Prediction of sanding in subsurface hydrocarbon reservoirs.

Abstract

Sand production in oil and gas wells can occur if the fluid velocity exceeds a
certain value. Due to drilling operations, the mechanical stresses can exceed the load bearing capacity of the rock. As the local stresses exceed certain level, a certain amount of rock is fractured into sand. Then, the sand is carried by the fluid through the wellbore depending on the flow rate. The amount of the solids can be less than a few grams per cubic meter of reservoir fluid or an essential amount. In the later case erosion of the rock and removing sufficient quantities of rock can occur. This can produce subsurface cavities which collapse and destroy the well.

When sanding is unavoidable it is necessary to estimate the characteristics of the process. Our aim was to generate a simple one-dimensional local model, which predicts the volume of sanding, the radius and the porosity of the yielded zone. Such model will help the company in the development of complex 3D models.