Abstract: This disclosure includes a current sensor configured to detect a signal current in a drilling system component of a drilling system, a telemetry system, and a method for detecting a signal current. The current sensor includes a magnetic body, at least one field coil positioned on the magnetic body, and at least one drive coil positioned on the magnetic body. The at least one field coil configured to detect a first magnetic field that passes within the magnetic body that is induced by the signal current carried by the drill system component when the current sensor is positioned in proximity to the drilling system component. The at least one drive coil configured to generate a second magnetic field. The current sensor is configured to modulate the second magnetic field such the at least one field coil detects the modulated magnetic field.

Abstract: This disclosure includes a current sensor configured to detect a signal current in a drilling system component of a drilling system, a telemetry system, and a method for detecting a signal current. The current sensor includes a magnetic body, at least one field coil positioned on the magnetic body, and at least one drive coil positioned on the magnetic body. The at least one field coil configured to detect a first magnetic field that passes within the magnetic body that is induced by the signal current carried by the drill system component when the current sensor is positioned in proximity to the drilling system component. The at least one drive coil configured to generate a second magnetic field. The current sensor is configured to modulate the second magnetic field such the at least one field coil detects the modulated magnetic field.

Abstract: The present invention provides a system for drilling boreholes having a downhole subassembly which contains an acoustic measurement-while-drilling system. The acoustic system contains an acoustic transmitter and receiver for determining the acoustic velocity through the formations surrounding the borehole ad an acoustic transmitter and a set of receivers for determining the bed boundaries surrounding the borehole formation utilizing the acoustic velocities measured by the system. The downhole subassembly also contains a computing system which performs computations downhole and transmits certain answers uphole during the drilling operations. The bed boundary information is utilized to drill the wellbore along a desired wellbore path. The downhole computing system correlates the acoustic sensor measurements with other measurement-while-drilling measurements and transmits selected correlated information uphole.