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Well logging

Subclass of:

367 - Communications, electrical: acoustic wave systems and devices


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Class / Patent application numberDescriptionNumber of patent applications / Date published
367035000 Borehole or casing condition 52
367028000 Amplitude measurement 44
367027000 Time interval measurement 19
367034000 Received signal cycle discrimination 5
20080285382METHODS AND SYSTEMS FOR DETECTING ARRIVALS OF INTEREST - 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.11-20-2008
20110188345Downhole Sonic Logging Tool Including Irregularly Spaced Receivers - 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.08-04-2011
20100149914MULTI-FREQUENCY BOREHOLE IMAGER - 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.06-17-2010
20110019501Acoustic Anisotropy and Imaging by Means of High Resolution Azimuthal Sampling - 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.01-27-2011
20110149684Method for Initializing Receiver Channels in a Cement Bond Logging Tool - 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.06-23-2011
367033000 Depth recording or control 3
20110051552METHODS AND APPARATUS TO CALCULATE A DISTANCE FROM A BOREHOLE TO A BOUNDARY OF AN ANISOTROPIC SUBTERRANEAN ROCK LAYER - Methods and apparatus to calculate a distance from a borehole to a boundary of an anisotropic subterranean rock layer are disclosed. A disclosed example method includes transmitting a first signal from a first transmitter at a first location in a borehole traversing a subterranean formation, receiving the first signal at a first receiver after a first time period at a second location in the borehole, receiving the first signal at a second receiver after a second time period at a third location in the borehole, and calculating a first distance from the first transmitter to a first portion of a boundary of a subterranean rock layer adjacent to the borehole by compensating for an anisotropy of the subterranean rock layer based on the first time period and the second time period.03-03-2011
20120147703METHODS AND APPARATUS FOR IMPROVED ACOUSTIC DATA ACQUISITION - A technique is designed to facilitate obtaining of acoustic data. The technique comprises traversing a tool through a subterranean formation from a first depth to subsequent depths. The tool receives a seismic signal during pre-determined time windows. The seismic signal is generated by a seismic source which is activated at varying times relative to the predetermined time windows based on the depth of the tool.06-14-2012
20110305110SYSTEM AND METHOD FOR GENERATING TRUE DEPTH SEISMIC SURVEYS - A surface seismic survey is generated or obtained from Earth's surface and is based on time in which acoustic waves are reflected to Earth's surface. One or more tools measure density and sonic velocity of a subsurface formation. An estimate of acoustic impedance is obtained from the density and the sonic velocity to generate a synthetic seismic survey. The synthetic seismic survey and the surface seismic survey are compared and/or correlated. The acoustic impedance can be iteratively estimated until the synthetic seismic survey matches the surface seismic survey. Matching the surface seismic survey with the synthetic seismic survey may ensure that the surface seismic survey may be calibrated in actual depth.12-15-2011
367026000 Threshold set system 1
20100177594ATTENUATION OF UNWANTED ACOUSTIC SIGNALS BY SEMBLANCE CRITERION MODIFICATION - Methods and related systems are described for modified semblance criterions based on the approach of thresholding the signal energy. A first criterion is derived by posing the problem as that of detecting a signal with energy (or amplitude) greater than the specified threshold and deriving the generalized likelihood ratio test statistic. A second criterion is derived using the same method by posing the problem as that of rejecting any signal with energy (or amplitude) below a specified threshold and detecting it if its energy is above another threshold greater than or equal to the first. These appropriately modify the original semblance criterion which is shown to be equivalent to the GLRT test statistic in the absence of any threshold on the signal amplitude. In addition simpler modifications are also described. Tests on synthetic data illustrate the effectiveness of all these modifications which perform comparably well at suppressing unwanted arrivals while accurately processing the desired signals.07-15-2010
