Abstract: Systems and methods for active ranging-while-drilling (ARWD) for collision avoidance and/or well interception. A method for ranging while drilling may comprise employing a rotating magnet assembly to induce a changing magnetization and/or electric current in a conductive member disposed in a target wellbore, wherein the rotating magnet assembly may be employed in a second wellbore; measuring at least one component of a magnetic gradient tensor using receivers; and calculating a relative location of the conductive member based at least in part on the measurements of the at least one component of the magnetic gradient tensor.

Abstract: A system includes a gradient sensor arrangement deployed in a first borehole, the gradient sensor arrangement having a plurality of spaced sensors at a single measured depth position. The system also includes an electromagnetic (EM) transmitter deployed in a second borehole. The system also includes a processor configured to determine a distance or direction of the EM transmitter relative to the gradient sensor arrangement based on EM field measurements collected by the gradient sensor arrangement in response to an EM field emitted by the EM transmitter. The system also includes a directional drilling controller configured to update a trajectory for either the first borehole or the second borehole in response to the determined distance or direction.

Abstract: A method includes cementing a target well with a target well cement comprising resistive cement having resistivity that is greater than a resistivity of a subsurface formation through which the target well passes. The method includes injecting an injected signal into a conductive casing material at least partially surrounded by the target well cement. The method also includes receiving a resulting signal that results from the injecting at a signal receiver disposed within at least one of the target well and a drilling well separated from the target well.

Abstract: A system for well comparison, comprising at least one electromagnetic field generator shaped for insertion into a first well and capable of generating an electromagnetic field; at least one detector capable of measuring in the second well the field generated in the first well; wherein the first well is substantially perpendicular to the second well; and wherein measurements of the field of the at least one generator are capable of being used to calculate a distance, direction or curvature of the second well with respect to the first well.

Abstract: A series of electromagnetic field strength measurements is acquired from a sensor at multiple depths in a first well, responsive to an electromagnetic field originating at a second well, via at least one of a direct transmission and a backscatter transmission. A drilling phase associated with drilling operations conducted in the first well is determined. A sensor separation depth associated with the drilling phase is selected. An approximate range between the first well and the second well is calculated, based on the series of electromagnetic field strength measurements and the sensor separation depth.

Abstract: A series of electromagnetic field strength measurements is acquired from a sensor at multiple depths in a first well, responsive to an electromagnetic field originating at a second well, via at least one of a direct transmission and a backscatter transmission. A drilling phase associated with drilling operations conducted in the first well is determined. A sensor separation depth associated with the drilling phase is selected. An approximate range between the first well and the second well is calculated, based on the series of electromagnetic field strength measurements and the sensor separation depth.

Abstract: A magnetic ranging system, in some embodiments, comprises: a wellbore in a formation; a conductive casing in said wellbore; and excitation and return electrodes electrically coupled to the conductive casing, the excitation electrode positioned downhole relative to the return electrode, the excitation and return electrodes generating a current in the casing, said current resulting in an electromagnetic signal that propagates through said formation toward a sensor in another wellbore.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to detect and determine a relative distance and/or azimuthal direction of nearby target well conductors such as pipes, well casing, etc., from within a borehole of a drilling well.

Abstract: A surface excitation ranging method includes selecting a first well with a metal casing as a target well and selecting a second well with a metal casing as a ground well. The method also includes installing a supplemental grounding arrangement for a power supply located at earth's surface, wherein the ground well and the supplemental grounding arrangement fulfill an impedance criteria or ranging performance criteria. The method also includes conveying an electrical current output from the power supply along the target well. The method also includes sensing electromagnetic (EM) fields emitted from the target well due to the electrical current. The method also includes using distance or direction information obtained from the sensed EM fields to guide drilling of a new well relative to the target well.

Abstract: A surface excitation ranging method includes installing a customized grounding arrangement for a power supply located at earth's surface, wherein the customized grounding arrangement fulfills an impedance criteria or ranging performance criteria. The method also includes conveying an electrical current output from the power supply along a target well with a metal casing. The method also includes sensing electromagnetic (EM) fields emitted from the target well due to the electrical current. The method also includes using distance or direction information obtained from the sensed EM fields to guide drilling of a new well relative to the target well.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to acquire a series of electromagnetic field strength measurements from a single sensor at multiple depths in a first well, responsive to an electromagnetic field originating at a second well, via direct transmission or backscatter transmission. Further activities include determining a drilling phase associated with drilling operations conducted in the first well, selecting a sensor separation depth associated with the drilling phase, and calculating an approximate range between the first well and the second well, based on the series of electromagnetic field strength measurements and the sensor separation depth. Additional apparatus, systems, and methods are disclosed.

Abstract: A well ranging apparatus, systems, and methods which operate to detect and determine a relative distance and/or azimuthal direction of nearby target well conductors such as pipes, well casing, etc., from within a borehole of a drilling well. An electromagnetic signal receiver is rotated in a first borehole. During the rotating, an electromagnetic ranging signal is received at the electromagnetic signal receiver. The electromagnetic ranging signal originates from an electromagnetic source in the first borehole or a second borehole. A null in an Earth electromagnetic signal spectrum associated with a signal induced by the rotating within a magnetic field of the Earth is determined. The electromagnetic source to is set to operate at an excitation frequency that is selected based, at least in part, on the determined null.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to receive normal and tangential components of electromagnetic field strength measurements within a first well as a set of field strength components from at least one sensor, wherein the at least one sensor is used to take multiple azimuthal field strength measurements at a single depth. Further activities include determining an approximate range from the at least one sensor to a second well that serves as a source of an electromagnetic field, via direct transmission or backscatter transmission, when a ranging direction associated with a housing upon which the at least one sensor is mounted is unknown. Additional apparatus, systems, and methods are disclosed.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to acquire a series of electromagnetic field strength measurements from a single sensor at multiple depths in a first well, responsive to an electromagnetic field originating at a second well, via direct transmission or backscatter transmission. Further activities include determining a drilling phase associated with drilling operations conducted in the first well, selecting a sensor separation depth associated with the drilling phase, and calculating an approximate range between the first well and the second well, based on the series of electromagnetic field strength measurements and the sensor separation depth. Additional apparatus, systems, and methods are disclosed.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to detect and determine a relative distance and/or azimuthal direction of nearby target well conductors such as pipes, well casing, etc., from within a borehole of a drilling well.

Abstract: Disclosed embodiments include well ranging apparatus, systems, and methods which operate to detect and determine a relative distance and/or azimuthal direction of nearby target well conductors such as pipes, well casing, etc., from within a borehole of a drilling well.