Abstract: Systems and methods for imaging properties of subterranean formations (136) in a wellbore (106) include a formation sensor (120, 200) for collecting currents (304A, 304B) injected into the subterranean formations (139) and a formation imaging unit (118). The formation imaging unit (118) includes a current management unit for collecting data from the currents injected into the subterranean formations (136) and a formation data unit (116) for determining at least one formation parameter from the collected data. The formation imaging unit (118) also includes an inversion unit for determining at least one formation property by inverting the at least one formation parameter. The inversion unit is suitable for generating an inverted standoff image and an inverted permittivity image for comparison with a composite image of the formation imaging unit.

Abstract: A downhole tool system may include a Stoneley wave emitter, located in a downhole tool, designed to emit Stoneley waves into a borehole. The downhole tool system may include one or more Stoneley wave sensors, located in the downhole tool, and a processor. The processor may be designed to receive signals from the one or more Stoneley wave sensors based on the detection of the Stoneley waves. The processor may use the signals to obtain a temporal measurement of the Stoneley waves. Based at least in part on the temporal measurement, the processor may calculate a distance from the downhole tool or a bottom-hole assembly to the bottom of the borehole.

Abstract: A downhole tool system may include a Stoneley wave emitter, located in a downhole tool, designed to emit Stoneley waves into a borehole. The downhole tool system may include one or more Stoneley wave sensors, located in the downhole tool, and a processor. The processor may be designed to receive signals from the one or more Stoneley wave sensors based on the detection of the Stoneley waves. The processor may use the signals to obtain a temporal measurement of the Stoneley waves. Based at least in part on the temporal measurement, the processor may calculate a distance from the downhole tool or a bottom-hole assembly to the bottom of the borehole.

Abstract: A technique generates seismic data that may be analyzed. A combination sensor is operated and deployed in a borehole to obtain orientation data, such as data related to the local magnetic field and a log of the magnetic field direction in the borehole. Following the combination sensor, at least one multi-component seismic source is deployed downhole into the borehole. The at least one multi-component seismic source comprises sensors, such as an inclinometer and a magnetometer. Data from the combination sensor and from the at least one multi-component seismic source is processed to determine an absolute orientation of the at least one multi-component seismic source.

Abstract: A downhole device may include a closed ring of ferromagnetic material mounted on a conductive pipe. The downhole device may also include a first coil spirally wound around the closed ring comprising an electrically conductive flat metallic strip to substantially cover the closed ring.

Abstract: A well-logging tool includes a magnetic field logging tool and a borehole seismic array, which includes a plurality of seismic sensor devices coupled together in series. Each seismic sensor device includes a sensor housing and at least one seismic sensor carried by the sensor housing. A magnetometer is carried by the sensor housing to sense the local magnetic field. A controller cooperates with the magnetic field logging tool to generate a log of the local magnetic field relative to the true earth geographic pole. The controller cooperates with the borehole seismic array to determine an orientation of each seismic sensor device based upon the respective sensed local magnetic field and log of the local magnetic field relative to the earth geographic pole.

Abstract: Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ?? can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.

Abstract: Techniques involve determining the conductivity profile of a formation from a well between a surface location and a borehole location. The method involves placing a first sensor at the surface location, a second sensor located at the borehole location, obtaining a first signal by detecting Schumann resonances from the electric field occurring at the first location, obtaining a second signal by detecting Schumann resonances from the electric field occurring at the second location with the second sensor; and combining the first and the second signal to determine the conductivity profile of the formation between the first location and the second location.

Abstract: A downhole device may include a closed ring of ferromagnetic material mounted on a conductive pipe. The downhole device may also include a first coil spirally wound around the closed ring comprising an electrically conductive flat metallic strip to substantially cover the closed ring.

Abstract: A technique generates seismic data that may be analyzed. A combination sensor is operated and deployed in a borehole to obtain orientation data, such as data related to the local magnetic field and a log of the magnetic field direction in the borehole. Following the combination sensor, at least one multi-component seismic source is deployed downhole into the borehole. The at least one multi-component seismic source comprises sensors, such as an inclinometer and a magnetometer. Data from the combination sensor and from the at least one multi-component seismic source is processed to determine an absolute orientation of the at least one multi-component seismic source.