20130044566Seismic Source Controller and Display System - A seismic survey system for performing offset borehole seismic survey measurement operations. The system may include a first seismic survey subsystem having a first wireless digital communication device and a second seismic survey subsystem having a second wireless digital communication device and remotely located from the first seismic survey subsystem. The first and second digital communication devices may be configured to provide a digital communication link for transporting digital information between the first seismic survey subsystem and second seismic survey subsystem. The system may be configured to enable a user at the first seismic survey subsystem to remotely modify at least a portion of a first plurality of operating parameters associated with at least one source signal device located at the second seismic survey subsystem. The system may also be configured to utilize GPS information in order to improve accuracy of source signal firing timing synchronization.02-21-2013
20100149913ANALYSIS OF FRACTURE NETWORKS - A method of analysing the dynamic behaviour of fracture networks in a seismic volume is provided. The method includes providing a plurality of seismic time lapse vintages of the same geological volume; identifying and parameterising fractures within fracture networks of each vintage; determining one or more distributions of fracture parameters for the fracture networks of each vintage; and identifying changes to the fracture networks by comparing corresponding distributions across the vintages.06-17-2010
20090154290METHOD FOR ENHANCING LOW FREQUENCY OUTPUT OF IMPULSIVE TYPE SEISMIC ENERGY SOURCES AND ITS APPLICATION TO A SEISMIC ENERGY SOURCE FOR USE WHILE DRILLING - A method for operating an impulsive type seismic energy source in a firing sequence having at least two actuations for each seismic impulse to be generated by the source. The actuations have a time delay between them related to a selected energy frequency peak of the source output. One example of the method is used for generating seismic signals in a wellbore and includes discharging electric current through a spark gap disposed in the wellbore in at least one firing sequence. The sequence includes at least two actuations of the spark gap separated by an amount of time selected to cause acoustic energy resulting from the actuations to have peak amplitude at a selected frequency.06-18-2009
20120182831ACOUSTIC VELOCITY MEASUREMENTS USING TILTED TRANSDUCERS - Apparatus, systems, and methods may operate to emit acoustic pulses into a drilling fluid in a well bore, using a first acoustic transducer in a downhole tool, and detecting the acoustic pulses after reflection from the wall of the well bore, using a second acoustic transducer in the downhole tool. The faces of the first and second acoustic transducers are non-parallel. Further activities include emitting additional acoustic pulses into the drilling fluid using the second acoustic transducer, and detecting them using the second acoustic transducer. The acoustic velocity of the drilling fluid can be determined based on respective travel times. Additional apparatus, systems, and methods are described.07-19-2012
20130070560Arranging Source-Receiver Orientations to Reduce High-Order Modes in Acoustic Monopole Logging - The present disclosure relates to methods and apparatuses for estimating a parameter of interest of an earth formation. The method may include using an acoustic sensor azimuthally positioned relative to a monopole acoustic source to reduce at least one high-order mode due to the monopole acoustic source. The monopole acoustic source may include one or more acoustic elements. The method may include generating a monopole acoustic pulse. The apparatus may include at least one acoustic source element and at least one acoustic sensor disposed on a housing configured for conveyance in a borehole. The at least one acoustic sensor may be azimuthally positioned relative to the at least one acoustic source to reduce at least one high-order mode.03-21-2013
20130064039ACOUSTIC LOGGING WHILE DRILLING TOOL WITH ACTIVE CONTROL OF SOURCE ORIENTATION - The subject disclosure relates to sonic logging while drilling. A transmitter and at least one receiver are mounted on a drill collar for performing sonic investigations of the formation traversing a borehole.03-14-2013
20090010102METHOD FOR ADJUSTING A SEISMIC WAVE VELOCITY MODEL ACCORDING TO INFORMATION RECORDED IN WELLS - The invention is a method for defining the development conditions of a hydrocarbon reservoir by updating a velocity model by means of log data. A first seismic depth image representative of the reservoir is established by using seismic data and a velocity model. A series of log data is acquired from wells. Differences between seismic reflector depths observed in the first seismic depth image and depths for these reflectors identified in the wells are measured. The velocity model is modified to minimize these errors, using a prestack kinematic inversion technique allowing constraints to be taken into account. A new seismic depth image from which the development conditions of the hydrocarbon reservoir are determined is deduced therefrom. The invention has application for hydrocarbon reservoir development.01-08-2009
