Investigation of the time-lapse changes with the DAS borehole data at the Brady geothermal field using deconvolution interferometry

TitleInvestigation of the time-lapse changes with the DAS borehole data at the Brady geothermal field using deconvolution interferometry
Publication TypeConference Proceedings
Year of ConferenceSubmitted
AuthorsChang, H, Nakata, N
Conference NameSEG Annual Meeting 2020
PublisherSociety of Exploration Geophysicists
Abstract

The distributed acoustic sensor (DAS) has great potential for monitoring natural-resource reservoirs. In this study, we investigate the DAS borehole data at the Brady geothermal field. We analyze the seismic velocity perturbations of the waves propagating along the borehole during an eight-day period and analyze the velocity variations across depth, time, temperature, and pressure. The results suggest that this reverberation is caused by poor coupling between the cable and the well-casing, and the reverberations provide useful information to measure the time-lapse changes of the observation system and potentially the surrounded structure. This type of signal can occur when the cable is not fixed to the well-casing even with good cement condition.

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