Modelling of the Steam Chamber Growth During SAGD – Effects of Reservoir Heterogeneities on 4D Seismic

The performance of heavy-oil production by Steam-Assisted Gravity Drainage (SAGD) can be affected by near-well reservoir heterogeneities. However, as many factors interact during thermal production such as changes in oil viscosity, fluid saturations, pore pressure, stresses..., the monitoring of the steam chamber growth by 4D seismic data is not direct. An integrated workflow is presented. Based on a Canadian heavy oil field, the approach consists of three steps: 1/ the construction of an initial static model, 2/ the simulation of the thermal production of heavy oil with two coupled fluid-flow and geomechanical models, 3/ the production of synthetic seismic cubes at different stages of steam injection. The impacts of heterogeneities, production conditions and reservoir properties are evaluated for several production stages. Results show that heterogeneity distribution has a strong impact on mechanical results and then on the synthetic 4D seismic data. This study also highlights the impact of the shale mechanical behaviour on the steam chamber development during thermal production. Finally, this study demonstrates the added value of 4D seismic data in the context of steam-assisted heavy oil production.