The performance optimization of the stripper rubber for the rotating blowout preventer based on experiments and simulation

The rotating blowout preventer (RBOP) is an essential safety-ensuring equipment in underbalanced drilling. RBOP is vulnerable to fatigue failure resulted from being subject to a cyclic alternating load during pressure drilling. To enhance the lifespan of RBOP, this paper used a finite element simulation combined with experiments to realize a structural optimization of RBOP. The results showed that the optimal thickness of the iron frame for the stripper rubber is 34 mm, the optimal radius of the fillet is 12 mm, and the optimal inner diameters for the stripper rubber that seals 2–3/8″, 2–7/8″, 3–1/2″, 4″, 4–1/2″, and 5″ drill pipes are respectively 48 mm, 58 mm, 75 mm, 87 mm, 95 mm, and 100 mm. The optimized RBOP was examined in a test center and demonstrated a lifespan that was 2.18 times the national standard. When it was deployed in the drilling site, its lifespan was 2.8 times that before optimization. The improvement in the performance and lifespan of RBOP is very meaningful for ensuring security in the drilling site and lowering drilling cost for oil production.