Abstract: Signals from an acoustic transducer used in a borehole include overlapping, ringing reflections from the casing walls, voids in the cement and the formation. By using the Hilbert transform, an envelope of the signals is determined and individual echoes are detected by using a Gauss-Laplace operator.

Abstract: Systems, methods, and computer programs for monitoring a drilling operation in a subterranean formation include receiving, from a first sensor array, one or more signals caused, at least in part, by the fracturing operation in the subterranean formation; receiving, from the first sensor array, one or more electromagnetic signals generated by an electroseismic or seismoelectric conversion of the seismic signals caused, at least in part, by the fracturing operation in the subterranean formation; and determining a property of one or more of a fracture or the subterranean formation based, at least in part, at least in part, on the signals received from the first sensor array.

Abstract: Systems, methods, and computer programs for monitoring a drilling operation in a subterranean formation include receiving, from a first sensor array, one or more seismic signals caused, at least in part, by the drilling operation in the subterranean formation; receiving, from the first sensor array, one or more electromagnetic signals generated by an electro seismic or seismoelectric conversion of the one or more seismic signals caused, at least in part, by the drilling operation in the subterranean formation; and determining a property of one or more of the drillstring and the subterranean formation based, at least in part, on the seismic signals and the corresponding electromagnetic signals received from the first sensor array. The first sensor array is arranged to monitor the drilling operation.

Abstract: Systems, methods, and computer programs for monitoring production of fluids from a subterranean formation includes receiving, from a first sensor array at a first time, a first set of electromagnetic signals generated by an electro seismic or seismoelectric conversion of seismic signals caused, at least in part, by the production of fluid from the subterranean formation; receiving, from the first sensor array at a second time, a second set of electromagnetic signals generated by an electroseismic or seismoelectric conversion of seismic signals caused, at least in part, by the production of fluid from the subterranean formation; and determining one or more reservoir properties based, at least in part, on the first and second sets signals received from the first sensor array.

Abstract: A system and method to synchronize distributed measurements in a borehole are described. The system includes a plurality of wired segments coupled together by couplers and a plurality of nodes configured to measure, process, or relay information obtained in the borehole to a surface processing system, each of the plurality of nodes comprising a local clock and being disposed at one of the couplers or between couplers. The system also includes a surface processing system coupled to a master clock and configured to determine a time offset between the master clock and the local clock of an nth node among the plurality of nodes based on a downhole generated synchronization signal.

Abstract: The output spectrum of a controllable swept-frequency acoustic source at a given frequency can be controlled by making the rate of change of frequency equal to the desired output power spectrum divided by the squared envelope amplitude of the source output signal, both measured at the time after the start of its frequency sweep at which the sweep frequency passes through the given frequency. The system and method can also be used to correct for propagation effects outside the source by dividing the desired spectrum by the propagation effect. The method can further be used either to obtain an output spectrum of a desired shape from a source operating at maximum output or to design a sweep of a minimum feasible duration that will result in an output spectrum of a specified shape and with a specified amplitude.

Abstract: Techniques for estimating velocity ahead of a drill bit include generating seismic waves at a surface from at least two different source positions in the vicinity of a borehole, receiving seismic waves reflected from a reflector ahead of the drill bit at one or more locations in the borehole, determining travel times of the seismic waves received at the one or more locations in the borehole, and inverting the travel times to determine a velocity of a formation ahead of the drill bit. One embodiment includes transforming the velocity into pore pressure of the formation.

Abstract: A system and method to obtain acoustic information from a borehole penetrating the earth are described. The system includes a light source to provide a continuous output beam and a modulator to modulate the continuous output beam with a modulation signal to provide a frequency modulated continuous wave (FMCW) to be sent out on an optical fiber disposed along the borehole, the optical fiber including a plurality of reflectors at known locations along the optical fiber. The system also includes a processor to process a light reflection signal from the optical fiber to determine the acoustic information.

Abstract: A method for surveying, may include receiving, by a processor, first survey data from a first source, the first source comprising a first signal generated by a subsurface earth formation in response to a passive-source electromagnetic signal, wherein the electromagnetic signal is generated by an electroseismic or seismoelectric conversion of the passive-source electromagnetic signal. The method may also include receiving, by the processor, second survey data from a second source and processing the first survey data and the second survey data to determine one or more properties of a subsurface earth formation.

Abstract: Systems, computer readable media, and program code to provide for filtering noise and/or restoring attenuated spectral components in acoustic signals, are provided. An exemplary embodiment of a system is configured for dynamically filtering each of a plurality of raw FFT data samples of a record to remove or attenuate background noise contained therein to thereby produce a corresponding plurality of cleaned FFT data samples. The sample-specific background noise is removed or attenuated by a record-specific dynamic filter to produce the corresponding cleaned FFT data samples.

