Abstract: A method for reconstructing a borehole image includes determining a spatial sensitivity function for a borehole imaging tool and using the imaging tool to obtain a borehole image of a subterranean formation. A reconstructed image is then computed from the borehole image and the spatial sensitivity function.

Abstract: Determining an electrical property of a formation fluid. At least some of the illustrative embodiments are methods comprising drawing formation fluids into a tool within a borehole, applying a swept frequency electric field to the formation fluids by way of a first winding, inducing a current flow in a second winding based on the swept frequency electric field, and determining a property of the formation fluids based, at least in part, on the current flow in the second winding.

Abstract: The present invention is directed to methods for assessing flow-induced electrostatic energy in an oil and/or gas well wherein electric current or electrostatic potential or both are measured to produce data correlating to at least one flow characteristic of a tubular segment in the well. In some embodiments, electric current and electrostatic potential are produced separately for a plurality of segments, and measured. The system further may adjust at least one flow characteristic of a segment of the well to increase hydrocarbon production from the well.

Abstract: A drilling system includes integral drill bit body and logging while drilling tool body portions. There are no threads between the drill bit and the LWD tool. In one exemplary embodiment the drilling system includes a unitary tool body, i.e., a tool body formed from a single work piece. In another exemplary embodiment the drill bit body portion is welded to the LWD tool body portion. At least one LWD sensor is deployed in the drill bit. The drilling system enables multiple LWD sensors to be deployed in and near the bit (e.g., on both the side and bottom faces of the bit). The absence a threaded connection facilitates the placement of electrical connectors, LWD sensors, and electronic control circuitry at the bit.

Abstract: Method and apparatus to determine the relative and/or absolute position of a phase change in a fluid reservoir comprising hydrocarbons by providing a first wire in a borehole within the reservoir; providing a reference system to the first wire in the borehole; transmitting an electromagnetic signal through the first wire; detecting a detected response to the electromagnetic signal from the first wire; generating a reference response from the reference system; using the reference response to correct the detected response; and determining the phase change position using data from the corrected response. Reference systems in the form of a second wire; a transmission line and an electronic equivalent circuit simulation model; and an electrical model of the first wire and borehole, are described.

Abstract: An apparatus and method for measuring the conductivity of borehole fluid. Based on the fluid conductivity, the fluid type may also be identified. The apparatus and method can be useful in differentiating between native water and injected water in oil recovery operations. The apparatus and method presented can also be used to calibrate testing and production equipment allowing for more reliable and accurate measurements. The apparatus and method presented can further be used to better characterize water to oil ratio in reservoirs.

Abstract: A method of measuring the permittivity and/or conductivity of a multiphase fluid flowing through a conduit is provided. The method includes the steps of measuring the signal from a first electromagnetic transmitter to a first electromagnetic receiver separated by a first distance, measuring the signal from the first electromagnetic transmitter to a second electromagnetic receiver separated by a second distance, measuring the signal from a second electromagnetic transmitter to the first electromagnetic receiver separated by a distance substantially equal to the second distance, measuring the signal from the second electromagnetic transmitter to the second electromagnetic receiver separated by a distance substantially equal to the first distance, and wherein the first and second distances are substantially different.

Abstract: A body coil assembly for a magnetic resonance apparatus has a first coil and a second coil for generating a radio-frequency field in space, and a power control apparatus connected to the first coil and the second coil for controlling the transmitting power of the first coil and the second coil. In a method for generating a radio-frequency field using such a body coil assembly, the transmitting powers of the first coil and the second coil are controlled, to provide unequal transmitting powers to the first coil and the second coil when needed to generate a required radio-frequency field distribution, so as to form a stronger field strength at a certain position, thus improving the signal to noise ratio at that position during the receiving process.

Abstract: Embodiments of the present invention provide systems and methods for detection and/or measurement of gaseous components of multiphase mixtures containing one or more hydrocarbons that may be retrieved down a wellbore or may be being transported in a pipeline. More specifically, but not by way of limitation, embodiments of the present invention may provide for separation of the gaseous components from the multiphase mixtures and detection and/or measurement of the separated gaseous components by direct oxidation or reduction.

