A 3D geomechanical model (again, consisting of stress magnitudes and orientation, pressure and mechanical properties) is often constructed at a field or reservoir scale, though a local, sector scale is also possible. The 3D geomechanical model is constructed using information from from regional or field-scale geology, seismic and reservoir data, as well as multiple well data sets, in order to account for structural complexity, lateral stress variations, and dynamic production/injection effects often not captured in a single 1D geomechanical model. 3D geomechanical models can be constructed at nearly any size from 10 – 200 km2 or more and from the surface to depths exceeding 7 kms; however, the size of a 3D model is constrained by computational horsepower (run times), memory (number of zones or elements), and the data to feed 10 to 20 million different zones or elements.

Numerical codes for 3D geomechanical models are largely ubiquitous, particularly FEM codes. OFG most often uses the code FLAC3D to build our  geomechanical models, but we are glad to use codes most suited for the client and their needs and their workflows. 

The development of most every 3D geomechanical model begins with the collection or development of 1D geomechanical models for the region. Preferably, the 1D geomechanical models help capture the spatial variability in the geomechanical parameters. The 3D model itself is constructed from a 3D structural representation of the region being evaluated including formation tops, faults and other structures. The 3D model domain is populated with the necessary calibrated geomechanics data from, for example, a pressure cube or seismic inversion. Model conditions (boundary conditions, solution methodology, etc) are set and an equilibrium simulation is developed. 3D model results are compared to 1D geomechanical model results and adjustments made in various 3D model inputs (input data, boundary conditions and structural feature corrections) until the 3D model results match the 1D geomechanical model results.