Abstract: A method for applying separated wave-field imaging onshore (1) by artificially creating up-going and down-going fields and (2) by using these fields in a migration algorithm. If there are any surface multiples in the data, the resulting image created using the migration algorithm will be distorted by the unknown free-surface reflection coefficient. In fact, the surface multiples may be generated with a complex series of reflection coefficients. The distortions found in the resulting image created using the migration algorithm are then removed.

Abstract: Apparatus and methods are described, including identifying an arrival of a first arriving S-wave emitted from a seismic source at an array (120) of sensors (129, 140) in real-time, by continuously analyzing waveforms received by the sensors (120, 140), and continuously monitoring back-azimuth and slowness data within the detected waveforms. Arrival of a first arriving P-wave emitted from the seismic source at the array (120) of sensors (129, 140) is identified, based upon the back-azimuth and slowness data. Slowness and back azimuth of the first arriving P-wave are determined, by analyzing a waveform of the P-wave, and based upon the determined slowness of the first arriving P-wave, the arrival of the first arriving S-wave at the array (120) of sensors (129, 140) is identified. Other applications are also described.

Abstract: Methods, systems, devices, and products for hydrocarbon tubular evaluation. Methods comprise conveying the logging tool in the tubular with a carrier; inducing with a transmitter a horizontal shear (SH) wave; identifying higher order SH mode signals received at a plurality of offset receivers responsive to a higher order SH mode engendered by the horizontal shear (SH) wave; estimating a dominant frequency for higher order SH mode from the higher order SH mode signals; estimating a group velocity for the higher order SH mode from the higher order SH mode signals; and estimating a tubular parameter using the dominant frequency and the group velocity. The tubular parameter may be at least tubular thickness. The method includes estimating the tubular parameter independent of the fundamental horizontal shear wave mode (SH0).

Abstract: The present invention discloses a device for measuring dynamic evolution of a three-dimensional disturbed stress under mining disturbance, comprising an outer steel cylinder. Three three-direction sensing units are arranged on the outer steel cylinder. Any two of three stress measurement directions of each three-direction sensing unit are perpendicular to each other. Nine stress measurement directions of the three three-direction sensing units are different. The present invention also discloses a method for measuring dynamic evolution of a three-dimensional disturbed stress under mining disturbance. In the present invention, stresses are measured from three perpendicular directions which are inclined, so the difficulty in measuring a three-dimensional stress in a borehole is overcome; and a spatial stress value is measured by three three-direction sensing units, and thus the size and direction of a disturbed principal stress in the borehole are calculated.

Abstract: A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

Abstract: A structural health monitoring system comprises a first set of sensors operable for coupling to a structure positioned under ground, the first set of sensors further configured to detect an impact upon the structure while the first set of sensors is positioned under the ground; a second set of sensors operable to be positioned on or proximate to a surface of the ground, the second set of sensors further configured to detect an audible event occurring at a distance from the second set of sensors and the structure; and a computer readable memory storing one or more audio signatures that may correspond to the audible event.

Abstract: The claimed invention relates to means for analysis of a mineral deposit under development using noise logging. The aim of invention consists in increasing accuracy of sound source position determining at surveying in wells with complicated multi-barrier design. The method for locating an acoustic noise source in a well comprises the stages of: computer simulation of acoustic field generated by one or more sources of acoustic signal in the well; simultaneous recording of acoustic signals inside the wellbore using a device for recording acoustic signals comprising at least two acoustic sensors; locating the sought acoustic signal sources in the well by means of co-processing of computer simulation data and data on acoustic signals inside the wellbore recorded using the aforementioned device.

Abstract: A method for generating a geophysical image of a subsurface region includes defining a computational sub-volume for the geophysical image including a predetermined number of seismic traces of a plurality of seismic traces and a predetermined number of samples per each one of the plurality of seismic traces, generating a data matrix corresponding to a first sub-volume of the subsurface region based on the defined computational sub-volume, the data matrix comprising the predetermined number of samples for the predetermined number of traces of a portion of a seismic dataset corresponding to the first sub-volume. The method also includes performing a singular value decomposition and estimating a coherence between the predetermined number of traces of the data matrix by performing a weighted sum of a variance of a plurality of right singular vectors of the data matrix, and assigning the estimated coherence to a location in the geophysical image.

