Specialised Back-Gas Systems verification testing for Johan Sverdrup “Bridges” Hook-up

Maintenance & Modifications
Norway, Continental Shelf
Project manager
Peter Bjørnsen
Project type
Field Service

Project description

To perform verification testing for welding operations on piping for the Johan Sverdrup “Bridges” Hook-up fazes, the client required a solution and custom-designed flexible welding purge barrier which can be removed from the piping system through 1” NS Threadolet with an ID of 28mm, after completion of welding. This was to avoid revised engineering and a total replanning of the offshore Hook-up spool Tie-in operations. This would have significantly extended the commissioning period and cost.  


The planned operation offshore included different pipe dimensions, from 2 to 24 inches, and with varying schedules of pipe. Within two months, IK Topside developed three different back-gas system solutions to cover all the pipe sizes. The solutions allow for very efficient welding operations due to sophisticated purge methods. A total of 8 different tests were successfully performed at the client’s yard, replicating as closely as possible the conditions for the offshore operation, such as facilities, rigging methods, installation, welding operation and retrieval of back-gas systems through the 1-inch Threadolet. 


The verification tests on all products were successful and proved to be the chosen method for Back-gas isolation for the Johan Sverdrup “Bridges” Hook-up operations.  


Without IK’s specifically designed Back-gas solutions, the engineered piping and hook-up spools would have required several revisions resulting in the use of traditional Back-Gas techniques and standards, all of which would have prolonged the production start-up of possibly Norway’s most prestigious offshore Oil & Gas installation hook-up of all time. The time and cost savings for the end client are unimaginable.  

“We were very proud to have been awarded this verification testing campaign as it shows trust and respect from the major Norwegian Oil & Gas operators and contractors for specialized solutions and services from local experienced suppliers. This is an advisable recipe for efficient, safe, and cost-effective delivery to the Norwegian offshore market.” 

– Peter Bjørnsen