Sanding Mechanism In Unconsolidated Sandstone

A serious of sand production often occurs in unconsolidated sandstone. It will bring a lot of troubles, such as the erosion or damage of pipeline and equipment, even leading casing failure and production reduction. Sand production, especially for heavy oil in unconsolidated sandstone, is often accompanied with foamy oil flow, in which a higher change of pressure and viscosity promotes sanding and deformation of rock skeleton. So the study of sanding mechanism and foamy oil flow in unconsolidated sandstone will have more significance in petroleum production.From the understanding of the geological characteristics and main mechanical properties of unconsolidated reservoir, the sanding mechanism, influence factors and foamy oil flow in unconsolidated sandstone have been studied in this paper. Firstly, a coupled geomechanical model between saturated single-phase flows and rock deformation was been developed in order to predict sand production.Then a simulating code for the coupled model has been devised by FEPG generator. Such influence factors during sanding as the rock strength, in-situ stress, production pressure drawdown, foamy oil flow were discussed respectively. A series of quantitative results about the sand volume, the concentration of sanding particle, the fraction of gas bubble have been presented. Finally a practical case was analyzed, and therefore, some basic data for sand control design in petroleum production were provided.