PSI - Issue 6

I. Bazyrov et al. / Procedia Structural Integrity 6 (2017) 228–235 Author name / Structural Integrity Procedia 00 (2017) 000–000

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Figure 3. Algorithm of coupled hydro-geomechnical model construction

Grid creation (stage 1): The base for the geomechanical model was the hydrodynamic model, while the sectors of the hydrodynamic model were cut from the geological model. The initial geological model was characterized by a large number of cells with high vertical detail. To optimize the time for construction of the hydrodynamic model, the vertical resolution of the model was upscaled by reducing the number of layers. 3D geomechanical model construction (stage 2): A 3D geomechanical model was based on mechanical properties models of the key wells (1D models). Mechanical properties model is a numerical representation of rock and pore pressures, tectonic stresses, mechanical and strength rock properties. The calculation was based on drilling, well logging and geological data. The model was calibrated using mechanical properties tests, measurements (pore pressure and stresses) and drilling events. Hydrodynamic modeling (stage 3): The hydrodynamic model was built on the following time steps: before well exploitation, at the time of the first hydraulic fracturing and at the time of the second fracturing. Geomechanical modeling (stage 4): The finite element method was used to calculate the stress state. At each stage the model was checked by the results of 1D geomechanical modeling and well data (fracture closure pressure). Coupling: There are several approaches to hydro-geomechanical coupling. We used “one-way” coupling simulation, which considers that the information is transferred only in one way from a hydrodynamic simulator to geomechanics module. Post-Processing (stage 5): Within the post-processing the coupled model analysis is carried out. As a result, stresses, effective stresses, strain tensors, elastic moduli, pore pressure and displacement vectors were calculated. Figure 4 illustrates the stress alteration calculated by the hydro-geomechanical reservoir simulation.

Figure 4. Fracture orientation prediction for the well-candidates A and B