Wellhead & Ball valves as interface between subsurface geothermal reservoirs and plant

Wellhead & Ball valves as interface between subsurface geothermal reservoirs and plant Wellheads at the geothermal heat plant of SWM in Munich, Germany (source: SWM)
Alexander Richter 27 Jan 2021

Connecting the subsurface to surface plant infrastructure - wellheads and valves play an important role in geothermal operations and German company, so we connected with Hartmann Valves to learn a bit more.

In the context of geothermal energy development and utilisation, one talks a lot about either the power plant or the drilling for the resource on the other hand. There is though a crucial interface between the subsurface geothermal resource and the plant where the energy is either transformed into electricity or heating.

This interface is represented by wellheads and valves, like the ones in the picture above at the heat plant of SWM, the city utility of Munich. The plant, located within the city of Munich in Bavaria, Germany, has been transformed drilling wells into a geothermal reservoir below the city to provide clean and renewable energy heating to the city’s district heating network.

As part of the project, German Hartmann Valves installed 6 wellheads (see picture above). The red wellheads are the production valves and the blue are the reinjection wellheads. Initially working for the oil and gas industry, Hartmann Valves has utilised its decades of experience to optimise its valves for the geothermal market in Germany and beyond. The wellheads and valves delivered now address specific requirements for deep geothermal resources, such as large pipe diameters, vertical or horizontal cable conductors, suspension of the downhole pumps, high temperatures and the resistance against corrosion and scaling. Especially the Hartmann API 6A ball valves ensure availability, tight shut-off and long-term resilience which a standard gate valve cannot achieve.

For projects, as such for Munich it is crucial to cooperate closely with the parties involved and this already in the engineering phase. Components need to be optimised based on well depth, pipe dimension, geology and the chemical composition of the geothermal water.

With the specific know-how and experience, this has allowed for an optimization towards fast and cost efficient well realisation from the spud-in down to the on-site installation of the complete wellhead. Together with an around the clock service team and above average service life, Hartmann has established itself as a key supplier of this crucial components in geothermal operations.

Hartmann Valves is a family-owned business in its 75th year founded in 1946 and is now run by the third generation of the Hartmann family in Celle, Germany.

We wanted to learn a little bit more on the background on the company and its geothermal activities, so we connected with Werner Hartmann, Managing Director of the company.


With its strong background in oil and gas, when and how did Hartmann Valves entered the geothermal arena and where?

Bruchsal in Germany was the first involvement in the geothermal arena. We delivered the first wellhead in the late 1970s. Due to economic problems it was stopped in the mid 1980s. Reactivated at the turn of the millennium it is now producing heat and electricity – still with our components.

What has been the technically most challenging element to adapt your valves business to geothermal?

Geothermal water can have various compositions. Our wellheads and valves need to resist these different conditions. Examples of adaptions are coatings and overlay welding as corrosion protection, increased torques to break scaling layers, high temperature seals, flushing and injection systems and incorporation of high power cable connectors as well as sensors ports and control lines.



How have you grown in your geothermal service offerings since the early beginnings?

We have grown in all departments of Hartmann. Today we have more people working in the sales and engineering for the geothermal business. We are here to provide our experience to the customer – already during planning phase. We have adjusted our machine shop to cope with the increased dimensions. However, the biggest growth experienced our service department, with more service technicians, new tools and a whole lot of rental components.

With your experience in Germany, have you also targeted markets outside Germany and maybe even beyond Europe?

We are already very active in Europe. Switzerland, Austria, Netherlands, Belgium and UK to name a few countries. Outside of Europe, we have delivered products to Turkey. Our target are the challenging conditions rather than a specific country. And of course, political willingness is a driver to promote geothermal energy as one of the keys to emission free energy supply.

You can learn more about the company’s activities and a case study from the combined geothermal heat and power plant in Traunreut Germany > here < and ask for their new reference list.