Abstract: Land seismic survey including providing at least two vibrators in a first group, wherein each vibrator in the first group is assigned to a respective source line, where the source lines of the first group run substantially parallel to one another; providing at least two vibrators in a second group, wherein each vibrator in the second group is assigned to a respective source line that is different than the source lines assigned to vibrators from the first group; actuating the vibrators in the first group simultaneously using different frequency bandwidth sweeps and different phase encodings; actuating the vibrators in the second group at the same time as those in the first group, and simultaneously using different frequency bandwidth sweeps and different phase encodings; and detecting the resulting seismic signals with a plurality of seismic sensors that are placed in contact with the earth and as part of a seismic spread.

Abstract: Systems and methods are provided for sensing acoustic signals using a floating base vector sensor. A vector sensor according to an embodiment of the present disclosure can be used to detect and characterize low frequency sound wave(s) in a viscous medium (e.g., air, water, etc.) by detecting a periodic motion of the media particles associated with the sound wave(s). The orientation of the particle velocity deduced from such measurements can provide information regarding the wave vector of the sound wave(s), can define the direction of arrival (DOA) for the acoustic signal, and can assist locating the source of the sound of interest.

Abstract: The present invention discloses a submarine seismic monitoring apparatus and system based on the submarine Internet of things.

Abstract: A hierarchical data acquisition system and method applied to a marine information network are provided. Multiple sensor nodes are arranged in clusters, each of the clusters includes a cluster head node and multiple ordinary nodes. The multiple ordinary nodes acquire data information of a seafloor and transmit the acquired data information to the cluster head node, and the cluster head node aggregate the data and transmits the aggregated data to an autonomous underwater vehicle, reducing energy consumption of each of the sensor nodes, prolonging service lives of sensors of a data acquisition layer, and improving data acquisition efficiency of a data acquisition layer. In addition, after each of data acquisition periods, a sensor node in each of the clusters is selected as a cluster head node in a next data acquisition cycle. Cluster head nodes are continuously updated in cycles.

Abstract: Systems and methods are provided for sensing acoustic signals using a floating base vector sensor. A vector sensor according to an embodiment of the present disclosure can be used to detect and characterize low frequency sound wave(s) in a viscous medium (e.g., air, water, etc.) by detecting a periodic motion of the media particles associated with the sound wave(s). The orientation of the particle velocity deduced from such measurements can provide information regarding the wave vector of the sound wave(s), can define the direction of arrival (DOA) for the acoustic signal, and can assist locating the source of the sound of interest.

Abstract: Techniques are disclosed relating to geophysical surveying and data processing using streamers at different depths. In one embodiment, a method includes obtaining geophysical data specific to a geophysical formation that includes a first set of data representative of a first particle motion signal and a first pressure signal recorded using sensors at a first depth and a second set of data representative of a second particle motion signal and a second pressure signal recorded using sensors at a second, greater depth. In this embodiment, the method includes generating first and second wave separation equations from the first and second sets of data and determining a cross-line wavenumber value that reconciles the first and second equations. The determined cross-line wavenumber may be used to separate measured up-going and down-going wavefields.

Abstract: The present invention discloses a model test system and method for seabed seismic wave detection. The model test system includes a model test unit which specifically includes a testbed for simulating a seabed, wherein a module for simulating bedrock and geology is arranged in the testbed; a water source supply unit supplies simulation seawater into the testbed; a sea wave generation apparatus is configured to act on the simulation seawater at different speeds and different forces to generate different sizes of sea waves. The present invention provides support and guidance for the advancing investigation of geologic parameters in a detection area such as distribution situations of faults, a range of landslides, a depth and morphology of a glide plane and the like.

Abstract: An autonomous underwater base for handling an autonomous underwater vehicle (AUV) equipped with seismic sensors for recording seismic signals during a marine seismic survey. The autonomous underwater base includes a storing module configured to store the AUV; an inlet/outlet module configured to control access of the AUV to the storing module; and a control module having a positioning system configured to adjust a position of the base in water. The positioning system autonomously drives the storing module from a first position to a second position underwater.