Abstract: The present disclosure relates to a method to determine a characteristic of a subsurface formation using a downhole logging tool. A downhole logging tool having the ability to make substantially concurrent disparate measurements on the subsurface formation is provided and substantially concurrent disparate measurements on the formation using the downhole logging tool are made. Those measurements are used to solve a system of equations simultaneously and the solution to the system of equations is used to determine the characteristic of the subsurface formation.

Abstract: The present invention relates to the development of tracer fluids, more generally, that of aqueous liquids, intended to be injected under pressure in an oil reservoir, for example from an injection well up to a production well. The object of the invention is to propose a new method of study of a solid medium, i.e. an oil reservoir, by diffusion of a liquid (i.e. injection waters) containing tracers, through said solid medium, which is simple to implement and economical and which remedies the drawbacks of the known tracers for injection waters of oil reservoirs.

Abstract: An apparatus for estimating a property of a fluid in a borehole penetrating the earth includes a piezoelectric material configured to be at least partially immersed in the fluid and embedded with a first electrode pair and a second electrode pair. An electronic unit is coupled to the first electrode pair and the second electrode pair and configured to measure motion impedance of the fluid caused by motion of the piezoelectric material by applying a first electrical stimulus to the first electrode pair and a second electrical stimulus to the second electrode pair and by receiving a first electrical signal from the first pair of electrodes and a second electrical signal from the second pair of electrodes to estimate the property. The resulting motion impedance measurement has a reduced influence from electrical properties of the fluid.

Abstract: A system for measuring a resistivity parameter of an earth formation includes: at least one measurement electrode electrically connected to a first electrical source; at least one guard electrode; a shielding electrode interposed between the at least one guard electrode and the at least one measurement electrode, the shielding electrode being electrically connected to a second electrical source independent from the first electrical source, and the guard electrode being electrically connected to a third electrical source independent of the first and second electrical sources; at least one return electrode; insulators positioned between (i) the measurement electrode and the shielding electrode, (ii) the shielding electrode and the guard electrode and (iii) the measurement electrode, the guard electrode and the return electrode; and a processor configured to adjust at least one of the first electrical source and the second electrical source to minimize a current flow through the shielding electrode.

Abstract: A fluid sensor (and method) for determining at least one parameter of a fluid of a wellbore is provided. The fluid sensor has a base positionable in the wellbore, a base electrode operatively positionable in the insulation, and a raised electrode having at least one base portion and at least one raised portion. The base comprises insulation. The base portion is operatively positionable in the insulation. The at least one raised portion is positionable a distance above the base electrode such that a space is defined therebetween for the passage of the wellbore fluid therethrough. A voltage is applied across the base electrode and the raised electrode to generate a current therebetween whereby at least one parameter of the wellbore fluid may be determined. The fluid sensor is deployable into the wellbore via the downhole tool.

Abstract: A fluid sensor and method for determining at least one parameter of a fluid of a wellbore is provided. The fluid sensor has a base positionable on a downhole tool and a pair of electrodes. The base is provided with insulation. The pair of electrodes is operatively positioned in the insulation. The pair of electrodes has a space therebetween for passage of the wellbore fluid therethrough. A first of the pair of electrodes is interlaced with a second of the pair of electrodes such that at least a portion of the second of the pair of electrodes is surrounded by the first of the pair of electrodes. A voltage applied across the pair of electrodes generates a current therebetween whereby at least one parameter of the wellbore fluid may be determined. The fluid sensor is deployable into the wellbore via the downhole tool.

