Detecting and imaging hard-to-find legacy abandoned wells and pipelines

摘要

The four case studies presented in this paper were selected from dozens of field examples collected over a two-year period. The apparent success of these four examples should not be construed or interpreted that this novel digital multi-frequency EM tool will be able to find a majority of abandoned wells scattered across the country. Although we have examples where the EM survey did not find any direct or indirect indication of abandoned wells in proposed study areas, we believe that this digital multi-frequency EM method is the best geophysical tool available to address abandoned well detection and imaging. Considering the serious public safety and environmental issues raised earlier, a 50% success rate is a significant improvement over historical searches which have relied mainly on personal communication and hunches for these hard-to-find abandoned wells where their steel casings had been removed more than 60 years ago.