DAS VSP within hybrid coiled tubing intervention program for geothermal exploration

This study shows the effective use of Hybrid Coiled Tubing Technology (HCTT) integrated with fiber optic sensing to perform Distributed Acoustic Sensing (DAS) Vertical Seismic Profiling (VSP) in geothermal exploration. Geothermal energy holds significant potential, but accurate subsurface data is essential for successful exploration. The project aimed to address regional geothermal data deficiencies by utilizing innovative technologies to collect detailed seismic information. A well-structured coiled tubing intervention program facilitated efficient and costeffective data acquisition. The project focused on sandstone formations at depths of 500–4000 meters, using explosive sources with charges ranging from 220 to 880g. The results demonstrated that DAS VSP delivered high-quality seismic data despite challenges such as uncemented casing and poor coupling, which affected signal in the vertical part of the well. The consistent signal-to-noise ratios for all four explosive charges demonstrated that future operations could rely on the smallest 220g charge. Post-processing further enhanced signal clarity, allowing accurate depth correlation and reservoir characterization. The combination of HCTT and distributed fiber optic sensing proved to be a successful, cost-effective approach for geothermal exploration, with the potential for real-time production and injection profiling.