Abstract: A optical target assembly is disclosed herein. The optical target assembly is movable about orthogonal pitch, yaw and roll axes and includes a reflector, a pitch and yaw angular sensor assembly, and a roll sensor assembly. The reflector is configured to engage a source of laser light. The pitch and yaw angular sensor includes a laser light sensor and an angle detection sensor. The pitch and yaw angular sensor assembly is configured to measure 360 degrees of motion about the pitch and the yaw axes. The roll sensor assembly is configured to measure 360 degrees of motion about the roll axis. The reflector can include an aperture configured to permit a portion of laser light incident on the reflector to pass through the reflector and onto the laser light sensor. The roll sensor assembly can include a roll angle sensor and a roll level sensor coupled to a two-dimensional pendulum.

Abstract: Processing data representing a wavefield propagating through a medium by defining, based on one or more properties of a region of the medium and of the wavefield therein, a desired timestep and a desired spatial step for a discrete operator. Discrete seed operators having an initial timestep and an initial spatial step less than the desired timestep and the desired spatial step are then defined, and these seed operators are compounded to obtain an operator having a greater timestep and upscaled to obtain an operator having a greater spatial step. The compounding and upscaling are repeated until an operator having the desired timestep and the desired spatial step is obtained. The operator having the desired timestep and the desired spatial step may be applied to the data representing the wavefield propagating through a medium to propagate the data backwards in time to recreate the wavefield at earlier times.

Abstract: Methods and systems that compute an approximate vertical-velocity wavefield based on a measured pressure wavefield and knowledge of the free-surface shape when the pressure wavefield was measured are described. The measured pressure wavefield is used to compute an approximate frozen free-surface profile of the free surface. The approximate frozen free-surface profile and the measured pressure wavefield are then used to compute an approximate vertical-velocity wavefield that does not include low-frequency streamer vibrational noise. The approximate vertical-velocity wavefield and measured pressure wavefield may be used to separate the pressure wavefield into up-going and down-going pressure wavefields.

Abstract: Apparatus, computer instructions and method for combining first and second records to form a substantially deghosted seismic record.

Abstract: An underwater sensor assembly includes a frame configured to sit on a bottom of a body of water and at least one first sensor connected to the frame. The at least one first sensor is configured to measure at least one parameter related to the body of water. A system for environmental monitoring includes the underwater sensor assembly, at least one buoy at a surface of the body of water, and at least one cable attached at a first end to the frame and attached at a second end opposite the first end to the at least one buoy. The at least one buoy comprises at least one second sensor configured to measure at least one parameter above the surface of the body of water.

Abstract: A method for improving a 4-dimensional (4D) repeatability by modifying a given path to be followed by a source during a seismic survey. The method includes receiving the given path at a control device associated with a vehicle that caries the source; following the given path during a first seismic survey that is a baseline survey for the 4D seismic survey; deviating from the given path to follow a new path when encountering an obstacle on the given path; and updating the given path, based on the new path, to obtain an updated given path when a deviation condition is met.

Abstract: Systems and methods are provided for directional de-noising on seismic data recorded byseismic receivers. A method includes: receiving a seismic dataset, wherein the seismic dataset includes a model dataset and an input dataset to filter; decomposing the model dataset into a plurality of model directions, identifying which of the model directions to keep; and mapping the input dataset along the identified model directions resulting in a filtered output.

Abstract: The present disclosure provides a technique for marine seismic imaging that processes data acquired from two or more different seismic surveys in a combined manner to advantageous effect. The different seismic surveys may use seabed sensors at same positions on the seabed, but they may have different shot locations and may be performed at different times. In one use case, the technique may be used to image a subsurface location that is difficult to image using either survey alone. In another use case, the technique may be used to image a subsurface location under an obstruction. The technique may also be utilized to efficiently monitor a reservoir over time.

