Abstract: In-situ calibration of a resistivity logging tool is accomplished using a variety of methods in which deep measurement signals are calibrated using acquired and simulated measurement signals.

Abstract: The present disclosure is related to estimation of a far field signature in a second direction from a far field signature in a first direction. For a number of source elements, where the number of source elements corresponds to a seismic source, an impulse response in a first direction and a second direction can be determined. A transfer function that transforms a far field signature of the seismic source in the first direction to a far field signature of the seismic source in the second direction can be determined based on corresponding impulse responses in the first direction and the second direction. An estimated far field signature for the seismic source in the second direction can be determined based on the transfer function.

Abstract: An air gun for use in generating seismic energy impulses operable at pressures below 1000 psi that reduces high frequencies and cavitation around the discharge of the air gun in order to mitigate damage to the marine environment, the air gun providing a sliding seal at the firing piston, an extension of port widths beyond the diameter of the firing piston and capability to control the speed of the shuttle assembly to reduce and eliminate some of the possible causes of the objectionable high frequencies and cavitation.

Abstract: A compact seismic source for seismic acquisition generating a humming signal includes a casing and a low-frequency reciprocating drive. The casing defines a fluid tight chamber and comprises a first casing section and a second casing section of roughly equal mass. The drive is disposed within the fluid tight chamber and, in operation, reinforces the natural reciprocating oscillation of the first and second casing sections relative to one another at a low seismic frequency. In one aspect, this action omni-directionally radiates the low frequency, humming seismic signal. On another aspect, the compact seismic source is substantially smaller than the wavelength of the low seismic frequency. Such a compact source may be deployed to omni-directionally radiate a low frequency, humming seismic signal during a seismic survey.

Abstract: An item may be outfitted with a cartridge for varying a net density of the item and deposited in a body of liquid for storage. The cartridge may cause a net density of the item to exceed a density of the liquid, or to fall below the density of the liquid, and to descend or ascend within the liquid, as desired. The cartridge may also cause a net density of the item to equal the density of the liquid, and thus remain at a constant depth. The cartridge may be configured to receive acoustic signals or other forms of instructions for varying a net density of the item, and may send acoustic signals or other messages identifying a depth or position of the item. The cartridge may thus enable an item to be stored at any depth within the liquid, and be retrieved upon demand.

Abstract: Various implementations described herein are directed to a method of performing a seismic survey operation. The method may include receiving a target acoustic output for a seismic survey. The method may include selecting an operating chamber liner for an airgun to be used in a seismic survey that corresponds to the target acoustic output. The method may also include performing a seismic survey using the airgun having the selected operating chamber liner.

Abstract: Methods and systems for improving azimuth distribution in a seismic acquisition system are described. A survey acquisition system includes a plurality of streamers towed by a plurality of streamer vessels, including a first streamer vessel and a second streamer vessel and a plurality of sources towed by a plurality of source vessels. The plurality of streamer vessels and plurality of source vessels are configured relative to one another such that the plurality of source vessels are positioned at one or more predetermined inline distances behind a portion of the first streamer vessel and are also positioned at one or more predetermined inline distances in front of a portion of the second streamer vessel. The plurality of streamer vessels and plurality of source vessels are also spaced apart from one another in a cross-line direction.

Abstract: A sound source includes a first gas filled underwater resonator, a second gas filled underwater resonator connected to the first resonator and at least one excitation member configured to excite the first gas filled underwater resonator and the second gas filled underwater resonator, where the first gas filled underwater resonator is permanently tuned to produce a first resonant frequency upon excitation by the at least one excitation member, where the gas filled underwater second resonator is permanently tuned to produce a second resonant frequency upon excitation by the at least one excitation member, and where the first resonant frequency is different from the second resonant frequency.

Abstract: The invention is an electric sweep type seismic vibrator source of the type used in seismic prospecting for hydrocarbons. The source uses an engine and generator combination to create electric power for all systems on the source such as driving a frame of linear electric motors that direct a rod or piston to contact the ground in a recurring fashion along with driving the source from location to location through a survey area. Preferably, a foot is arranged on the bottom end of the rod or piston for contact with the ground and by engaging the grid of motors to push down against the ground in a rapid progression, acoustic energy is created and delivered into the ground for geophones to sense and record.

Abstract: The invention relates to a source device for the emission of seismic waves designed to operate by being towed by a vessel. The source device according to the invention comprises at least three support-beams, a plurality of guns placed along each support-beam, a central hub receiving one end of support-beams and arranged such that support-beams can be deployed according to a star-like geometry, and the means to keep support-beams in this geometry during operation.

