Screen Flow Velocity Through A Cased Hole Gravel Pack Completion

The project was about finding a relationship between the velocity of fluid coming through the casing perforation and the velocity impinging on the well screen through a cased-hole gravel-pack completion. This led to finding how different size casings and screens can affect the fluid velocity significantly. We also wanted to prevent high velocities from hitting the screen to avoid serious damage. This relationship helped understand the importance of selecting the correct sizes for the completion to efficiently produce hydrocarbons. If the screen is too large, the gravel pack completion will not be as effective to reduce the velocity impinging on the well screen. On the contrary if the well screen is too small, it will be a very small pipe to produce hundreds of thousands of barrels of fluid. It will not be an efficient process. To find this relationship, we used COMSOL Multiphysics to simulate the experiments with the various sizes. We built the models, then we simulated the fluid traveling from a given perforation through a porous medium, which in this case was the gravel pack, to the well screen. From this, we were able to extract the average velocity values and compare the initial velocity and the velocity hitting the screen. We compared three casing sizes with various screen sizes for each. We were able find that as the thickness between the casing and the screen increases, the velocity decreases. The gravel pack is acting as a cushion zone to reduce velocity.