Abstract: A submersible sound system may include a housing, an end piece, an elastic membrane, an end cap affixed to the elastic membrane, and a subwoofer speaker system disposed within the housing and supported by a speaker support. A bubble sound source may be defined by the speaker support, the speaker diaphragm, an anterior end of the housing, the elastic membrane, and the end cap. The housing, end piece, and a posterior surface of the speaker support may form a sealed enclosure. The sound system may include a tuning pipe disposed between the sealed enclosure and the bubble sound source. A Helmholtz resonator may be disposed anteriorly of the speaker system. Multiple sound system may be assembled to form a cluster. The cluster may be defined by the vertices of regular polyhedron. The sound systems may be controlled to maintain the speaker systems within acceptable thermal limits.

Abstract: A multi-stage inversion method for deblending seismic data includes: a) acquiring blended seismic data from a plurality of seismic sources; b) constructing an optimization model that includes the acquired blended seismic data and unblended seismic data; c) performing sparse inversion, via a computer processor, on the optimization model; d) estimating high-amplitude coherent energy from result of the performing sparse inversion in c); e) re-blending the estimated high-amplitude coherent energy; and f) computing blended data with an attenuated direct arrival energy.

Abstract: Techniques are disclosed relating to geophysical surveying and data processing using streamers at different depths. In one embodiment, a method includes obtaining geophysical data that is specific to a geophysical formation and representative of: a particle motion signal recorded using sensors at a first depth, a first pressure signal recorded using sensors towed at the first depth, and a second pressure signal recorded using sensors towed at a second, greater depth. In this embodiment the method includes modifying a low-frequency range of the particle motion signal using particle motion information estimated based on the second pressure signal. The modified particle motion signal may then be used to separate up-going and down-going wavefields. In some embodiments, obtaining geophysical data is performed by towing a first streamer at the first depth and a second streamer at the second depth. In some embodiments, the second streamer does not include particle motion sensors.

Abstract: A method for estimating a time variant signal representing a seismic source obtains seismic data recorded by at least one receiver and generated by the seismic source, the recorded seismic data comprising direct arrivals and derives the time variant signal using an operator that relates the time variant signal to the acquired seismic data, the operator constrained such that the time variant signal is sparse in time.

Abstract: A system for acquiring a marine seismic survey makes use of a propelled vessel (40) towing at least a seismic source assembly (100) behind it. The navigation control system (42) of the propelled vessel is instructed to steer the propelled vessel in response to position information repetitively generated by a source global positioning system (GPS, 130) which forms part of the seismic source assembly being towed. The position information from the source GPS is thus used to navigate the seismic source assembly to a target location. The position information from the source GPS is also used to trigger activation of the seismic source when the seismic source is located within a pre-determined distance from the target location.

Abstract: A system and method for acquiring seismic streamer data is provided. Embodiments may include performing a marine seismic survey using an unmanned marine vessel having a power source configured to drive and provide propulsion to the unmanned marine vessel. Embodiments may further include acquiring one or more of long and ultra-long seismic survey data using a multi-dimensional seismic sensor array coupled with the unmanned marine vessel and providing the seismic survey data as a reduced data set that includes long and ultra long offsets.

Abstract: An unmanned vessel system can include a hull system configured to provide buoyancy, one or more seismic sources configured to generate seismic energy, and a deployment apparatus configured to deploy the seismic sources from the hull system to a water body or water column. A control system can be configured to operate the deployment apparatus, in order to deploy the one or more seismic sources so that the seismic energy propagates through the water column. A compressed air source can be provided on board the unmanned vessel system, with a source line configured to provide compressed air to the seismic sources.

Abstract: Apparatus and methods to operationally deploy land-based seismic nodes. An autonomous or semi-autonomous vehicle includes apparatus for placing, monitoring, testing, servicing, and collecting nodes in a harsh environment such as, e.g., tundra or desert. Associated methods of node deployment and retrieval are disclosed including a ‘rollover deployment.

Abstract: Method and system for acquiring seismic data. The marine seismic acquisition system includes a first vessel that follows an inline direction (X); a first source array (S1) configured to generate first seismic waves; and a second source array (S2) configured to generate second seismic waves. The first and second source arrays are towed by the first vessel along the inline direction (X) and a first inline distance (d) between (i) a first center of source (CS1) of the first source array (S1) and (ii) a second center of source (CS2) of the second source array (S2) is different from zero.

