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: Devices for sensing gradients are constructed from material whose properties change in response to gradients. One embodiment of the device is a transducer (200) for sensing gradients that includes the material (210) and two or more electrodes (240, 270) coupled to the material. In one embodiment, gradients in a surrounding medium (110) modify the energy gap of the material in the transducer (130) producing a diffusion current density (150). The material is configured to connect to a current or voltage measurement device (520, 530, 540) where a measurement is used to determine the gradient in the medium (160). The devices can be used to measure pressure, temperature, and/or other properties. The transducer can be built on the same substrate as complementary circuitry. A transducer made of Indium. Antimonide is used in marine seismology to measure pressure gradients.

Abstract: The presently disclosed technique includes a method for use in a marine survey comprising randomizing the distribution of receivers and sources during a coil shoot acquisition. The randomizing can be implemented in a number of ways. For example, in one embodiment, randomizing the distribution includes randomizing the positions of the circle centers defining the sail lines. This may be implemented by, for example, distributing the same number of circle centers as would be used in a non-random sampling in a uniform random distribution. In another embodiment, randomizing the distribution includes permitting the streamers in which the receivers are allowed to drift while controlling crossline streamer separation. Other embodiments may combine these approaches or utilize still other approaches.

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

Abstract: A method and a marine front-end gear for connecting a set of streamers to a towing vessel. The front-end gear includes ropes for connecting a first sub-set of streamers to the vessel; lead-ins for connecting a second sub-set of streamers to the vessel; and a back loop cable electrically connected between tails of first and second adjacent streamers. The first streamer belongs to the first sub-set of streamers and the second streamer belongs to the second sub-set of streamers, and streamers of the first sub-set are interspersed with streamers of the second sub-set.

Abstract: An ocean bottom seismic cable recording apparatus comprising a plurality of seismic node casings (1), said node casings being separated from each other by separate stress member sections (2), each stress member section having acoustic decoupling arrangements (3) at each end connecting to said seismic node casings (1), and where each seismic node casing comprising an autonomous sensor capsule (5) for sensing and recording seismic data, and wherein the autonomous sensor capsule (5) is removable from said seismic node casing (1), and wherein each seismic node casing (1) further comprising an inner compartment (4) accommodating the autonomous sensor capsule (5).

Abstract: A seismic source array includes at least one float. A plurality of rigid conduit sections each includes a bracket for suspension from the float at a selected depth in a body of water and configured to suspend a seismic energy source therefrom. At least one bend strain relief is coupled between adjacent rigid conduit sections. Each bend strain relief includes a coupling at each longitudinal end. Each bend strain relief includes woven fiber molded into flexible plastic for transmitting axial loading while absorbing bending and torsional stress. A seismic energy source is suspended from each bracket. Lines for operating the seismic energy sources pass through the rigid conduit sections and the at least one bending strain relief.

Abstract: Methods for indirect data acquisition via exact inverse receiver extrapolation. The desired data are obtained from extrapolation of directly measured data containing a wavefield quantity (e.g. pressure) and a component of its gradient. The methods use exact representations of scattering reciprocity. Methods of evaluating/validating the extrapolated data are also disclosed. These methods can be used in any industries involving imaging, such as geophysical/seismic exploration, bio-medical imaging, non-destructive remote sensing, acoustic space architecture, design and engineering.

Abstract: A seismic sensor node 1 comprising one or more seismic sensors (8,9) and an annular skirt (3) defining an annular axis. The annular skirt (3) has a cutting edge (10) which appears serrated when viewed at a right angle to the annular axis. The skirt (3) also has a series of ribs (15) and channels (11) which terminate at the cutting edge so that the cutting edge has an undulating shape when viewed parallel with the annular axis. The ribbed shape of the skirt (3) makes it particularly resistant to ellipsoid or modal oscillation, so that it can transmit seismic vibrations to the seismic sensor (s) with minimal distortion, attenuation or damping.

Abstract: A technique includes receiving seismic data acquired in a seismic survey in the vicinity of a reflecting interface. The survey has an associated undersampled direction. The technique includes providing second data indicative of discrete samples of incident and reflected components of a continuous seismic wavefield along the undersampled direction and relating the discrete samples to a linear combination of the continuous incident and reflected seismic wavefields using at least one linear filter. Based on the relationship, an unaliased representation of the linear combination of the continuous incident and reflected seismic wavefields is constructed.