20110280101UNIPOLE AND BIPOLE ACOUSTIC LOGGING WHILE DRILLING TOOLS - An acoustic logging while drilling tool includes a single unipole acoustic transmitter longitudinally and azimuthally spaced apart from a single linear array of unipole acoustic receivers. In certain preferred embodiments, the linear array of unipole receivers is azimuthally spaced apart from the unipole transmitter by about either 90 or 180 degrees. A bipole logging while drilling tool includes two unipole acoustic transmitters and two linear arrays of unipole acoustic receivers.11-17-2011
20080259727MICROSEISMIC EVENT DETECTION AND LOCATION BY CONTINUOUS MAP MIGRATION - The present invention provides methods and systems for microseismic hydraulic fracture monitoring in real-time. The methods and systems of the present invention may include continuous map migration of recorded microseismic signals. The methods and systems provide robust automated simultaneous detection and location of microseismic events.10-23-2008
20110286304Downhole Acoustic Emission Formation Sampling - A method, system and apparatus for testing properties of a rock formation surrounding a wellbore in situ. The apparatus includes a tool body, one or more indenters, and one or more acoustic sensors. The body includes an outer surface that defines one or more cavities therein. Each cavity extends into the body. Each indenter is positioned within a corresponding cavity and is positionable into an operating position and a non-operating position. The acoustic sensor is positioned within the cavity and adjacent to the indenter. The indenter is positioned at least partially beyond the outer surface when in the operating position. The acoustic sensor senses one or more acoustic events occurring when the indenter is in the operating position. The apparatus is inserted into the wellbore. Once inserted, the indenter applies a load onto the rock formation causing cracking and the sensor receives the generated acoustic transmissions. The transmissions are analyzed.11-24-2011
20110292763DETECTION OF SEISMIC SIGNALS USING FIBER OPTIC DISTRIBUTED SENSORS - A fiber optic distributed vibration system for detecting seismic signals in an earth formation is provided. The system includes a fiber optic cable deployed in a borehole that extends into the earth formation and which is configured to react along its length to a seismic wave incident on the fiber optic cable from outside the borehole. An optical source launches an optical signal into the fiber optic cable while the seismic wave is incident thereon. A receiver detects coherent Rayleigh noise (CRN) produced in response to the optical signal. A processing circuit processes the detected CRN signal to determine characteristics of the earth formation.12-01-2011
20090185445BOREHOLE APPARATUS AND METHODS FOR SIMULTANEOUS MULTIMODE EXCITATION AND RECEPTION TO DETERMINE ELASTIC WAVE VELOCITIES, ELASTIC MODULII, DEGREE OF ANISOTROPY AND ELASTIC SYMMETRY CONFIGURATIONS - An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool. The system comprises apparatus for generating and sensing acoustic signals in a borehole in an earth formation, and further comprises a processing method by which the sensor response signals are processed and analyzed to obtain desired formation parameters of interest.07-23-2009
20110170372WALKAWAY VSP CALIBRATED SONIC LOGS - Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.07-14-2011
20120294115AUTOMATIC PROGRAMMED ACQUISITION USING DOWNHOLE SEISMIC SOURCES - The present disclosure relates to making seismic measurements using a seismic source disposed in a wellbore. One or more seismic sources are provided and carried on a conveyance mechanism. One or more seismic receivers are provided and placed on or near the earth's surface, in the same wellbore as the seismic sources, or in another wellbore. The one or more seismic sources are run into and/or out of the wellbore using a controller or sequencer. The one or more seismic sources are positioned, manually or automatically, at one or more locations in the wellbore, using a set of computer-controlled instructions. Seismic measurements are made at the one or more locations by activating the one or more seismic sources and detecting a seismic source signal using the seismic receivers. The receivers may be carried on a conveyance mechanism and their position controlled, manually or automatically, using the set of computer-controlled instructions.11-22-2012