Abstract: Systems and methods for grounding power generation units with silicon carbide MOSFET power converters are provided. A power generation unit can include a power generator configured to generate multiphase alternating current power at a first voltage. The power generation unit can also include a power converter configured to convert the multiphase alternating current power from the power generator at the first voltage to multiphase alternating current power at a second voltage. The power converter can include one or more silicon carbide MOSFETs and at least one heatsink configured to remove heat from the power converter. The at least one heatsink of the power converter can be electrically connected to a local ground formed by one or more components of the power generation unit.

Abstract: Method and system for acquiring seismic data. The system includes a first streamer vessel configured to tow a first source array and a first streamer spread; a first source vessel configured to tow a second source array; and a second source vessel configured to tow a third source array. The first to third source arrays are distributed along a non-linear profile while the first streamer vessel and the first to second source vessels move along an inline direction (X).

Abstract: A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

Abstract: Disclosed herein are various embodiments of a method and apparatus to enhance spatial sampling in all nominally horizontal directions for Dual-Sensor seismic data at the bottom of a body of water such as the ocean. The sensor apparatus on the water bottom is comprised of sensing elements for linear particle motion, for rotational motion, for pressure measurement, for pressure gradients, and for static orientation. Stress and wavefield conditions known at the water bottom allow numerical calculations that yield enhanced spatial sampling of pressure and nominally vertical linear particle motion, up to double the conventional (based on physical sensor locations) Nyquist spatial frequency in two nominally horizontal independent directions. The method and apparatus have a wide range of application in Ocean Bottom Seismic 3D, 4D, and Permanent Reservoir Monitoring surveys, and other marine seismic surveys, in oil and gas exploration and production.

Abstract: Measurement data is received from first and second seismic sensors, where the first and second seismic sensors are oriented in opposite directions. Each of the first and second seismic sensors has a sensing element responsive to pressure and particle motion. The signals can be combined to remove the particle motion component of the measurement data and obtain pressure-only data. Alternatively, the signals can be combined to deghost the received measurement data.

Abstract: A system and method for handling seismic cable having sensor stations thereon is provided. The seismic cable is positionable about the seismic field for measuring seismic parameters of a subsurface structure. The system includes a mobile unit, a reel and a winch assembly. The mobile unit is positionable about the seismic field, and has a platform. The reel is supportable on the platform with the seismic cable disposable about the reel. The winch assembly is carried by the mobile unit and includes a plurality of cable guides. At least one of the cable guides has a passageway with an adjustable dimension for aligning and guiding the seismic cable and the sensor stations passing therethrough.

Abstract: Methods and apparatuses for land seismic survey are provided. The methods and apparatuses utilize spatial derivatives of a seismic wavefield to interpolate, regularize or extrapolate seismic data. The methods and apparatuses may considerably reduce land seismic field efforts and/or compensate data gaps.

Abstract: Method for estimating source signature of a marine seismic source array in a naturally band-limited subsurface region, for designature processing of resulting seismic data. Direct arrivals identified in the streamer receivers' records (131) provide a far-field estimate of the source signature, provided that the subsurface naturally limits frequencies to below the first notch frequency in the amplitude response of the seismic streamer receiver array. Processing of the direct arrivals may include move out or alignment correction (132), signal enhancement (133), summing of direct arrival traces over all offsets (134), windowing or tapering of direct arrivals (135), and deterministic corrections to the combined direct arrivals to compensate for ghosting and streamer array effects (136).

Abstract: A marine vibrator may include a containment housing, a sound radiating surface, and a compliance chamber. The compliance chamber may include a compliance chamber housing, a non-linear linkage assembly, and a low pressure chamber. The compliance chamber housing may define at least a portion of a compliance chamber internal volume having a compliance chamber internal gas pressure. The low pressure chamber may comprise a low pressure piston and a low pressure chamber housing. The low pressure chamber housing may define at least a portion of a low pressure chamber internal volume having a low pressure chamber internal gas pressure. The low pressure piston may be configured to move in response to a pressure differential across the low pressure piston such that a resonance frequency of the marine vibrator may be changed.

Abstract: The method of controlling recoil in a disrupter comprises: providing liquid in a liquid chamber of the disrupter, the liquid chamber having a front nozzle for expelling the liquid therethrough; providing combustible propellant in a propellant chamber of the disrupter that communicates with the liquid chamber and that has a rear nozzle for expelling combustion gases therethrough; providing a bather between the liquid and the propellant to avoid admixing both; and igniting the propellant to generate expanding combustion gases that will expel the liquid out of the disrupter through the front nozzle in a first direction, either rupturing or propelling the barrier in the process, the combustion gases exhausting out of the disrupter at least partly through the rear nozzle in a second direction, with the first and second directions being at least partly opposite one another to control the recoil of the disrupter.