Abstract: A deployment method and system for ocean bottom seismometers (OBS) includes providing a plurality of circular shaped, wireless, self-contained OBS units. The circular shaped OBS units are loaded into a carrier and transported from a surface vessel to the ocean floor where a remotely operated vehicle (ROV) is utilized to individually place the plurality of circular OBS units on the ocean floor. Placement of each OBS unit is accomplished by utilizing suction mechanism attached to a robotic arm. The suction mechanism is defined about an axis and employs a suction cup to individually engage each circular shaped OBS unit so that the suction mechanism is coaxially aligned with the OBS unit, and move the OBS unit from a first location to the ocean floor.

Abstract: A configuration for the deck of a marine vessel, wherein parallel and perpendicular travel paths, for movement of individual OBS unit storage baskets, are formed along a deck utilizing, in part, the storage baskets themselves. A portion of the deck is divided into a grid defined by a series of low-to-the-deck perpendicular and parallel rails and each square in the grid is configured to hold an OBS unit storage basket. Around the perimeter of the grid is an external containment wall which has a greater height than the rails. Storage baskets seated within the grid are configured to selectively form internal containment walls. Opposing internal and external containment walls define travel paths along which a storage basket can be moved utilizing a low, overhead gantry. A basket need only be lifted a minimal height above the deck in order to be moved along a path. The containment walls and the deck itself constraining uncontrolled swinging of baskets, even in onerous weather or sea conditions.

Abstract: Marine seismic survey using an array (6) of streamers (8) towed behind a vessel (2) and carrying acoustic sources (4) and sensors (10), spreading means (12, 14, 22, 23, 24) for keeping the streamers (8) at a given distance by lateral tensioning, and bridles (16) for connecting the spreading means and towing ropes and cables. The bridles (16) are comprising at least one solid link or connection device (26) for releasable connection to lines under tension and extending in different directions.

Abstract: A marine seismic survey using one or more moving marine seismic vibrators, where the vibrator sweeping function is based on smearing error criteria and is a downward-sweeping non-criteria linear sweep function. The acquired seismic data can either be used as is without desmearing or desmeared easily.

Abstract: A method for determining an equipment constrained acquisition design.

Abstract: Marine seismic survey using one or more marine seismic vibrators, where the vibrator sweep function is based on a quality requirement, which may be a final image quality requirement or an environmental requirement. The sweep function may be nonlinear and the energy spectrum may not match the energy spectrum of an airgun.

Abstract: Methods and apparatus for cable termination and sensor integration at a sensor station within an ocean bottom seismic (OBS) cable array are disclosed. The sensor stations include a housing for various sensor components. Additionally, the sensor stations can accommodate an excess length of any data transmission members which may not be cut at the sensor station while enabling connection of one or more cut data transmission members with the sensor components. The sensor stations further manage any strength elements of the cable array.

Abstract: Embodiments described herein relate to an apparatus and method of transferring seismic equipment to and from a marine vessel and subsurface location. In one embodiment, a marine vessel is provided. The marine vessel includes a deck having a plurality of seismic sensor devices stored thereon, two remotely operated vehicles, each comprising a seismic sensor storage compartment, and a seismic sensor transfer device comprising a container for transfer of one or more of the seismic sensor devices from the vessel to the sensor storage compartment of at least one of the two remotely operated vehicles.

Abstract: A method and apparatus for a seismic cable is described. In one embodiment, a method for performing a seismic survey in a water column is described. The method comprises providing a length of flexible cable from a cable storage device disposed on a vessel to a cable handling device adjacent the cable storage device. The flexible cable comprises a specific gravity that is greater than a specific gravity of water in the water column. The method further comprises routing the flexible cable to pass adjacent a workstation disposed on the vessel, deploying a free end of the flexible cable into the water column, attaching at least one of a plurality of seismic sensor units to the cable as the cable passes the workstation, and controlling the motion of the vessel and the rotational speed of the cable handling device to allow the flexible cable to rest on the bottom of the water column.

Abstract: A disclosed geophysical survey cable includes a signal amplifier coupled between two electrodes spaced apart along the length of the geophysical survey cable (the electrodes being coupled to the signal amplifier by a first conductor pair), and a noise amplifier coupled to a second conductor pair positioned substantially parallel to the first conductor pair. The geophysical survey cable further includes a combiner that combines a noise signal provided by the noise amplifier with a sensor signal provided by the signal amplifier to provide a sensor signal with a reduced noise component.

