Abstract
Pulling the blowout preventer (BOP) stack or Lower Marine Riser Package (LMRP) on a floating drilling rig has always cost everyone involved a significant amount of money. However, when operating in the ultra-deepwater theater, those costs regularly exceed $1,000,000 per event. As a result, developing and utilizing methods to ensure operative BOP equipment and systems continues to grow in importance to avoid this downtime cost.
The first known field predictive test on BOPs was conducted on ram locking systems in the North Sea in 1987. Since that time, the tests have been refined to identify other modes of failure so they can be corrected while on the surface, providing increased assurance of their ability to function when they are needed on the wellhead. Additionally, predictive tests have been devised and their effectiveness demonstrated on ram locking systems, connectors, annulars, failsafe valves and control systems.
This paper will outline each of the predictive tests developed and validated from field testing and working with equipment manufacturers, describe the principles upon which they are based, and provide case study examples where they have proven to identify pending failure.