Abstract: The invention relates to a seismic node (100), comprising at least one seismic sensor with associated electronics, a primary oscillator (106) for timing sensor signals, a reference oscillator (104), a memory, a power source, a switch (102) for turning the reference oscillator on and off, and a processor (112) for digitizing sensor signals and storing them in the memory, calibrating a frequency of the primary oscillator (106) based on the frequency of the reference oscillator (104), and turning the reference oscillator on and off.

Abstract: A marine vibrator may include a containment housing, a sound radiating surface, and a compliance chamber. The compliance chamber may include a compliance chamber housing, a non-linear linkage assembly, and a low pressure chamber. The compliance chamber housing may define at least a portion of a compliance chamber internal volume having a compliance chamber internal gas pressure. The low pressure chamber may comprise a low pressure piston and a low pressure chamber housing. The low pressure chamber housing may define at least a portion of a low pressure chamber internal volume having a low pressure chamber internal gas pressure. The low pressure piston may be configured to move in response to a pressure differential across the low pressure piston such that a resonance frequency of the marine vibrator may be changed.

Abstract: A hydrodynamic foil system for a sensor streamer array includes at least two tow ropes each coupled at one end to a survey vessel and at the other end to a paravane. the paravanes configured to provide lateral outward force as the vessel and paravanes are moved through a body of water. A spreader cable is coupled to each of the paravanes. A plurality of laterally spaced apart sensor streamers coupled at forward ends thereof to the spreader cable. A plurality of foils is disposed on the spreader cables. The foils configured to provide hydrodynamic lift in a vertical direction as the spreader cables are moved through the water.

Abstract: Measurement data is received from first and second seismic sensors, where the first and second seismic sensors are oriented in opposite directions. Each of the first and second seismic sensors has a sensing element responsive to pressure and particle motion. The signals can be combined to remove the particle motion component of the measurement data and obtain pressure-only data. Alternatively, the signals can be combined to deghost the received measurement data.

Abstract: A seismic source array includes a first source and a second source. The first source has a first spectral output and the second source has a second spectral output different than the first spectral output. The first source has a first total volume different than a second total volume of the second source.

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: An acoustic reflector primarily for underwater use comprising a shell surrounding a core in which holes are provided in the shell to allow air and water freely to enter and leave the interior of the shell when the reflector is immersed in water. Various embodiments are described including the use of a metal shell matched to a water core, the use of a mounting bar, provision of a frame to reflect acoustically alpha numeric characters, a soluble plug to delay operation of the reflector, and coating the reflector with polyurethane to limit damage. Also proposed is a pulse pattern to improve the identification of an acoustic reflector in some circumstances. Designs of reflectors particularly suitable for use with the relatively low frequency sonars found in the fishing industry with an aluminum or aluminum alloy shell are described, as are reflectors with a non-metal shell suitable for use with the higher frequency sonars in the underwater exploration industry.

Abstract: There is a method for determining a shape and structure of a piston for a vibratory seismic source element. The method includes generating a cost function J that is function of plural variables; applying plural constraints to the cost function J; calculating a piston shape and piston design that fulfills the plural constraints; and modifying the calculated piston shape and piston design based on practical implementations of the vibratory source element.

Abstract: The invention concerns a device for emitting seismic waves designed to operate by being towed by a vessel, characterized in that it comprises means capable of discharging compressed air under high pressure into water, to generate a bubble (44) of a general annular shape.

Abstract: A logging tool for use in a wellbore having a sensor portion for making measurements. The tool has a sleeve enclosing the sensor portion and made of a material that is transparent to the measurements being made. One or more structural elements having physical characteristics different from the material comprising the sleeve are carried on the sleeve to enhance the mechanical properties of the sleeve.

Abstract: Methods and apparatus for generating borehole seismic surveys are disclosed. The methods and apparatus enable more accurate surveys than previous surveying systems. In some embodiments, firing of remote seismic sources is synchronized with data recording in a borehole. In some embodiments, the synchronization is based on a universal time standard. In some embodiments, GPS positioning technology is used to predict firing times and synchronize firing times with downhole and surface recording.