Abstract: A technique for acquiring wide azimuth seismic data using simultaneous shooting is presented in which a plurality of seismic sources are positioned to achieve a desired crossline sampling as a function of the number of passes. This is accomplished by “interleaving” sources as deployed in the spread, as positioned in multiple passes, or some combination of these things, to achieve an effective shotline interval during acquisition or an effective crossline sampling less than their crossline source separation.

Abstract: A method for determining a sail plan for a towed-array marine seismic survey includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines. The set of nodes defining a regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern.

Abstract: A system comprises towed marine geophysical equipment, adapted for towing through a body of water; and a surface covering, comprising a textural attribute of shark skin, attached to the marine geophysical equipment. A method comprises towing marine geophysical equipment having a surface covering, comprising a textural attribute of shark skin, attached thereto.

Abstract: The invention relates to a method for acquiring seismic data at a plurality of positions spread out over a zone on the seabed which includes transmitting acoustic waves in the water layer above the zone by a plurality of sources, for each of the acquisition positions, dropping from the surface a seismic acquisition equipment, the equipment comprising a seismic acquisition unit and autonomous guiding equipment adapted to receive while descending acoustic signals from the sources and to control its trajectory according to the received acoustic signals so as to direct said equipment towards said position, performing the seismic acquisition, causing the acquisition equipments to move up to the surface, and retrieving the acquisition equipments on the surface.

Abstract: Disclosed are methods and systems for controlling depth profiles of marine geophysical sensor streamers as they are towed in a body of water. An embodiment discloses a method for marine geophysical surveying, the method comprising: towing a geophysical sensor streamer in a body of water having a surface and a floor, the geophysical sensor streamer being coupled to a survey vessel by a lead-in cable, the lead-in cable having a length that extends from the survey vessel; adjusting the length of the lead-in cable to cause a forward end of the geophysical sensor streamer to follow a depth profile; and deflecting the geophysical sensor streamer in the vertical plane at one or more spaced apart locations.

Abstract: To analyze content of a subterranean structure, electric field measurements at plural source-receiver azimuths in a predefined range are received. Total magnetic field measurements are also received at plural source-receiver azimuths in the predefined range. The electric field measurements and the total magnetic field measurements are provided to an analysis module to enable determination of electrical resistivity anisotropy of the subterranean structure.

Abstract: Control mechanisms, computer software and methods for driving vibrational source arrays underwater. An incoherent acquisition scheme drives individual source elements simultaneously and incoherently while a coherent acquisition scheme drives high-frequency individual source elements simultaneously and incoherently and low-frequency individual source elements simultaneously and coherently. Thus, denser coverage and an increased energy input is achieved for the source arrays.

Abstract: A marine vibrator has a housing that comprises a displacement member, the displacement member having a first position and a second position, the housing and the displacement member together defining an internal volume. A linear electromagnetic motor interacts with the displacement member so as to move the displacement member between a first position and a second position and correspondingly strokes the displacement member to cover a volume. The linear electromagnetic motor comprises magnets and coils that when energized create an electromagnetic force there between, wherein the linear electromagnetic motor comprises a piston and a guide that substantially surrounds the piston. The piston has incorporated therein either the coils or the magnets, and the guide having incorporated therein the other of the coils or the magnets. The piston is in interaction with the displacement member.

Abstract: A technique for use in marine seismic surveying includes a method and an apparatus. In one aspect, the method includes towing a seismic spread including a source multiple streamers on a generally curved advancing path, the streamers being actively steered. The source is fired and data is acquired on the curve. In other aspects, the method is performed with only a single vessel or the generally curved advancing path is a sincurve advancing path. The method may include a dual circular shoot in another aspect. And, in yet another aspect, the invention includes an apparatus comprised of a computing apparatus on board a tow vessel receiving positioning data from the marine seismic streamers. It is also programmed to: sail the tow vessel in a generally curved advancing path and actively steer the marine seismic streamers through the generally curved advancing path.

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 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: Methods and apparatus for borehole seismic survey are disclosed comprising a first seismic source under water at a first location and a second seismic source at a second, deeper location. Seismic signals from the seismic sources are recorded with synchronized sensors located in a borehole and source signature data are obtained by combining the recorded seismic signals such that low and high frequency content of the combined source signature data is extended relative to the source signature of the first seismic source and the second seismic source.

