Received Signal Cycle Discrimination Patents (Class 367/34)
  • Patent number: 9448321
    Abstract: A method for torsional wave logging in a borehole of a subterranean formation. The method includes obtaining a torsional wave measurement of the borehole, wherein the torsional wave measurement represents characteristics of a torsional wave propagating within a cylindrical layered structure associated with the borehole, wherein the cylindrical layered structure comprises the subterranean formation and a completion of the borehole, analyzing, by a computer processor, the torsional wave measurement to generate a quality measure of the completion, and displaying the quality measure of the completion.
    Type: Grant
    Filed: January 4, 2013
    Date of Patent: September 20, 2016
    Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: Bikash K. Sinha, Sandip Bose, Jiaqi Yang, Ting Lei, Tarek M. Habashy, Smaine Zeroug, Ma Luo
  • Patent number: 8902703
    Abstract: Downhole positioning systems and associated methods are disclosed. In some embodiments, the system comprises a downhole source, an array of receivers, and a data hub. The downhole source transmits an electromagnetic positioning signal that is received by the array of receivers. The data hub collects amplitude and/or phase measurements of the electromagnetic positioning signal from receivers in the array and combines these measurements to determine the position of the downhole source. The position may be tracked over time to determine the source's path. The position calculation may take various forms, including determination of a source-to-receiver distance for multiple receivers in the array, coupled with geometric analysis of the distances to determine source position. The electromagnetic positioning signal may be in the sub-hertz frequency range.
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: December 2, 2014
    Assignee: Halliburton Energy Services, Inc.
    Inventor: Paul F. Rodney
  • Publication number: 20140192618
    Abstract: An acoustic logging tool is provided with a first acoustic source that generates an acoustic signal primarily directed into the formation, the acoustic signal including a noise signal carried axially along the tool, a second acoustic source adapted to generate a noise canceling signal along the tool that actively and significantly cancels the noise signal, and a plurality of acoustic sensors axially spaced from each other along the tool and spaced from the first acoustic source and the second acoustic source. The acoustic sensors receive and record indications of pressure signals resulting from the acoustic signal and the noise canceling signal. The pressure signal indications may be processed in order to generate information regarding the formation.
    Type: Application
    Filed: January 8, 2013
    Publication date: July 10, 2014
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: JAHIR PABON, GREGOIRE CASOETTO
  • Patent number: 8625390
    Abstract: A method for making acoustic logging measurements includes grouping received acoustic waveforms into one of a plurality of groups, each group being representative of a measured borehole condition (e.g., a range of measured standoff values and/or a range of measured azimuth angles). The waveforms stored in at least one of the groups are stacked so as to obtain an averaged waveform. The averaged waveform may be further processed, for example, via a semblance algorithm to obtain at least one acoustic wave slowness.
    Type: Grant
    Filed: August 18, 2010
    Date of Patent: January 7, 2014
    Assignee: Schlumberger Technology Corporation
    Inventors: Tsili Wang, Paul Boonen
  • Publication number: 20130343158
    Abstract: A tool is described for seismic data collection which may have sensors mounted along its entire length to sample both geophysical signal and noise including at least one of acoustic noise, system noise, and noise resulting from the interaction between the two. Systems and methods for acquiring borehole seismic data are also described. In contrast to conventional systems which attempt to avoid introducing noise into the collected data stream, the present systems include a sufficient type, number, and spacing of sensors to intentionally sample at least one source of noise. The methods include operating a borehole seismic acquisition system to sample both a target signal and at least one source of noise and using a processor with machine-readable instructions for separating the noise from the signal.
    Type: Application
    Filed: May 30, 2013
    Publication date: December 26, 2013
    Inventors: Julian Edward Kragh, Philip A. F. Christie, Emmanuel Coste, Nicolas Goujon, Clement Kostov
  • Patent number: 8547789
    Abstract: A method for determining on a real time logging while drilling (LWD) basis gas within earth formations traversed by a borehole. Continuous LWD acoustic measurements are recorded and processed including coherent energy and attenuation attributes to detect downhole gas zones and kick during drilling operations.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: October 1, 2013
    Assignee: Schlumberger Technology Corporation
    Inventors: Peter T. Wu, Alain Dumont, Pierre Campanac, David Linton Johnson
  • Patent number: 8542553
    Abstract: A downhole acoustic measurement tool includes at least one transmitter longitudinally spaced apart from a non-uniformly spaced longitudinal array of acoustic receivers. The array has a non-uniform spacing such that a first spacing between a first pair of consecutive acoustic receivers in the array is not equal to a second spacing between a second pair of consecutive acoustic receivers in the array. Non-uniform spacing of the receivers in the array reduces aliasing when the received waveforms are processed, for example, to obtain semblance data.
