The withdrawal of fluid from a reservoir results in a decline of the fluid
pressure followed by a consequent change in stress state in porous rocks.
Stress change may cause irreversible deformation and compaction. Such
compaction is generally the result of pore collapse and shear-enhanced compaction
caused by changes at a microscopic level in the porous rocks. Pore
collapse and shear-enhanced compaction are considered as potential problems
during reservoir production and drilling operations. The purpose of
this paper is to analyze the pore collapse and shear-enhanced compaction in
hydrocarbon reservoirs using coupled poro-elastoplasticity and permeability.
This coupling is implemented using a sequentially coupled scheme with a
fixed stress split. In this coupling, the poro-elastoplasticity analysis includes
the linear component based on Biot’s theory and the nonlinear component
based on a cap plasticity model. The fluid flow formulation is defined by
Darcy’s law, including nonlinear permeability model. The numerical approximation
is implemented using continuous finite element approximations for
rock deformation and mixed finite element approximation for pore pressure
and flux. Several numerical simulations are performed to indicate the onset of pore collapse and shear-enhanced compaction and evaluate their effects on
reservoir performance.