Abstract: Methods and systems are presented for generating and performing a seismic data acquisition mission based on an a priori sea current model and a seismic data acquisition operation model and a shooting solution model based on the a priori sea current model. The individual models can be updated based on releasing sample buoys through the survey area both before and during mission execution.

Abstract: A seabed region (18) that lies under a seabed surface area of at least one square meter, is analyzed by an acoustic analysis of the region. Locations of the generation and detection of sound are precisely correlated to the location of a vertical drill hole in the sea bed by mounting an acoustic imaging apparatus (16) that holds acoustic transducers (44, 46), on a carriage (26) that is positioned with respect to the drill hole, using the drill hole as the horizontal position reference. The carriage of the acoustic imager apparatus is clamped to a post that lies in the drill hole. An arm (30 and/or 32) is supported on the carriage through a frame (28), with at least one acoustic generator (44) and one acoustic echo detector (46) mounted on the arm. The arm can be rotated to positions lying about the hole axis (14) to accurately scan a wide area.

Abstract: A method of acquiring marine seismic data using an acoustic source to generate an acoustic signal, a portion of which is reflected at one or more subsurface formation interfaces as a seismic signal is described. The method includes sailing a surface vessel along a sail line which lies over a survey area while towing a seismic streamer, the sail line having a sinusoidal configuration defined by an amplitude and a wavelength. The streamer includes a plurality of hydrophones for receiving the reflected portion of the acoustic signal. The method is characterised in that the streamer follows the sinusoidal configuration of the sail line while seismic data is acquired, the streamer having a length at least equal to the distance travelled by the surface vessel as it sails along one full wavelength of the configuration as measured along the sinusoidal sail line.

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 comprises a frame in which is mounted a structure for seating and releasing said receivers. The structure may comprise a movable carousel or a movable conveyor or fixed parallel rails or a barrel. The structure includes a discharge port on said frame and a discharge mechanism for removing and retrieving said receivers. A method for deployment and retrieval of ocean bottom seismic receivers comprises the steps of loading a carrier with a plurality of receivers, attaching said carrier to an ROV, utilizing said ROV to transport the carrier from a surface vessel to a position adjacent the seabed and thereafter utilizing said ROV to remove receivers from said carrier and place the receivers on the seabed.

Abstract: A method for estimating subsurface elastic parameters is described herein. One or more slowness vectors may be determined based on a vertical seismic profile of a subsurface area. A model containing anisotropy parameters and a well deviation estimate may be generated based on survey data. The slowness vectors may be corrected for the well deviation estimate based on the model. One or more modeled slowness vectors may be calculated using the corrected slowness vectors and the anisotropy parameters in the model.

Abstract: The invention concerns a method to acquire seismic waves by means of a streamer towed by a vessel and comprising a plurality of seismic receivers. The streamer comprises a head portion that is slanted relative to the water surface and a tail portion having at least one section with a different slant.

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: A method and apparatus for a seismic cable is disclosed. In one embodiment, the seismic cable includes a first cable segment and a second cable segment coupled together by a connector that prevents transmission of power and data signals between the first cable segment and the second cable segment. Each cable segment includes an inner jacket defining a hollow core, a braided strength fiber surrounding the inner jacket, and an outer jacket circumferentially surrounding the braided strength fiber, wherein the connector isolates the first and second cable segments.

Abstract: A method and apparatus for carrying out a seismic exploration. A seismic event is applied to the earth's surface, particles at the earth's surface move in response to the event and the response to the event is detected using an interferometer. The earth's surface and the interferometer move with respect to each other. The detectors of the interferometer may be arranged in an array. The detected response may be analyze.

Abstract: Method for determining a seismic survey configuration of a multi-vessel acquisition system. The method includes a step of receiving number that corresponds to vessels to be used in the multi-vessel acquisition system; a step of receiving a cross-line distance between first and last straight line paths corresponding to first and last vessels, respectively, of the multi-vessel acquisition system; a step of receiving an inline distance between the first and last vessels; a step of selecting shapes of undulating paths for the vessels of the multi-vessel acquisition system; a step of receiving a desired azimuth and/or offset distribution of receivers towed by one or more streamer vessels of the multi-vessel acquisition system relative to source vessels of the multi-vessel acquisition system; and a step of calculating amplitudes (Ai), periods (Ti) and phases of the undulating paths.