    Type: Grant
    Filed: February 4, 2010
    Date of Patent: September 24, 2013
    Assignee: Schlumberger Technology Corporation
    Inventor: Tsili Wang
  • Patent number: 8270248
    Abstract: A method for initializing the input of each of m receiver channels of a receiving transducer in a well logging tool comprising the steps of selecting a logging tool having a multi-element receiving transducer wherein each element of the multi-element receiving transducer operates in an anti-resonant mode below its resonant frequency, and executing a routine in an initialization mode wherein a predetermined number of run cycles are operated and receiver input responses are measured and averaged for each of the m channels while transmitter firing signals are disabled.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: September 18, 2012
    Assignee: Probe Technology Services, Inc.
    Inventors: Brian Hurst, John L. Marshall
  • Publication number: 20120120765
    Abstract: A method of interrogating a formation includes generating a conical acoustic signal, at a first frequency—a second conical acoustic signal at a second frequency each in the between approximately 500 Hz and 500 kHz such that the signals intersect in a desired intersection volume outside the borehole. The method further includes receiving, a difference signal returning to the borehole resulting from a non-linear mixing of the signals in a mixing zone within the intersection volume.
    Type: Application
    Filed: November 9, 2011
    Publication date: May 17, 2012
    Applicants: Los Alamos National Security, Chevron U.S.A. Inc.
    Inventors: Cung Khac VU, Christopher Skelt, Kurt Nihei, Paul A. Johnson, Robert Guyer, James A. Ten Cate, Pierre-Yves Le Bas, Carène S. Larmat
  • Publication number: 20110188345
    Abstract: A downhole acoustic measurement tool includes at least one transmitter longitudinally spaced apart from a non-uniformly spaced longitudinal array of acoustic receivers. The array has a non-uniform spacing such that a first spacing between a first pair of consecutive acoustic receivers in the array is not equal to a second spacing between a second pair of consecutive acoustic receivers in the array. Non-uniform spacing of the receivers in the array reduces aliasing when the received waveforms are processed, for example, to obtain semblance data.
    Type: Application
    Filed: February 4, 2010
    Publication date: August 4, 2011
    Applicant: SMITH INTERNATIONAL, INC.
    Inventor: Tsili Wang
  • Publication number: 20110149684
    Abstract: A method for initializing the input of each of m receiver channels of a receiving transducer in a well logging tool comprising the steps of selecting a logging tool having a multi-element receiving transducer wherein each element of the multi-element receiving transducer operates in an anti-resonant mode below its resonant frequency, and executing a routine in an initialization mode wherein a predetermined number of run cycles are operated and receiver input responses are measured and averaged for each of the m channels while transmitter firing signals are disabled.
    Type: Application
    Filed: February 11, 2011
    Publication date: June 23, 2011
    Applicant: Probe Technology Services, Inc.
    Inventors: Brian Hurst, John L. Marshall
  • Publication number: 20110019501
    Abstract: In an acoustic logging system utilizing one or more acoustic sources, each with a specified radiation pattern around a source orientation, an acoustic signal is transmitted into a formation with a source oriented in a first source orientation. An acoustic waveform is received in response with a receiver oriented in a first direction. The slowness of the formation in the first direction is calculated using the received acoustic waveform.
    Type: Application
    Filed: April 1, 2009
    Publication date: January 27, 2011
    Inventor: Jennifer Anne Market
  • Publication number: 20100149914
    Abstract: An apparatus for imaging an earth formation, the apparatus including: a logging instrument configured to be conveyed through a borehole penetrating the earth formation; a source of acoustic waves disposed at the logging instrument, wherein the source is configured to emit first acoustic waves having at least a first frequency and to enable intermodulation of the first acoustic waves in a medium having a nonlinear acoustic property resulting in generating new acoustic waves that are transmitted to the earth formation, the new acoustic waves having a new frequency different from the at least first frequency; and a receiver of acoustic waves configured to receive the new acoustic waves reflected from the earth formation, wherein the received new acoustic waves provide an image of the earth formation.
    Type: Application
    Filed: December 10, 2009
    Publication date: June 17, 2010
    Applicant: BAKER HUGHES INCORPORATED
    Inventor: Anjani R. Achanta
  • Patent number: 7675813
    Abstract: Methods and systems for taking measurements related to subterranean formations. The methods and systems provide robust, reliable first arrival data for component signals of interest, which may be used to estimate formation slowness, characterize formation slowness zones, or act as an input to other processes. The methods and systems are capable of automatically providing good first arrival data based on signals received without any human interaction, and without setting or changing any parameters.