Abstract: A high voltage power supply particularly for use in small diameter spaces such as in oil well logging devices. An axial linear high voltage step-up transformer has an integral through hole in the internal ferrite, low voltage sensing signals may be passed through from the output section of the power supply. In addition, a magnetic field shield is designed into the device to prevent eddy currents from forming in the metallic pressure vessel housing which is used to contain the neutron generating tube which is under pressure of an insulating gas such as sulfur hexafluoride. By constructing an axial transformer, and passing the signal leads through the internal hole, the largest amount of internal dielectric may be utilized, increasing the reliability of the transformer. By containing the magnetic field and limiting the eddy currents induced in outside metals, the converter efficiency may be raised to the maximum possible.

Abstract: An electrochemical sensor for the presence or concentration of an analyte has at least one electrode and at least one electrochemically active species able to undergo electrochemical reaction in response to electrical potential applied to the electrode, where the said reaction is modified by the presence of the analyte. This sensor has the novel characteristic that at least one said electrochemically active species is encapsulated within polymer particles. These particles are preferably formed from an amorphous polymer with a glass transition temperature above the temperature of the fluid to which the sensor is exposed. The encapsulating polymer protects the analyte species from degradation, but a small analyte such as a hydrogen or bisulfide ion can pass through the polymer and undergo reaction at the active species.

Abstract: Methods for imaging geological structures include injecting magnetic materials into the geological structures, placing at least one magnetic probe in a proximity to the geological structures, generating a magnetic field in the geological structures and detecting a magnetic signal. The at least one magnetic probe may be on the surface of the geological structures or reside within the geological structures. The methods also include injecting magnetic materials into the geological structures, placing at least one magnetic detector in the geological structures and measuring a resonant frequency in the at least one magnetic detector. Methods for using magnetic materials in dipole-dipole, dipole-loop and loop-loop transmitter-receiver configurations for geological structure electromagnetic imaging techniques are also disclosed.

Abstract: The position of a movable downhole component such as a sleeve in a choke valve is monitored and determined using an array of sensors, preferably Hall Effect sensors that measure the strength of a magnetic field from a magnet that travels with the sleeve. The sensors measure the field strength and output a voltage related to the strength of the field that is detected. A plurality of sensors, with readings, transmits signals to a microprocessor to compute the magnet position directly. The sensors are in the tool body and are not mechanically coupled to the sleeve. The longitudinal position of the sleeve is directly computed using less than all available sensors to facilitate the speed of transmission of data and computation of actual position using known mathematical techniques.

Abstract: This invention relates to a method for evaluating and measuring the geometry of a fracture.

Abstract: A system for detecting a location of a subsurface water channel includes an anchor electrode for disposal in a first body of water and a mobile electrode for disposal in a second body of water. An electric current source can be coupled to at least one of the mobile electrode and the anchor electrode to generate an electric current between the mobile electrode to the anchor electrode. A lead line can be coupled to the mobile electrode to enable the mobile electrode to move a distance in the second body of water. An ammeter can be coupled to the anchor electrode to measure the electric current from the mobile electrode. A processor can compare the current with the length of the lead line to determine the location of the subsurface water channel.

Abstract: A method of monitoring an extent of a hydrocarbon reservoir (2) below the earth's surface (4), includes the steps of applying a current between a bottom current electrode (6) and a top current electrode (8) that is part of a plurality of electrodes that are spaced apart from one another along a part of the earth's surface located above and optionally over the hydrocarbon reservoir. The bottom current electrode is positioned below the hydrocarbon reservoir. The method includes the step of measuring an electrical potential, which is caused by the current, by means of a measurement electrode (10A) that is also part of the plurality of electrodes. The method includes the step of inferring from the measured electrical potential the extent of the hydrocarbon reservoir, in a direction that is oriented substantially parallel with the earth's surface.

Abstract: Subterranean sensing devices configured or designed for downhole use to sense a local condition in the well. The sensing devices comprise one or more transistor having at least one carbon nanotube field effect transistor (CNT FET) configured or designed for operation downhole, within a borehole.

