S4CE partner TWI went to St Gallen, one of our geothermal field-site in Switzerland for a week of testing. From the 27th to the 29th of August, Sofia Sampethai (TWI) and Thomas Bloch (St Gallen) have been testing new techniques developed by TWI: Acoustic Emission and Guided Wave.
TWI has been investigating the most appropriate technique, or combination of techniques, for monitoring geothermal well casings, with the objective of identifying any failure in advance of it happening. Two condition monitoring techniques namely acoustic emission and guided wave have already been applied to the testing of a 6m long, concrete-covered metal pipe. The testing team found that while the emitted waves and guided waves propagate in the structure, they suffer a gradual decrease in amplitude, which reduces the range of inspection. Therefore, the attenuation effect on the propagating waves is tested. Based on the preliminary results both techniques could be used for certain ranges but further investigation is needed.
Therefore, those techniques have been tested in the field site of St. Gallen with two commercial systems one for Acoustic Emission and one for Guided Wave. The data processing and interpretation will follow and the first results will be presented at the S4CE consortium meeting in Salerno.