Project & Construction Management in GLT Plus Grijpskerk Masterplan







Refining & petrochemicals

Associated capabilities


To extend the life time and to ensure continued reliable and safe operation of the Underground Gas Storage installation for the next 15 years NAM needed to replace obsolete equipment and improve the reliability of the fire protection on the well area. This resulted in a schedule and cost driven project scope with brownfield execution in frozen shutdown windows, in order to guarantee the supply of high caloric gas to NAM’s industrial and foreign customers.


Together with NAM GLT-PLUS developed a masterplan with an integrated approach of OPEX and CAPEX projects and an integrated organization of projects and maintenance. Key factor in this masterplan was the close cooperation with NAM Operations. Stork was responsible for project & construction management, including subcontractor management for the numerous multi-disciplined projects. Some characteristics:

• Replacement of 66 frequency convertors, 550 obsolete field instruments, air-fuel ratio controls of the furnaces and controllers from the Process and Off-gas Recycle Heaters, including commissioning of new instruments.

• Fire fighting scope: demolishing the existing firewater system and prefab and install new firewaterline (approx. 300 mtr) from underground ring to all wells (X-mass trees), including hydrotesting and fireproofing insulation.

• Inspection on Corrosion Under Insulation: risk based inspection of coating, using 3D piping modelling and blasting and painting of corroded piping surfaces.

• Delivery and mounting of new X-mass trees executed under supervision of NAM, including dismantling and reinstallation of all interfering flowlines, hydraulics and instrumentation.

• Inspection and coating.

• Coating scope: blasting and coating of piping in production unit (50% of total capacity), including dismantling and protection of instruments and valves, blasting and painting, partly in confined spaces, and installation of supports and insulation.

Since GLT-PLUS also executed a similar masterplan at the co-located gas production unit, all lessons learned from that masterplan were implemented in the preparation and execution of the 2016 scope. This resulted in improved planning and processes and significant costs savings.


The masterplan was completed safely and according to the frozen shutdown schedule. The plant was available on time, vastly within target budget and according to all quality standards. It had a “plug and play” start-up after total shutdown. After the Masterplan completion the plant integrity and plant availability for the replaced parts is secured for another 15 years of smooth operation. The fire protection is fully set according to the latest standards and philosophy.