Abstract: An air, fuel, and water mixture is injected into a resonance chamber forming micro-packets. The micro-packets are ignited forming micro-explosions in a combustion chamber containing a central resonance chamber creating a standing wave interfering with a standing wave in the resonance chamber generating the micro-packets. The interfering waves are in phase aiding in the disassociation of molecules, including hydrogen and oxygen, in the air, fuel and water mixture. Efficient combustion is achieved with a nearly zero carbon emissions. The heat generated from the combustion may be used to produce work by any conventional device, such as a steam engine or turbine or generate heat for a building.

Abstract: A method for acquiring seismic data. The method may include towing one or more seismic streamers in the water, towing a first air gun array and a second air gun array in the water at a first depth, and towing a third air gun array and a fourth air gun array in the water at a second depth greater than the first depth. While towing the air gun arrays, the first and second air gun arrays and the third and fourth air gun arrays may be separated by a cross line distance that depends on a separation between the seismic streamers. The method may also include firing seismic energy, by the first, second, third and fourth air gun arrays, through the water into the earth. After firing the seismic energy, the method may record seismic signals reflected from strata in the earth beneath the water.

Abstract: A coupling structure for a resonant microgyroscope produced on a substrate, wherein the coupling structure enables a vibratory movement provided by an excitation mechanism to be detected along a first axis, and enables it to be transmitted to seismic masses lying in a plane containing the first axis. The coupling structure includes a closed assembly of beams connected to the seismic masses so as to be anchored only to the seismic masses, wherein the assembly is positioned to detect the vibratory movement provided by the excitation mechanism, and to transmit it to the seismic masses along at least a second axis contained in the plane, wherein the coupling structure has no point of anchorage to the substrate.

Abstract: A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end. The at least one overpressure wave generator is oriented so the plurality of overpressure waves are not directed directly towards a target media. The recoil force of the at least one overpressure wave generator occurring during generation of the plurality of overpressure waves is coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

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: 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.

Abstract: An improved system and method for controlling and directing sound waves is provided. A fuel-oxidant mixture is supplied to at least one detonator having at least one spark initiator. The fuel-oxidant mixture flows through the at least one detonator and into the closed end of at least one detonation tube also having an open end. The timing at least one spark initiator is controlled to initiate at least one spark within the at least one detonator while the fuel-oxidant mixture is flowing through the at least one detonator thereby initiating a detonation wave at the closed end of the at least one detonation tube. The detonation wave propagates the length of the at least one detonation tube and exits the open end of the at least one detonation tube as a sound wave. When multiple detonation tubes are detonated with controlled timing, the resulting sound waves are directed to a desired location. Sound waves can be directed from groups of detonation tubes and from a sparse array of detonation tubes.

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 improved system and method for ignition of a gaseous or dispersive fuel-oxidant mixture is provided where a gaseous or dispersive fuel-oxidant mixture is supplied to a detonator tube having a fill point and an open end and an igniter placed at an ignition point within the detonator tube is ignited while the gaseous or dispersive fuel-oxidant mixture is flowing through the detonator tube. A detonation impulse is produced at the ignition point that propagates to the open end of said detonator tube where it can be supplied to a detonation tube having an open end, to an internal combustion engine, a combustion chamber, and to a pulse detonation engine.

Abstract: A method and apparatus for acquiring seismic data. In one embodiment, the method includes: moving a first air gun array in the water at a first depth and a second air gun array in the water at a second depth greater than the first depth, in which the total volume of the first air gun array is less than the total volume of the second air gun array, in which the first air gun array is separated from the second air gun array by a distance substantially equal to a shot point interval, firing seismic energy through the first and second air gun arrays through the water into the earth, and recording seismic signals reflected from strata in the earth beneath the water.

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.

Abstract: An improved system and method for ignition of a gaseous or dispersive fuel-oxidant mixture is provided where a gaseous or dispersive fuel-oxidant mixture is supplied to a detonator tube having a fill point and an open end and an igniter placed at an ignition point within the detonator tube is ignited while the gaseous or dispersive fuel-oxidant mixture is flowing through the detonator tube. A detonation impulse is produced at the ignition point that propagates to the open end of said detonator tube where it can be supplied to a detonation tube having an open end, to an internal combustion engine, a combustion chamber, and to a pulse detonation engine.