20110267921MULTICOMPONENT SEISMIC INVERSION OF VSP DATA - A method for seismic inversion of vertical seismic profile (VSP) data in an oilfield. The method includes obtaining an initial velocity model of a subterranean formation including acoustic velocities of wave propagation in proximity to the wellbore, determining an acquisition geometry for obtaining the VSP data including receiver locations within the wellbore and a source location, performing a seismic survey to obtain the VSP data based on the acquisition geometry, analyzing arrival signals of the VSP data to generate transit time data for wave propagation from the source location to the receiver locations, modifying the initial velocity model to generate an updated velocity model by performing a tomographic inversion of the transit time data, generating an elastic model of the subterranean formation by performing the seismic inversion of the VSP data using the updated velocity model, and adjusting the operations of the oilfield based on the elastic model.11-03-2011
20090034366VSP Pattern Recognition in Absolute Time - 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(02-05-2009
20100142319Electromagnetic Linear Drive Source for Logging-While-Drilling/Wireline Acoustic Applications - An apparatus and method for providing a downhole acoustic source is disclosed. The acoustic source includes a piston configured to oscillate in an axial direction of the acoustic source and produce an acoustic signal in a medium in contact with an exterior surface of the piston, and an elastomer disposed on an interior side of the piston, an acoustic impedance of the elastomer selected to match an acoustic impedance of the piston. A permanent magnet is configured to provide a permanent magnetic field oriented in the axial direction, and a coil disposed on an interior side of the piston produces an alternating magnetic field in the region of the permanent magnetic field. The elastomer may be, for example, a silicon rubber, a silicone jelly, and a silicone oil. A plurality of acoustic sources may be arranged to produce an acoustic dipole configuration or an acoustic quadrupole configuration.06-10-2010
20090129203MONOPOLE ACOUSTIC TRANSMITTER COMPRISING A PLURALITY OF PIEZOELECTRIC DISCS - A monopole acoustic transmitter with at least one disc assembly with a plurality of piezoelectric discs configured to optimized acoustic pressure output within a desired frequency range while meeting physical restrictions of LWD and MWD logging systems. The transmitter is disposed in a recess or “slot” in the perimeter of a logging tool housing to reduce acoustic pressure waves transmitted directly along the tool housing and to optimize acoustic energy transmission into the borehole environs. In order to increase acoustic pressure output at a desired logging frequency range, the plurality of piezoelectric discs in each of at least one disc assembly are connected electrically in parallel and fired simultaneously. The polarity of the discs and the wiring arrangement are such that each disc expands or contracts in a common direction during simultaneous firing by an applied voltage. The desired output frequency is obtained by selectively polarizing and dimensioning the discs within the one or more disc assemblies. Each disc assembly is preferably disposed within an oil filled pressure housing that is pressure and temperature compensated. The axis of the at least one disc assembly can be parallel or perpendicular to the major axis of the logging tool.05-21-2009
20090086574Superheterodyne seismic vibrator and method - A seismic energy source includes at least a first and a second acoustic radiator operatively coupled to a non-linear medium proximate an upper limit of formations in the Earth's subsurface. The first and second acoustic radiators are configured to convert electrical energy directly into acoustic energy. The source includes means for operating the first and the second acoustic radiator at respective first and second frequencies. The first and second frequencies are selected such that substantially no acoustic energy propagates through the non-linear medium. The first and the second frequencies are selected such that a difference therebetween is swept through a range of frequencies of seismic energy capable of propagating through the Earth's subsurface to at least one acoustic impedance boundary within the Earth's subsurface.04-02-2009