Abstract: A method for collecting information about a subsurface region, comprises a) providing a set of data comprising a plurality of scattered signals, where each scattered signal is a portion of an acoustic seismic signal that has been scattered by and at least one scatterer and received at a receiver, b) using spatial deconvolution to process the scattered signals so as generate a coherent arrival, and c) using the coherent arrival to output human readable information about the subsurface region. The receiver may be a geophone or a fiber optic distributed acoustic sensor and may be in a borehole or at the surface. The acoustic seismic signal may originate at the surface or below the surface and may be an active or passive source.

Abstract: Methods of providing for filtering noise and/or restoring attenuated spectral components in acoustic signals, are provided. An exemplary embodiment of a method includes dynamically filtering each of a plurality of raw FFT data samples of a record to remove or attenuate background noise contained therein to thereby produce a corresponding plurality of cleaned FFT data samples. The sample-specific background noise is removed or attenuated by a record-specific dynamic filter to produce the corresponding cleaned FFT data samples. The method can also include restoring the attenuated high-frequency components of the cleaned data samples through application of a record-specific Restoring Processor at least partially defined by a portion of the cleaned data samples and a Gain Function to thereby produce cleaned and restored data samples, and applying an inverse transformation to convert the cleaned and restored data samples into cleaned and restored data samples in time domain data.

Abstract: In some aspects, a boundary is computed based on locations of microseismic events associated with a stimulation treatment of a subterranean region. A major axis of a stimulated reservoir volume (SRV) for the stimulation treatment is identified based on the boundary. In some examples, the boundary is an ellipsoid, and the major axis of the ellipsoid is identified.

Abstract: In some aspects, a first boundary is computed based on microseismic event locations associated with a first stage of a multi-stage injection treatment of a subterranean region. A second boundary is computed based on microseismic event locations associated with a second stage of the multi-stage injection treatment. Based on the first and second boundaries, an overlap between stimulated reservoir volumes (SRVs) associated with the first and second stages is determined.

Abstract: A method for determining fracture plane orientation from seismic signals detected above a subsurface formation of interest includes detecting seismic signals using an array of seismic sensors deployed above the subsurface formation during pumping of a hydraulic fracture treatment of the subsurface formation. A time of origin and a spatial position of origin (hypocenter) of microseismic events resulting from the hydraulic fracture treatment are determined. Time consecutively occurring ones of the hypocenters falling within a selected temporal sampling window are selected. A best fit line through the selected hypocenters using a preselected linear regression coefficient is determined. The selecting hypocenters and determining best fit lines is repeated for a selected number of windows.

Abstract: A method for analyzing seismic data by generating a post-migration common image gather in a dip angle domain from measured seismic data; detecting concave features related to reflection events in the common image gather and apexes; filtering out part of the concave features in the common image gather in a vicinity of the detected apexes; applying a hybrid Radon transform to the filtered common image gather to separate residues of the concave features from other image features related to diffraction events; and applying an inverse hybrid Radon transform to an image containing the separated features related to diffraction events to obtain a transformed common image gather in the dip angle domain.

Abstract: The present invention provides a method and apparatus for enhanced monitoring of induced seismicity and industrial vibration to comprehensively measure all aspects of potentially damaging motion. The invention utilizes various combinations of multi-component low frequency linear seismic sensors and multi-component rotational seismic sensors. Sensors are jointly deployed in arrays on the free surface of the earth, and/or in arrays of shallow monitoring holes, which may be intended to be permanent deployments. The method has a wide range of risk/damage monitoring applications for industrial activity, and in oil and gas exploration and production for seismic surveys, hydraulic fracturing, and waste injection wells. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: A system and a method includes generating a first signal at a first frequency; and a second signal at a second frequency. Respective sources are positioned within the borehole and controllable such that the signals intersect in an intersection volume outside the borehole. A receiver detects a difference signal returning to the borehole generated by a non-linear mixing process within the intersection volume, and records the detected signal and stores the detected signal in a storage device and records measurement parameters including a position of the first acoustic source, a position of the second acoustic source, a position of the receiver, elevation angle and azimuth angle of the first acoustic signal and elevation angle and azimuth angle of the second acoustic signal.

