ABSTRACT: Productivity forecast of Cyclic Steam Stimulation (CSS) coupled with reservoir geomechanics is essential for its effective application in heavy oil reservoirs. Unconsolidated and poorly cemented porous media related to CCS are subjected to processes such as a high temperature-pressure fluid injection and depletion that may induce stress and strain variations with irreversible changes in reservoir permeability. Therefore, considering reservoir permeability dependent on strain it is significant to analyze the impact of geomechanics, pressure and temperature front, and directional permeability models over the reservoir performance.
In this paper, strain-dependent permeability behavior is correlated with stress path and productivity in CSS using coupled reservoir flow and geomechanical behaviour modeling. This modeling process is implemented by using an in-house software and a commercial thermal simulator as CMG-STARS. Analyzed data include CSS operational parameters, stress path and a strain-dependent directional/volumetric permeability model. Results of oil production rates and permeability profiles show competitiveness between periods of dilation and compaction that modify pore structure of the porous media during injection and production stages; there is a significant influence of stress state, strain and injected energy on the permeability parameter. Approximations of this study might be used for feasibility assessment and optimization of CSS when integrating reservoir flow and geomechanical behaviour analysis in productivity forecast.
