Method and apparatus for electrical surveys of subsurface structures utilizing cell-to-cell techniques with correction to direct potential measurements

摘要

Offshore or onshore electrical surveys of buried or submerged structures such as pipeline are conducted in a fixed-cell-to-moving-cell fashion either before or after one or more established pipe-to-electrolyte potentials can be obtained. The results of the fixed-cell-to-moving-cell survey are then corrected by a summation of the fixed-to-moving-cell recorded potential and the established potential at the location of the established potential to obtain a reliable electrical survey of the structure. As indicated, the fixed-cell-to-moving-cell survey may be conducted either before or after the established potential is obtained or either before or after a disposable wire survey using a direct connection to the structure.