Abstract: Methods and apparatus for performing sonic well logging within a wellbore based on optical Distributed Acoustic Sensing (DAS) are provided. A sonic well logging system based on DAS may be capable of producing the functional equivalent of tens, hundreds, or even thousands of acoustic sensors. In this manner, the emplacement of the sonic well logging system based on DAS may not be nearly as complex or expensive as emplacing a sonic well logging system based on traditional methods. Furthermore, multiplexing may be simpler, downhole electronics need not be used, and the sonic well logging system may be used in extreme, high temperature environments.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to monitor a first condition associated with transmitting or receiving a signal in a formation or on a drill string, or both, over a first selected interval of a drill string located down hole; to monitor a second condition associated with transmitting or receiving the signal in the formation or on the drill string or both, over a second selected interval of the drill string; to compare the first condition to the second condition to provide a comparison result; and based on the comparison result, to select one of the first selected interval or the second selected interval to transmit or receive the signal in the formation or on the drill string, or both. Additional apparatus, systems, and methods are disclosed.

Abstract: Apparatus, computer instructions and method for controlling an energy output of a source array to be used in a seismic survey for illuminating a subsurface. The method includes generating a model (?) based on up-going (U) and down-going (D) components of seismic waves generated by source elements that form the source array; calculating the amplitudes and phases of each source element based on the model (?); and driving the source array based on the calculated amplitudes and phases for the source elements so that a ghost generated by the source array is reduced at emission.

Abstract: The invention relates to methods and apparatuses for a new signal processing method for substantial noise reduction with the goal of making small microquakes detectable and localizable, giving more data points and detail regarding fracking geometry. According to some aspects, the invention provides a fully integrated system including a novel self-focusing adaptive beamformer.

Abstract: A system and a method for investigating rock formations includes generating, by a first acoustic source, a first acoustic signal comprising a first plurality of pulses, each pulse including a first modulated signal at a central frequency; and generating, by a second acoustic source, a second acoustic signal comprising a second plurality of pulses. A receiver arranged within the borehole receives a detected signal including a signal being generated by a non-linear mixing process from the first-and-second acoustic signal in a non-linear mixing zone within the intersection volume. The method also includes-processing the received signal to extract the signal generated by the non-linear mixing process over noise or over signals generated by a linear interaction process, or both.

Abstract: Disclosed are a system, apparatus, and method for optical fiber well deployment in seismic optical surveying. Embodiments of this disclosure may include methods of deploying a spooled optical fiber distributed sensor into the wellbore integrated in a ballast or weight for a seismic optic tool, to achieve deployment of a lightweight disposable fiber optic cable against the wellbore walls via gravity. The method may further include unspooling the spooled optical fiber distributed sensor and using the optical fiber as a distributed seismic receiver. Once the fiber optic distributed sensor is deployed according to methods of the present disclosure, surveys may be obtained and processed by various methods.

Abstract: Systems and methods for the estimating a plurality of anisotropic elastic constants (Cij) using borehole dispersions and refracted compressional headwave velocity at a single logging depth in a vertical, deviated, or horizontal wellbore in a transversely-isotropic with a vertical axis of symmetry (“TIV”) formation. The estimated elastic constants can then be used to calculate near-wellbore stress distributions in the wellbore, which aids in an optimal completion design, such as for shale-gas production in the presence of shale heterogeneity.

Abstract: A disclosed example method includes providing, in a borehole, a transmitter (Tx) and receivers (Rxs) spaced linearly from Tx at known distances, measuring linear propagation times (LPts) for a signal to propagate from Tx to each of Rxs, determining an inline velocity (VINL) based on LPts, measuring reflection times (Rts) for a signal to propagate from Tx to each of the Rxs via a boundary, for each of Rts, providing a time-distance anisotropic velocity (TDAV) relationship depending on an effective signal velocity (ESV) in an anisotropic formation adjacent the boundary as a function of reflection angle for the reflection time signal to the boundary, VINL and orthogonal velocity, performing semblance processing to combine the TDAV relationships with VINL for a best-fit calculation of the ESVs for the different reflection angles of the reflection time signals, and calculating a distance for the corresponding receiver to the boundary on the calculation.

Abstract: An illustrative seismic while drilling system includes a drill string having at least one seismic sensor that can be employed to detect seismic signals during pauses in the drilling process, e.g., when extending the length of the drill string. An embedded processor digitizes a signal from the seismic sensor to obtain a digital waveform and processes the digital waveform to derive a compressed waveform representation for storage or transmission. Compression is provided by adaptively reducing the sampling rate and quantization resolution subject to one or more quality constraints including, e.g., error in first break timing, error in first break sign, mean square error, and bit count. Reasonably good representations of the received acoustic waveforms can be achieve with less than 200 bits.