20100002540DEVICE AND METHOD FOR GENERATING A BEAM OF ACOUSTIC ENERGY FROM ABOREHOLE, AND APPLICATION THEREOF - In some aspects of the invention, a device, positioned within a well bore, configured to generate and direct an acoustic beam into a rock formation around a borehole is disclosed. The device comprises a source configured to generate a first signal at a first frequency and a second signal at a second frequency; a transducer configured to receive the generated first and the second signals and produce acoustic waves at the first frequency and the second frequency; and a non-linear material, coupled to the transducer, configured to generate a collimated beam with a frequency equal to the difference between the first frequency and the second frequency by a non-linear mixing process, wherein the non-linear material includes one or more of a mixture of liquids, a solid, a granular material, embedded microspheres, or an emulsion.01-07-2010
20100238763SINGLE WELL RESERVOIR CHARACTERIZATION APPARATUS AND METHODS - An apparatus and a method for characterizing parts of a reservoir surrounding a borehole are provided including using at least one transmitter to emit a probing signal into the borehole and at least one receiver to receive a signal representing a response of the formation to the probing signal, with the distance separating the transmitter and the receiver being variable while suspended in the borehole using for example an apparatus which can be decoupled in the borehole into a stationary and a mobile section, carrying transmitter and receiver.09-23-2010
20100322029SYSTEM FOR GENERATING A BEAM OF ACOUSTIC ENERGY FROM A BOREHOLE, AND APPLICATIONS THEREOF - In some aspects of the invention, a device, positioned within a well bore, configured to generate and direct an acoustic beam into a rock formation around a borehole is disclosed. The device comprises a source configured to generate a first signal at a first frequency and a second signal at a second frequency; a transducer configured to receive the generated first and the second signals and produce acoustic waves at the first frequency and the second frequency; and a non-linear material, coupled to the transducer, configured to generate a collimated beam with a frequency equal to the difference between the first frequency and the second frequency by a non-linear mixing process, wherein the non-linear material includes one or more of a mixture of liquids, a solid, a granular material, embedded microspheres, or an emulsion.12-23-2010
20110085415METHOD FOR SYNCHRONIZING SEISMIC DATA RECORDED BY TWO OR MORE SEPARATE RECORDING SYSTEMS - A method for synchronizing recordings of seismic sensor signals between at least two time indexed recording units includes cross-correlating signals recorded by each of a first and a second recording unit from a same reference sensor. The reference sensor is deployed proximate a subsurface volume to be evaluated and generates at least one of an optical and an electrical signal in response to seismic amplitude. Peaks in a power spectrum of the cross correlated signals are determined. The reference signals recorded by each of the first and second recording units are notch filtered using at least one notch frequency selected from the power spectrum. The notch filtered reference signals are cross correlated and a time offset between recordings made by the first recording unit and the second recording unit is determined from the cross-correlated, notch filtered signals.04-14-2011
20080247268Autonomous Depth Control For Wellbore Equipment - A method for tracking a wellbore tool includes: obtaining a first image of the wellbore using an imager associated with the tool; obtaining a second image of the wellbore using the imager after a selected time period; matching the first image with the second image by shifting one of the first and second images; determining an amount of the shifting; and comparing the amount of the shifting with a reference distance to determine a distance of tool movement. A method for tracking a wellbore tool includes: obtaining an image of a wellbore feature using a first imager associated with the tool; moving the tool in the wellbore; and registering a distance of tool movement when the image of the wellbore feature is detected by a second imager spaced apart from the first imager, wherein the distance of tool movement equals a spacing between the first and second imagers.10-09-2008
20100165788ACOUSTIC TRANSCEIVER ASSEMBLY WITH BLOCKING ELEMENT - An acoustic transceiver assembly including a housing, an oscillator, and a blocking element. The housing has at least one inner wall defining a cavity. The cavity has a first end and a second end defining an axis of said acoustic transceiver assembly. The oscillator is provided in said cavity. The oscillator is provided with a transducer element, and a backing mass positioned adjacent to the transducer element. A blocking element is positioned inside the cavity and adjacent to the oscillator. The blocking element is adapted to restrain a portion of said backing mass at a first pressure to thereby restrain the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly. The blocking element is also adapted to release the backing mass at a second pressure.07-01-2010
