Sand production during the extrusion of hydrocarbons from geological formations: A review

In model development, some basic mechanisms have been recognized as responsible for sand production: shear and tensile failure, the critical pressure gradient and drawdown pressure, and erosion. Tensile failure occurs when the effective minimum principle stress applying on the rock mass reaches its tensile strength, and shear failure occurs when the applied stress on some planes in the wellbore area is higher than their bearing capacity. Reduction of reservoir pressure causes the effective hydrostatic stresses on it to be increased, breaking its pore structure, and the rock formation can be eroded internally and externally, producing sand by dynamic seepage drag forces. To date, both continuum and discrete element method (DEM) approaches have been considered in sand production models. Most approaches have been developed considering the hydro-mechanical or shear failure mechanisms and some have combined them.