Distributed Fiber Optic Strain Sensing for Geomechanical Monitoring: Insights from Field Measurements of Ground Surface Deformation

Geosciences

Rasha Amer¹  Tsutomu Hashimoto¹  Takeya Nagata¹  Ziqiu Xue¹ 

[1] Geological Carbon Dioxide Storage Technology Research Association, 9-2 Kizugawadai, Kizugawa-shi, Kyoto 619-0292, Japan;

关键词: distributed fiber optic strain sensing;    ground surface deformation;    static load;    dynamic load;    uplift;    subsidence;   

DOI  :  10.3390/geosciences11070285

来源: DOAJ

【 摘 要 】

In recent years, distributed fiber optic strain sensing (DFOSS) technology has demonstrated a solution for continuous deformation monitoring from subsurface to surface along the wellbore. In this study, we installed a single-mode optical fiber cable in a shallow trench to establish an effective technique for ground surface deformation mapping. We conducted three experimental field tests (iron plate load, water tank filling up load, and airbag inflation) in order to confirm the strain sensitivity of DFOSS for static loads, dynamic overload, excavation, subsidence, and uplift. This paper also presents two installation methods to couple the fiber cable with the ground under various environmental conditions; here, the fiber cable was installed in a shallow trench with one part buried in the soil and another part covered with cement. Our results suggest that covering the cable with cement is a practical approach for installing a fiber cable for ground surface deformation monitoring. By combining this approach with wellbore DFOSS, accurate surface–subsurface deformation measurements can be obtained for three-dimensional geomechanical monitoring of CO₂ storage and oil and gas fields in the future.

【 授权许可】

Unknown