20100195436METHODS AND SYSTEMS FOR DEPLOYING SEISMIC DEVICES - Methods and systems for acoustically determining reservoir parameters of subterranean formations. A tool comprising at least one seismic source or seismic receiver mounted thereon; a conveyance configured for movement of the acoustic tool in a borehole traversing the subterranean formations; and a source retainer configured or designed for permanent deployment in the borehole to removably retain the acoustic tool in the borehole. The source retainer when deployed provides acoustic coupling with the borehole and removably retains the acoustic tool in the borehole so that, over multiple deployments, the acoustic tool is repeatedly deployed at the same predetermined location and orientation relative to the subterranean formation, and with the same acoustic coupling to the borehole.08-05-2010
20100020638MONOPOLE ACOUSTIC TRANSMITTER RING COMPRISING PIEZOELECTRIC MATERIAL - A monopole acoustic transmitter for logging-while-drilling comprising as a ring that comprises one or more piezoelectric arc segments. The ring is oriented in a plane whose normal is essentially coincident with the major axis of a logging tool in which it is disposed. The ring disposed within a recess on the outer surface of a short, cylindrical insert. The insert is inserted into a drill collar, rather than into the wall of the collar. The ring can comprise a continuous ring of piezoelectric material, or alternately arc segments or active ring segments of piezoelectric ceramic bonded to segments of other materials such as alumina to increase the frequency or heavy metals such as tungsten to reduce the frequency. The material and dimensions of the material used in-between the piezoelectric segments is chosen to alter the frequency of the ring.01-28-2010
20100238764METHOD AND SYSTEM TO DETERMINE THE GEO-STRESSES REGIME FACTOR Q FROM BOREHOLE SONIC MEASUREMENT MODELING - Methods and systems for analyzing subterranean formations in-situ stress are disclosed. A method for extracting geological horizon on-demand from a 3D seismic data set, comprises receiving sonic log data; computing the anisotropic shear moduli C09-23-2010
20120026831METHOD AND APPARATUS FOR MEASURING FORMATION ANISOTROPY WHILE DRILLING - A logging system for measuring anisotrophic properties of the materials penetrated by a borehole. A downhole or “logging tool” element of the system comprises a source section that comprises either a unipole or a dipole acoustic source. The receiver section comprises a plurality of receiver stations disposed at different axial spacings from the acoustic source. Each receiver station comprises one or more acoustic receivers. The system requires that the source and receiver sections rotate synchronously as the logging tool is conveyed along the borehole. Receiver responses are measured in a plurality of azimuthal angle segments and processed as a function of rotation angle of the tool. The logging system can be embodied as a logging-while-drilling system, a measurement-while-drilling system, and a wireline system that synchronously rotates source and receiver sections. All embodiments require that the acoustic source operate at a relatively high frequency.02-02-2012
20080316860Borehole Seismic Acquisition System - A borehole seismic acquisition system is described with a plurality of sensors arranged so as to identify within the data measured by the pressure sensors P- and S-wave related signals converted at the boundary of the borehole into pressure waves, the sensors being best arranged in groups or clusters sensitive to pressure gradients in one or more directions.12-25-2008
20120120762METHODS AND SYSTEMS FOR SEISMIC SIGNAL DETECTION - Methods and systems utilizing seismic sensors configured or designed for use in seismic signal detection. An electrical current is applied to a seismic sensor such that the moving coil is located at a neutral position relative to the magnetic field in the seismic sensor to compensate for gravitational acceleration.05-17-2012
20120120761INTEGRATED SYSTEM FOR INVESTIGATING SUB-SURFACE FEATURES OF A ROCK FORMATION - A system for investigating non-linear properties of a rock formation around a borehole is provided. The system includes a first sub-system configured to perform data acquisition, control and recording of data; a second subsystem in communication with the first sub-system and configured to perform non-linearity and velocity preliminary imaging; a third subsystem in communication with the first subsystem and configured to emit controlled acoustic broadcasts and receive acoustic energy; a fourth subsystem in communication with the first subsystem and the third subsystem and configured to generate a source signal directed towards the rock formation; and a fifth subsystem in communication with the third subsystem and the fourth subsystem and configured to perform detection of signals representative of the non-linear properties of the rock formation.05-17-2012
