The ability to repair pipelines remotely becomes critical as water depths of offshore field developments continue to increase beyond diving limits. While there have been several proposed solutions available, very few repairs have been carried out remotely. In October 2012, a Houston based team comprising of Subsea 7, Quality Connector Systems LLC and Stress Engineering Services, Inc. successfully completed a repair in 3, 200 FSW from a light construction vessel (M/V Grant Candies).
The extent of this operation was to assess the damage to the pipeline, remove pipeline coatings, and to install a QCS diverless repair clamp connector; with the limitation that all work had to be carried out only using work class ROVs. Detailed engineering, planning, ROV tool interfacing and a complete system integration test including equipment trials were critical to minimizing vessel downtime and meeting an aggressive schedule. Repair of the pipeline being critical to the long term integrity, and life expectancy following the discovery of a defect.
This paper reviews the current state of remote intervention based pipeline repair technology and provides an overview of the challenges faced when dealing with regulatory agencies (BSEE/BOEM), lessons learned in implementing this repair and considerations to be able to transfer this technology to greater water depths and harsher environments.
