Did You Know...
...Daniel Webster invented a "bull plow" to pull out tree stumps. It didn't catch on because it was huge and required four oxen to pull it!
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 7969152 | Systems and methods for measuring sea-bed resistivity A method for measuring the resistivity of sea-bed formations is described. An electromagnetic field is generated using at least one stationary long-range transmitter. The frequency of the electromagnetic field is between and/or including the ULF/ELF range. At least ... | 06/28/2011 |
| 7392137 | Determination of formation anistrophy, dip and azimuth Multifrequency focusing is applied to measurements made with a multicomponent resistivity logging tool in an earth formation having resisitivity anisotropy. From knowledge of relative dip and azimuth of the borehole relative to the formation, two modes can be separa... | 06/24/2008 |
| 7286100 | Adjustable antenna apparatus and method An adjustable antenna apparatus and method includes an antenna wire control device for controlling the release and retrieval of antenna wire. Antenna wire is attached to the antenna wire control device and an antenna wire tensioning device is attached to the antenna... | 10/23/2007 |
| 7262602 | Active geophysical prospecting system An active system and method for determining the physical characteristics and geological composition of subterranean formations is described. Plane polarized electromagnetic waves at specific frequencies are transmitted by a mobile transmitting antenna held stationar... | 08/28/2007 |
| 7031839 | Multi-frequency focusing for MWD resistivity tools An induction logging tool is used on a MWD bottom hole assembly. Due to the finite, nonzero, conductivity of the mandrel, conventional multi frequency focusing (MFF) does not work. A correction is made to the induction logging data to give measurements simulating a ... | 04/18/2006 |
| 7026820 | Method and apparatus for minimizing direct coupling for downhole logging devices A method and apparatus for minimizing direct coupling between transmitters and receivers on a downhole logging tool are disclosed. One embodiment includes a transmitter, a bucking device, and a plurality of receivers, where signals may be directly coupled from the t... | 04/11/2006 |
| 7023213 | Subsurface conductivity imaging systems and methods A subsurface imaging cable includes a plurality of sensor modules, wherein the plurality of the sensor modules are flexible and each of the plurality of the sensor modules is spaced apart on the subsurface imaging cable at a selected distance; and a flexible medium ... | 04/04/2006 |
| 7023331 | Peripheral monitor for monitoring periphery of vehicle The invention solves a problem of fluctuation in performance in the conventional peripheral monitor for monitoring periphery of a vehicle that measures a distance to other vehicle or any other object by transmitting radio waves and informs a driver of the distance d... | 04/04/2006 |
| 6963301 | System and method for near-field electromagnetic ranging A system for measuring distance between a first locus and a second locus includes: (a) at least one beacon device; a respective beacon device of the at least one beacon device being situated at the first locus and transmitting a respective electromagnetic signal; an... | 11/08/2005 |
| 6794875 | Induction well logging apparatus and method A coil arrangement and method of collecting and processing data in induction logging of wells is disclosed. The coil arrangement includes three essentially identical coils made of elliptical conductive loops lying in a plane tilted from the axis of the logging tool.... | 09/21/2004 |
| 6777940 | Apparatus and method for resistivity well logging Well logging apparatus and methods for determining formation resistivity at multiple (>3) depths of investigation. At least one transmitter antenna and at least two receiver antennas are mounted in a logging tool housing, on substantially a common axis. The a... | 08/17/2004 |
| 6703837 | Wellbore resistivity tool with simultaneous multiple frequencies The present invention is a propagation resistivity system that utilizes one or more transmitter coil antennas, or "transmitters" and at least two receiver coil antennas, or "receivers". The system uses a wellbore resistivity tool which may be embodied as ... | 03/09/2004 |
| 6646441 | Well logging system for determining resistivity using multiple transmitter-receiver groups operating at three frequencies An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole logging tool component of the system employs eight transmitters ... | 11/11/2003 |
| 6603312 | Multi-frequency array induction tool An apparatus and method is disclosed for induction logging of electrical properties of earth formations that operates at low frequencies while remaining resistant to skin effect and maintaining mutual balancing. The apparatus includes a plurality of trans... | 08/05/2003 |
