This paper summarises the experiences from the first hot tap on the Norwegian continental shelf and recommendations for future hot tap operations in the Norwegian sector. The work was carried out in accordance with the latest standards, Rules and Regulations issued by Statoil, Det Norske Veritas(DNV) and Norwegian Petroleum directorate(NPD). The "Safety First" policy of Statoil and Stolt Rockwater Joint Venture resulted in the development of new equipment and methods including carrying out parts of the offshore operation diverless. This is an essential issue for further developments to completely diverless hot taps. The hot tap connection solution has high potential for future utilization of pipeline networks, particularly with reference to the favourable impact on the economics and environmental advantages.
In 1997, Esso, on behalf of the Jotun group, signed an agreement with Statoil, representing the Statpipe partners, to connect the Jotun field to the Statpipe transport system. New Tees are installed on Norfra and Åsgard pipelines for increased utilisation of the transport system and for future tie-ins of gas fields around the pipeline route. The Tee design used has varied somewhat but for all types, the pipe wall has to be penetrated when the tie-in is executed. As this was the first time the hot tap method was used on the Norwegian continental shelf, experience from similar operations in neighbouring sectors were used as the basis for the Jotun hot tap. It has been a challenge to build up confidence that the hot tap method was a safe operation and that the integrity of the pipeline system could be maintained. Despite that several hot tap studies had already been carried out to establish the basis for potential tie-ins to existing pipeline systems, exhaustive verification work and hazard studies had to be carried out.