Sand Control Screen Erosion- When are you at Risk?

Abstract

Abstract For Stand Alone Screen (SAS) completions in open hole oil/gas wells, the sand control screen must retain the formation sand effectively, and provide a conduit for fluids to flow into a producing well. The screen's performance and service life depends on the well's operating conditions. A failure may occur while completing the well, or at some time during the well's operating life. The root cause of the screen failure is often difficult to determine with absolute accuracy. Often, it is determined that screen failure occurs due to a combination of plugging and erosion resulting in the loss of sand control. A comprehensive test program was undertaken over a two year period to evaluate erosion of different screen types for open hole completions. Completions were simulated for wire wrap and metal mesh sand screens commonly used in open hole completions. Configurations of each screen type were installed in a test fixture, and several tests were conducted at different velocities and sand concentrations. The sand was sized to pass through the screen with minimal plugging, which would simulate fines production over time in a producing well. The specific wear rates and per cent of rate loss were determined for each test. Micro photos were used in the analysis of the wear patterns, along with pre and post test measurements of the wire wrap slots or metal mesh pore sizes. This paper will describe the test methods used, the test results and lessons learned, and will describe a model that can be used to predict a screen's service life based on a given set of well conditions in a SAS open hole completion. Introduction Sand screens are often used to provide sand control in open hole completions. A common completion method is a stand alone screen (SAS) where by the screen aperture is sized to directly retain the formation sand. A typical completion is shown in Figure 1.