Tripling safety margins with dual-material seals.
CHALLENGE
Rod and piston seals inside blowout preventers were deforming and extruding under high pressure, jeopardizing safety standards.
SOLUTION
System Seals replaced standard sealing materials with a proprietary blend of HNBR, and added two anti-extrusion devices machined from our L120 high performance polymer.
RESULT
Test results revealed that the new system Seals design performed flawlessly – three times longer than the manufacturer’s specification. All existing BOP seals in the field have been replaced.
The failed blowout preventer (BOP) on the Deepwater Horizon sent shock-waves through the drilling industry, signaling that no link in the safety chain is impervious to catastrophic disaster. So, when a major BOP manufacturer in Houston, Texas experienced issues with the seals on their BOP’s, engineers grew concerned and investigated the problem.
They discovered the existing D-shaped nitrile seals were deforming under high pressure, occasionally rolling inside their grooves. In rare instances, the seals extruded almost completely out of the housing. Tests showed that the gap between components was too large for the soft nitrile seal to handle at pressures up to 10,000 PSI.
Despite several attempts at redesigning the metalwork and substituting seal materials, the seals continued to fail. The company then turned to System Seals, which has extensive experience with high-pressure seals and custom sealing system design.
System seals’ research led to the creation of our seal types 132 and232; a new heavy-duty seal profile for use in both the rod and piston applications. Both profiles are dual-material designs with a proprietary HNBR sealing element, protected by two anti-extrusion rings made from our ML120 high-performance polymer. This combination maximizes sealing capabilities, while resisting the potential for rolling and extrusion.
At the request of the manfacturer, a prominent oil-and-gas company began testing the System Seals products in their BOP’s.To maintain a clear margin of safety, the seals needed to endure 250 cycles over a 6-month period without issue to be approved.
After reaching the 250 cycles required, the rig engineers wanted to push the test further, running an additional 500 cycles! After operating for 3-times longer than required, the company was convinced.
The end result is the customer replacing the previous seal supplier with System Seals products for the BOP’s. They also recalled faulty seals from units still in the field. System Seals is now working with the manufacturer to improve sealing reliability in other equipment.