    Type: Grant
    Filed: August 6, 2008
    Date of Patent: March 9, 2010
    Assignee: Schlumberger Technology Corporation
    Inventors: Henri-Pierre Valero, Mauricio Tejada
  • Publication number: 20080285382
    Abstract: Methods and systems for taking measurements related to subterranean formations. The methods and systems provide robust, reliable first arrival data for component signals of interest, which may be used to estimate formation slowness, characterize formation slowness zones, or act as an input to other processes. The methods and systems are capable of automatically providing good first arrival data based on signals received without any human interaction, and without setting or changing any parameters.
    Type: Application
    Filed: August 6, 2008
    Publication date: November 20, 2008
    Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION
    Inventors: HENRI-PIERRE VALERO, MAURICIO TEJADA
  • Patent number: 7423930
    Abstract: Methods and systems for taking measurements related to subterranean formations. The methods and systems provide robust, reliable first arrival data for component signals of interest, which may be used to estimate formation slowness, characterize formation slowness zones, or act as an input to other processes. The methods and systems are capable of automatically providing good first arrival data based on signals received without any human interaction, and without setting or changing any parameters.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: September 9, 2008
    Assignee: Schlumberger Technology Corporation
    Inventors: Henri-Pierre Valero, Mauricio Tejada
  • Patent number: 6920083
    Abstract: A method for automatic classification, according to various selection criteria, of seismic or microseismic events picked up by seismic receivers coupled with an underground formation under development, according to whether the events are purely of microseismic nature or depend, on any account, on artifacts related to the outer environment or to formation development or monitoring activities, and for selection of the significant parts of traces for the purpose of analysis. The method has an application for monitoring of production or storage reservoirs under development.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: July 19, 2005
    Assignee: Institut Francais du Petrole
    Inventors: Jean-François Therond, Jean-Pierre Deflandre, Christian Grouffal
  • Patent number: 6837332
    Abstract: An apparatus (10) and method are disclosed for eliminating a noise signal from at least one source during an acoustic measurement of a subsurface geological formation or borehole. The apparatus (10) includes a longitudinal body for positioning in the borehole and a transmitter (22) supported by the body for transmitting acoustic signals into the formation and borehole. A sensor (23), substantially isolated within the body, is used to detect one or more noise signals and a receiver (24) is carried by the body for receiving acoustic signals traversing the formation and borehole, and for receiving one or more noise signals.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: January 4, 2005
    Assignee: Halliburton Energy Services, Inc.
    Inventor: Paul F. Rodney
  • Patent number: 6643220
    Abstract: Apparatus and methods are disclosed for enabling vapor handling in printing. In certain implementations, for example, one or more volatiles emitted during an ink-based printing process may be condensed into one or more liquids. The one or more liquids may be directed into absorbent materials such that the combined liquids and absorbent materials form a substance that qualifies as a solid, as determined by a given solid definition or regulatory standard. In certain (alternative but non-exhaustive) implementations, the volatiles emitted during printing may include water and oil, with the oil vapor being condensed into a liquid and added to the absorbent materials while the water vapor is being forwarded under the force of, e.g., negative air pressure.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: November 4, 2003
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Richard Anderson, Yi-Hua Tsao
  • Patent number: 6630890
    Abstract: A borehole logging tool system includes a surface system, a logging array, and a logging cable providing power supply and data paths connecting the logging array to the surface system, wherein the logging array includes a series of discrete sondes connected together. The sondes in the logging array, for example a borehole seismic logging array, are connected to their neighbours by means of lengths of logging cable. Such cable can be the same as that connecting the logging array to the surface system. The logging array can also include a master controller module which communicates with the surface system and which includes a first controller module which connects to the surface system and a second controller which controls operation of the sondes in the logging array independently of any other borehole logging tools connected to the surface system.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: October 7, 2003
    Assignee: Schlumberger Technology Corporation
    Inventors: Tatsuki Endo, David Mathison, Jiro Takeda
  • Patent number: 6618322
    Abstract: A method and apparatus for determining acoustic mud velocity and bore hole caliper in a downhole environment. A highly accurate acoustic signal is adjusted for mud velocity as continuously measured. The borehole standoff is utilized to compensated data collected downhole in determining a parameter of interest in the wellbore or an adjacent formation.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: September 9, 2003
    Assignee: Baker Hughes Incorporated
    Inventor: Dan T. Georgi
  • Patent number: 5780784
    Abstract: A system for eliminating the tool mode signal from a received combined signal comprising both tool mode and formation mode components, comprising: a formation receiver for receiving said combined signal, a reference receiver for receiving a tool mode reference signal, a filter for processing said tool mode reference signal and generating a predicted tool mode component of the combined signal, and a summation element for subtracting said predicted tool mode component from said combined signal and generating a predicted formation mode component. The filter preferably incorporates a portion of the output of the summation element as an error signal, enabling the filter to adapt to changing conditions and update the algorithm on which it makes its predictions. According to an alternative system, an average value for the tool mode signal is updated according to a moving average to which new data points are added as they become available.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: July 14, 1998
    Assignee: Halliburton Energy Services, Inc.