Abstract: A method for water monitoring about a deviated well is disclosed. The method includes positioning a series of electromagnetic (EM) receivers in a completed deviated wellbore, said receivers being spaced along substantially the length of the well located in a region of a reservoir to be monitored. The method also includes positioning an electromagnetic (EM) source at a first Earth surface location. Then the EM source is activated for a first survey measurement of the reservoir, and an EM field detected at each EM receiver is recorded. The EM source is moved to a second Earth surface location, and activated for a second survey measurement of the reservoir, and an EM field detected at each EM receiver is recorded. From the first and second survey measurements at each of the receivers, an inversion is performed to determine position of water about (and specifically below) the horizontal well.

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.

Abstract: 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.

Abstract: 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.

Abstract: Methods of and apparatus to image one or more subsurface formation features are disclosed. An example method includes generating acoustic waves with a transmitter and receiving the acoustic waves and acoustic data contained therein at one or more receivers. The example method also includes extracting one or more S-S, P-S or S-P reflected waveform data from the acoustic data, estimating a dip of the one or more subsurface formation features, migrating the one or more S-S, P-S or S-P reflected waveform data with the estimated dip and mapping the migrated one or more S-S, P-S or S-P reflected waveform data. In addition, the example method includes identifying one or more permeable subsurface formation features using the mapped migrated one or more S-S, P-S or S-P reflected waveform data.

Abstract: A method of detecting seismic waves traveling through a subsurface formation includes lowering a cable into a borehole in the subsurface formation, the cable having at least one optical fiber associated therewith, and causing descent of a remote end of the cable to be arrested. The method further includes feeding a further length of the cable into the borehole such that the cable is slack and in contact with at least part of a wall of the borehole, and using an interrogator coupled to the at least one optical fiber to detect seismic waves traveling through the subsurface formation and into the cable.

Abstract: A method, having application to petroleum exploration or production, for picking the arrival time of seismic waves and use thereof for orienting the components of a multi-component sensor. After acquisition of seismic data using a VSP type method, with a multi-component sensor, a module signal is constructed by calculating the square root of the sum of the squares of at least two orthogonal seismic components. Arrival times of a direct seismic wave are then picked on an amplitude extremum of this module signal. Based on this picking, the seismic components can then be oriented in a unique reference frame whatever the depth of the sensor. A time window is defined on either side of the picked arrival times and the azimuthal direction is determined by maximizing the energy of the horizontal components within this time window. Finally, the three components are oriented in a reference frame defined with respect to the azimuthal direction, which is identical for each depth.

Abstract: A seismic generation system may include an electrical source, a conductor coupled to the electrical source and to be positioned in a wellbore in a subterranean formation with a casing therein, and a seismic generation source assembly to be positioned in the wellbore and coupled to the conductor. The seismic generation source assembly may include a source element having a sealed housing, an armature within the sealed housing, source electromagnets coupled to the armature, and electromagnetic clamps coupled to the armature, each electromagnetic clamp having opposite magnetic poles. The sealed housing may include respective ferromagnetic portions adjacent the opposite magnetic poles of each electromagnetic clamp, and non-ferromagnetic portions between the opposite magnetic poles of each electromagnetic clamp.

Abstract: A well system and associated method can include an acoustic generator which can be used to excite a formation with acoustic waves transmitted from the acoustic generator. Another well system and associated method can include an acoustic generator which can transmit acoustic waves into cement surrounding a casing. Another well system and associated method can include an acoustic generator which can be used to transmit acoustic waves into an annulus surrounding a well screen during or after a gravel packing operation. Another well system and associated method can include an acoustic generator which can be connected in a drill string in close proximity to a drill bit, with the acoustic generator transmitting acoustic waves into a formation ahead of the bit.

Abstract: A method for determining permeability of a porous medium of a formation, the method including: placing a logging instrument into a borehole that traverses the porous medium, the borehole filled with a borehole fluid; measuring a pressure, p(1), of an acoustic wave in the borehole at about a boundary between the porous medium and the borehole, the acoustic wave comprising a frequency that is about a resonant frequency of a system that includes the borehole and the porous medium; calculating the permeability from the pressure; and providing the permeability as output to a user.

Abstract: Systems and methods are provided for acquiring data using a wireless network and a number of nodes that may be configured to collect acquired data and forward data to a central recording and control system. The acquired data may include seismic and/or auxiliary data. A node for use in data acquisition may include an acquisition module in operative communication with a buried sensor array operable to output acquired data. The processor may also be operable to receive acquired data from another data acquisition module in the wireless network.

Abstract: 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.

