A coupled Geomechanics-Hydrodynamic model for numerical prediction of sand production

In the oil industry, production of sand particles or detached sand clumps together with the formation fluids is called sand production. Sand production in oil wells is usually related to two fundamental mechanisms. The first mechanism is mechanical instability and degradation of the rock in the vicinity of the wellbore and the other is hydrodynamical instability due to flow induced drag force on the degraded material. In this paper, considering both the mechanisms, a new numerical model for predicting the onset of sanding as well as the amount of sanding is proposed. Implementation of the model in an explicitly coupled flow and deformation finite element program is described. The proposed model by removing the elements that have satisfied the sanding criteria as well as isolated rock chunks from reservoir can capture cavity evolution associated with sand production. The model is calibrated and validated against published results of a sanding experiment in a perforated reservoir rock. Results of the model in terms of initiation and amount of sanding are compares well with the experimental observations which suggests it can be used for sanding analysis of oil wells.