Geomechanical modeling is playing an increasingly important role at Saudi Aramco during the earliest phases of field development planning. Field development decisions are aided by an accurate assessment of well design options that are closely tied to the existing geological and engineering data set using geomechanics technology.
Beginning at the reservoir, completion design in highly productive mechanically weak sandstone formations, and stronger – less productive formation intervals that must be fracture stimulated to produce, depend heavily on the accuracy of the Pre-Khuff geomechanical model that recognizes the complexity of this geological environment.1
The Pre-Khuff model finds formation layer stress and rock strength to be to extremely anisotropic, with stress magnitude and horizontal stress differences linked closely to formation layer stiffness, namely, static Young's modulus. The impact of interval stress and strength complexities to sanding potential, frac-pack design in sand-prone intervals, and hydraulic fracture stimulation design in stronger sanding-free intervals, is modeled using commercially available petrophysics and fracture stimulation design software. Perforation stability is modeled by customized and calibrated numerical modules developed by Saudi Aramco specialists and ChevronTexaco's Rock Mechanics Analysis group.
An overview of the Pre-Khuff geomechanical earth model is presented in the paper. Perforation stability forecasts, including the impact on perforation design and completion type selection is also presented with field performance results. Calibration to the geomechanical model for various fields and reservoir conditions are also illustrated.