Gasunie’s regional gas transportation network consists, in addition to pipelines, of valve stations, pressure regulating and measuring stations and gas receiving stations. The majority of these stations have been built in the period 1960-1980. This raises questions on the remaining technical life-time of these stations and adequate measures to comply with safety and transport standards in the future. Gasunie has developed the Gasunie Network Improvement Program (GNIP) in which replacement of these assets is carried out, prioritized based on their expected condition.
Gasunie uses the Deming circle in order to identify lessons learned from executing GNIP and verification thereof in the GNIP Verification Project (GVP). In the GVP, life-time critical parts of the replaced stations are inspected, in situ as well as in laboratories, in order to assess their actual condition. Lessons learned and results from the GVP have lead to adjustments in the program in terms of scope and pace. DNV GL has supported Gasunie with developing the GVP, has analyzed all GVP results and recommended adjustments both for GNIP and GVP.
This paper gives first, as an introduction a general overview of GNIP and GVP is presented. Secondly, the results of the GVP will be presented. Thirdly, the actions Gasunie has taken based on the GVP will be discussed.