    Inventor: Carl A. Robbins
  • Patent number: 5724308
    Abstract: A downhole acoustic logging tool having a random access memory for storing acoustic waveforms in digital format. The waveforms being transmitted from a surface logging system to the random access memory in the downhole logging tool. The logging tool playing back the stored waveforms by converting the stored digital format into an analog signal that is amplified sufficiently for driving an acoustic transmitter. A received pilot signal is used to determine the signal attenuation of the logging cable and a correction is made therefrom to the actual received acoustic signal. Complex waveform types may be programmed into the random access memory for specific formation characteristics. Tapered turn-on and turn-off of the signal waveform amplitudes reduce higher frequency spectral noise that may interfere when correlating the received acoustic signal with the transmitted acoustic signal.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: March 3, 1998
    Assignee: Western Atlas International, Inc.
    Inventors: Martin H. Sorrells, Thomas S. Smith, Donald L. Canterbury
  • Patent number: 5654938
    Abstract: A method for detecting alteration of earth formations penetrated by a wellbore. The method includes determining a first arrival velocity of dipole acoustic energy propagated through the earth formations. A first frequency dependent velocity of the dipole acoustic energy is then determined. A first dispersion characteristic is determined from the difference between the first arrival and frequency dependent velocities. The method includes determining a frequency dependent velocity and a first arrival velocity for synthesized waveforms for an unaltered formation. The synthesis uses the first arrival velocity of the dipole acoustic energy as a shear velocity. A second dispersion characteristic, related to a difference between the frequency dependent velocity and the first arrival velocity of the synthesized waveforms is determined. The alteration is detected by finding a difference between the first dispersion characteristic and the second dispersion characteristic.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: August 5, 1997
    Assignee: Western Atlas International, Inc.
    Inventor: Xiaoming Tang
  • Patent number: 5541890
    Abstract: A method of determining the acoustic propagation velocity of an earth formation penetrated by a wellbore by processing signals from an array acoustic wellbore logging tool. The tool includes a transmitter and a plurality of receivers axially spaced apart from the transmitter. The method includes the steps of combining signals generated by ones of the receivers in response to acoustic energy propagated through the wellbore from the transmitter, to generate a synthesized signal corresponding to another one of the receivers. The step of combining includes time shifting signals from the ones of the receivers by an amount corresponding to a predetermined velocity for each propagation mode and the axial distance between the ones of receivers and the other receiver. The synthesized signal is compared to the signal generated at the other receiver in response to the acoustic energy to determine a degree of correspondence between the synthesized signal and the received signal.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: July 30, 1996
    Assignee: Western Atlas International, Inc.
    Inventor: Xiaoming Tang
  • Patent number: 5502686
    Abstract: A method for concurrently gathering acoustic and resistivity data for mapping the texture of the sidewall of a borehole using a single imaging tool. The data are sampled, formatted and merged to provide a single composite image of the borehole sidewall.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: March 26, 1996
    Assignee: Western Atlas International
    Inventors: Efraim Dory, Martin Evans, Albert A. Alexy
  • Patent number: 5289433
    Abstract: A multi-mode receiver sonde having individual receiver stations. The receiver stations have transducers which have a flat frequency response over a selected bandwidth so that there is an approximately constant ratio in amplitude and substantially little phase difference between the response signal and an input acoustic signal from a liquid containing borehole.The wide-band output response signals are combined to form composite signals which represent selected borehole propagation modes. Accurate comparisons can then be made between the composite signals obtained by separate receiver stations so that changes in phase and amplitude over distance and time can be determined.In one highly preferred embodiment, the receiver sonde has a semi-rigid receiver array. The semi-rigid receiver array is adapted to decouple noise (tool-mode noise and/or road-noise) in one location within the array from other locations within the array by using compliant spacers between the receiver stations to absorb and scatter the noise.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: February 22, 1994
    Assignee: Shell Oil Company
    Inventors: Christopher S. Cowles, Jacques P. Leveille, Paul J. Hatchell, Jesus A. Mireles, Robert D. Clifton
  • Patent number: 5278805
    Abstract: Methods and related apparatus for conducting shear slowness logging are set forth. The methods broadly comprise: detecting dispersive waves such as flexural or Stoneley waves; Fourier transforming the received signals; backpropagating the Fourier transformed signals according to equations using different dispersion curves; stacking the backpropagated signals; and finding semblances in order to choose the dispersion curve of maximum semblance and thereby identifying the shear slowness of the formation. Formation shear slowness may be plotted over borehole depth. Different embodiments are set forth. In one preferred embodiment (QDSTC), prior to Fourier transforming, the signals are stacked according to a previous estimation of slowness (S.sub.0), and are windowed for maximum energy. The reduced set of data in the window are then extracted for Fourier transformation, and prior to backpropagation, multiplied by S.sub.0 to reset them for backpropagation and stacking.
