Assessment of Sand Control Methods for Cased Dual-Annulus Gas Wells: Scaled Laboratory Experiments

Abstract Sand production poses a significant challenge in high flow rate offshore gas wells, as the elevated flow velocities can lead to well completion erosion, perforations blockage and subsequent sand influx. This paper presents a comprehensive analysis to assess and rank multiple sand control solutions for mitigating sand production, plugging and erosion in a cased dual-annulus gas well. A sand retention testing (SRT) setup accommodating a purpose-built component mimicking the dual-annulus wellbore completion was employed to quantify sanding and plugging performance. A novel erosion testing setup was used to assess the erosion risk of different sand control screens. Wire-wrapped screen (WWS), slotted liner (SL), and punched screen (PS) were assessed in conjunction with a novel multi-layer open cell matrix polymer (OCMP) filter. Actual wellbore conditions were replicated to ensure a representative evaluation. The testing used flow rates per single perforation shot and matched sand mineralogy, particle size distribution, gas viscosity, and perforation shot size. The laboratory tests demonstrated that the OCMP filter exhibited superior performance in sanding, plugging and erosion compared to the other three screens tested. Sand retention performance of WWS was poor, with 0.27 lbm/ft2 being produced compared to 0.015 lbm/ft2 and 0.07 lbm/ft2 for slotted liner and punched shroud, respectively, and the OCMP produced zero sand throughout the test. The WWS also exhibited a high susceptibility to erosion, and the PS displayed a high tendency for erosion and plugging. The OCMP filter was also examined for long-term exposure to formation fluids and short-term exposure to aqueous and solvent-based chemical treatments that are potentially employed in the wells, with no adverse effects observed. This paper reports, for the first time, a comprehensive study replicating a cased dual-annulus in offshore gas field conditions comparing multiple remedial sand control solutions, including OCMP, offering the industry objective data to aid sand control selection.