Design and Qualification of a New Erosion Resistant Sand Control Screen

Abstract

The issue of screen erosion is a complex problem that doesn't lend itself very easily to modeling and computer aided design, particularly when it comes to metal mesh screens. Interactions between solid and liquid (settling/suspension) and between the solids and the screen material (plugging) are complex and evolving over time due to wear and fluctuations associated with multiphase flow or other reservoir related changes over the life of the well. As a result, screen development is best performed using pilot testing to simulate downhole conditions and optimize the design. In that regard, the setting of standard performance tests is essential. A series of time lapse erosion tests performed on mesh screens recently highlighted the benefits of shielding the screen from the basepipe perforations to improve erosion resistance. This new feature provided several fold improvements in the mesh screen erosion resistance and was implemented in a novel screen design. It consists in placing a partially perforated inner shroud underneath a regular screen cartridge, with blind spots precisely located over the basepipe holes to prevent direct line of sight flow and reducing local velocity by diffusing flow across the entire screen area. An extended continuous erosion test was used to validate the design and qualify metal meshes, and mechanical testing as per the new API19ss standard for sand control screens was performed to qualify the new screen and demonstrate its reliability. Comparing the performance of the new screen design against similarly built screens confirmed that the addition of the new diffusion shroud does not adversely impact the mechanical performance of the screen while imparting improved erosion resistance to the screen.