A major issue for deepwater high rate wells is delivering completion reliability and performance that ensures well life sand control and operational simplicity. Multi-path screen systems are designed to ensure placement of the annular gravel pack in frac pack applications by transporting proppant slurry past annular bridges or by filling voids within the pack and in open hole by bypassing areas of formation collapse. The next generation of multi-path screen technology has been optimized to reduce rig time, eliminate excessive fluid velocity and provide enhanced proppant placement by incorporating a spiral design. This paper reviews the design improvements, testing and development process for technology advancement, as well as the field installation process and results of delivering void free annular gravel placement in high rate wells.
The first field installations of the next generation multi-path screen were in the deepwater subsea development, Simian/Sienna, offshore Egypt. The application of this technology was driven by the need to have placement of an effective sand control completion in the presence of highly reactive shales. Analysis showed that the most productive completion method was an open-hole completion. This completion type was challenging given that water based fluids were to be used for drilling and completing with exposed reactive shales. The operational risks were centered around completing the wells from a floating rig while experiencing hole instability during completion equipment placement and while placing the annular gravel pack.
To ensure well life sand control, the latest state of the art multi-path screen system was chosen because of its ease of assembly, ability to transport proppant slurry past annular blockages, and the minimization of multi-path tube slurry exit velocity. For proppant transport, the latest non-ionic viscoelastic surfactant (VES) was selected for its shale stabilizing properties, excellent sand suspension and transport properties, and high return permeability characteristics.