Abstract: The present invention relates to a cluster bomblet having an improved bomblet body, the cluster bomblet comprising: a cylindrical bomblet body (10) packed with high explosives; a fuse assembly (20) having a striker screw (21) for exploding the high explosives and coupled to the top side of the bomblet body; and a conical penetrator (15) provided inside the rear end portion of the bomblet body.

Abstract: The present inventive concept includes a duct system and method for using same to map and locate ducts. A preferred embodiment of the duct system includes a duct, a plurality of electronic information modules and an oversheath at least partially covering the plurality of information modules and fixing the information modules to the duct. The plurality of information modules are configured to emit a positional signal to enable location of the information modules and associated duct(s) and/or mapping of the duct system.

Abstract: An electronic unit is constructed having a casing, at least partially flexible, at least partially made of a polymer material. The casing extends along a longitudinal axis (X) between two lateral ends and has a hollow cylindrical core for housing a portion of a core cable of a streamer, and a plurality of walls outwardly extending from the hollow cylindrical core, delimiting spaces configured for housing electronics, and having free ends. One of the walls and the hollow cylindrical core of the casing have a through-slot that extends longitudinally over a total length of the casing from one lateral end to another lateral end. An electronic board has at least one flexible part and configured for at least partially resting on free ends of at least two of the plurality of walls.

Abstract: Various embodiments include apparatus and methods to extract reflections from acoustic array data collected from a receiver array. A beam-former can be generated to detect a reflection wave in the presence of a direct wave identified from collected waveforms, where the beam-former can be correlated to receiver and depth for the array. The direct wave and the reflection wave can be separated to extract the reflection wave, where the separation is correlated to receiver and depth for the array. The extracted reflected wave can be used to image and/or analyze entities associated with the borehole. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods for efficiently acquiring full-azimuth towed streamer survey data are described. The methods use multiple vessels to perform coil shooting.

Abstract: Methods for efficiently acquiring full-azimuth towed streamer survey data are described. The methods use multiple vessels to perform coil shooting.

Abstract: A system and method are provided for filtering scatterer noise energy from land seismic waves using three dimensional (3D) iterative filtering in a cross-spread source-receiver pattern. The system and method isolate scatterer noise energy associated with a scatterer based on a filtering process performed using a scatterer referential time delay. Then, the isolated scatterer noise energy can be subtracted from the surface wave data. This process can be repeated for each scatterer in the covered area to remove each of their contributions, and can be performed, for example, after a preliminary filtering of the surface wave data using 3D fk filtering or the like.

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: Microseismic mapping using buried arrays with the integration of passive and active seismic surveys provides enhanced microseismic mapping results. The system is initially set up by recording seismic data with the buried array installation while shooting a significant portion of the 3D surface seismic survey. The 3D surface seismic survey provides the following data: shallow 3D VSP data from the buried arrays; P-wave and converted wave data for the area covered by the buried array that benefits from the planned data integration processing effort; and microseismic data and associated analysis.

Abstract: This invention provides a method for characterizing natural fracture networks or other textural networks in an Earth formation when using microseismic monitoring of a hydraulic fracturing job. The method comprises receiving (120) microseismic data from a hydraulic fracturing event, identifying a data subset (153) comprising components of the microseismic data associated with the one or more hydraulic fractures; and obtaining a remainder dataset (156) of the microseismic data by removing the subset from the microseismic data. One approach for identifying the data subset, after removing high uncertainty microseismic events, is to create a Voronoi diagram of a plurality of cells each associated with one of the microseismic events, determine a density for each cell, create a connectivity matrix of the high density cells and identify event clusters in the connectivity matrix which are aligned with a main growing direction of the hydraulic fracture.

Abstract: An autonomous underwater vehicle (AUV) is configured to record seismic signals during a marine seismic survey. The AUV includes a body having a base (B) and first and second sides (A, C), the body having a head part and a tail part; a propulsion system for guiding the AUV to a final target on the ocean bottom; jet pumps connected to corresponding nozzles on the first and second sides (A, C); a control device connected to the jet pumps; and a seismic sensor configured to record seismic signals. The jet pumps are actuated by the control device in a given sequence so that the base (B) penetrates into the ocean bottom.

