Decommissioning of the Buchholz UGS
VNG Gasspeicher GmbH (VGS) owns and operates the Buchholz underground gas storage facility, south-west of Berlin. The facility is located about 25 km southwest of the city of Potsdam in the state of Brandenburg, in the district of Potsdam-Mittelmark, south or southwest of the city of Beelitz, near the villages of Salzbrunn and Buchholz.
The storage facility has been in operation since 1976 and has contributed to a secure supply of natural gas for more than 40 years. Due to the age of the facilities and changing market conditions, VGS decided in 2015 to permanently decommission the Buchholz UGS, maintain the storage facility and carry out a complete and sustainable dismantling of all facilities. In preparation for this, VGS carried out the necessary approval procedure with the competent state authority, the Brandenburg State Office for Mining, Geology and Raw Materials (LBGR). The final operating plan submitted for this purpose was approved in December 2016. In addition, the extraction of residual gas at the site was discontinued at the end of 2018.
The current planning envisages the following sequence of dismantling work:
- From October 2019: Start with the first soil remediation measures.
- From May 2020: first civil engineering work and successive construction of the temporary drilling sites.
- From August 2020: Start of the first underground emplacement work and then successive emplacement of all 25 probes with the aid of a drilling rig.
- November 2022: Completion of the work
Directly affected residents, property managers and owners will be informed in detail about the construction processes and time periods.
Currently, there are 25 existing wells (production and observation wells, as well as an injection well), all of which are drilled vertically and have final depths ranging from 300 meters to 1,055 meters. Except for the observation wells, the target horizon of the drilling was the sediment of the middle Buntsandstein formation. As part of the construction project, all 25 wells will be securely closed, and the following ancillary facilities will be dismantled. These are as follows:
- 8 production wells
- 16 observation wells
- 1 injection well
- Installed underground and above-ground equipment at the well sites
Work on the drill sites is required prior to drilling. Of the 25 sites in question, 9 have the appropriate site structures. The access roads to these 9 well sites are also adequately sized and do not need to be widened prior to the maintenance work. The remaining 16 monitoring wells have site structures that are not adequately sized. These sites are concrete and fenced. Prior to well custody, these sites will need to be temporarily expanded to a size of 40 m x 60 m (2,400 m²), incorporating the previous probe site, to provide a suitable area for placement of the work-over facility with the appropriate equipment (containers, etc.). The field piping system from the well sites to the plant site includes underground pipelines (DN 150/PN 100 or DN 100/PN 100) and a brine and brine injection pipeline (DN 60/PN 25) including associated cables or cable protection pipes. All pipelines will be completely salvaged and dismantled. After all underground and surface facilities in the area have been dismantled in 2022, dismantling of the actual operating site will begin. The site will also be completely deconstructed and renaturalized.
Health, Safety, and Environmental Protection
The dismantling activities within designated landscape protection areas, agriculturally used areas, and in close proximity to inhabited areas of the town of Salzbrunn pose particular challenges. Therefore, since the beginning of the planning process, all necessary measures have been consistently considered to limit the impact on people, flora, and fauna.
To ensure the safety of all parties involved, only certified and qualified specialized companies are employed.