| 6501276 | Frequency domain electromagnetic geophysical mapping instruments A frequency domain electromagnetic geophysical mapping instrument has a transmitter, a transmitter coil connected to the transmitter, the transmitter generating current pulse waveforms formed by half-sinusoidal output waveform segments of a waveform havin... | 12/31/2002 |
| 6466021 | Deep underground imaging utilizing resistivity regularization for magnetotelluric processing A method and apparatus for imaging deep underground objects utilizes the application of a spectral regularization routine that is applied to measured data prior to the application of an inversion routine to measured surface impedances to map subsurface co... | 10/15/2002 |
| 6344746 | Method for processing the lapse measurements Resistivity data acquired at two different epochs using different types of tools are jointly inverted. For example, a multiple propagation resistivity (MPR) tool is run first, preferably at several frequencies and several transmitter-receiver spacings. At... | 02/05/2002 |
| 6285190 | Skin depth compensation in underground boring applications Arrangements, specific apparatus and associated methods for skin depth compensation in underground boring applications are described. Compensation for skin depth error is accomplished by measuring a locating signal transmitted from a boring tool such that... | 09/04/2001 |
| 6218842 | Multi-frequency electromagnetic wave resistivity tool with improved calibration measurement A resistivity tool for use in an LWD system includes an asymmetric transmitter design with multiple transmitters capable of generating EM signals at multiple frequencies. A pair of receivers are positioned at one end of the transmitter array to detect the... | 04/17/2001 |
| 6104193 | System and method for detecting low metal content buried mines A method and apparatus for detecting mostly-plastic mines having steel firing pins and copper igniter cups. A frequency spectrum is transmitted, and response signals from the metal components induced by resultant eddy currents are detected. The firing pin... | 08/15/2000 |
| 5966013 | Determination of horizontal resistivity of formations utilizing induction-type logging measurements in deviated borehole A method for determining horizontal resistivity of an anisotropic formation and a formation anisotropy response factor with an induction logging tool is claimed. The method utilizes two differing induction type measurements to determine the horizontal res... | 10/12/1999 |
| 5963035 | Electromagnetic induction spectroscopy for identifying hidden objects A spectrogram of secondary magnetic field strength as a function of frequency and spatial relationship is used to identify hidden objects. A time-varying multi-frequency primary electromagnetic field is generated, preferably over the range 100 Hz to 300 k... | 10/05/1999 |
| 5907242 | Balanced passive bandpass filter and preamplifier for a receiver A balanced bandpass preamplifier assembly (23) is disclosed for use in a locator (10) for locating a beacon transmitter (18) housed within an underground boring device (12). The bandpass preamplifier assembly (23) includes a balanced bandpass filter (28) ... | 05/25/1999 |
| 5859533 | Process for the production of a supply current of a solenoid for a measuring probe for electromagnetic tomography An emitter for a system of electromagnetic tomographic measurements, as well as a process and a generator (5) adapted to produce a variable frequency current supplying a solenoid (1), constituted of turns wound about a magnetic core (3). The solenoid (1) ... | 01/12/1999 |
| 5777476 | Ground global tomography (CGT) using modulation of the ionospheric electrojets An apparatus and method for performing geological mapping utilizes an HF transmitter to heat ionospheric electrons to cause the current in an overhead electrojet to be modulated, thereby injected a low frequency EM signal into the Earth-ionosphere wavegui... | 07/07/1998 |
| 5650726 | Emitter for an electromagnetic tomography measurement system which connects a greater number of windings to a magnetic core at low frequencies than at high frequencies aN emitter for a system of electromagnetic tomographic measurement, as well as a process and a generator (5) adapted to produce a variable frequency current supplying a solenoid (1), constituted of turns wound about a magnetic core (3). The solenoid (1) i... | 07/22/1997 |
| 5642050 | Plural frequency method and system for identifying metal objects in a background environment using a target model A system for detecting metal targets located in a background environment such as the ground evaluates metal targets by processing components of signals at two or more different frequencies. A component of the received signal induced by the ground can be e... | 06/24/1997 |
| 5640092 | Electromagnetic pipe mapper for accurate location and depth determination The device comprises a target signal transmitter to induce an electromagnetic signal in the hidden object, a position reference transmitter to transmit a signal for positioning purposes, a sensor unit to detect changes in the magnetic flux of the hidden o... | 06/17/1997 |