    Type: Grant
    Filed: October 26, 1992
    Date of Patent: January 11, 1994
    Assignee: Schlumberger Technology Corporation
    Inventor: Christopher V. Kimball
  • Patent number: 5226017
    Abstract: The invention relates to a method and apparatus for acquiring borehole seismic data in two opposite directions in a borehole. Acquisition consists in emitting a pressure wave (R, R') at a point (E) in the borehole (PU), and, at a point (R) in the borehole (PU) that is offset relative to the pressure wave emission point (E), in detecting the echoes reflected and refracted by the adjacent geological formations (Ci) in such a manner as to discriminate between pressure waves reflected and refracted by the above-mentioned geological formations in a longitudinal plane of symmetry (P) of the borehole (PU). The discrimination is performed on the basis of detecting the sum and the difference of echo signals coming from opposite directions. The invention is applicable to determining horizons above and below an inclined borehole.
    Type: Grant
    Filed: August 19, 1991
    Date of Patent: July 6, 1993
    Assignee: Compagnie Generale de Geophysique
    Inventor: Jean-Pierre Fortin
  • Patent number: 5159577
    Abstract: Improved techniques are provided for correcting signals from a downhole sensor on a drill collar eccentrically rotating within a borehole. The corrected sensor signal may be used to generate a well log which more accurately represents the conditions which the sensor would have generated had the tool been rotating such that the spacing between the sensor and the borehole well remained constant. The sensor signals are generated at time intervals of less than half the period of rotation of the drill collar. The frequency components of the time-varying sensor signals are plotted, and the frequency component attributable to the eccentric rotation between the drill collar and the borehole may be determined. The magnitude of this frequency component may be used to generate a correcting sensor signal, which then modifies the average sensor signal so that a more accurate well log may be obtained.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: October 27, 1992
    Assignee: Baroid Technology, Inc.
    Inventor: James R. Twist
  • Patent number: 5159578
    Abstract: A borehole logging tool having a dipole acoustic energy source and at least one spaced-apart dipole acoustic energy receiver is lowered into a deviated borehole. A motor rotates the source and receiver about the axis of the borehole tool. A first signal is produced representing source and receiver rotational position relative to a vertical direction. A second signal is produced representing a fixed reference level. A comparator produces a third signal of the difference between the first and second signals. The motor rotates so as to minimize such third signal, thereby maintaining the focus of the source and receiver in a horizontal direction that is perpendicular to the direction of eccentricity of the borehole tool with respect to the borehole axis.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: October 27, 1992
    Assignee: Mobil Oil Corporation
    Inventors: Will K. Lenhardt, Charles L. Dennis, Denis P. Schmitt
  • Patent number: 5130950
    Abstract: Pulse echo apparatus and methods are disclosed for measuring characteristics of a borehole while it is being drilled. A component of a bottomhole assembly, preferably a drilling collar, is provided with one or more ultra-sonic transceivers. A pulse echo sensor of the transceiver is preferably placed in a stabilizer fin of the collar, but may also be placed in the wall of the collar, preferably close to a stabilizing fin. Electronic processing and control circuitry for the pulse-echo sensor is provided in an electronic module placed within such collar. Such pulse echo apparatus, which preferably includes two diametrically opposed transceivers, generates signals from which standoff from a borehole wall may be determined. A method and apparatus are provided for measuring standoff and borehole diameter in the presence of drilling cuttings entrained in the drilling fluid. In a preferred embodiment, such signals are assessed by the electronic processing and control circuity to determine if gas has entered borehole.
    Type: Grant
    Filed: May 16, 1990
    Date of Patent: July 14, 1992
    Assignee: Schlumberger Technology Corporation
    Inventors: Jacques Orban, James C. Mayes
  • Patent number: 5124952
    Abstract: A method for enhancing a plurality of recorded waveforms from sonic logging is disclosed. As a function of depth along a well borehole, a plurality of sonic waveforms is obtained. Adjacent waveforms are registered by time shifting so that common event coincides between adjacent waveforms. Typically this is the arrival of the P, S or S.sub.t wave component. Then, adjacent waveforms are subtracted from one another to provide a difference waveform, and the difference waveforms are then presented. This enhances oblique occurring events. Further, instantaneous waveform characteristics for each of the recorded waveforms are presented to further assist in data interpretation to locate and identify oblique occurring events.