Abstract: Vibration transducers, sensors including the vibration transducers, and methods for manufacturing the same. The vibration transducer may include a magnet. The vibration transducer may include a bobbin disposed about the magnet. The vibration transducer may include a first coil disposed about the bobbin. The vibration transducer may include a controllable damping coil disposed about the bobbin. The first coil is movable relative to the magnet. The magnet is polarized with respect to the axis of the vibration transducer.

Abstract: A seismic sensor system collects seismic data in a well. The system includes a pipe to be deployed inside the well, the pipe having a distal end; a first sensor located inside the pipe, next to the distal end; and a bladder jacket in which the pipe is placed, the bladder jacket being configured to hold a fluid. The pipe has holes next to the first sensor so that the fluid surrounds and contacts the first sensor.

Abstract: A system for creating a log during gas detection and monitoring is disclosed herein. The system can include a gas detection and well logging device for sensing and transmitting data, which can include a processor in communication with a monitoring device. The monitoring device can monitor, acquire, and transmit data associated with a drilling operation. The processor can receive the data, calibrate the data, and log the data into files. The processor can capture sensed data based on a time event and a depth event. The processor can scale the data and form a geological-hydrocarbon log for transmission. A client device can be in communication with the gas detection and well logging device, and can have computer instructions for querying the geological hydrocarbon log, the data, and the files to obtain real time streaming data for instant display.

Abstract: A method for surveying, may include receiving, by a processor, first survey data from a first source, the first source comprising a first signal generated by a subsurface earth formation in response to a passive-source electromagnetic signal, wherein the electromagnetic signal is generated by an electroseismic or seismoelectric conversion of the passive-source electromagnetic signal. The method may also include receiving, by the processor, second survey data from a second source and processing the first survey data and the second survey data to determine one or more properties of a subsurface earth formation.

Abstract: Disclosed is a method for estimating a property of an earth formation penetrated by a borehole. The method includes: transmitting acoustic waves into the formation from an acoustic source disposed in the borehole and away from a wall of the borehole; generating radial acoustic eigenwaves within a space between the wall of the borehole and the acoustic source using the transmitted acoustic waves; receiving an acoustic signal with an acoustic receiver disposed at the wall of the borehole; sensing an electric field signal with an electric field sensor disposed at the wall of the borehole; and estimating the property using the received acoustic signal and the sensed electric field signal.

Abstract: Methods and related systems are described for measuring and analyzing refracted acoustic energy. A plurality of receivers mounted are on a downhole tool, and are arranged and adapted to receive refracted acoustic energy from a downhole formation. Measurements of refracted acoustic energy is analyzed such that information relating to an azimuthal direction relative to the downhole tool of an interface within the downhole formation can be estimated. The receivers can be mounted on a drill collar as part of a LWD tool and steering of the drilling trajectory can be based in part on the estimated formation information.

Abstract: The present disclosure is related to apparatuses and methods for downhole acoustic logging. The tool may be used for generating a guided borehole wave that propagates into the formation as a body wave, reflects from an interface, and is converted back into a guided borehole wave. Guided borehole waves resulting from reflection of the body wave are used to image a reflector. Methods may include processing of acoustic logging signals including: wavefield separation, auto-correlation of wavefield components, filtering using a dip filter, and estimating a distance to the reflective interface.

Abstract: 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.

Abstract: Methods and apparatus that use microseismic event data, stress data, seismic data, and rock properties to predict the hydrocarbon production success of a well location are disclosed. An example method generates a hydrocarbon production function based on information associated with at least a first well location, obtains information associated with a second well location, and calculates the hydrocarbon production function using the information associated with the second well location to predict the hydrocarbon production of the second well location.

Abstract: The method uses a gas processor, various data collection devices each having a unique device protocol to receive drilling data, calibrate the devices and graphically present the data using both time events and depth events. The method includes computer implemented steps to scale the data and form the geological-hydrocarbon executive dashboard for transmission to various client devices to obtain real time streaming data, real time calibration information, while adding and removing detection devices and sensors online without shutting down the entire monitoring and analysis system for instant display.

Abstract: The system includes a gas processor with gas processor data storage and computer instructions to receive in various device protocols simultaneously information from rig based sensors and gas analysis devices drilling data, calibrate the devices and graphically present the data using both time events and depth events. Computer instructions scale the data and form the geological-hydrocarbon executive dashboard for transmission to various client devices to present real time streaming data, real time calibration information, real time alarms while enabling users to add and remove detection devices and sensors, including rig servers and remote servers, online without shutting down the entire monitoring and analysis system.