One-way coupled reservoir-geomechanical modeling of the lost hills oil field, California

We describe coupled reservoir-geomechanical modeling of production at the Lost Hills oil field. We first review a database that was developed to discern the depth distribution of casing damage and to motivate model development. We then describe the development of constitutive models for the overburden formations, reservoir formations, and underlying strata. 3D reservoir fluid flow and geomechanical models that cover portions of Sections 4, 5, 32, and 33 were developed. Black oil reservoir simulations were performed that included 229 wells and modeled 17 years of primary production and waterflooding. The time-dependent reservoir pressures were then used as input to non-linear finite element geomechanical simulations. The simulations predict surface subsidence and shearing displacements in the subsurface that can result in well casing damage. Multiple simulations were performed to assess sensitivity to the initial stress state and to the friction coefficient at the contact surfaces that are used to model the behavior of thin claystones.