Abstract: The present disclosure generally relates to systems and methods for acquiring seismic data. In one exemplary embodiment, a method for acquiring seismic data is described in which recorder instruments are deployed to the seafloor and utilized for recording pressure wave and shear wave data. An acoustic array, displaced from the seafloor, is also provided for sending acoustic signals to the instruments on the seafloor. The orientation of the instruments on the seafloor is determined via acoustic communication between the acoustic array and the instruments. Related systems and methods for acquiring seismic data are also described.

Abstract: A seismic ocean bottom cable array is provided for use in subsurface exploration. The array includes receiver stations for measuring seismic signals, and a cable including conductors for data transmission and an externally attached stress member. The array is assembled during deployment by attaching the data transmission cables and receiver stations to the stress member as it is lowered into the water.

Abstract: A method includes recording a first set of data using a first type of sensor; recording a second set of data using a second type of sensor, the first and second sets of data being contemporaneously acquired by co-located sensors; and removing noise from the first data set using the second data set. An apparatus includes a survey vessel towing an array of towed streamers including a plurality of paired, co-located sensors densely distributed along the streamers. A first one of each sensor pair is of a first type and a second one of each sensor pair is of a second type. A computing apparatus records a first set of data acquire by the first type of sensor and a second data set acquire by the second type of sensor. The computing apparatus then removes noise from the first data set using the second data set.

Abstract: A method for wrapping continuous strands of steel wire about a seismic cable including interconnected sensor sections and conductor sections where a cross sectional diameter of the sensor section is at least four times that of the conductor section. Two layers of armoring are provided with a first layer wrapped in a first angular direction opposite that of the second layer. A stranding assembly is provided which has two selective positions, one for providing a die hole for stranding the conductor section, another for providing a passage hole for allowing the sensor section to pass after wrapping with armor wire.

Abstract: A seismic data acquisition telemetry system includes a seismic vessel including a data recording system thereon. The system includes a seismic data gathering unit in operative connection with at least one seismic sensor. The system includes a first antenna disposed on the seismic vessel and a second antenna disposed on the data gathering unit, at least one of said first and second antennas being directional. Means are included for orienting a sensitive direction of the directionally sensitive antenna toward the other of said first and second antennas.

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 seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of the streamer and is disposed inside the jacket. At least one seismic sensor is disposed in a sensor spacer affixed to the at least one strength member. An encapsulant is disposed between the sensor and the sensor spacer. The encapsulant is a substantially solid material that is soluble upon contact with a void filling material. A void filling material is disposed in the interior of the jacket and fills substantially all void space therein. The void filling material is introduced to the interior of the jacket in liquid form and undergoing state change to substantially solid thereafter.

Abstract: A seismic streamer and a method for positioning a group of hydrophones in a seismic streamer. The hydrophones in a group are spaced irregularly along the length of the streamer to reduce the influence of bulge-wave noise and flow noise on the hydrophone group response. The irregular spacing may be produced as pseudorandom deviations of the actual positions of the hydrophones from a nominal uniform spacing of hydrophones.

Abstract: Methods, systems, and computer readable media are provided for interactively determining optimum deghosting parameter values for suppressing ghost reflections. Seismic data are obtained from various hydrophone/geophone receiver locations. Energy traces are generated which include measures of the deghosting parameter values from the seismic data obtained from each of the hydrophone/geophone receiver locations. The energy traces are displayed. A set of seed values is provided by the user. In response to receiving the user seed values, deghosting parameter values are picked based on the energy traces. The picked deghosting parameter values are displayed. A user then interactively edits and/or smooths the picks to obtain optimum deghosting parameter values. The optimum deghosting parameter values are utilized for suppressing ghost reflections in the seismic data.

