Abstract: A method for modeling geomechanical subsurface pumped energy storage systems. In one embodiment, the method comprises applying a mechanical model developed for storage lens behavior during flowback (production), shut-in, and inflation (storage) stages. The model couples elastic deformation of the lens with Darcy-Weisbach fluid flow spanning the laminar to turbulent regimes, and includes an energy-based inlet boundary condition governing fluid flow rate out of the lens and up to the Earth's surface. The model also introduces pressure-dependent leakoff of fluid to the surrounding rock and the impact of intact rock bridges, which can arise from the lens having multiple petals or lobes, on lens compliance.

Abstract: Method and apparatus for forecasting curving of an hydraulic fracture to be initiated in the vicinity of one or more previously placed fractures along a bore hole. Physical parameters that will affect the growth of the hydraulic fracture are received by a dimensionless parameter deriver which derives a series of dimensionless parameters as groupings of the physical parameters that are selected as similarity parameters with respect to the shape of the hydraulic fracture path. The dimensionless parameters may comprise a dimensionless viscosity parameter, a dimensionless confining stress parameter, a coefficient of friction parameter and a dimensionless deviatoric stress parameter. A comparator sequentially compares the determined dimensionless parameters with predetermined threshold values to provide an indication as to possible curving of the hydraulic fracture.

Abstract: Method and apparatus for forecasting curving of an hydraulic fracture to be initiated in the vicinity of one or more previously placed fractures along a bore hole. Physical parameters that will affect the growth of the hydraulic fracture are received by a dimensionless parameter deriver which derives a series of dimensionless parameters as groupings of the physical parameters that are selected as similarity parameters with respect to the shape of the hydraulic fracture path. The dimensionless parameters may comprise a dimensionless viscosity parameter, a dimensionless confining stress parameter, a coefficient of friction parameter and a dimensionless deviatoric stress parameter. A comparator sequentially compares the determined dimensionless parameters with predetermined threshold values to provide an indication as to possible curving of the hydraulic fracture.