Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire a first signal from a first magnetometer at least partially disposed within a Helmholtz coil, to acquire a second signal from a second magnetometer having a sensitivity at least one thousand times less than the first magnetometer, to process the second signal to determine a N drive signal, to drive the Helmholtz coil using the drive signal so as to null an ambient Earth magnetic field surrounding the first magnetometer, and to process the first signal as one of a down hole location signal or a down hole telemetry signal, the location signal to determine a range to a sub-surface object, and the telemetry signal to provide data from down hole drilling operations. Additional apparatus, systems, and methods are disclosed.

Abstract: An apparatus comprising an encoded pressure signal propagating in a fluid flowing in a conduit. An optical fiber measurement element has a reflector on one end and is disposed around at least a portion of the conduit. A light source injects a second optical signal and a third optical signal propagating in first and second optical fibers, respectively. A delay section is disposed in the second optical fiber. The second optical signal and the third optical signal are directed into the optical fiber measurement element and are reflected back from the reflective end such that at least a portion of the reflected second and third optical signals propagate through the second and first optical fibers respectively to an optical detector. The optical detector senses an interference between the reflected optical signals and outputs a first signal related thereto.

Abstract: An electromagnetic telemetry repeater. At least some of the illustrative embodiments are methods comprising inducing an electrical signal along a metallic tubular (the electrical signal carrying the information and the inducing within a borehole beneath the ocean floor), sensing an electric field proximate to the ocean floor, sensing a magnetic field proximate to the ocean floor, recreating the information using one sensed field as indicative of the information and the other sensed field as indicative of the noise, and sending the information toward the ocean surface.

Abstract: Treating a subterranean formation includes injecting a magnetically permeable material into the formation and energizing the magnetically permeable material using electromagnetic radiation. The magnetically permeable material reacts to the electromagnetic radiation by producing heat. In some embodiments, a fracturing fluid is made magnetically permeable, injected into the formation to fracture the formation, and heated in response to electromagnetic radiation applied to the magnetically permeable material. In some embodiments, electromagnetically heated material is caused to explode. In some embodiments, the magnetically permeable material is tracked or monitored for fluid or fracture propagation. A system includes a fluid treatment tool disposed on a tubing string for injecting magnetically permeable material and an electromagnetic wave generator disposed on the tubing string proximate the fluid treatment apparatus for applying electromagnetic radiation to the magnetically permeable material.

Abstract: A method and system for determining a property of a sample of fluid in a borehole. A fluid sample is collected in a downhole tool. While collecting, X-rays are transmitted proximate the fluid from an X-ray source in the tool and an X-ray flux that is a function of a property of the fluid is detected. The detected X-ray flux data is processed to determine the property of the fluid.

Abstract: An improved system and method for ranging while drilling, in effect, induces a dynamic hot spot on the casing of a nearby well. The induced hot spot acts as a magnetic source that can be reliably detected from within the drillstring and in such a manner as to infer the relative position and orientation of the casing to the drillstring. At least some disclosed method embodiments employ one or more rotating magnets in the drillstring, an array of at least two magnetometers in the drillstring and one or more phase-locked loops that are used to enhance the signal to noise ratio of the magnetic signal scattered off of the casing from the rotating magnetic field. The rotating magnet or magnets may be magnetic dipoles or magnetic multipoles, and may be modulated to enable the use of multiple magnetic field sources.

Abstract: A method of characterizing a formation is disclosed. A well bore is drilled in the formation. Cuttings are retrieved from the well bore while drilling the formation and a hyperspectral image of the cuttings is continuously obtained. The hyperspectral image of the cuttings is analyzed to determine formation characteristics.

Abstract: A downhole sensor calibration apparatus includes a rotational or gimbaling mechanism for guiding a sensing axis of an orientation responsive sensor through a three-dimensional orbit about three orthogonal axes. A method includes using measurements taken over the three-dimensional orbit to calibrate the sensor and determine other characteristics of the sensor or tool.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to launch a set of currents into a corresponding set of existing well casings; monitor, in a well under construction, changes in at least one of a magnetic field or an electric field perturbed by the set of currents after each one of the set is launched; and determine a location of the well under construction in relation to the set of existing well casings. In some embodiments, the activities include inducing current into a drillstring located in a well under construction; monitoring, at a set of existing well casings, changes in at least one of a magnetic field or an electric field perturbed by the current after the current is induced; and determining a location of the well under construction in relation to the set of existing well casings. Additional apparatus, systems, and methods are disclosed.