Abstract: Systems and methods for marine seismic cable deployment and retrieval are described. One system comprises a plurality of portable containers, each container temporarily storing a marine seismic component, at least some of the containers able to be removably fastened to a deck of a vessel of opportunity, and at least one of the portable containers storing a main cable winch on which is wound a marine seismic cable. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Methods and systems for determining position of seismic sources and receivers are disclosed. Signals received by a first antenna are processed to determine its 3D coordinate position. Signals received by the first antenna and a second antenna are combined and processed to estimate a spatial vector between the first and second antennas. The spatial vector is added to the 3D coordinate position of the first antenna to provide a 3D coordinate position of the second antenna. Using the 3D coordinate position of the second antenna, a 3D coordinate position of a seismic source unit or receiver may be calculated, as well as a vertical correction for reflected seismic signals received by the receiver. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: The survey technique for use in a marine environment to survey a subterranean structure includes providing an arrangement of plural signal sources in a body of water to produce corresponding signals. The signals of the signal sources in the arrangement are set to cause reduction of at least one predetermined signal component in data received by a receiver in response to the signals.

Abstract: The present invention provides a method and apparatus for seismic data acquisition. One embodiment of the method includes accessing data acquired by at least two particle motion sensors. The data includes a seismic signal and a noise signal and the at least two particle motion sensors being separated by a length determined based on a noise coherence length. The method may also include processing the accessed data to remove a portion of the noise signal.

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 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: A cleaning device for a seismic streamer includes a housing placeable the exterior of the streamer. A turbine is associated with the housing and is configured to be rotationally driven by movement of the streamer through a body of water. A drive element is associated with the housing and is configured to convert rotational motion of the turbine to motive power to move the housing along the streamer. At least one cleaning element is associated with the housing and is cooperatively engaged with the exterior of the seismic streamer. A method for cleaning a streamer includes towing the streamer through the water. Motion of water is converted into motive power to move a cleaning device along the streamer.

Abstract: A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of the jacket inside the jacket. At least one seismic sensor is disposed inside the jacket. The seismic sensor is disposed in a mount. The mount defines a sealed, liquid filled chamber inside the jacket. A material fills the void spaces inside the jacket and outside the chamber. The material is introduced to the void spaces in liquid form and cures to a gel thereafter.

Abstract: A technique includes obtaining different sets of data, which are provided by seismic sensors that share a tow line in common. Each data set is associated with a different spatial sampling interval. The technique includes processing the different sets of data to generate a signal that is indicative of a seismic event that is detected by the set of towed seismic sensors. The processing includes using the different spatial sampling intervals to at least partially eliminate noise from the signal.

Abstract: A seismic streamer includes at least one array of sensors each disposed in a sensor holder at longitudinally spaced apart locations. A longitudinal orientation of at least one sensor or at least one sensor holder is different from that of the other sensors along the length of the array.

Abstract: Signals of pressure sensors and particle motion sensors located in marine seismic streamers are combined to generate pressure sensor data and particle motion data with substantially the same broad bandwidth. The noisy low frequency part of the motion signals are calculated from the recorded pressure signals and merged with the non-noisy motion signals. The two broad bandwidth data sets can then be combined to calculate the full up- and down-going wavefields.

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: There is provided herein a system and method for the imaging and monitoring of hydrocarbon reservoirs and other subsurface features preferably using seabed or surface sensors in conjunction with one or more downhole sensors. In one preferred embodiment, recordings will be simultaneously made using both seabed and downhole receivers. The energy source might be either a controlled seismic source or ambient noise. In one embodiment, the data will be used to compute a virtual VSP, checkshot, or similar survey by cross correlating a trace recorded at the surface with a trace recorded at depth. In another embodiment , the surface and well sensors will be permanently emplaced and repeated recordings over time will be used to form a time-varying (4-D) image of the subsurface.

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: An up-going wavefield and a down-going wavefield are calculated at a sensor position from a pressure sensor signal and a particle motion sensor signal. Then, an up-going wavefield is calculated at a water bottom position substantially without water bottom multiples from the up-going and down-going wavefields at the sensor position. In one embodiment, the up-going wavefield at the sensor position is backward propagated to the water bottom, resulting in an up-going wavefield at the water bottom. The down-going wavefield at the sensor position is forward propagated to the water bottom, resulting in a down-going wavefield at the water bottom. The up-going wavefield at the water bottom without water bottom multiples is calculated from the backward propagated up-going wavefield at the water bottom, the forward propagated down-going wavefield at the water bottom, and a reflection coefficient of the water bottom.

