Abstract: Various systems and methods for implementing an azimuthally sensitive resistivity logging tool are disclosed. One such method involves transmitting a primary magnetic field from one or more coils placed on a drill collar and receiving several electrical signals, where each of the electrical signals is received from a respective one of several sensors. The sensors are distributed around a circumference of a drill collar, and an axis of at least one of the sensors is perpendicular to an axis of the drill collar. Each of the electrical signals indicates a respective magnitude of a measurement of a reflected magnetic field, where the reflected magnetic field is reflected from an anomalous geological formation. The method calculates a vector measurement of the reflected magnetic field, based upon the electrical signals.

Abstract: Various techniques for generating a polar display include a method, which involves receiving information identifying a formation property of an anomaly within a geologic formation from a measurement-while-drilling (MWD) tool that includes several sensors. The formation property is identified by at least one magnitude and at least one distance. The formation property is also identified relative to a corresponding property of the geologic formation. The method also involves receiving information identifying an azimuthal angle from the MWD tool, where the azimuthal angle relates a position of the anomalous formation to a position of a first sensor. The method then generates a graphic, based upon the at least one magnitude and the at least one distance and the azimuthal angle, and displays the graphic on a polar display, in which a center of the polar display corresponds to a location of the borehole in which the MWD tool is located.

Abstract: Various techniques for generating a polar display include a method, which involves receiving information identifying a formation property of an anomaly within a geologic formation from a measurement-while-drilling (MWD) tool that includes several sensors. The formation property is identified by at least one magnitude and at least one distance. The formation property is also identified relative to a corresponding property of the geologic formation. The method also involves receiving information identifying an azimuthal angle from the MWD tool, where the azimuthal angle relates a position of the anomalous formation to a position of a first sensor. The method then generates a graphic, based upon the at least one magnitude and the at least one distance and the azimuthal angle, and displays the graphic on a polar display, in which a center of the polar display corresponds to a location of the borehole in which the MWD tool is located.

Abstract: Various systems and methods for implementing an azimuthally sensitive resistivity logging tool are disclosed. One such method involves transmitting a primary magnetic field from one or more coils placed on a drill collar and receiving several electrical signals, where each of the electrical signals is received from a respective one of several sensors. The sensors are distributed around a circumference of a drill collar, and an axis of at least one of the sensors is perpendicular to an axis of the drill collar. Each of the electrical signals indicates a respective magnitude of a measurement of a reflected magnetic field, where the reflected magnetic field is reflected from an anomalous geological formation. The method calculates a vector measurement of the reflected magnetic field, based upon the electrical signals.

Abstract: Various systems and methods for implementing an azimuthally sensitive resistivity logging tool are disclosed. One such method involves transmitting a primary magnetic field from one or more coils placed on a drill collar and receiving several electrical signals, where each of the electrical signals is received from a respective one of several sensors. The sensors are distributed around a circumference of a drill collar, and an axis of at least one of the sensors is perpendicular to an axis of the drill collar. Each of the electrical signals indicates a respective magnitude of a measurement of a reflected magnetic field, where the reflected magnetic field is reflected from an anomalous geological formation. The method calculates a vector measurement of the reflected magnetic field, based upon the electrical signals.

Abstract: Various systems and methods for implementing an azimuthally sensitive resistivity logging tool are disclosed. One such method involves transmitting a primary magnetic field from one or more coils placed on a drill collar and receiving several electrical signals, where each of the electrical signals is received from a respective one of several sensors. The sensors are distributed around a circumference of a drill collar, and an axis of at least one of the sensors is perpendicular to an axis of the drill collar. Each of the electrical signals indicates a respective magnitude of a measurement of a reflected magnetic field, where the reflected magnetic field is reflected from an anomalous geological formation. The method calculates a vector measurement of the reflected magnetic field, based upon the electrical signals.

Abstract: A method and apparatus for a downhole antenna comprising a housing having an outer surface and a longitudinally bored inner cavity, the outer surface having a first slot and a corresponding second slot extending from the outer surface to the longitudinally bored inner cavity; a first removable downhole antenna segment disposed in the first slot in a first transverse cross section of the housing, the first removable downhole antenna segment comprising at least one coil to inductively couple a signal from the longitudinally bored inner cavity to the earth formation. A second removable downhole antenna segment, interchangeable with the first removable downhole antenna segment, disposed in the corresponding second slot, the second slot in a second transverse cross section of the housing, the second removable downhole antenna segment comprising at least one coil to inductively couple a signal from the earth formation to the longitudinally bored inner cavity.

Abstract: A method and apparatus for a downhole antenna comprising a housing having an outer surface and a longitudinally bored inner cavity, the outer surface having a first slot and a corresponding second slot extending from the outer surface to the longitudinally bored inner cavity; a first removable downhole antenna segment disposed in the first slot in a first transverse cross section of the housing, the first removable downhole antenna segment comprising at least one coil to inductively couple a signal from the longitudinally bored inner cavity to the earth formation. A second removable downhole antenna segment, interchangeable with the first removable downhole antenna segment, disposed in the corresponding second slot, the second slot in a second transverse cross section of the housing, the second removable downhole antenna segment comprising at least one coil to inductively couple a signal from the earth formation to the longitudinally bored inner cavity.

Abstract: An inductive collar locator tool is provided that provides improved sensitivity and precision in locating collars and other discontinuities in a casing string. In a preferred embodiment, the collar locator includes a transmitter coil that produces an oscillating magnetic field, which couples to the casing string proximate the tool. The tool also includes a pair of spaced receiver coils connected to signal processing circuitry which provides an output signal representing the difference in the phase of the magnetic field detected by the receiver coils. The phase difference is relatively constant when the tool is in plain casing pipe, but it changes rapidly when the tool passes through pipe that includes discontinuities, such as joints or collars. The collar locator tool may include an on-board oscillator and digital signaling capabilities. The collar locator is preferably enclosed in a titanium pressure housing that is adapted for through-tubing operations.