    Type: Grant
    Filed: May 17, 1989
    Date of Patent: June 23, 1992
    Assignee: Halliburton Logging Services, Inc.
    Inventors: Stanislav Knize, John W. Minear
  • Patent number: 5058077
    Abstract: The technique according to the present invention is useful for generating a corrected well log which otherwise would include erroneous signals from downhole sensor. Such signal error may be caused, for example, by periodic movement of the drill collar axis with respect to the borehole axis, eccentric rotation of the drill collar with respect to the borehole, or a whirling or precessing of the drill collar in the borehole. According to the technique of the present invention, these sensor signals are generated at time intervals of less than one-half the period of the highest frequency of the periodic movement. Discrete sensor signals are averaged to generate an average sensor signal as a function of borehole depth. Discrete sensor signals are also recorded to generate a time-varying sensor signal profile, the magnitude of frequency components of the time-varying sensor signal profile is determined, and the average sensor signal is corrected as a function of the determined magnitude of the frequency components.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: October 15, 1991
    Assignee: Baroid Technology, Inc.
    Inventor: James R. Twist
  • Patent number: 5010527
    Abstract: The depth of a hydraulic fracture zone is determined by sensing and recording seismic wave motion at a series of spaced depths in a portion of a bore hole subjected to fracturing pressure during a shut-in period after the application of pressure while the fracture zone is unstable, and analyzing such motion recordings by eliminating components not attributable to the fracturing and discrete components from seismic sources attributable to the fracturing to determine an average background level of vertical and horizontal components, and comparing the average background level of the horizontal components of motion to the vertical component of motion to provide an indication of the presence or absence of fracturing at each depth.
    Type: Grant
    Filed: November 29, 1988
    Date of Patent: April 23, 1991
    Assignee: Gas Research Institute
    Inventor: Kenneth D. Mahrer
  • Patent number: 4985873
    Abstract: A well logging system includes a digital threshold crossing data generation system (TCDG System) disposed in a well tool, adapted to be disposed in a borehole, and a digital first motion detection (DFMD) software disposed in a memory of a well truck computer. The TCDG system generates a series of threshold crossings for each analog signal received from a receiver of the well tool, the threshold crossings including a plurality of threshold crossing events for each analog signal and representing compressed versions of digitized analog waveforms. The well logging truck computer receives the threshold crossing data from the TCDG system and executes the DFMD software. When the software is executed, a first set of compressional wave first arrival times are determined from a startup routine in the software using the threshold crossing data.
    Type: Grant
    Filed: October 20, 1989
    Date of Patent: January 15, 1991
    Assignee: Schlumberger Technology Corporation
    Inventors: Kevin A. Eyl, Andrew L. Kurkjian, David J. Lineman, Edward A. Pierce, Joseph M. Steiner, Jr.
  • Patent number: 4951266
    Abstract: The present invention is directed to filtering out unwanted components contained in acquired sonic well logging data, e.g., reflected wave components, converted wave components, casing arrivals, tool arrivals and/or noise. In the filtering method, the waveform components of each waveform are treated as vectors, each vector having n samples. The vectors, described in n-dimensional space, are rotated to a new coordinate system whose directions, characterized as eigenvectors, are aligned with the primary directions of the wave component vectors. The eigenvectors are ordered such that the first eigenvector represents the wave components' main direction, the second eigenvector represents the wave components' next main direction, et cetera. By projecting the waveform components onto the principal eigenvectors, the reflected wave components, converted wave components and/or noise component of each waveform is substantially eliminated. Methods are also disclosed for approximating the eigenvectors.
    Type: Grant
    Filed: April 28, 1989
    Date of Patent: August 21, 1990
    Assignee: Schlumberger Technology Corporation
    Inventor: Kai Hsu
  • Patent number: 4901289
    Abstract: A system is provided for acquiring and recording signals delivered by a set of sensors disposed in one or more probes lowered into a well at the end of a multi-function cable.The different signals to be transmitted are multiplexed before being applied to an acquisition chain adapted for amplifying them, digitizing them and coding them before applying them to a transmission channel in the form of blocks of digitized words. The multiplexing means may comprise several multiplexing units. The sampling frequency of each signal and the formation of the blocks of words are adapted to the number of units effectively used. In the surface installation, the blocks of words are dissociated and stored in a memory in a single mode suitable for all the blocks whatever their formation.