Abstract: Seismic data sets representative of a marine seismic streamer survey are constructed with test coverage holes in the data sets. The data sets are processed and data quality degradation in the processed data due to the test coverage holes is evaluated. Maximum acceptable coverage holes for the survey are determined from the evaluation of data quality degradation.

Abstract: A sensor arrangement is provided for use in the seismic investigation of geological formations below the seabed. A plurality of sensor nodes (20) are provided and are positioned gfor deployment on the seabed to collect pressure waves and shear waves from the geological formations and to transfer seismic data to a surface receiver. Each sensor node (20) may include a cylindrical structure (22), which is intended to penetrate downwardly into the seabed. At least one, preferably three, geophones (30-32) are positioned in connection with this structure (22). An advantageous method for operating a seismic mapping system with sensor arrangements orderly deployed on the seabed records data concerning system behavior and seismic data. This data may be further processed separately.

Abstract: The present invention provides a method for analyzing traces collected along a plurality of adjacent sail lines in a marine seismic survey area. The method comprises selecting a plurality of trace groups, at least one trace in each group sharing a common midpoint with at least one trace from another group, determining an initial zero-offset travel time for each trace in the trace groups, and generating a plurality of updated zero-offset travel times and a plurality of time corrections for the trace groups using a pre-selected function of the initial zero-offset travel times.

Abstract: A method for computing a pressure signal gradient. The method includes recording a plurality of pressure signals at least one of a first receiver and a second receiver. The first receiver and the second receiver are disposed within a cluster. The method further includes recording a plurality of pressure signals at the second receiver; computing a calibration filter for removing the difference in distortions between the pressure signals recorded at the first receiver and the pressure signals recorded at the second receiver; and computing the pressure signal gradient between the pressure signals recorded at the first receiver and the pressure signals recorded at the second receiver using the calibration filter.

Abstract: An embodiment of a method for conducting a bathymetric survey across a seismic spread includes the steps of emitting a signal from a pinger positioned within the seismic spread, measuring the arrival time of a bottom reflection of the signal at a receiver positioned within the seismic spread, measuring the arrival time of a direct arrival of the signal at the receiver, and determining the water depth utilizing the measured arrival times of the signal.

Abstract: A method of analysing results from a controlled source electromagnetic survey of a region of interest containing a previously identified geological structure suitable for bearing hydrocarbons is described. The method comprises providing a first survey data set obtained outside the region of interest, i.e. off-target, for a range of source-receiver orientations and offsets, and providing a second survey data set obtained inside the region of interest, i.e. on target, for a range of source-receiver offsets. The method further comprises performing a mathematical inversion of the first survey data set to provide a model of the subterranean strata outside the region of interest, and processing the second survey data set to provide a model of the subterranean strata inside the region of interest, wherein the processing of the second survey data set takes account of the results of the inversion of the first survey data set.

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: A method of seismic surveying comprises emitting seismic energy at two or more different depths during a sweep. In one embodiment, the depth of a seismic source is varied during a sweep, by raising or lower the source while it is emitting seismic energy. In another embodiment, an array of two or more marine vibrators is used as the source of seismic energy, with the vibrators in the array being disposed at different depths. The invention allows notch frequencies in the amplitude spectrum to be eliminated, and allows improvements in both the spectral flatness and the amplitude at low frequencies.

Abstract: In one embodiment the invention comprises a particle velocity sensor that includes a housing with a geophone mounted in the housing. A fluid that substantially surrounds the geophone is included within the housing. The particle velocity sensor has an acoustic impedance within the range of about 750,000 Newton seconds per cubic meter (Ns/m3) to about 3,000,000 Newton seconds per cubic meter (Ns/m3). In another embodiment the invention comprises method of geophysical exploration in which a seismic signal is generated in a body of water and detected with a plurality of co-located particle velocity sensors and pressure gradient sensors positioned within a seismic cable. The output signal of either or both of the particle velocity sensors or the pressure gradient sensors is modified to substantially equalize the output signals from the particle velocity sensors and the pressure gradient sensors. The output signals from particle velocity sensors and pressure gradient sensors are then combined.