Abstract: An improved system and method for controlling and directing sound waves is provided. A fuel-oxidant mixture is supplied to at least one detonator having at least one spark initiator. The fuel-oxidant mixture flows through the at least one detonator and into the closed end of at least one detonation tube also having an open end. The timing at least one spark initiator is controlled to initiate at least one spark within the at least one detonator while the fuel-oxidant mixture is flowing through the at least one detonator thereby initiating a detonation wave at the closed end of the at least one detonation tube. The detonation wave propagates the length of the at least one detonation tube and exits the open end of the at least one detonation tube as a sound wave. When multiple detonation tubes are detonated with controlled timing, the resulting sound waves are directed to a desired location. Sound waves can be directed from groups of detonation tubes and from a sparse array of detonation tubes.

Abstract: One example of a seismic vibrator system includes a baseplate having a bottom surface and a coupling mechanism, the coupling mechanism being operable to a deployed position; a hold-down mass connected to the baseplate; a lifting mechanism in operational connection with the hold-down mass and the baseplate to apply a selected hold-down weight to the baseplate; and a driving mechanism functionally connected to the baseplate to transmit seismic energy through the baseplate into a ground surface to which the baseplate is coupled, wherein the coupling mechanism is urged outward from the bottom surface and into physical contact with the ground surface when operated to the deployed position.

Abstract: A seabed seismic source apparatus includes a control module adapted for deployment at a seabed. The control module has a receiver for receiving a remote signal and a firing controller for generating a firing signal in response to the remote signal. The seabed seismic source apparatus further includes at least one seismoacoustic source module adapted for deployment at the seabed with the control module. The seismoacoustic source module has a seismoacoustic source for generating a seismic signal and a firing device for firing the seismoacoustic source to generate the seismic signal. The seabed seismic source apparatus further includes a transmission link between the firing controller and the firing device, wherein the firing device fires the seismoacoustic source upon receiving the firing signal generated by the firing controller.

Abstract: A method for obtaining seismic data is disclosed. A constellation of seismic energy sources is translated along a survey path. The seismic energy sources include a reference energy source and a satellite energy source. The reference energy source is activated and the satellite energy source is activated at a time delay relative to the activation of the reference energy source. This is repeated at each of the spaced apart activation locations along the survey path to generate a series of superposed wavefields. The time delay is varied between each of the spaced apart activation locations. Seismic data processing comprises sorting the traces into a common geometry domain and replicating the traces into multiple datasets associated with each particular energy source. Each trace is time adjusted in each replicated dataset in the common-geometry domain using the time delays associated with each particular source.

Abstract: Waveforms for controlled source electromagnetic surveying. The waveforms have frequency spectra that include three or more frequencies spaced at substantially equal intervals on a logarithmic frequency scale and spanning a bandwidth of about one decade or more, at least three of which frequencies have approximately equal corresponding amplitudes.

Abstract: The present invention provides a method and apparatus for positioning a center of a seismic source. The method includes determining a desired center-of-source of the seismic source and selecting one of a first and a second plurality of guns to form the seismic source based upon the desired center-of-source, a center-of-source of the first plurality being different than a center-of-source of the second plurality.

Abstract: A 4D seismic source comprising a series of sub-arrays of guns on flotation devices. Each flotation device has a GPS device. For firing, the guns in the e.g. three sub-arrays identified as being closest to the desired firing location are selected.

Abstract: A marine seismic source method capable of retaining low frequencies is disclosed. One embodiment of the method comprises a seismic source that generates an up-going wave and first down-going wave with opposite polarity. The up-going wave reflects off the ocean surface as a second down-going wave having the same polarity as the first down-going wave and the first and second down-going waves combine substantially in-phase to form a third down-going wave. A source apparatus to accomplish the method is also disclosed. One source apparatus embodiment comprises a device wherein at least part of the device is below the surface of the water and the device is adapted to cause oscillations below the surface of the water, and means for oscillating the device in the water to create an up-going wave and a first down-going wave and the up-going wave has reverse polarity relative to the first down-going wave.

Abstract: A method and apparatus for controlling seismic sources. The method and apparatus enable firing of a seismic sources at either a precise time or a precise position of the seismic source. Controlling the firing of the seismic source facilitates more accurate seismic data and a more consistent seismic source signature.

Abstract: A seismic acquisition system comprising a remote-controlled buoy for conducting seismic acquisition operations. The buoy comprises an operating system for operating a seismic wave production device on the buoy, a placement system, a communications system, and dynamic position locating system. The seismic acquisition system also comprises a remote control system for controlling the buoy systems. The seismic acquisition system also comprises receivers for receiving the seismic wave and generating a data signal indicative of the received seismic wave. The seismic acquisition system operates by controlling the placement system with the remote control system to position the buoy and then controlling the operating system with the remote control system to produce a seismic wave from the seismic wave production device. The receivers then receive the seismic wave and generate a data signal indicative of the seismic wave.