    Type: Grant
    Filed: May 31, 1988
    Date of Patent: February 13, 1990
    Assignee: Institut Francais Du Petrole
    Inventors: Jacques Cretin, Jean-Francois Therond
  • Patent number: 4875197
    Abstract: A method of measuring the propagation velocity of one or more of a plurality of different types of elastic waves in a borehole. It employs a source of elastic waves at a given location in a borehole. The elastic waves generated have a given known frequency. There are a plurality of receivers spaced at different distances from the source. The signals developed by the receivers are digitally multiplexed at a high scan rate relative to the generated frequency. Then the multiplexed signals are analyzed to determine the wave lengths of the received signals. From the wave lengths the propagation velocities, v, may be computed by using the fundamental relationship v=f.lambda., in which f is the frequency and .lambda. is the wave length.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: October 17, 1989
    Assignee: Texaco Inc.
    Inventor: Eike Rietsch
  • Patent number: 4817059
    Abstract: Waveform data obtained in a borehole by a tool having a sonic source and an array of sonic detectors is analyzed to obtain an image of formation features within several tens of feet of the borehole, such as fractures, bed boundaries and other boreholes. A value of background sonic slowness is derived from the data and used to determine the sonic energy transit time from the source to each detector via each point in a grid of points extending into the formation and along the borehole. The time for a particular detector/point pair is used to extract the amplitude of the waveform from that detector at that time relative to operation of the source. Such amplitudes for the same point and for different detectors and tool positions are cumulated. The final values for all points are plotted as a variable density display which provides the desired image.
    Type: Grant
    Filed: June 26, 1987
    Date of Patent: March 28, 1989
    Assignee: Schlumberger Technology Corporation
    Inventors: Brian E. Hornby, Ralphe Wiggins
  • Patent number: 4771724
    Abstract: A non-pyrotechnic lighting device is disclosed whereby intrusion into a restricted area can be monitored and detected by the use thereof. Triggering of the device is effected remotely by the unsuspecting subject.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: September 20, 1988
    Assignee: American Cyanamid Company
    Inventors: Bruce H. Baretz, C. Dexter Ware
  • Patent number: 4703427
    Abstract: A method for evaluating the quality of the cement surrounding a borehole casing is provided. The method generally comprises obtaining signals which were recorded by a CET tool known in the art, and processing the signals by: dividing each signal into particularly defined time windows; determining absolute magnitudes for each signal which are functions of the energy of the signal in the respective windows; determining normalized magnitudes for each signal from the absolute magnitudes and normalization parameters; and evaluating the quality of cementation as a function of the fact that the normalized magnitudes for each signal obey a predetermined law, and as a function of the relationship between each normalized magnitude and a pair of threshold values respectively associated therewith.According to another aspect of the invention, information obtained from a CBL tool known in the art is compared to the information gained from the CET tool.
    Type: Grant
    Filed: August 21, 1985
    Date of Patent: October 27, 1987
    Assignee: Schlumberger Technology Corporation
    Inventors: Gerard Catala, Ian Stowe, Daniel Henry
  • Patent number: 4531204
    Abstract: In a representative embodiment of the invention described herein, a well logging system for investigating subsurface formations is controlled by a general purpose computer programmed for real-time operation. The system is cooperatively arranged to provide for all aspects of a well logging operation, such as data acquisition and processing, tool control, information or data storage, and data presentation as a well logging tool is moved through a wellbore. The computer controlling the system is programmed to provide for data acquisition and tool control commands in direct response to asynchronous real-time external events. Such real-time external events may occur, for example, as a result of movement of the logging tool over a selected depth interval, or in response to requests or commands directed to the system by the well logging engineer by means of keyboard input.
    Type: Grant
    Filed: August 18, 1980
    Date of Patent: July 23, 1985
    Assignee: Schlumberger Technology Corporation
    Inventor: David J. Vanderschel
  • Patent number: 4527260
    Abstract: A seismic exploration method is disclosed for filtering the signals produced by a detector placed at different depths in a well in response to an emission of acoustic waves from a source on the surface: the signals comprising downgoing wave components and upgoing wave components.The filtering consists in sampling from among the N signals to be processed a group of n signals s.sub.1 . . . s.sub.n detected at respective levels x.sub.1 . . . x.sub.n, in determining the propagation time t.sub.k of the acoustic waves from the level x.sub.1 to each level x.sub.k, in both advancing and delaying the signals s.sub.k by the time t.sub.k in relation to s.sub.1, in adjusting the signals for the effects of the acoustic impedance of the formation, in combining s.sub.1 and the signals s.sub.k thus shifted and adjusted to obtain a sum z.sub.1 ', in calculating a sum y.sub.1 ' of s.sub.1 and of the thus delayed and adjusted signals s.sub.k, and in generating a signal u.sub.1.sup.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: July 2, 1985
    Assignee: Schlumberger Technology Corporation
    Inventor: Leon Horowicz
  • Patent number: 4524432
    Abstract: By establishing a slow compressional wave in subsurface formations, and then measuring the velocity of the slow compressional wave, one can obtain useful information about the porosity and formation factor of the formations through which the slow compressional wave has passed.
