English abstract
In recent years, many high-producing carbonate reservoirs encountered significant solids
production associated with the reservoir fluids during depletion. The production of solid particles
from such rich reservoirs has caused concerning consequences ranging from the high operational
costs and safety hazards to dramatic drop in wells productivity. The onset of this problematic
phenomena is influenced by the stress distribution around the wellbore and the properties of the
reservoir rocks and fluids. Therefore, it is important to evaluate the potential of confronting solids
production during the life of the reservoir, and properly assess the need for any solids management
and control.
In this study, the onset of carbonate rocks geomechanical failure is estimated using a three
dimensional stability model. The stability model adopts the poroelastic constitutive law in
conjunction with the Mogi-Coulomb failure criterion. A sensitivity study is performed to identify
the model's critical inputs for Oman carbonates. It has been found that the stability model is
sensitive to the in-situ stresses followed by the rock geomechanical properties, that are cohesion
and friction angle for carbonate reservoirs. The impact of the intermediate principal stress on the
sensitivity was highlighted by comparing the sensitivity results using the three dimensional Mogi Coulomb failure criterion against the use of the classical Mohr-Coulomb failure criterion. It has
been observed that the intermediate principal stress significantly impacts carbonate solids
production prediction.
The adopted geomechanical approach in this study for carbonate shear failure during production
has been justified using three real field cases. The studied fields stress regimes are from all stress
regimes, that is, normal fault, strike slip and reverse fault. In all the different conditions, the applied
approach mimic carbonate fields at high level and encourages the utilization of the suggested
geomechanical model.
