Publications

Is a steel-cased borehole an electrical transmission line?

Aldridge, David F.; Weiss, Chester J.; Knox, Hunter A.; Schramm, Kimberly A.; Bartel, Lewis C.

Under certain restricting assumptions, an electrically energized steel-cased geologic borehole may be modeled as an electrical transmission line. Current waveforms are obtained by solving the governing telegraph equation in the frequency-domain, followed by numerical inverse Fourier transformation. Electric current pulses propagating along the borehole undergo progressive amplitude loss and waveform distortion with distance, arising from leakage of current into the surrounding geology. A major modeling uncertainty involves the proper boundary condition to impose at the end of a borehole transmission line.