The geothermal project in Geneva explores the geothermal potential for the city, which has resumed drilling after a 7 week gap due to the covid-19 situation.
After 7 weeks of disruption due to covid-19, the geothermal project in Satigny, Geneva has resumed drilling activities. The main target of Lully’s exploration drilling is in accordance with the Cretaceous and Upper Jurassic limestone layers.
After crossing more than 800 meters of various geological layers, and after discovering a geological size shock in the form of a large thickness of clay and so-called siderolytic sand, drilling continued on May 4, 2020 to strike the most expected.
Indeed, Cretaceous and Upper Malm (Jurassic) limestone layers will now be drilled to provide valuable geological and hydrological information. These layers are one of the main targets for the development of medium-deep geothermal energy in Geneva: the expected results will provide important information such as the possibility of water, composition, temperature level or nature of rocks being traversed.
Work will continue into the summer to reach depths of around 1,200 – 1,300 meters and what is called the complex reef layer. This is a layer of limestone that settled in a warm, shallow sea some 140 million years ago and has characteristics that can make it a quality geothermal reservoir.
The purpose of exploratory drilling at Lully is to verify estimates made from the surface and to control the presence of water and its flow.
At this moderate depth, water temperatures can reach 47 degrees. “The Geneva basement is full of water, but it is distributed in a heterogeneous way,” said Nathalie Andenmatten, project manager of GEothermie2020 in the canton of Geneva. Over the past five years, the States of Geneva and GIS have carried out precise mapping of cantonment layers as part of the GEothermie 2020 program. But to verify this forecast, you must drill. “