Heterogeneity Consideration and Upscaling of Elastic Properties in Coupled Geomechanical Flow Simulation of SAGD.

摘要

Geomechanical processes occurring during steam assisted gravity drainage (SAGD) thermal recovery influence petrophysical and rock mechanical properties of both reservoir and caprock formations. While geostatistical techniques provide multiple equiprobable geological realizations for petrophysical properties, rock mechanical properties are traditionally considered as homogenously in reservoir geomechanical simulations of the SAGD process. This research has shown that consideration of heterogeneous facies and rock mechanical properties will result in a larger range of possible outcomes, such as vertical displacement within the reservoir, than simulation models that adopt homogeneous facies and property distributions.;Upscaling of geological models and moving from high resolution geological models to coarse scale simulation models results in reduction of number of cells and accordingly reduction of computational cost. A new numerical technique for upscaling of elastic properties has been proposed. Two major advantages of the new geomechanical upscaling technique include the ability to consider transversely isotropic deformation and independence from coarse scale properties with respect to facies configuration.;The ranking and upscaling approaches were applied to a McMurray Formation field case study dataset. In comparison to upscaling techniques based on averaging, the numerical upscaling technique provided a reduction in simulation error. In addition, application of the upscaling technique to real field data confirmed the reduction in computational time for reservoir geomechanical simulations.;Typically, only a select number of geological realizations are selected for simulation. Randomly selecting geological realizations will not accurately represent uncertainty and they should be selected based on appropriate ranking criteria. A ranking criterion, which is in good correlation with expected elastic deformation of reservoir, has been developed in this research. The developed ranking technique is based on expected elastic deformation of each cell considered in numerical simulation of SAGD. Geometrical calibration parameters are adopted within the developed ranking technique.