Abstract: The present invention relates to streamer cables. One embodiment of the present invention relates to a method for preparing a streamer cable. The method may comprise retrofitting the streamer cable with a solid void-filler material, where the streamer cable was configured as a liquid-filled streamer cable. The retrofitting may comprise introducing a void-filler material into the streamer cable when the void-filler material is in a liquid state and curing or otherwise solidifying the void-filler material to a solid state. In another embodiment, the present invention relates to a streamer cable comprising an outer skin and-at least one sensor positioned within the outer skin. The streamer cable may also comprise a solid void-filler material positioned between the outer skin and the at least one sensor, wherein the solid void-filler material is coupled to the at least one sensor.

Abstract: A method for determining a sail plan for a towed-array marine seismic survey, includes: dividing a survey area into a regular grid of tiles; and identifying a subset of the tiles as nodes around which continuously curved sail lines are defined. The nodes define regular pattern further including: a first subpattern of nodes; and a second subpattern of nodes offset from the first subpattern. In alternative aspects, a computer-readable program storage medium may be encoded with instructions that, when executed by a processor, perform the method, or a computing apparatus may be programmed to perform the method. A method for conducting a towed array marine survey includes: traversing a plurality of continuously curved sail lines across a survey area, each sail line being relative to a node; and acquiring seismic data while traversing the continuously curved sail lines.

Abstract: A seismic streamer system for acquiring seismic data includes a plurality of first cable sections each employing a first sensor configuration therein, and at least one second cable section operatively connected to one or more of the first cable sections and employing a second sensor configuration therein. In various embodiments of the streamer system, one or more of the second cable sections are sparsely integrated into a streamer, a streamer array, and/or a seismic spread. The first sensor configuration may, e.g., include a conventional hydrophone distribution, and the second sensor configuration may, e.g., include multicomponent sensors such as at least one of a particle velocity sensor, a pressure gradient sensor, an accelerometer, and a combination thereof. The present invention is useful for attenuating noise in the measured seismic data as well as deghosting the data.

Abstract: A method for towing marine geophysical sensor streamers in a body of water includes moving a towing vessel at a selected speed along the surface of the body of water. At least one geophysical sensor streamer is towed by the vessel at a selected depth in the water. A velocity of the streamer in the water is measured at at least one position along the streamer. The selected speed of the towing vessel is adjusted if the measured velocity exceeds a selected threshold.

Abstract: To acquire near-zero offset survey data, a survey source and a first streamer attached to the survey source are provided, where the first streamer has at least one survey receiver. A second streamer separate from the survey source and the first streamer includes survey receivers. Near-zero offset data is measured using the at least one survey receiver of the first streamer.

Abstract: The technologies described herein include systems and methods for performing a first seismic survey and performing a second seismic survey after a predetermined amount of time has lapsed between the first seismic survey and the second seismic survey. The shot times and the shot positions of the second seismic survey may be substantially the same as the shot times and the shot positions of the first seismic survey. After performing the seismic surveys, seismic data generated by the first seismic survey may be processed to generate a first image, and seismic data generated by the second seismic survey may be processed to generate a second image. After generating the first and second images, a difference between the first image and the second image may be computed to generate a time lapse difference image.

Abstract: A method of deploying a seismic recorder array on a seafloor is disclosed. The seismic recorder array comprises a plurality of removable seismic data recorders. The method comprises the step of forming the seismic recorder array by connecting a plurality of recorder housings in series, wherein adjacent recorder housings are connected by a connector cable. The recorder housings are configured to retain the removable seismic data recorders. The method comprises the step of loading the plurality of removable seismic data recorders in the recorder housings, and lowering the seismic recorder array into water until the seismic recorder array is positioned on the seafloor underlying the water. The method comprises the step of operating the seismic data recorders to detect seismic signal reflections and to record seismic data representing the reflections.

Abstract: A method for acquiring three-dimensional seismic data for sub-surface geologic features wherein a seismic source array is moved along a survey pattern having a plurality of source lines of unequal lengths that are substantially parallel to each other and intersect a receiver line. The survey pattern can be repeated in an overlapping and interleaved fashion to survey a larger area.