A few cased-hole gas wells in Southeast Asia that were initially completed without any sand control are now producing sand, and the operators want to remediate these wells via standalone sand screen inside the production tubing. In these wells, the fluid (gas/sand) produced through the perforations would impinge rather directly on the screen, and erosion of the screens could be one of the major concerns. Therefore, a project was undertaken with the main objective of comparing the gas-erosion resistance and sand control efficiency of different types of sand screens via laboratory experiments.
The results demonstrate that the erosion resistance was dependent on the screen type, gas velocity, and particle size distribution of the abrasive media (sand). Poorly sorted sand with more fines exhibited more damage than well sorted uniform sand, emphasizing the importance of right sizing of sand to minimize screen damage. The erosion lifetime of the screens was ranked as: bead screen > mesh screen > wire-wrapped screen. The time to failure for the bead screen was at least 2.5 times higher than the premium mesh screen protected by a louvered shroud, while the wire wrap screens only lasted a fraction of time before losing its sand retention capacity. However, sand plugging was found to be a concern for the bead screen, suggesting that it must be behind another primary sand control such as gravel packing to protect it against plugging, and would be very effective fail-safe sand control device under such configuration. The louver design shroud protecting the mesh screen proved to be ideal for sand producing gas wells due to its moderate erosion resistance, low concerns due to sand plugging, and high sand control efficiency.