Abstract: Arrangement for use for seismic surveys of geological formations in a seabed, where a plurality of such arrangements, which are provided with sensor units 26, are placed on the seabed for collecting pressure waves and shear waves reflected from the geological formations. There exist arrangements for transferring seismic data to a surface receiver placed on a vessel, an offshore installation, or an onshore installation. Each sensor unit 26 is held by a carrier 10 and is connected to a cylindrically skirt-shaped structure 19 adapted to be led down into the seabed, and each sensor unit 26 comprises at least one geophone. The carrier 10 comprises a holder 12 for the cylindrically skirt-shaped structure 19, which structure 19 shall penetrate down into the seabed, as this holder 12 is adapted to be moved between a lower position and an upper position, to be able to be mechanically released from the skirt-shaped structure 19.

Abstract: An apparatus for three-dimensional single-channel seismic measurements, wherein at least one seismic source and hydrophone devices are towed behind a vessel, and a pair of submerged deflectors are used and which, as the vessel moves, seek to move in a direction transverse to the vessel's direction of travel. Fastened between the deflectors is a wire which limits the spacing between the deflectors. Along the wire there are also mounted thereon hydrophone devices which in relation to the spacing of the devices have a short lengthwise extent. The devices are connected together by a hydrophone signal cable. An additional signal cable connects the cable to the signal processing equipment on the vessel. The seismic source may be connected to signal equipment on the vessel and located in an area between the vessel and the wire, or at least one of the deflectors may be equipped with a seismic source.

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: A method for wrapping continuous strands of steel wire about a seismic cable including interconnected sensor sections and conductor sections where a cross sectional diameter of the sensor section is at least four times that of the conductor section. Two layers of armoring are provided with a first layer wrapped in a first angular direction opposite that of the second layer. A stranding assembly is provided which has two selective positions, one for providing a die hole for stranding the conductor section, another for providing a passage hole for allowing the sensor section to pass after wrapping with armor wire.

Abstract: A marine seismic streamer steering device comprises at least two hinged sections pivotally coupled to each other and connected between two adjacent sections of the seismic streamer, and a bend control unit that controls bending of the hinged sections relative to the longitudinal axis of the seismic streamer. The steering device further comprises a roll sensor which determines rotational orientation of the body and transmits the orientation to the bend control unit, a lateral position sensor which determines lateral position of the body and transmits the lateral position to the bend control unit, and a depth sensor which determines depth of the body and transmits the depth to the bend control unit. The bend control unit then controls the bending of the hinged sections based on the transmitted rotational orientation, lateral position, and depth of the body.

Abstract: A method of determining seismic properties of a layer of the seabed, in particular a surface or near-surface layer (5), comprises directing seismic energy propagating in a first mode at a boundary face of the layer so as to cause partial mode conversion of the seismic energy at the boundary face. For example partial mode conversion may occur when seismic energy propagates upwards through the interface between a surface or near-surface layer (5) and the basement (6), owing to the difference in seismic properties between the surface or near-surface layer (5) and the basement (6). In the invention, the two modes of seismic energy—that is the initial mode and the mode generated by mode conversions at the interface—are received at a receiver. The difference in travel time of the two modes between the interface and the receiver is determined from the seismic data acquired by the receiver.

Abstract: A seismic streamer cleaning device includes a means for converting motion of water past a seismic streamer into movement of the device as the streamer is towed through the water. A cleaning element is cooperatively engaged with the device and an exterior surface of the streamer. In one embodiment, the cleaning element includes brush bristles.

Abstract: The combination of a portable article and a security system. The security system has a flexible element/tether with a length. The flexible element/tether is connected between the portable article and a support to confine movement of the portable article within a range dictated by the length of the flexible element/tether. The flexible element/tether has a flexible core and a protective layer over the core. The protective layer is made at least partially from a material that is resistant to being cut to thereby avoid severance of the flexible core.