20120314537Methods and Systems for Seismic Signal Detection - Methods and systems utilizing seismic sensors configured or designed for use in seismic signal detection. An electrical current is applied to a seismic sensor such that the moving coil is located at a neutral position relative to the magnetic field in the seismic sensor to compensate for gravitational acceleration.12-13-2012
20120127827TECHNIQUE AND SYSTEM FOR PERFORMING A CROSS WELL SURVEY - A technique includes providing a source in a first well and a seismic receiver in a second well to detect a seismic event that is caused by the source. The technique includes referencing clocks in the source and receiver to a common reference time frame and determining a time in the reference time frame at which the seismic source generates the seismic event.05-24-2012
20110182141METHOD AND SYSTEM FOR MONITORING A LOGGING TOOL POSITION IN A BOREHOLE - The invention relates to the area of borehole acoustics, in particular, to monitoring a logging tool position in a borehole, namely detection and estimation of a borehole logging tool eccentricity based on the measurement and analysis of mixed surface waves waveforms. The method is characterized by the steps of registering acoustic signals generated by passage of acoustic waves in the borehole while logging and detecting the misalignment of the logging tool to the axis of the borehole by the presence of mixed surface waves. A system for monitoring a logging tool position in a borehole comprising means for registering acoustic signals generated by passage of acoustic waves while logging and data processing means for detecting mixed surface waves propagating along the borehole wall.07-28-2011
20100027376Optimizing Seismic Processing and Amplitude Inversion Utilizing Statistical Comparisons of Seismic to Well Control Data - A method for obtaining enhanced seismic data and optimized inverted reflectivities includes computing statistical well characterizations based upon band-limited well reflectivities for a subsurface region. Sets of processed seismic data are computed by applying differing processing sequences to seismic data corresponding to the subsurface region. Inverted reflectivities are computed by inverting the sets of processed seismic data. Statistical seismic characterizations are computed based upon the inverted reflectivities. Statistical difference measurements (SDMs) are computed between the statistical well and seismic characterizations. An optimal processing sequence is selected based upon the computed SDMs. Enhanced seismic data is obtained by processing the seismic data corresponding to the subsurface region. An optimal seismic inversion algorithm is obtained based upon the computed SDMs. The seismic data is inverted using the optimal seismic inversion algorithm to produce a set of optimized inverted reflectivities.02-04-2010
20120257475Optical Fiber Based Downhole Seismic Sensor Systems and Methods - Various optical fiber-based seismic monitoring system embodiments include a light source that drives an optical fiber positioned within a borehole. At least one light sensor analyzes Rayleigh backscattered light to obtain an acoustic signal for each of multiple points along the borehole. One or more processors operate to determine microseismic event direction, distance, and/or intensity based at least in part on phase information of said acoustic signals. The acoustic signal cross-correlations, semblances, or phase-sensitive similarity measures can be determined as a function of scanning direction to accurately determine the relevant microseismic event information. The optical fiber may be positioned in the cemented annulus of a cased borehole having a shape that extends along more than one dimension (e.g., an L-shaped borehole).10-11-2012
20100296366METHODS AND SYSTEMS FOR SEISMIC SIGNAL DETECTION - Methods and systems utilizing seismic sensors configured or designed for use in seismic signal detection. An electrical current is applied to a seismic sensor such that the moving coil is located at a neutral position relative to the magnetic field in the seismic sensor to compensate for gravitational acceleration.11-25-2010
20110222368Detecting Seismic Data in a Wellbore - In one general embodiment, a seismic tool system includes a cable adapted to be deployed within a borehole; and one or more seismic tools suspendable from the cable in the borehole. At least one of the seismic tools includes at least one seismic sensor enclosed within a housing; one or more rollers attached to the housing and adapted to engage the borehole; and a bow spring attached to the housing and including one or more rollers adapted to engage the borehole. The one or more of the rollers are in acoustic communication with the seismic sensor.09-15-2011