Abstract: Embodiments of a system are provided for forming enhanced seismic array traces using virtual seismic sensors in addition to the real seismic sensors to form a virtual seismic array. The system receives the signal responses from the real sensors, processes the signal responses from the sensors to define virtual signals using a narrowband decomposition of the complex envelope of the sensor signal responses, calculates second- and fourth-order statistics to derive steering vectors for the array of real sensors, and forms a virtual seismic array in response thereto. Machines, computer program product, and computer-implemented methods are provided for forming enhanced seismic array traces by receiving the array responses from sensors, processing the signals to define virtual sensor signals and a virtual seismic array, and forming an array response for the virtual seismic array to form a seismic trace of enhanced resolution.

Abstract: A method for marine seismic surveying includes towing a streamer in a body of water. The streamer includes a plurality of spaced apart sensor groups, each including a plurality of longitudinally spaced apart pressure sensors and particle motion responsive sensors. Signals are detected at each of the sensors in response to actuation of a seismic energy source. Components of the sampled motion signals in each group above a selected frequency are combined to generate respective group motion signals. Components of the motion responsive signals below the selected frequency are velocity filtered. The velocity filtered signals are combined with the group motion signals to generate full bandwidth motion responsive signals corresponding to each sensor group.

Abstract: Systems, methods, and instructions encoded in a computer-readable medium can perform operations related to refining information on characteristics of natural fractures of a subterranean formation. Fracture pattern models are generated based on sampling an initial distribution of values for a fracture parameter. Each fracture pattern model may include, for example, a model of natural fractures in a subterranean formation. Each fracture pattern model is compared to microseismic event data for a subterranean region. A refined distribution for the fracture parameter is generated based on the comparison. Generating the refined distribution may include, for example, selecting values of the fracture parameter from fracture pattern models that correlate with the microseismic event data. In some implementations, an injection treatment may be simulated and/or designed based on the refined distribution.

Abstract: The described invention relates to a method for acquiring seismic data in icy waters comprising positioning a fixed structure or movable vessel (102) at or near an established water opening; deploying into the water opening, from said structure or vessel one or more ROV or AUV units (104), said ROV or AUV units remaining connected to said structure or vessel; operating the one or more ROV or AUV units to deploy seismic sensors recording equipment (106) and/or one or more seismic source equipment (108) on or near the water bottom; generating and applying control signals to one or more of the more ROV or AUV units to generate and to record seismic signals (110); operating the one or more ROV or AUV units on the water bottom to move (114) and/or recover (116) the seismic source equipment and/or seismic sensors recording.

Abstract: Neutrally-buoyant tools for seismic data collection are provided that may range from several hundred meters to several kilometers in length and have integrated sensors which move along with the borehole fluid in response to a passing seismic wave. The disclosure also provides methods of deploying neutrally-buoyant tools, which includes using a tractor, adding a weight or both to the tool in order to overcome the difficulty of lowering a neutrally buoyant tool into a borehole, and optionally occasionally clamping the tool to the borehole to alleviate tension in the tool. This disclosure also provides methods of acquiring seismic data, which involves positioning a neutrally-buoyant tool in a borehole such that the tool is able to move relatively freely along with the borehole fluid in response to a seismic wave passing through the fluid, firing a seismic source, and using the sensors to collect seismic data generated thereby.

Abstract: Adaptive filtering method to remove ground roll from seismic data. In an M channel adaptive filter, weights Wi are set using an adaptive algorithm based on seeking the minimum in the partial differential of cost function J. The cost function includes an expansion of the primary trace d into d=dg+?d (where: dg is ground roll contribution and ?d=dsig+dran, where dsig is the reflected signal component and dran is a random noise component) and a corresponding expansion of the reference x into x=xg+?x (where xg is ground roll contribution and ?x=xsig+xran; where xsig is a reflected signal component and xran is a random noise component). The delta components are included in the denominator of cost function J to provide an optimal solution of the filter coefficients biased by the reflection signal and random noise is removed.

Abstract: A technique includes obtaining multi-component seismic data acquired by two or more seismic sensors while in tow. The multi-component seismic data is indicative of a pressure wavefield and particle motion. The technique includes based on the data, determining at least one high order (i.e., second order or higher) spatial derivative of the pressure wavefield.

