The basis for creating a 3D geomechanical model is a structural geological model, the results of surface and borehole seismic processing, wellbore geomechanical models.
- Selection of reference and test wells. The results of 1D modeling are analyzed. Reference wells are selected, which will be used for calculations, and test wells - they will be used to calibrate the constructed model, the so-called "blind tests"
- Building a frame. The simulated volume is divided into layers, the necessary lateral detail is determined, and a single model frame is built. At this stage, it is necessary to achieve a balance between the detail of the mesh and the computer time spent on the calculation.
- Propagation of properties. The mechanical properties calculated in 1D reference well models apply to the entire simulated volume. To do this, the results of surface seismic inversion are used, attributes for parameter binding and property propagation algorithms are determined.
- Loading. The frame is completed to the required boundaries, on which the boundary values of the load are set.
- Calculation of pressures and stress-strain state. An iterative calculation of stresses and reservoir pressures is carried out.
- Convergence analysis. The calculation is checked for the convergence of the result with the values obtained in 1D - simulation of test wells. If the convergence is insufficient, the model is reconfigured and the calculation is performed again, until the specified discrepancy between the results of 1D and 3D calculations is reached. This is a time-consuming process that requires experience and often creativity. Convergence must be achieved both in terms of scalar values - pressures and rock properties, and vector values - values and directions of natural stresses.