Abstract: Physical parameters are measured for an array of seismic sources, preferably for each activation of the seismic sources. Calibration functions are obtained and the measured physical parameters and calibration functions are applied to a model, which generates a calibrated source signature for the array of seismic sources. Alternatively, the measured physical parameters are applied to a model, which generates a modeled source signature, and then the calibration functions are applied to the modeled source signature to generate the calibrated source signature. Alternatively, modeled source signatures are generated for each seismic source and then the calibration functions are applied to the modeled source signatures to generate a calibrated source signature for each seismic source. Then the calibrated source signatures for each seismic source are combined, preferably by linear superposition, to generate the calibrated source signature for the array of seismic sources.

Abstract: An apparatus and method is provided for transporting, installing, retrieving, and replacing a sensor array of individual sensor pods at a geographically remote location, such as on the sea floor. The apparatus consists of a remotely operated vehicle (ROV), a carousel attached to the ROV, a pod ejector mechanism attached to the carousel, and a manipulator with a manipulator end effector attached to the ROV. The carousel contains a plurality of sensor pod holders, where each sensor pod holder is capable of holding a sensor pod. The pod ejector mechanism is capable of discharging a fresh sensor pod, while the manipulator end effector is capable of lifting a depleted sensor pod and placing the depleted sensor pod in an empty sensor pod holder in the carousel.

Abstract: A marine acoustic source system has relativley densely packed energy sources arrayed in a tandem-like fashion along a horizontal plane. Preferably, a longitudinal axis of each source lies orthogonal to a pre-determined towing direction. The system includes protective tubes that encloses supply lines and auxiliary equipment, and a harness. The harness provides the primary mechanical connection for towing the sources through the water. To minimize bending of the supply lines, connectors having angular portions connect the sources to the supply lines. Further, the sources can be arranged such that source connection interfaces for receiving power, hydraulic fluid, or data point alternately in opposing directions. During use, the sources, e.g., air guns, are supported at a predetermined depth beneath the water's surface by a floatation buoy. Upon activation, the sources of a cluster each release individual air bubbles into the water.

Abstract: A non-explosive acoustic source utilizes the combustion of aluminum and water to generate an acoustic pulse. The operation of the non-explosive acoustic source relies on a water/aluminum reaction to generate a burst pressure. The source may be deployed as a single charge or as one element of a multiple charge array and is configurable to explode at variable depths with variable energy levels. The inherent safety of the non-explosive acoustic source obviates the necessity for auxiliary safety features or procedures to protect against inadvertent explosion. As a result, the non-explosive acoustic source facilitates the implementation of sonic detection systems and reduces the operational costs associated with such systems.

Abstract: A staggered vertical marine seismic source contains upper and lower arrays (10, 11) of emitters of seismic energy (S11, S12; S21, S22). The upper array (10) is horizontally displaced relative to the lower array (11). The source is used in a marine seismic surveying arrangement that has means for moving the source and at least one seismic receiver. In use, the source is moved through the water in a direction parallel to the direction in which the two arrays are displaced. The arrays (10, 11) are fired sequentially, and the time delay between the firing of the first-fired array and firing of the second-fired array is chosen such that each seismic emitter in one array is fired at the same x- and y-co-ordinates as the corresponding emitter in the other array. The seismic wavefields generated by firing the two arrays are thus generated at the same x- and y-co-ordinates, but at different depths.

Abstract: Methods and apparatus for suppression of wave energy within a fluid-filled borehole using a low pressure acoustic barrier. In one embodiment, a flexible diaphragm type device is configured as an open bottomed tubular structure for disposition in a borehole to be filled with a gas to create a barrier to wave energy, including tube waves. In another embodiment, an expandable umbrella type device is used to define a chamber in which a gas is disposed. In yet another embodiment, a reverse acting bladder type device is suspended in the borehole. Due to its reverse acting properties, the bladder expands when internal pressure is reduced, and the reverse acting bladder device extends across the borehole to provide a low pressure wave energy barrier.

Abstract: A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic pickups (geophones (6), hydrophone (7) which receive acoustic or seismic signals from the underlying formation are arranged at the bottom of the water body. When collection sessions for the signals received by the pickups are scheduled, mobile active acquisition stations (11) connected to permanent passive reception stations (1) are positioned at the bottom of the water body. The signals picked up are then recorded, for the time required to carry out at least one session of acquisition and recording of the acoustic or seismic signals received by the passive stations in response to the emission of seismic waves by one or more seismic sources.

