N2 Leak Test & Hydrostatic Pressure Testing of Gas Injection Riser ESV

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

Project description

This project was based on the supply of suitable weld isolation and hydrostatic/ N2 pressure testing equipment for the planned operation of the 12″ “Skarv” gas injection riser. For weld isolation purposes, a Twin Tyre Flexible Plug was used. This tool can navigate through bends and has a Double Block and Bleed (DB&B) function for hydrocarbon system requirements.  


A specially designed IJT was manufactured to perform a local leak test and verify not only the ESV flanged connection but the complete ESV after the flange face was repaired. This solution is a much safer and more efficient method of leak/pressure testing than full-scale leak testing of the entire riser section, which would entail an extremely large volume of N2 gas at a pressure of 460 bar. g., decreasing substantially the operation risk.  


For testing the FW of the new welded Flange, a shorter IJT with the same design concept was manufactured for the required 628,5 bar. g hydrostatic pressure test.  

“A focused, fast-track campaign for the client and IK Topside is needed. This was a risk mitigation compilation of customized testing equipment and solutions. The result was a highly efficient offshore operation, successfully performed by IK Topside.” 

– Peter Bjørnsen