Abstract: A method for processing seismic data. The method includes receiving the seismic data acquired at one or more receivers due to one or more marine vibroseis sources that emit one or more vibroseis sweeps. The method then applies a receiver motion correction algorithm to the received seismic data to generate receiver motion corrected seismic data. After generating the receiver motion corrected seismic data, the method transforms the receiver motion corrected seismic data into a temporal Fourier domain to generate seismic data as a function of frequency. The method then reconstructs the transformed seismic data as a function of frequency to correct for one or more motions of the one or more marine vibroseis sources. After reconstructing the transformed seismic data, the method transforms the reconstructed seismic data to the time domain. The method then generates a seismic image of a subsurface of the Earth based on the transformed reconstructed seismic data.

Abstract: A marine source sub-array and method for generating a pressure wave in a body of water. The marine source sub-array includes a float configured to float in the body of water; base plates connected to the float through cables; plural individual source elements connected to the base plates and configured to generate pressure waves underwater; and a coverage plate located between the plural individual source elements and the float. The coverage plate has a surface area larger than a surface area of the float.

Abstract: A marine source sub-array and method for generating a pressure wave in a body of water. The marine source sub-array includes a float configured to float in the body of water; base plates connected to the float through cables; plural individual source elements connected to the base plates and configured to generate pressure waves underwater; and a coverage plate located between the plural individual source elements and the float. The coverage plate has a surface area larger than a surface area of the float.

Abstract: A method for seismic exploration of subsurface rock formations includes actuating an impulsive seismic energy source proximate the rock formations. A non-impulsive seismic energy source is actuated. A near field waveform of each of the impulsive and non-impulsive seismic energy sources is detected. A far field waveform of the combined output of the impulsive and non-impulsive seismic energy sources is determined from the near field waveforms. An impulse response of the subsurface rock formations is determined by deconvolving the far field waveform with detected seismic signals.

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 seismic energy source includes an inlet aperture and an inlet pipe in fluid communication with an outlet of the inlet aperture at an inlet end of the inlet pipe. The inlet pipe is in fluid communication with an accumulator at an outlet end of the inlet pipe. An outlet pipe is in fluid communication with the accumulator at an inlet end of the outlet pipe and is connected to an outlet valve at an outlet end of the outlet pipe. The outlet valve is actuated by fluid pressure in the outlet pipe. An actuation pressure of the valve, and diameter, length and material properties of the outlet pipe are selected to cause a reflected water pressure wave resulting from closure of the valve to travel within the outlet pipe at a selected velocity. Motion of the seismic source through the water provides water pressure to operate the source.

Abstract: A method for communicating between marine vessels includes the steps of connecting a communication hub and a first marine vessel via a cable; transmitting an electronic signal via the cable between the communication hub and the first marine vessel; and transmitting the electronic signal wirelessly between the communication hub and a second marine vessel. The cable may be a seismic cable such as, and without limitation to, a streamer and an ocean bottom cable. The seismic cable may include one or more seismic sensors such as hydrophones and geophones.

Abstract: A seismic energy source includes an inlet aperture and an inlet pipe in fluid communication with an outlet of the inlet aperture at an inlet end of the inlet pipe. The inlet pipe is in fluid communication with an accumulator at an outlet end of the inlet pipe. An outlet pipe is in fluid communication with the accumulator at an inlet end of the outlet pipe and is connected to an outlet valve at an outlet end of the outlet pipe. The outlet valve is actuated by fluid pressure in the outlet pipe. An actuation pressure of the valve, and diameter, length and material properties of the outlet pipe are selected to cause a reflected water pressure wave resulting from closure of the valve to travel within the outlet pipe at a selected velocity. Motion of the seismic source through the water provides water pressure to operate the source.

Abstract: A method for attenuating out of band energy emitted from a seismic source used in a marine seismic survey. The method includes disposing the seismic source in a body of water and releasing a gas into a volume of water surrounding the seismic source. The released gas may be configured such that it displaces the volume of water surrounding the seismic source at a rate less than 2.9×106 cubic-meters per cubic-second.

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 subsea monitoring system.

Abstract: A seismic source array 15 comprises a plurality of seismic source 26 arranged about a central point of the source array 15 in such a way that an imaginary circle drawn with said central point at its center, and containing all of said seismic sources 26, can be divided into at least three whole sectors each of which contains a substantially identical arrangement of seismic sources 26.