Abstract: An underwater sound source which comprises a housing having an inner and an outer surface and a monopole driver suspended within the center of the housing. The housing is adapted to receive fluid therein to form a fluid column inside the housing. The underwater sound source resonates at a frequency of 260 Hz when the monopole driver excites the fluid column.

Abstract: The present invention provides marine vibroseis methods and apparatus that operate in an acquisition time frame significantly shorter than current marine vibroseis acquisition methods and comparable to marine airgun seismic source acquisition, while providing data seismic energy comparable or superior to marine airgun seismic sources, by apportioning a desired vibroseis bandwidth signal over a plurality or multiplicity of vibroseis projectors (sources).

Abstract: Controlled-polarization marine seismic shear-wave source has a base suitable for positioning on a seafloor, beneath a water body. Twin water-blast tubes (seismic-impulse-generation thrusters) are mounted on the base, aimed upwardly, outwardly in opposite directions at equal acute angles &bgr; relative to the base. These blast tubes are positioned symmetrically on opposite sides of vertical centerline CL of the source. When submerged, water enters open mouths at upper ends of the tubes. The base has multiple downwardly projecting blade-like teeth for penetrating into the seafloor. Firing a compressed-air discharger mounted in a lower end of a water-blast tube hurls a powerful slug of water upwardly along the tube, producing a powerful reaction impulse acting downwardly generally parallel with the tube axis.

Abstract: A sound mitigation system and method reduce the transmission of acoustic output from explosions underwater. The system is submerged to bottom terrain of a body of water and has at a series of gas-generating devices providing volumes of gas that are fed to refractory heat resistant tubing assemblies and flexible general tubing assemblies. The heat resistant and general tubing assemblies extend between adjacent gas generating devices and are provided with at least one row of holes to vent bubbles of gas and form a virtually continuous curtain of bubbles rising to the surface of the water between detonating explosives and areas of interest. The curtain of bubbles mitigates the effects of the explosions on marine mammals and endangered, threatened, or protected species within an area adjacent to the explosions.

Abstract: A cable system for installation on the ocean floor or under another body of water includes a plurality of sub-sea junction boxes installed at spaced locations throughout a predetermined sub-oceanic cable network. At least some of the junction boxes are located at a predetermined distance off-shore from a respective on-shore cable junction node. A single main, high fiber count conduit extends from each off-shore junction box to the respective on-shore cable junction node. Each off-shore junction box has plurality of ports for releasable connection to a selected offshore cable terminated at the junction box, and a fiber routing unit in the junction box connects at least some of the ports to fibers in the main conduit.

Abstract: A seismic pulse generator (1) has a chamber (4) pressurised with gas. The generator includes a solenoid valve (60) which can be actuated to cause the release to atmosphere of only a small amount of pressurised gas from a small control chamber (34) behind a main piston (30) to enable the piston to move away from a valve seat (32) around an outlet (26). This permits the abrupt release of the pressurised gas in the chamber (4) through the outlet and the “firing” of the generator. The arrangement maximises the use of the main pressurised gas for actual “firing” of the generator.

Abstract: A molded protective body member for seismic cable hydrophone and geophone sensors and their cable splice connections from underwater obstructions and pay-out and retrieval apparatus. The body member is a one piece polymeric member having interior cavities, risers and apertures. When in use, the body member is folded longitudinally in half around the seismic cable at a hydrophone or geophone splice joint and secured in place with recessable molded straps having threaded fasteners passing through each of the body halves thus clamping the body to the cable. At least one interior diametrical cavity is provided consistent with the type seismic cable sensor used. With the sensor and its associated cable and connector positioned within the protective body member, tie wraps are threaded through apertures along and adjacent the longitudinal edges of each half thus closing the interior of the body member. Cavities are also provided internally for placing lead weights.

Abstract: An apparatus for quickly and virtually complete purging of seawater from combustion chambers of an outboard engine that has been submerged or a submersible outboard engine. A poppet valve is incorporated in the combustion chamber portion of the engine head. The valve has discharge ports radially disposed around its periphery so that when the poppet valve is pneumatically operated, the ports permit the discharge of entrapped water from the combustion chamber as the engine is turned over.

Abstract: An explosive actuated acoustic device emits sound to be used in torpedo countermeasures. Numbered devices are delivered over an extended area and sink through the water. The devices are actuated at different times as they sink, to provide sound masking over an extended period of time. The devices also include safety devices which prevent premature actuation from jarring or jolting and from impact with the water.