JIP Addresses Subsea Wellhead Monitoring - Offshore Engineer

Published in Offshore Engineer 1st January 2014

Bernard Herman van Bilderbeek, CEO of Plexus Group, explains how its friction-grip technology can be applied to subsea wellheads

Since early 2000, the US Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE), formerly the Minerals Management Service (MMS), has considered the impact of sustained casing pressure (SCP) on the safety of offshore operations in the Gulf of Mexico.

A detailed survey of operations disclosed that the vast majority of surface wells at some stage experience SCP, and in 2002, the MMS concluded that if such incidence occurred on platforms, then the same things must be happen- ing subsea. However, the fact remains that subsea wellheads – although similar in design to unitized surface wellheads – do not have outlet valves through which events in the various casing annuli can be monitored.

Effectively, subsea wells are “out of sight, out of mind” where it comes to annuli, and as a result, the MMS did not have data to back up its supposition. The agency did conclude that SCP is a threat to operations and the environment, and statistics show that it has a point. In 2002, the MMS asked US operators to do something about subsea annulus management. After years of “toing and froing,” it was concluded that the available solutions were too complex, involved too many additional risks, and were too expensive in the long term. The MMS abandoned the project in December 2005. In its final report, it lamented that subsea monitoring would only come about through regulator intervention.

Fast forward to 2013, and suddenly, at least in the UK, the quest to stop “flying blind” is once again rearing its head in the form of a call for solutions by UK industry organization ITF.

Following Macondo, Plexus Holdings was asked by a group of operators to study the application of its patented friction-grip technology to subsea well- heads. As a direct result of this inquiry a joint industry project (JIP) was formed, supported by major operators, including Shell, Wintershall, EIN, Total, Tullow and Maersk. The project is now 18 months underway with the aim to come up with a new approach in wellhead engineering, focused on addressing the systemic shortcomings of conventional subsea wellhead techniques, as exposed by Macondo.

Full article can be read here