Abstract: An apparatus and method for estimating the at least one resistivity parameter using at least one processor to estimate capacitance information, wherein the capacitance information is estimated using only one selected frequency electromagnetic signal. The apparatus may include at least one measure electrode. The apparatus may also include a transverse antenna. The method may include imparting an electric current at only one selected frequency into a formation using the at least one measure electrode. The method may also include using capacitance information to estimate a standoff between the at least one measure electrode and a borehole wall. In some embodiments, the estimated capacitance information may be used to reduce errors due to eccentricity.

Abstract: An apparatus and method for estimating a parameter of interest in a downhole fluid using fluid testing module. The fluid testing module may include: a substrate comprising at least one microconduit, and a sensor. The sensor may be disposed within the at least one microconduit or external. The apparatus may include a fluid mover for moving fluid within the microconduit. The method includes estimating a parameter of interest using the fluid testing module.

Abstract: An apparatus and method for reducing coupling between at least one measure electrode and at least one return electrode in a logging tool in a borehole with non-conductive drilling fluid using a conductive shield disposed between the at least one measure electrode and the at least one return electrode. The apparatus may be configured to impart an electrical current into a formation and to receive a return current from the formation. The method may include using the apparatus.

Abstract: A method for determining water saturation in a subsurface formation include determining an invasion depth in the formation from a plurality of measurements made within a wellbore drilled through the formation. The measurements have different lateral depths of investigation into the formation. Carbon and oxygen in the formation are measured at substantially a same longitudinal position as at a position of the determining the invasion depth. The measured carbon and oxygen and the invasion depth are used to determine the water saturation in a substantially uninvaded part of the formation.

Abstract: A sensor for measuring water fraction in a fluid mixture flowing in a conductive tubing within a borehole. The sensor comprises: an active probe, a reference probe, and an electronic unit. The active probe includes a first electrode and a second electrode isolated from each other by a first insulating layer, the first and second electrodes are preferably in contact with the fluid mixture. The reference probe is formed from an internal wall of the conductive tubing contacting the fluid mixture and isolated from the reference probe by a second insulating layer. The electronic unit is coupled to the first and second electrodes, and to the reference probe, the electronic unit preferably includes a capacitance module for measuring a capacitance between the active probe and the reference probe.

Abstract: A sensor used to determine the height of one or more fluids in a fluid column and to determine a location of an interface or boundary between a plurality of fluids in a fluid column is disclosed. The sensor includes a plurality of sensing elements comprising a capacitor and other components, such as resistors and inductors. The sensor also includes an oscillator that alters a frequency of an electrical current applied to the sensor, from which the dielectric constant of the fluid in which each sensing element is disposed can be determined. Methods of using such a sensor to determine the relative heights of various fluids in a fluid column are disclosed. In particular, methods of using embodiments of the invention in a well, such as water and petroleum wells, are described.

Abstract: Disclosed is a method and apparatus for measuring in-situ stress in rock using a thermal crack. The method involves forming a borehole, cooling a wall of the borehole, applying tensile thermal stress, forming a crack in the borehole wall, and measuring temperature and cracking point. Afterwards, the borehole wall is heated to close the formed crack, the borehole wall is cooled again to re-open the crack, and temperature is measured when the crack is re-opened. The in-situ stress of the rock is calculated using a first cracking temperature at which the crack is formed and a second cracking temperature at which the crack is re-opened. Further, the apparatus cools, heats and re-cools the borehole wall, thereby measuring the first cracking temperature, the second cracking temperature, and the cracking point.

Abstract: An apparatus for estimating a property of a downhole fluid, the apparatus includes: a carrier configured to be conveyed through a borehole penetrating the Earth; a downhole fluid extraction device disposed at the carrier and configured to extract the downhole fluid; and a dielectric spectrometer disposed at the carrier and configured to transmit electromagnetic energy into the extracted downhole fluid at a plurality of frequencies and to measure a plurality of responses to determine a permittivity of the extracted downhole fluid as a function of frequency; wherein the permittivity is used to estimate the property.

Abstract: A transient electromagnetic wave is generated using an electromagnetic instrument in a borehole. An apparent resistivity is estimated using a received signal responsive to the generated wave and further used to estimate a resistivity property of a fluid in the borehole.