Abstract: A method for seismic surveying includes disposing a plurality of seismic sensors in a selected pattern above an area of the Earth's subsurface to be evaluated. A seismic energy source is repeatedly actuated proximate the seismic sensors. Signals generated by the seismic sensors, indexed in time with respect to each actuation of the seismic energy source are recorded. The recorded signals are processed to generate an image corresponding to at least one point in the subsurface. The processing includes stacking recordings from each sensor for a plurality of actuations of the source and beam steering a response of the seismic sensors such that the at least one point is equivalent to a focal point of a response of the plurality of sensors.

Abstract: Systems, sensors, and methods for high-speed image monitoring of baseplate movement in a vibrator. The systems can include a baseplate defined by an area, disposable at a ground surface to direct a seismic force into the ground surface. The system can include a reaction mass coupled to and positioned above the baseplate to generate the seismic force at the baseplate. The system can include an actuator assembly coupled to the reaction mass to vibrate the reaction mass, as well as high-speed image units directed at the area of the baseplate. The high-speed image units can include photo detectors to sense a distribution of acceleration across the area of the baseplate, and a light source emit light to be sensed by the photo detectors. The system can also include a controller coupled to the actuator assembly, that drives the actuator assembly.

Abstract: A sensor assembly has first sensors spaced apart along a first direction, and second sensors oriented in a second direction generally orthogonal to the first direction. Differencing of outputs of the first sensors is performed, and differencing of outputs of the second sensors is performed. A signal output is produced by combining the differenced outputs of the first sensors and the differenced outputs of the second sensors, where the signal output represents a seismic response of a subterranean structure.

Abstract: A deployment and retrieval apparatus for ocean bottom seismic receivers, the apparatus being a remotely operated vehicle (ROV) having a carrier attached thereto and carrying a plurality of receivers. The carrier includes a frame in which is mounted a structure for seating and releasing the receivers. The structure includes one or more movable conveyors disposed to move receivers along a linear path relative to the frame in order to discharge and retrieve ocean bottom seismic receivers.

Abstract: A downhole tool for subsurface disposal is provided. The tool comprises an elongated tool body, an enclosure attached to an exterior surface of the tool body. The enclosure comprises at least one transducer disposed at an angle with respect to a longitudinal axis of the enclosure, and an electronics board coupled to and disposed adjacent to the at least one transducer. The enclosure also defines an internal cavity, and the internal cavity contains a fluid for insulating the at least one transducer from a downhole environment. The fluid is in direct contact with the at least one transducer and the electronics board.

Abstract: A measurement method for a granular compaction pile 10 using a crosshole seismic test. The measurement method includes forming first to fifth measurement holes around the granular compaction pile, injecting grouting material into the first to fifth measurement holes and inserting casings into the first to fifth measurement holes, respectively, and installing an oscillator and a detector of a crosshole seismic tester in the first to fifth holes and detecting a velocity of a shearing wave, thereby measuring a diameter of the granular compaction pile according to a construction depth thereof. The shape and the diameter of the granular compaction pile are easily checked without causing damage to the granular compaction pile.

Abstract: An enclosure for housing a transducer and electronics for disposal on a downhole tool. A transducer is disposed at an angle with respect to a longitudinal axis of the enclosure, wherein the enclosure contains a fluid surrounding the transducer. Enclosures also include transducers linked to motor means for selective rotation of the transducers within the enclosure. Enclosures with transducer arrays for phased or targeted signal transmission/detection.

Abstract: A deployment and retrieval apparatus for ocean bottom seismic receivers, the apparatus being a remotely operated vehicle (ROV) having a carrier attached thereto and carrying a plurality of receivers. The carrier includes a frame in which is mounted a structure for seating and releasing the receivers. The structure may include a movable conveyor or fixed parallel rails or a barrel. The structure includes a discharge port on the frame and a discharge mechanism for removing and retrieving the receivers. A method for deployment and retrieval of ocean bottom seismic receivers includes the steps of loading a carrier with a plurality of receivers, attaching the carrier to an ROV, utilizing the ROV to transport the carrier from a surface vessel to a position adjacent the seabed and thereafter utilizing the ROV to remove receivers from the carrier and place the receivers on the seabed.

