Sealing performance of new plunger in Sulige Gas Field deep well

Plunger lift is crucial for resolving fluid accumulation in the deep wells of the Sulige Gas Field (5000–6500 m). Traditional cylindrical plungers exhibit poor sealing performance at these depths, resulting in significant leakage and inefficient operation. This study introduces innovative plunger designs—rhombus array, triangular array, spiral combination, and composite plungers—to address these challenges specifically for deep well applications. Through comparative computational fluid dynamics simulations using the volume of fluid method, we evaluated both gas channeling and fluid leakage performance across designs. The rhombus array plunger demonstrated superior sealing effectiveness, significantly outperforming conventional cylindrical plungers by reducing gas channeling velocity by approximately 30% and minimizing liquid leakage across all tested pressure conditions (0–1 MPa). Further optimization of the rhombus array design identified three key parameters that maximize sealing performance: horizontal gap width (0.05–1.85 mm), vertical distance between rhombus centers (11–12 mm), and rhombus edge curvature (5/9π–3/4π). This novel design approach provides a practical solution to enhance plunger lift efficiency in challenging deep well operations, offering a viable alternative to conventional plunger designs for the unique conditions of the Sulige Gas Field.