Plexus Holdings PLC, owner of the proprietary POS-GRIP® method of wellhead engineering, has announced that BG International Ltd, a subsidiary of BG Group, has signed up as the sixth major oil and gas consulting partner to Plexus’ on-going Joint Industry Project.
The JIP’s objective is to develop and commercialise a new and safer subsea wellhead HGSS™, utilising Plexus’ patented POS-GRIP friction-grip technology to address key technical issues and challenges highlighted by regulators following the Gulf of Mexico incident in April 2010.
The JIP members now include BG, Total E&P Recherche Developpement SAS, Maersk Oil North Sea UK Ltd, Shell International Exploration and Production B.V., Wintershall Noordzee B.V., Tullow Oil, Eni S.p.A, Oil States Industries Inc., Senergy Holdings Limited, and the UK entity of the world’s largest offshore drilling company.
The HGSS subsea wellhead engineering and testing stages are well advanced with a targeted completion of the prototype by the end of 2014 calendar year. The wellhead is designed to be safer, has fewer parts, and delivers instant casing hanger lock down to avoid the use of lock rings and lock down sleeves as required by conventional designs. It has rigid metal-to-metal annular seal technology qualified to match the standard of premium casing couplings and in due course will incorporate annulus monitoring and bleed-off capability to address sustained casing pressure situations together with diagnostic and remedial capability. The inclusion of these key features and capabilities in a subsea wellhead will be an industry first, and to date monitoring of casing annuli capability is not considered feasible for a number of technical and cost reasons.
The JIP members continue to contribute to the design and engineering process. The next significant milestones for the JIP will include completion of the HGSS testing programme followed by the building of a prototype with a targeted first time installation in 2015.
Plexus’ CEO, Ben Van Bilderbeek, said, “I believe that the addition of another major operator to the JIP team is testimony to the significance of this project for the international oil and gas community. BG joining is one more step towards our goal of sharing the potential of friction grip technology with the industry at large. The subsea wellhead is a critical link in the extensive subsea production system chain. Clearly our proprietary technology has to be dovetailed into the product mix customarily provided by the major subsea technology suppliers in order to facilitate its seamless integration. Plexus is in the process of communicating our strategic desire to build such bridges across the industry, and we are confident that these efforts will prove successful in the future. The drivers on which we rely for this strategy are true and reusable metal-to-metal sealing in Ultra-High Pressure/High Temperature applications, and substantial installation time cost savings which are in tune with the industry’s stated desire to limit the unbridled growth in operating costs.”
Key features that Plexus and the JIP partners are working towards incorporating into the new POS-GRIP HGSS subsea wellhead design include:
– 18-3/4″ full bore system, rated to 15,000 psi 350 deg F;
– Upgradeable to 20,000 psi, 450 deg F;
– 4,000,000 lbs ‘instant’ casing hanger lockdown capacity;
– Avoidance of acknowledged problems associated with use of lock down rings;
– Annulus monitoring and bleed-off capability to address sustained casing pressure (‘SCP’) situations, with diagnostic and remedial capability;
– Ability to open and reseal the casing annulus to enable remedial cement job procedures;
– Rigid metal annular seal technology qualified to match the standards for premium casing couplings;
– Meeting the requirements of API 17D/ISO 13628-4, recently provided additional operator requirements, and Plexus ‘life cycle’ testing.