Patent ID: 9726008
Date: 2017-08-08
CPC Classifications: E21B

Claim:
1. A method to detect the relative position of a drill bit with respect to a selected underground formation boundary or boundaries using an electric-field borehole telemetry apparatus, that includes the steps: a) providing a measure-while-drilling apparatus that includes inclination sensors, directional sensors, logging sensors of choice and an electric-field borehole telemetry apparatus, b) within the electric-field borehole telemetry apparatus, in addition to monitoring the inclination, direction and logging parameters, monitoring one or more parameters of an electrical output of the electric-field borehole telemetry apparatus, c) transmitting to a surface computer the inclination, direction, and logging parameters as well as the one or more parameters of the electrical output by means of the electric-field borehole telemetry apparatus, d) computing drilling parameters to guide a drill string along an intended path, e) determining from the one or more transmitted parameters of the electrical output from the electric-field borehole telemetry apparatus parameters indicative of approaching or penetrating the selected formation boundary or boundaries, and f) making corrections to the direction of drilling to maintain the drill string and drill bit in the selected formation, g) the method including: