Surface-Powered Impedance-Modulated Telemetry System and Related Methods

Abstract

A surface-powered and impedance-modulated telemetry system permits data from downhole to be telemetered to the surface from within a borehole by using a surface power source to provide a known, controlled, value (V or I) of an electrical signal. The electrical signal completes an electrical circuit through some portion of the downhole components, a surface conductor, and the formation. The downhole components are in contact with the formation and include an impedance-variation system to controllably vary the impedance of those components to encode desired data using a switch system control the impedance of the electrical connection of the upper components to the lower components. At the surface, a measured value of the circuit value (I or V), which depends upon that varying impedance, is acquired. The data encoded in the varying impedance is decoded using that controlled value and the measured value to form a signal.

Dependencies are inferred from the claim text.