Abstract: A method for determining permeability of a subsurface formation includes measuring a parameter related to fluid content of the formation at a first time from within a wellbore penetrating the formation. A rate of entry of fluid from the wellbore into the formation is determined from the measurement of the parameter made at the first time. The permeability is determined from the rate of entry.

Abstract: A logging sonde includes a tube defining a sealed chamber inside. An isolation layer is disposed on an exterior of the tube. At least one sensor is disposed on an exterior of the isolation layer. The sensor includes a lead in passing through a wall of the tube. An elastomer jacket is disposed on an exterior of the sensor and the isolation layer. A method for making a sonde includes affixing an electrically insulating isolator to an exterior of a tube. An hydraulic seal layer is affixed over an exterior of the isolator. A sensor is affixed over the exterior of the seal layer. An electrical connection is made from the sensor to an interior of the tube through the hydraulic seal layer and through the isolator. An elastomer jacket is applied over the exterior of at least part of the sensor and the exterior of the seal layer.

Abstract: The rock mass thermal excitation is performed by means of pumping the flush fluid through the wellbore using a tubing string, the flush fluid temperature differs from the rock mass temperature. Before the thermal excitation, during the thermal excitation and after the termination thereof differential electrical signals proportional to the well bore temperature difference are registered by at least one pair of the temperature transducers positioned along the wellbore axis. The distances between the transducers in the pairs and the number of pairs is selected in advance based on the required accuracy of the determination of the rock mass areas with different properties, minimum and maximum possible length of the rock mass areas identified and the nature and degree of the wellbore temperature noise.

Abstract: A scorotron corona charger including a grid electrode is provided. A layer including a zeolite, a resistance controlling agent, and a binder is formed on the grid electrode. The binder resin has a solubility parameter of 10.0 cal1/2cm?3/2 or less.

Abstract: Example vibrating helical spring sensors and methods to operate the same are disclosed. A disclosed example apparatus includes a housing, a helical spring held in tension, a flowline to expose the helical spring to a fluid, a magnet to expose the helical spring to a magnetic field, and a wire to electrically conduct an actuating current through the helical spring to displace the helical spring.

Abstract: Determining an electrical property of a formation fluid. At least some of the illustrative embodiments are methods comprising drawing formation fluids into a tool within a borehole, applying a swept frequency electric field to the formation fluids by way of a first winding, inducing a current flow in a second winding based on the swept frequency electric field, and determining a property of the formation fluids based, at least in part, on the current flow in the second winding.

Abstract: An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.

Abstract: A method of measuring a parameter characteristic of a rock formation in an oil well is provided for evaluating a reservoir treatment applied to a subterranean formation including the steps of injecting from a tool body suspended into a well at an injection location a known volume of fluid into the formation, performing a logging operation sensitive to a change of fluid content at several measuring points below and above the injection location; and using results of the logging operation to determine a depth profile along said well of a parameter related to fluid content.

Abstract: Measurements made by a multi-component induction logging tool are corrected for tool eccentricity in a deviated borehole. The eccentricity angle is determined from single frequency skin-effect corrected data and is then used to correct multifrequency data. Multifrequency focusing is then applied to the corrected multifrequency data. An inversion is then used to recover formation resistivity and relative dip and azimuth of the borehole.

Abstract: Embodiments of the present invention provide systems and methods for detection and/or measurement of gaseous components of multiphase mixtures containing one or more hydrocarbons that may be retrieved down a wellbore or may be being transported in a pipeline. More specifically, but not by way of limitation, embodiments of the present invention may provide for separation of the gaseous components from the multiphase mixtures and detection and/or measurement of the separated gaseous components by direct oxidation or reduction.