Abstract: A well-logging tool includes a magnetic field logging tool and a borehole seismic array, which includes a plurality of seismic sensor devices coupled together in series. Each seismic sensor device includes a sensor housing and at least one seismic sensor carried by the sensor housing. A magnetometer is carried by the sensor housing to sense the local magnetic field. A controller cooperates with the magnetic field logging tool to generate a log of the local magnetic field relative to the true earth geographic pole. The controller cooperates with the borehole seismic array to determine an orientation of each seismic sensor device based upon the respective sensed local magnetic field and log of the local magnetic field relative to the earth geographic pole.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of radiation travelling from a source to an absorber of a differential gravimeter. The differential gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of a radiation travelling from a source to an absorber of a differential gravimeter. The gravitational potential difference determined can be converted to a density of the geological formation, e.g., based on a concentric spherical shell model. The systems can be a part of a downhole tool.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A tandem-structured gravimeter uses two gamma radiations emitted to two directions to determine a gravitational potential difference between two positions of the geological formation. The gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Techniques involve determining the frequency-dependent dielectric permittivity spectrum of a rock sample. Determining the frequency-dependent dielectric permittivity may involve defining a series of electromagnetic measurement data having at least a measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ?? can be obtained. The electromagnetic measurement data also includes measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained. Using these measurements, the frequency-dependent spectrum of the sample may be determined.

Abstract: A method for determining the frequency-dependent dielectric permittivity spectrum of a rock sample, comprising:—defining a series of electromagnetic measurement data comprising at least a first measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ??, can be obtained; and at least second and third measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained; and—using the first, second and third measurements to determine the frequency-dependent spectrum of the sample.

Abstract: Techniques involve determining the conductivity profile of a formation from a well between a surface location and a borehole location. The method involves placing a first sensor at the surface location, a second sensor located at the borehole location, obtaining a first signal by detecting Schumann resonances from the electric field occurring at the first location, obtaining a second signal by detecting Schumann resonances from the electric field occurring at the second location with the second sensor; and combining the first and the second signal to determine the conductivity profile of the formation between the first location and the second location.

Abstract: A method of inverting induction logging data for evaluating the properties of underground formations surrounding a borehole, the data including induction voltage measurements obtained from a tool placed close to the formations of interest, the method includes: (a) defining a relationship relating the induction voltage to wave number, dielectric permittivity and conductivity; defining a cubic polynomial expansion of the relationship; and solving the cubic polynomial relationship using the voltage measurements to obtain values for conductivity that includes skin-effect correction, and apparent dielectric permittivity; and (b) using the obtained values for conductivity and apparent dielectric permittivity to derive a simulated value of induction voltage; determining the difference between the simulated value of the induction voltage and the measured induction voltage; and iteratively updating the values of conductivity and dielectric permittivity used for the derivation of the simulated value of induction voltag

Abstract: A method for determining spatial distribution of fluid injected into a subsurface rock formation includes injecting the fluid into the rock formation. The fluid includes therein electrically conductive solid particles dispersed in an electrolyte. An electromagnetic response of the formation is measured. The measured electromagnetic response is used to determine spatial distribution of the injected fluid.

Abstract: Methods and devices relating to a radiation detector comprising of a gas chamber having a cathode plate and a substrate separated by a gap. An array of nano-tips deposited on the substrate that forms an anode structure for electron charge collection. An external power source in communication with the cathode plate and the substrate, wherein the external power source is capable of generating a plurality of regions and each region includes an electric field near each nano-tip of the array of the nano-tips that results in initiating a radiation induced controlled discharge of electrons and ions from at least one gas or at least one gas mixture. Finally, the plurality of regions include multiple generated electric fields near tips of the array of nano-tips such as CNTs, that communicatively create a conductive path between the cathode plate and the substrate, the radiation detector is capable of determining at least one radiation property.