| 5521882 | Measurement of formation characteristics using acoustic borehole tool having sources of different frequencies Apparatus and methods for determining an indication of a nonlinear property of a formation traversed by a borehole are provided. An acoustic tool is used in a borehole to generate first and second signals of different frequencies. As a result of nonlinear... | 05/28/1996 |
| 5428293 | Logging while drilling apparatus with multiple depth of resistivity investigation In an MWD system, a mandrel for connection to the drill bit is set forth which supports shallow, intermediate and deep measuring resistivity systems. By transmitting upwardly and downwardly in alternate fashion, and receiving the transmitted signal at pai... | 06/27/1995 |
| 5408182 | Facility and method for the detection and monitoring of plumes below a waste containment site with radiowave tomography scattering methods An embodiment of the present invention is a toxic waste containment facility subject to leaking hazardous plumes into soils beneath and adjacent to the site. The facility includes a plurality of substantially horizontal underground drillholes adjacent to ... | 04/18/1995 |
| 5406206 | Method of evaluating a geological formation using a logging tool including slot antenna having two nonparallel elements A slot antenna has a square aperture and two current probes at angles to each other in the aperture. The two current probes are excited simultaneously or separately with different signals. By adjusting the amplitude or phase of the signals in the current ... | 04/11/1995 |
| 5278507 | Well logging method and apparatus providing multiple depth of investigation using multiple transmitters and single receiver pair having depth of investigation independent of formation resistivity An apparatus and method for determining formation resistivity at a plurality of radial distances from an earth borehole uses a single receiver pair and a plurality of electromagnetic energy transmitters sequentially spaced along the apparatus from the rec... | 01/11/1994 |
| 5231355 | Locator transmitter having an automatically tuned antenna The present invention generally relates to a system for use in determining the location and orientation of concealed underground objects and, more particularly, to an improved locator system having a unique and improved interface with an operator. In acco... | 07/27/1993 |
| 5208539 | Method for determining electromagnetically the locations of underground ore deposits A method and apparatus for determining electromagnetically the locations of electrically conductive bodies beneath the surface of the ground, wherein a primary electromagnetic field is generated with the aid of a loop through which a sinusoidal alternatin... | 05/04/1993 |
| 5185578 | Method for detecting anomalous geological zones by transmitting electromagnetic energy between spaced drillholes using different frequency ranges A method utilized with an underground conductor detection system for calibrating a downhole transmitter to compensate for detuning of the transmitter antenna by geologic formations. The method comprises sending a synchronization signal to the transmitter ... | 02/09/1993 |
| 5157605 | Induction logging method and apparatus including means for combining on-phase and quadrature components of signals received at varying frequencies and including use of multiple receiver means associated with a single transmitter Induction logging apparatus is disclosed which depends for its operation not only upon its arrangement of coils, but also upon the skin depth of the formation. The skin effect of the formation is used advantageously by operating a simple induction sonde a... | 10/20/1992 |
| 5066917 | Long feature vertical or horizontal electrical conductor detection methodology using phase coherent electromagnetic instrumentation A method utilized with an underground conductor detection system for calibrating a downhole transmitter to compensate for detuning of the transmitter antenna by geologic formations. The method comprises sending a synchronization signal to the transmtter a... | 11/19/1991 |
| 4965522 | Multifrequency signal transmitter with attenuation of selected harmonies for an array induction well logging apparatus A transmitter for an induction well logging tool, adapted to be disposed in the borehole of an oil well, develops an output signal for energizing the borehole formation which inherently consists of six separate signal components, the six components includ... | 10/23/1990 |
| 4942360 | A method and apparatus of discrimination detection using multiple frequencies to determine a recognizable profile of an undesirable substance A conducting metal discriminating detection apparatus which uses at least two different frequencies and in preference 3 to interrogate a target. The detection apparatus distinguishes reactive and resistant components of each of the received signals and co... | 07/17/1990 |