    Type: Grant
    Filed: December 15, 1981
    Date of Patent: June 18, 1985
    Assignee: Schlumberger Technology Corporation
    Inventor: David L. Johnson
  • Patent number: 4428072
    Abstract: Apparatus and method for recording seismic signals on a logging chart as a function of the depth of a logging sonde within a well bore includes apparatus for analyzing the seismic signals. The method utilizes the recording of information relating to the slope of a seismic signal received from the sonde. A recording trace is made using successive horizontal sweeps with no vertical deflection, and presence of a mark on the recording can indicate a positive slope for the seismic signal, and the absence of a mark can indicate a negative slope. An apparatus of the present invention utilizes this method to record well logging information obtained from seismic signals.
    Type: Grant
    Filed: October 6, 1980
    Date of Patent: January 24, 1984
    Assignee: Gearhart Industries Incorporated
    Inventor: Samuel E. Johns, Jr.
  • Patent number: 4397004
    Abstract: A seismic exploration method is disclosed for filtering the signals produced by a detector placed at different depths in a well in response to an emission of acoustic waves from a source on the surface: the signals comprising downgoing wave components and upgoing wave components.The filtering consists in sampling from among the N signals to be processed a group of n signals s.sub.l . . . s.sub.n detected at respective levels x.sub.l . . . x.sub.n, in determining the propagation time t.sub.k of the acoustic waves from the level x.sub.l to each level x.sub.k, in advancing the signals s.sub.k by the time t.sub.k in relation to s.sub.l and in adding s.sub.l and the signals s.sub.k thus shifted to obtain a sum z.sub.l, in calculating a sum y.sub.l of s.sub.l and of the signals s.sub.k delayed by the time t.sub.k in relation to s.sub.l, in generating a signal u.sub.l *, defined as an optimum estimation of the upgoing wave component, from the sums y.sub.l and z.sub.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: August 2, 1983
    Assignee: Schlumberger Technology Corporation
    Inventor: Seeman Bronislaw
  • Patent number: 4367541
    Abstract: The disclosure is directed to an apparatus and method for determining the velocity of acoustic wave energy propagating information surrounding a borehole. In accordance with one form of the apparatus, a transmitter is positioned in the borehole and periodically establishes acoustic wave energy in the surrounding formations. The acoustic wave energy is received at a plurality of spaced locations in the borehole and a plurality of signals are derived which are respectively representative of the wave energy received at the plurality of spaced locations in the borehole. Means are provided, for correcting a first portion of the signal from one of the receiver locations with first portions of signals from the other receiver locations. The time references of the first portion of the signals from the other locations are determined from an assumed velocity in conjunction with the time reference of the first portion of the signal from the one receiver location and the distance to each of the other receivers.
    Type: Grant
    Filed: December 6, 1979
    Date of Patent: January 4, 1983
    Assignee: Schlumberger Technology Corporation
    Inventor: Bronislaw Seeman
  • Patent number: 4320470
    Abstract: An improved well logging technique is provided for more accurately deriving acoustic measurements of subsurface earth formations. Method and apparatus are described for converting an acoustic signature which can be generated on a depth dependent or time dependent basis, into digital format and subsequently employing special processing techniques to yield parameters such as velocity of the transmitted acoustic energy through earth formations and the amplitude of the received acoustic energy. Processing further allows for the generation of noise immunity signals functionally related to a measured signature parameter and for the generation of amplitude control signals. Additionally, a control signal is generated to optimize transmitter firing rate.
    Type: Grant
    Filed: April 13, 1979
    Date of Patent: March 16, 1982
    Assignee: Dresser Industries, Inc.
    Inventor: Jorg A. Angehrn
  • Patent number: RE34975
    Abstract: Pulse echo apparatus and methods are disclosed for measuring characteristics of a borehole while it is being drilled. A component of a bottomhole assembly, preferably a drilling collar, is provided with one or more ultra-sonic transceivers. A pulse echo sensor of the transceiver is preferably placed in a stabilizer fin of the collar, but may also be placed in the wall of the collar, preferably close to a stabilizing fin. Electronic processing and control circuitry for the pulse-echo sensor is provided in an electronic module placed within such collar. Such pulse echo apparatus, which preferably includes two diametrically opposed transceivers, generates signals from which standoff from a borehole wall may be determined. A method and apparatus are provided for measuring standoff and borehole diameter in the presence of drilling cuttings entrained in the drilling fluid. In a preferred embodiment, such signals are assessed by the electronic processing and control circuity to determine if gas has entered borehole.
    Type: Grant
    Filed: May 11, 1994
    Date of Patent: June 20, 1995
    Assignee: Schlumberger Technology Corporation
    Inventors: Jacques Orban, James C. Mayes