Lsk. Fung et al., COUPLED GEOMECHANICAL-THERMAL SIMULATION FOR DEFORMING HEAVY-OIL RESERVOIRS, Journal of Canadian Petroleum Technology, 33(4), 1994, pp. 22-28
Citations number
21
Categorie Soggetti
Energy & Fuels","Engineering, Chemical","Engineering, Petroleum
The paper describes a novel numerical model for the solution of poro-e
lasto-plasticity and multiphase, thermal flow in unconsolidated heavy-
oil and oil-sand reservoirs. The elasto-plastic deformation is calcula
ted using a finite-element incremental plasticity model with Mohr-Coul
omb and Drucker-Prager as the yield criteria. This model is coupled wi
th CMG's thermal simulator STARS which is capable of handling many adv
anced thermal recovery processes. The geomechanical calculation is in
fact an effective stress analysis which solves a set of force balance
(equilibrium) equations based on total stresses. These are augmented b
y the elastic material behaviours, plastic yield criteria, plastic flo
w rule, work-hardening law, and the strain-displacement relationships.
Besides volumetric deformation, the solution gives the displacements
in each direction, stresses, and strain distribution in the reservoir.
The behaviours of reservoir multiphase flow and heat transfer process
es are most significantly affected by the volume change and the associ
ated permeability increase. The volume change is calculated by the pla
sticity model, whereas the permeability increase is related to the vol
ume change via tabular data. The prediction of shear failure region, t
he rotation of principal stress axis, and the reduction of effective s
tresses as a result of pore pressure increase, are all important pheno
mena affecting the placement of fluid and heat in the formation.