Residents of Schwerin, Germany, may be looking for a zero-emission heat source in their district heating network. The first well in the Shverin-Lankov geothermal duplex has already exceeded all expectations. The freshly dug re-injection has been well tested with very positive results. Geothermal Consultants at GTN, The German subsidiary of Manvet, Excited about the results.
Dr. Peter Sibbett explained, Managing Director of GTN on the GTN website, When asked about recent drilling results, “The Schwerin geothermal project is a milestone in the transition towards a carbon-neutral heat supply in northern Germany. We are very proud that we have been part of this beacon project from the beginning. Explain to the project that shallow reservoirs can also be a possible option for underground heat supply “Many projects in Germany are targeting deeper reservoirs around 3,000 metres. The project in the state capital of Mecklenburg-Vorpommern uses Postera sandstone which can already be reached at an altitude of 1,200 metres. Drilling costs are greatly reduced due to the shallow depth and lead, Despite the low temperatures, to high economic feasibility.
The temperature of the thermal waters is 56 degrees Celsius. And at the beginning of 2022, Stadtwerke Schwerin expects to start using it to provide an environmentally friendly heat source. Before supplying heat to the central heating network, The temperature is raised to 80°C through high temperature heat pumps. About 10% of Schwerin’s heat demand will be covered by the new geothermal heating plant. With additional projects, Total can be 60% possible.
In contrast to a vertical production well, The injection well was drilled near the “Sportspark ‘Lankow’ in Schwerin as an S-shaped inclined well. This allowed a subsurface distance of 1,100 meters between the ends of the two wells, Which is required for a well for sustainable use of the reservoir. at a depth of 410 m, The well deviated from perpendicular to an angle of 30 degrees. After an additional 550 metres, Angle smoothly again until the well returns to a vertical path. The target layer is reached at a vertical depth of 1220 square metres, Successful directional drilling has been achieved through careful planning and the use of specialized drilling equipment.
The Postera Sandstone target dates back to the Upper Triassic period (about 200-205 million years ago). Thick sand layers were deposited within a wide river plain that extended over much of today’s northern Germany. at the site of Schwerin, There are remnants of this river system that are more than 40 meters thick in sandy stones. Fine to medium grained Postera sandstones are poorly combined and provide the most favorable hydraulics characteristics, Which are necessary for efficient geothermal energy extraction.
Reservoir exploration at Schwerin-Lankov was carried out using the so-called “Sandsteinfazies” approach. This new exploration technology was developed by the University of Göttingen and GTN in the context of several research and development projects funded by BMWi (German Federal Ministry for Economic Affairs and Energy). One of the main findings of these research projects is a set of high-resolution maps that show subterranean surfaces, sandstone thicknesses, and reservoir quality.