Induced stress changes during fluid production (or injection) from (or into) porous reservoirs may lead to hazards such as ground movement, fluid leakage and earthquakes. Published data compiled for several reservoirs indicate that horizontal stress changes between 0.14 and 0.84 times the magnitude of the pore pressure change have been measured. Given the magnitude of these stress changes, there is a clear need for models that predict pore pressure-induced stress changes. Several such models are summarized in this paper, and two new poroelastic models are presented. The first model is valid for a reservoir in a homogeneous half-space under plain strain conditions. The second model accounts for material property contrasts between the reservoir and surrounding rocks, and it can be used for reservoirs with depths that are similar to, or greater than, their lateral dimensions. Results for both models are charted in terms of dimensionless parameters, which facilitates their application to a broad range of reservoir conditions.
Induced stress change during fluid production from hydrocarbon reservoirs, and fluid injection for enhanced oil recovery or greenhouse gas sequestration, may lead to rock deformation, induced fracturing and fault reactivation, and consequently major risks such as ground movement and subsidence, well failures, reservoir fluid leakage and earthquakes. Due to these potential consequences, to predict the performance of a project prior to injection/production, it is essential to analyze and predict the induced stress perturbation due to reservoir pressure change. [Note: The reservoir temperature changes resulting from fluid injection can also induce stresses changes. Although these thermally-induced changes are in many ways analogous to pressure-induced changes - and they can be analyzed using methods very similar to those described in this paper - the current discussion will focus solely on pressureinduced changes.