Abstract: An electronic-carrying module (640), for example for use with a seismic data acquisition cable (400), is disclosed. The preferred electronic-carrying module (640) includes, first, an electronics carrier (106) having access means (107) for providing an easy-to-reach access to wrap-around circuitry fitted inside a curved space (104a) within the electronics carrier (106). Second, a pair of rigid end-fittings (102) spaced apart axially by the electronics carrier (106) for connecting to a section of the seismic data acquisition cable (400). And third, an axial hole (100) formed in the electronics carrier (106) and the rigid end-fittings (102) defining the curved space (104a) between the axial hole (100), the access means (107) and the rigid end-fittings (102).

Abstract: A method for deploying and retrieving seafloor equipment modules is disclosed. A conveyor has a fixed end and a free end. The conveyor is deployed into a body of water until the free end reaches, or is proximate to, the seafloor. The conveyor is dragged through the water. The equipment modules are slidably attached to the conveyor. The equipment modules slide along the conveyor to the seafloor, where the equipment modules engage the seafloor and are secured at a fixed position.

Abstract: A method of de-ghosting seismic data acquired in a marine seismic survey comprises estimating ?zp (where p is the fluid pressure) from a time-derivative of p and a derivative of p in a horizontal direction such as the x-direction. The time-derivative of p and the derivative of p in the horizontal direction can be readily obtained from the acquired seismic data, and are used to provide an improved estimate of ?zp which, in general, cannot be directly determined from the acquired seismic data. Once ?zp has been estimated it can be used to de-ghost the acquired seismic data.

Abstract: The invention provides a method of determining the orientation of a seismic receiver (4, 6) from seismic data acquired at the receiver (4, 6). The determined orientation can be taken into account in subsequent analysis of the seismic data. This avoids inaccuracies that can occur if the receiver orientation is estimated. In a preferred embodiment the horizontal spatial derivatives of the pressure measured at the receiver are used in the determination of the orientation of the receiver. These may be calculated on either the source side or the receiver side. These are combined with horizontal components of the particle displacement, velocity or acceleration (or a higher time-derivative of the particle displacement). Alternatively, horizontal spatial derivatives of the particle displacement measured at the receiver may be used in place of the horizontal spatial derivatives of the pressure.

Abstract: Methods are disclosed employing seismic waves having infrasonic frequencies in the range of about 0.1–20 Hz for generating electromagnetic waves of similar infrasonic frequency in hydrocarbon bearing subterranean formations located at depths up to about 5000 meters, said electromagnetic waves having sufficient voltage amplitudes for detection at the earth's surface. Also disclosed are seismic sources capable of generating infrasonic seismic waves of sufficient amplitude for generating electromagnetic waves in hydrocarbon bearing formations at depths up to 5000 meters, said electromagnetic waves having voltage amplitudes sufficient for detection at the earth's surface.

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 method is disclosed for processing seismic data. The method includes determining a position of a seismic energy source and seismic receivers at a time of actuation of the source. A velocity of the seismic receivers with respect to the source position is determined at the time of actuation. An offset of the receivers is corrected using the velocity. A moveout correction is determined for the signals detected by the sensors based on the corrected offset and a velocity of earth media through which seismic energy passed from the source to the sensors.

Abstract: A method of performing a seismic survey of a hydrocarbon reservoir in the earth formations beneath a body of water includes deploying a seismic cable from a drum carried by a remotely operated vehicle on the seabed. The cable is deployed into a lined trench, which is formed either concurrently with cable deployment or during a previous survey, to ensure good repeatability of successive surveys of the reservoir, in order to enable changes in characteristics of the reservoir, eg due to depletion, to be monitored.

Abstract: The invention is a system designed for acquisition of seismic data by means of acquisition stations set on water bottom of a water body. The system comprises acquisition stations (DSAU) combining a streamlined boom suited to penetrate the bottom and thus couple seismic receivers with the underlying formation, a sealed body for electronic data acquisition and communication modules. These acquisition stations (DSAU) are placed in the water and drop to the bottom under the effect of gravity.