary element method. The fundamental mechanisms associated with cooling/heating of the rock in the context of drilling in enhanced geothermal systems are first described, and then the role of temperature and pore pressure in inducing failures and fractures of the wellbore 16A(78)-32 (also referred to as 16A) is considered to ascertain the thermal nature of the observed fractures.