Abstract: Methods and systems are provided for inducing seismic vibrations into an elastic medium such as subterranean formations. The methods and systems utilize seismic transducers having a sensor matrix for measurement of baseplate force distributions. Certain embodiments include a sensor matrix that is configured to measure a distribution of discrete force measurements across the surface area of the baseplate. Advantages of including such sensor matrices include a more accurate prediction of seismic transducer energy output. That is, these measurements can be used as feedback to adjust the operation of the seismic transducer. Additionally, these force measurements may be used to provide for a better interpretation of gathered seismic data. These advantages ultimately translate to improved seismic surveys, having higher resolution of the formations surveyed and reaching greater depths.

Abstract: A measurement package for disposal on an apparatus such as a downhole tool or a tool like device. The measurement package including an enclosure, a first acoustic transducer housed within the enclosure, a second acoustic transducer housed within the enclosure and electronics housed within the enclosure that is in communication with the first and second transducers. Further, an acoustic transmitter and receivers can be disposed at an angle with respect to a longitudinal axis of the enclosure. The enclosure can contain attenuative material surrounding the transmitter and receivers, and electronics for controlling the transmitter and receivers and communicating with the downhole tool.

Abstract: A method for seismic surveying includes disposing a plurality of seismic sensors in a selected pattern above an area of the Earth's subsurface to be evaluated. A seismic energy source is repeatedly actuated proximate the seismic sensors. Signals generated by the seismic sensors, indexed in time with respect to each actuation of the seismic energy source are recorded. The recorded signals are processed to generate an image corresponding to at least one point in the subsurface. The processing includes stacking recordings from each sensor for a plurality of actuations of the source and beam steering a response of the seismic sensors such that the at least one point is equivalent to a focal point of a response of the plurality of sensors.

Abstract: Seismic sensor systems and sensor station topologies, as well as corresponding cable and sensor station components, manufacturing and deployment techniques are provided. For some embodiments, networks of optical ocean bottom seismic (OBS) stations are provided, in which sensor stations are efficiently deployed in a modular fashion as series of array cable modules deployed along a multi-fiber cable.

Abstract: A method for seismic event mapping includes transforming seismic signals recorded at selected positions into a domain of possible spatial positions of a source of seismic events. An origin in spatial position and time of at least one seismic event is determined from space and time distribution of at least one attribute of the transformed seismic data.

Abstract: Seismic sensor systems and sensor station topologies, as well as corresponding cable and sensor station components, manufacturing and deployment techniques are provided. For some embodiments, networks of optical ocean bottom seismic (OBS) stations are provided, in which sensor stations are efficiently deployed in a modular fashion as series of array cable modules deployed along a multi-fiber cable.

Abstract: A method of acquiring seismic data that includes deploying a first array of seismic receivers and a second array of seismic receivers, and simultaneously receiving drill noise seismic energy produced as a wellbore is drilled relatively near the first and second arrays of seismic receivers using the first and second array of seismic receivers, wherein the first array of seismic receivers is closer to the source of the drill noise seismic energy than the second array of seismic receivers. A related method for processing seismic data and computer useable media are also described. Also a method of acquiring seismic data that includes deploying a first array of seismic receivers within a borehole, receiving seismic energy produced as a wellbore is drilled relatively near first array using said seismic receivers, and recording seismic data associated with the received seismic energy. A related method for acquiring and processing seismic data is also described.

Abstract: A marine seismic streamer includes a jacket substantially covering an exterior of the streamer. At least one strength member is disposed along the length of the jacket. A sensor mount is coupled to the strength member. At least one particle motion sensor is suspended within the sensor mount at a selected location along the jacket. The at least one particle motion sensor is suspended in the jacket by at least one biasing device. A mass of the particle motion sensor and a force rate of the biasing device are selected such that a resonant frequency of the particle motion sensor within the sensor jacket is within a predetermined range. The sensor mount is configured such that motion of the jacket, the sensor mount and the strength member is substantially isolated from the particle motion sensor.