Publication Date:
2020-05-19
Description:
To date, information about the wellbore integrity of high temperature and high pressure geothermal wells is scarce. Hardly any measurement data is available about the thermal and mechanical load onto the subsurface installation (casing and cemented annulus) during the operation of such wells. In order to monitor the response of the subsurface installation to changing load conditions, a fiber optic cable was installed behind casing of a geothermal well. To increase the knowledge about the wellbore integrity and to benefit from the combined application of different fiber optic sensing technologies, temperature, strain as well as acoustic noise measurements were performed during well completion and testing. These include the distributed temperature sensing (DTS) technology, based on Raman scattering, as well as the distributed strain and distributed acoustic sensing (DAS) technologies, both based on Rayleigh scattering. Here, we present information about the laboratory experiments, the cable installations and downhole measurement campaigns together with results of our analysis. It could be shown that the fiber optic measurements are well suited to monitor the well completion procedures. In addition, the technology offers a possibility to monitor well integrity throughout the lifetime of a geothermal well.
Language:
English
Type:
info:eu-repo/semantics/report
Format:
application/pdf
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