20120327742Borehole Flow Modulator and Inverted Seismic Source Generating System - The present invention relates to the vertical seismic profiling (VSP) of geological formations in which profiling is used to obtain information for performing precise interpretations of geophysical seismic data and better understanding of geophysical information. The disclosure involves using a sound source for generating primary and secondary seismic pulses within well boreholes. The seismic profiling system obtains information regarding a geological formation traversed by a borehole with controllable downhole seismic pulse generators with drill string tool(s). The tool(s) have contact with and are coupled to the formation. A seismic pulsing device (SPD) is attached to a portion of the drill string and a valve controller is used to control opening and closing the valve causing high amplitude short duration ultra wide band pressure pulses, generating primary seismic waves sent into surrounding geological formations. This generates secondary seismic waves received that can be detected by geophones or similar devices.12-27-2012
20080225640Fracture Cluster Mapping - Method for identifying one or more fracture clusters in an area of interest. In one implementation, the method may include determining a first inclination of each fracture cluster using borehole data. The first inclination refers to a first average angle with respect to horizontal. The method may further include extracting a first set of fracture clusters from seismic data using a filter based on the first inclination and a strike azimuth of each fracture cluster.09-18-2008
20130100768SIGNAL STACKING IN FIBER OPTIC DISTRIBUTED ACOUSTIC SENSING - A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprises a) transmitting an optical signal into a fiber optic cable (04-25-2013
20110267922MECHANICAL TUBE WAVE SOURCES AND METHODS OF USE FOR LIQUID FILLED BOREHOLES - The current application discloses methods and systems for generating mechanical tube waves in fluid filled boreholes penetrating subterranean formations. In one embodiment, the system of the current application comprises an energy storage chamber; a fast operating valve connected to the energy storage chamber; a pipe connected to the valve and extending to the liquid-filled borehole; where said energy storage chamber contains a first pressure that is substantially different from a second pressure in the pipe so that a fast operation of the valve generates a tube wave in the pipe.11-03-2011
20100315899SELF-STABILIZING DYNAMIC DIAPHRAGM FOR BROAD BANDWIDTH ACOUSTIC ENERGY SOURCE - An apparatus for estimating a property in a borehole penetrating the earth, the apparatus having: a carrier configured to be disposed in the borehole; and an acoustic transducer disposed at the carrier and configured to at least one of transmit and receive an acoustic wave used to estimate the property, the acoustic transducer comprising an acoustic diaphragm; wherein the acoustic diaphragm includes a surface in communication with a plurality of structural members configured to increase the rigidity of the surface, the surface being configured to interface with a medium that propagates the acoustic wave.12-16-2010
20120014214TIME REVERSE IMAGING OPERATORS FOR SOURCE LOCATION WITH BOREHOLE DATA - A method and system for processing synchronous array seismic data includes acquiring synchronous passive seismic data from a plurality of sensors to obtain synchronized array measurements. A reverse-time data propagation process is applied to the synchronized array measurements to obtain a plurality of dynamic particle parameters associated with subsurface locations. Imaging conditions are applied to the dynamic particle parameters to obtain image values associated with subsurface energy source locations.01-19-2012
20130194892Autonomous System for Hydrofracture Monitoring - A system includes a plurality of sensor assemblies that are adapted to be deployed in a wellbore and acquire sensor data indicative of microseismic activity due to a hydraulic fracturing operation in the wellbore. At least one of the sensor assemblies includes a command interface and at least one sensor and is adapted to use the command interface to identify a command stimulus that is communicated downhole and initiate an acquisition by the sensor in response to identifying the command stimulus.08-01-2013

Patent applications in class Well logging

Patent applications in all subclasses Well logging