Abstract: An apparatus for detecting data in a fluid pressure signal in a conduit comprises an optical fiber loop comprises a measurement section and a delay section wherein the measurement section is disposed substantially circumferentially around at least a portion of the conduit, and wherein the measurement section changes length in response to the fluid pressure signal in the conduit. A light source injects a first optical signal in a first direction into the measurement section and a second optical signal in a second direction opposite the first direction into the delay section. An optical detector senses an interference phase shift between the first optical signal and the second optical signal and outputs a first signal related thereto.

Abstract: A magnetostrictor assembly (100) includes a magnetostrictor element (105), a conductor coupled to the magnetostrictor element, and a bluff body (101) coupled to the magnetostrictor element via a transfer arm (103). The bluff body is to be placed in a fluid flow path to, at least in part, produce motion that, at least in part, causes strain in the magnetostrictor element. A preload mechanism comprising a control circuit (1100) may optimize a magnetostrictive generator.

Abstract: A downhole sensor calibration apparatus includes a rotational or gimbaling mechanism for guiding a sensing axis of an orientation responsive sensor through a three-dimensional orbit about three orthogonal axes. A method includes using measurements taken over the three-dimensional orbit to calibrate the sensor and determine other characteristics of the sensor or tool.

Abstract: A method and system for determining a property of a sample of fluid in a borehole. A fluid sample is collected in a downhole tool. While collecting, X-rays are transmitted proximate the fluid from an X-ray source in the tool and an X-ray flux that is a function of a property of the fluid is detected. The detected X-ray flux data is processed to determine the property of the fluid.

Abstract: An apparatus comprising an encoded pressure signal propagating in a fluid flowing in a conduit. An optical fiber measurement element has a reflector on one end and is disposed around at least a portion of the conduit. A light source injects a second optical signal and a third optical signal propagating in first and second optical fibers, respectively. A delay section is disposed in the second optical fiber. The second optical signal and the third optical signal are directed into the optical fiber measurement element and are reflected back from the reflective end such that at least a portion of the reflected second and third optical signals propagate through the second and first optical fibers respectively to an optical detector. The optical detector senses an interference between the reflected optical signals and outputs a first signal related thereto.

Abstract: Apparatus, systems, and methods may operate to receive radiated energy as scattered energy after the radiated energy interacts with a geologic formation, wherein the scattered energy is received at a sub-surface multi-channel sensor array that operates to transform the scattered energy into received signals, and wherein the radiated energy is provided by a sub-surface source of elastic energy; and to identify discontinuous features in the geologic formation by interferometric comparison of the received signals as elastic signals and/or electromagnetic signals among some sensors in the sensor array, or by time-reversal propagation of the received signals as elastic and/or electromagnetic signals in a numeric model of a volume of the geologic formation. Additional apparatus, systems, and methods are disclosed.

Abstract: Procedures are described for monitoring dynamics along a drill string during the drilling process using only surface instrumentation or using a combination of surface and downhole instrumentation. Events such as drill collar whirl may be identified from signatures found in signals generated by an electromagnetic sensor such as a magnetometer and/or from a mechanical sensor such as accelerometer. Additional embodiments are described.

Abstract: A method and device for measuring a property, such as torque, includes a plurality of sensors, and a measuring device. The sensors attach to a downhole apparatus at a distance from one another. The sensors provide signals indicating their positions. A logic circuit may calculate an angle between the sensors. The logic circuit then calculates the property based on the angle, the distance between the sensors, and other known physical properties of the downhole apparatus.

Abstract: A method of generating an axial shear wave in a formation surrounding a wellbore comprising urging a clamp pad into contact with a wall of the wellbore, and applying an axial force to the clamp pad to impart a shear force into the wall of the wellbore to generate a shear wave in the formation.

Abstract: In some example embodiments, a system includes a drill string having a drill bit. The drill string extends through at least part of a well bore. The system also includes a first vibrational sensor, positioned on the drill bit to measure, at a first location on the drill string, an amplitude of one or more of an axial vibration and a lateral vibration. The system also includes a second vibrational sensor, positioned above the drill bit and on the drill string. The second vibration sensor is to measure, at a second location on the drill string, one or more of an axial vibration and a lateral vibration. The system includes a processor unit to determine a type of vibration based on a comparison of the amplitude at the first location to the amplitude at the second location, wherein the type of vibration is at least one of bit whirl of the drill bit and a while of a bottom hole assembly that is part of the drill string.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to launch a set of currents into a corresponding set of existing well casings; monitor, in a well under construction, changes in at least one of a magnetic field or an electric field perturbed by the set of currents after each one of the set is launched; and determine a location of the well under construction in relation to the set of existing well casings. In some embodiments, the activities include inducing current into a drillstring located in a well under construction; monitoring, at a set of existing well casings, changes in at least one of a magnetic field or an electric field perturbed by the current after the current is induced; and determining a location of the well under construction in relation to the set of existing well casings. Additional apparatus, systems, and methods are disclosed.