A novel telemetry technique for empowering smart directional borehole drilling systems

Abstract

In this paper, a novel low-cost, reliable, and real-time telemetry technique in deep boreholes drilling is developed. This is accomplished by using the drilling pipe surrounded by the drilling mud as a Single Conductor Transmission Line (SCTL). A very compact transducer of dimensions 0.006λ×0.006λ×0.05λ (where λ is the free space wavelength) is designed for properly exciting a TM surface wave on the drilling pipe and drilling mud SCTL. Fitting the standard borehole size, the transducer comprises an open-ended helical conductor concentrically surrounding the drilling pipe and provides a transition from the coaxial line to the SCTL at low HF-band over 2% fractional bandwidth.