Abstract: A multicomponent induction logging tool is positioned within an alignment loop and the transmitter is activated at a number of rotation angles of the tool. Misalignment between the transmitter and receiver coils can be determined from the induced signals in the receiver coil.

Abstract: The present invention provides a method and apparatus for using an acoustic logging tool conveyed in a borehole in an earth formation for determining a characteristic of the formation. The method comprises using a first acoustic source for generating an acoustic signal in the earth formation at a first frequency. A second acoustic source spaced apart from the first source is used for generating an acoustic signal in the earth formation at a second frequency different from the first frequency. An acoustic receiver is used for receiving a third acoustic signal indicative of said characteristic. The third acoustic signal has a frequency substantially equal to a difference between the first frequency and the second frequency. The third acoustic signal is produced by a nonlinear interaction between the first signal and the second signal in a portion of said earth formation.

Abstract: A drilling system provides indications of the lithology of the formation being drilled by dynamically measuring at least one parameter of interest that is affected by the lithology of the formation being drilled. Suitably positioned sensors make dynamic measurements of parameters such as downhole weight on bit, bit torque, bit revolutions, rate of penetration and bit axial acceleration. One or more processors use the sensor measurements in conjunction with predetermined lithological models to determine whether the measurements indicate a change in formation lithology. Suitable models can be on derived expressions such as rock drillability, drilling response, dynamic drilling response, normalized or dimensionless torque; and formation shear strength. The lithological indications provided by the processor can be used to adjust drilling parameters, steer the BHA, monitor BHA health, and provide depth locations for bed boundaries and formation interfaces.

Abstract: Resolution of thin beds made by a natural gamma ray logging tool is improved using a relation between the width of the response and the bed thickness. The peak gamma ray of the bed is determined using another relation between the measured gamma ray response and the bed thickness.

Abstract: A method of estimating a formation pressure in a wellbore is provided that in one aspect includes measuring a hydrostatic pressure at a selected location in the wellbore, and estimating supercharge pressure as a function of time using a forward model that utilizes the hydrostatic pressure and at least one property of mud in the wellbore that is a function of time. In another aspect, the method may estimate an initial formation pressure at a selected location in a wellbore by obtaining a hydrostatic pressure and at least three formation pressure measurements at three separate times at the selected location, and estimating the initial formation pressure using the hydrostatic pressure, the three pressure measurements and an internal mudcake parameter.

Abstract: An apparatus for and a method of generating electrical power downhole using a quantum thermoelectric generator and operating a downhole device using the generated power.

Abstract: The present invention provides a method and apparatus for logging an earth formation and acquiring subsurface information wherein a logging tool is conveyed in borehole to obtain parameters of interest. The parameters of interest obtained may be density, acoustic, magnetic or electrical values as known in the art. The parameters of interest may be transmitted to the surface at a plurality of resolutions using a multi-resolution image compression method. Parameters of interest are formed into a plurality of Cost Functions from which Regions of Interest are determined to resolve characteristics of the Features of interest within the Regions. Feature characteristics may be determined to obtain time or depth positions of bed boundaries and borehole Dip Angle relative to subsurface structures, as well borehole and subsurface structure orientation. Characteristics of the Features include time, depth, and geometries of the subsurface such as structural dip, thickness, and lithologies.

Abstract: A seismic data acquisition system includes a connector housing and a mating electrical circuitry module. A single interface couples electrical circuitry housed in the electrical circuitry module to one or more signal data carriers that are consolidated at a single location in the connector housing. Preferably, the connector housing and electrical circuitry module each have a substantially contaminant-free interior regardless of whether these two parts are mated. An alternate connector housing has two plug casings, each of which are provided with a plug. A complementary alternate electrical circuitry module includes two receptacles complementary to the plugs and an interior space for holding the electrical circuitry. A locking pin disposed within the plug casing selectively engages the electrical circuitry module.

Abstract: Passive and active suppression of casing signals is used to improve the ability to measure formation velocities. Passive suppression includes the use of a magnet slidably coupled to the casing. Active suppression uses measurement of casing signals to control the output of an electromechanical acoustic transducer which cancels the propagating signal. Feedback control may be provided.

Abstract: Dynamic gain setting is provided for a multiphase flow measuring device that measures in-phase and quadrature signals. The average current at a plurality of measure electrodes is determined and subtracted from the individual measure currents to give a measurement with improved dynamic range.

Abstract: A procedure to determine VSP-WD (Vertical Seismic Profiling—While Drilling) first breaks in absolute time is described. By combining a seismic surface source and firing complex seismic pattern unique in time (with a highly accurate surface—downhole time reference system), an automatic downhole procedure for first break detection on the downhole data, even under harsh conditions (low signal to noise ratio), is established. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: Misalignment of the transmitter and receiver coils of an induction logging tool is determined by positioning the logging tool with a coil axially encompassing the transmitter coil and/or the receiver coil, and activating the transmitter at a plurality of rotational angles.

Abstract: Misalignment of the transmitter and receiver antennas of an induction logging tool is determined by positioning the logging tool with a conducting loop magnetically coupled to the transmitter antenna and/or the receiver antenna, and activating the transmitter at a plurality of rotational angles.

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: A phased array of transducers is used to generate elastic waves into the earth formation in a selected direction. The impedance measured at the input to the transducer array is indicative of the elastic impedance of the earth formation in the selected direction.

Abstract: A resistivity imaging tool is used in a borehole having a conductive fluid. Second differences between axially spaced apart electrodes are used in the imaging. A calibration compensates for the effects of borehole rugosity.

Abstract: Elemental analysis of an earth formation is obtained using measurements from a gamma ray logging tool. From the elemental analysis, an estimate of the Calcium, Magnesium and Carbon content of the formation is determined. The amount of organic carbon in the formation is estimated from the total Carbon content and the inorganic carbon associated with minerals in the formation. An indication of source rock may be obtained from the Th/U ratio.

Abstract: A system for remotely controlling, acquiring and monitoring the acquisition of seismic data. The system includes remote equipment for collecting seismic data and for transmitting and receiving communication signals to and from a remote location. The system also includes local equipment for transmitting and receiving communication signals to and from the remote location. In this manner, the collection of seismic data at remote locations can be controlled and monitored locally.

Abstract: Measurements made with a multicomponent logging instrument when used in a substantially horizontal borehole in earth formations provide diagnostic of the direction of beds relative to the position of the borehole. When the logging instrument is conveyed on a drilling assembly, the drilling trajectory may be maintained to follow a predetermined trajectory or to maintain a desired distance from a boundary such as an oil-water contact.

Abstract: A resistivity imaging device injects currents in two orthogonal directions using two pairs of return electrodes and performing impedance measurements of the buttons placed between the returns.