Influence of Metal C-Ring Key Parameters on Sealing Performance

Subsurface Safety Valves (SSSVs) safeguard offshore thermal-recovery wells under high temperature and pressure; their reliability hinges on metal C-ring sealing. Seal failure risks leaks, environmental hazards, and shutdowns, with performance dictated by compression ratio, opening method, opening height, and wall thickness. This study quantifies the geometric effects on sealing and frictional behavior via an experimentally validated finite element model covering 0–14% compression, through-center oblique and flat cuts, 2.00–2.40 mm opening heights, and 0.20–0.40 mm wall thicknesses. Results show that higher compression, opening height, or wall thickness increases maximum contact stress, contact area, and dynamic/static friction. Through-center oblique cutting lowers friction while preserving sealing, outperforming flat cutting. Exceeding 14% compression, 2.40 mm height, or 0.20 mm thickness approaches tensile fracture, endangering reliability. Dynamic sealing exhibits lower peak contact stress than static sealing owing to broader load distribution. The derived optimization criteria provide a design framework for metal C-ring seals in SSSVs, enabling safer, more efficient thermal-recovery operations and advancing offshore sealing technology.