NAM - Expansion of underground gas storage in Norg
Natural gas is still an important fuel resource in the Netherlands. Because the pressure is decreasing in the Groningen gas field, the current supply is insu cient to cope with the winter-peak demand. Moreover, the production from the gasfield has been reduced by the Dutch government. Underground bulk storage of gas, in porous rock, offers a solution so that producer NAM can guarantee the continuity of the gas supply. The gas that is produced in the summer is stored for usage in the winter. The storage can also be used for imported gas from other countries. A large storage site is located in Norg, in the north of Holland. In order to be able to meet the future demand, both the storage capacity and the production volume of this location had to be increased. The storage capacity was increased from 4 to 7 billion m3 and the production volume from 48 million m3 /24 hours to 76 million m3 /24 hours.
This was an enormous operation that had to be completed before winter arrived.
Within the GLT-PLUS consortium (see insert), Stork was responsible as construction partner for the revamping of the existing storage installation and increasing the total aboveground installation. This means that components were added on, such as a compressor, separators and coolers, and that bottlenecks in the current installation were removed.
The project was carried out in a brown field environment with a major shutdown for all connections. At its peak, during the shut-down period, 1,200 men in triple shifts were working on the expansion under the direction of Stork. This also included the management of all sub-contractors. The new wells for the expansion of the storage were drilled under the direction of NAM itself. In the project, the entire control system (DCS by Yokogawa) of the complex was replaced. A brain transplant, if you will, performed by Stork’s E&I specialists in partnership with Yokogawa engineers. Due to the importance and large scope of this part, this discipline was key in the total project.
The core of the activities had to be carried out during a 110-day shut-down. During this period, the complete installation was taken out of operation, cleaned and handed over in its entirety to GLT-PLUS, including the responsibility for the work permit system. The ongoing maintenance was also carried out under Stork’s direction.