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Patented solution to help mitigate geothermal well failure being tested in Iceland

Experimental Set-up to test the flexible coupling (Copyright: Lárus Gudmundsson)
Alexander Richter 27 May 2019

A new patented solution designed to reduce chances of casing failures in high-temperature geothermal wells will be tested in a full-scale experiment in Iceland as part of the GeoTHERMICA GeConnect project.

A recently innovated patented solution, so-called “Flexible couplings”, designed to reduce chances of casing failures in high-temperature geothermal wells, will be tested in a full-scale experiment in Iceland. The experiment will be conducted to demonstrate the technology within the framework of the GEOTHERMICA project GeConnect.

For medium- to high-enthalpy geothermal wells, thermal cycling has the potential to severely deteriorate the integrity of the cemented annulus. Additionally, for higher enthalpy wells, yielding of casings becomes a structural concern. The experiment composed of a 9?? casing equipped with a flexible coupling cemented into a 13?? casing will be constructed and installed on a well pad of an existing high-temperature geothermal well in Iceland. The aim is to investigate effects of thermal cycling on well integrity and to test the function of cemented-in flexible couplings. Along with testing the flexible coupling, cement sheath integrity and the cement-casing boundary behavior will be monitored and evaluated at moderate to high temperatures using various parameters, including strain, temperature, pressure and acoustic sensing. Structural models are used to analyze casing-cement interactions and to evaluate prospects and potential improvements of well integrity by using flexible couplings on experimental up to field scale.

The new technology will be presented at the upcoming European Geothermal Congress EGC 2019 in The Hague/ Netherlands.

Source: GFZ (sent by email)

Picture Note: Experimental Set-up to test the flexible coupling (Copyright: Lárus Gudmundsson)