Abstract: A sensor used to determine the height of one or more fluids in a fluid column and to determine a location of an interface or boundary between a plurality of fluids in a fluid column is disclosed. The sensor includes a plurality of sensing elements comprising a capacitor and other components, such as resistors and inductors. The sensor also includes an oscillator that alters a frequency of an electrical current applied to the sensor, from which the dielectric constant of the fluid in which each sensing element is disposed can be determined. Methods of using such a sensor to determine the relative heights of various fluids in a fluid column are disclosed. In particular, methods of using embodiments of the invention in a well, such as water and petroleum wells, are described.

Abstract: Transducer apparatus for subsurface use. A tubular configured for subsurface disposal is equipped with a cylindrical transducer module formed of a non-conductive material. The module is mounted to surround a section of the tubular and includes a transducer element disposed thereon such that only a surface of the element is exposed along the exterior of the module body. The transducer element is linked to a lead routed through the cylindrical body to exit near the inner bore of the body. The ends of the cylindrical body are covered with a material to form a hydraulic seal. A method for constructing the transducer apparatus.

Abstract: In a method and apparatus for estimating a downhole fluid parameter include a body having an elongated cavity defined by an electrically conductive inner surface, an central electrical conductor located coaxially within the cavity, wherein an annular region is defined by the cavity inner surface and an outer surface of the electrical conductor. A fluid is conveyed to the annular region. A first electrode is coupled to the central electrode, a second electrode coupled to the central electrode, and at least one intermediate electrode coupled to the central electrode between the first electrode and the second electrode. An input signal is applied to the central electrode and first and second output signals are emitted from the second electrode intermediate electrode. The output signals are used in part to estimate the fluid property of the fluid existing in the annular region.

Abstract: A method and apparatus are provided for insulating electrical connections to a resonator from fluid downhole under extreme pressure and temperature conditions downhole. The method and apparatus provide a pliable insulator that maintains electrical isolation between resonator electrical connections during exposure to high pressures downhole. The insulator is evacuated or placed in a vacuum prior to curing to remove bubbles from the insulator material. The insulator is then heat cured. The insulator is substantially chemically non reactive so that the insulator maintains electrical isolation between the resonator electrical connections during exposure to fluids downhole. The insulator has a thermal coefficient of expansion in a range so that the insulator maintains electrical isolation between the resonator electrical connections during exposure to high temperatures downhole.

Abstract: A method of determining the nature of a submarine or subterranean reservoir having an electromagnetic characteristic is described. The method comprises analyzing data associated with the application of a time varying electromagnetic field from above the reservoir using a data analysis methodology that does not utilize an estimate of the reservoir's geometry in determining one or more characteristics of the reservoir.

Abstract: A method and an apparatus for producing hyperpolarized samples for use in magnetic resonance imaging (MRI) are provided. The apparatus comprises an ultra-compact cryogen-free cryostat structure for use in polarizing a sample of selected material, wherein the cryostat structure comprises a central bore being adapted to be evacuated to create a vacuum region, and a cooling device inserted in the central bore or optionally close to the central bore for maintaining a selected temperature of the sample.

Abstract: An integrated framework is described for automating some or all of mud slowness estimation for both fast and slow formations. An estimation of fluid slowness based on monopole radial profiling is calculated if conditions permit. Alternatively, an estimation of fluid slowness based on Scholte wave slowness is estimated if conditions do not permit calculation based on monopole radial profiling. Tool standoff may also be estimated based on monopole radial profiling.

Abstract: An embodiment of the apparatus includes a first drill collar section having an outer surface, an MWD tool for interaction with an earth formation coupled to the first drill collar section, the MWD tool including a first fluid line and a first electrical conduit, a second drill collar section, and an interconnect assembly coupling the second drill collar section to the first drill collar section, the interconnect assembly comprising a fluid line connection coupled to the first fluid line and an electrical connection coupled to the first electrical conduit. Another embodiment of the apparatus includes a probe, an interconnect assembly adapted for fluid communication and electrical communication, and a sample bottle drill collar section including at least one removable sample bottle in fluid communication with the probe. Another embodiment of the apparatus includes a flush pump mounted in the power collar section and coupled to the probe.