Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars having raised bosses are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. An external device is attached to a pair of cuffs in the form of C-shaped cylindrical rings each with a circular inner surface. A gap in the ring interrupts the inner surface. The width of the gap is greater than the diameter of the bosses so that the cuffs may be slid onto the collars when the gaps are aligned with the bosses. The bosses are circumferentially offset when the cable is in its normal operating state to lock the cuff and the external device to the collars. The cuffs and the external device can be installed on or removed from the cable by twisting the cable to align the bosses and sliding the cuffs onto or off of the collars. When installed, the cuffs ride on the races to allow the cable to rotate inside the cuffs.

Abstract: A marine threat monitoring and defense system and method protects a target vessel in icy or other marine regions. The system uses communications, user interfaces, and data sources to identify marine obstacles (e.g., icebergs, ice floes, pack ice, etc.) near a target vessel performing set operations (e.g., a stationed structure performing drilling or production operations or a seismic survey vessel performing exploration operations with a planned route). The system monitors positions of these identified marine obstacles over time relative to the target vessel and predicts any potential threats. When a threat is predicted, the system plans deployment of support vessels, beacons, and the like to respond to the threat. For example, the system can direct a support vessel to divert the path or break up ice threatening the target vessel.

Abstract: Methods, apparatuses, and systems are disclosed that assist in determining a location to acquire seismic data. In one embodiment, a method includes modeling acquisition of seismic data in a first location based on a first factor that impacts acquisition of seismic data in the first location. The method also includes generating a modeled attribute based on the modeling, and determining whether to acquire seismic data in the first location based on the modeled attribute or the first factor.

Abstract: A method and system for controlling the shape and separation of an arrangement of streamers towed behind a survey vessel. Each streamer is steered laterally by lateral steering devices positioned along its length at specific nodes. Each streamer is driven by its lateral steering devices to achieve a specified separation from a neighboring streamer. One of these actual streamers, used as a reference by the other actual streamers, is steered to achieve a specified separation from an imaginary, or ghost, streamer virtually towed with the actual streamers.

Abstract: A method and system for controlling the shape and separation of an arrangement of streamers towed behind a survey vessel. Each streamer is steered laterally by lateral steering devices positioned along its length at specific nodes. Each streamer is driven by its lateral steering devices to achieve a specified separation from a neighboring streamer. One of these actual streamers, used as a reference by the other actual streamers, is steered to achieve a specified separation from an imaginary, or ghost, streamer virtually towed with the actual streamers.

Abstract: In seismic survey for icy waters, streamers are towed behind a vessel under the water's surface to avoid ice. GPS readings may not be consistently obtained because the ice prevents a tail buoy with a GPS receiver from trailing from streamer at the surface. Instead, a device tows on the streamer under the water's surface. The streamer's absolute position is tracked by intermittently bringing the towed device toward the surface so GPS readings can be obtained. The streamer's absolute position can then be used in conjunction with compass readings and can correlate various seismic sensor signals obtained along the streamer during the survey. The compass readings can be corrected for declination using declinometer readings, which can be compensated for iron effects from the vessel or other device carrying the declinometer.

Abstract: A multi-component sensor of a fluid-borne acoustic wave that senses pressure and up to three orthogonal particle motion components. The sensor is unresponsive to motion of the sensor mount. Furthermore, the sensor is substantially unresponsive to the turbulent flow of the acoustic medium past the sensor.

Abstract: A two-tier communication system for a seismic streamer. The communication system operates over an unshielded twisted-pair communication line extending the length of the streamer. Repeater units having a repeater function and a device controller function divide the twisted pair into line segments. Coils on each segment couple signals inductively to collocated external devices in a low-speed 2400 baud FSK data link between the devices and an associated device controller. A Gaussian 8-level FSK high-speed 60 kbit/s data link is established along all the segments with the repeaters re-transmitting boosted signals along the entire length of the communication line. The coils are transparent at the high-speed data rate. Time division multiple access (TDMA) or frequency division multiple access (FDMA) is used to accommodate the two links on the single twisted pair.

Abstract: A seismic streamer system and associated methods for estimating the shape of a laterally steered seismic streamer. The streamer is divided into a series of contiguous streamer segments by lateral-steering devices. Heading sensors positioned in forward and aft portions of each segment produce heading readings. Each segment is modeled as having a linear shape in the forward portion and a curved shape in the aft portion. The shape of the segment is estimated according to the model from the heading readings on the segment.

Abstract: A rope having an outer jacket made of braided fibers surrounding a PTFE core and a method for making the rope. The rope is useful in high-tension, high-friction applications, such as serving as a stress member in an isolation section of an instrumented ocean-bottom cable. The PTFE core, which may consist of one or more strings of PTFE valve packing material, squeezes through the braided jacket as the rope is deformed in high-stress regions such as around a bollard. The PTFE material squeezed through the outer jacket lubricates the outside of the rope in the high-stress region to lower the friction.

Abstract: Seismic acquisition systems are disclosed that allow contemporaneous seismic sources to be separated from a composite signal comprising two or more constituent seismic sources. In some embodiments, a representation of the composite signal may be developed that includes a noise contribution of undesired signals present in the composite signal. Additionally, an operator, referred to herein as an “annihilator”, may be developed such that it may be conditioned and inverted to minimize undesired noise contributions in the composite signal. This inversion may assist in recovering the constituent seismic sources from the composite signal. Furthermore, in some embodiments, the accuracy with which the constituent source measurements are approximated may be increased by implementing them as random sweeps having a conventional length.

Abstract: A system and a method for rejecting noise in an underwater sensor cable, such as a towed streamer or an ocean-bottom cable. An adaptive hydrodynamic model of the cable produces an estimated sensor signal from a raw sensor signal from a particle-motion sensor, such as an accelerometer. The estimated sensor signal represents an estimate of the response of the underwater cable to cable motion absent seismic events. A noise-reduced response to particle motion alone is produced by subtracting the estimated sensor signal from the raw sensor signal to reject cable motion and other noise effects in the raw sensor signal. A seismic event detector uses a hydrophone signal from an acceleration-canceling hydrophone to disable the adapting of the hydrodynamic model during seismic events. The hydrophone signal is combined with the response to particle motion by PZ summation to produce a deghosted seismic response signal.

Abstract: A method for verifying the accuracy of a wave velocity model. The method may include generating an extended image using the wave velocity model, operating on the extended image using an annihilator, where the extended images represent a geophysical field, and determining if the extended image obeys at least one physical characteristic. In the event that the extended image does not obey at least one physical characteristic the method may include recreating or altering the wave velocity model accordingly.

Abstract: A seismic information processing method and apparatus includes attenuating flexural wave noise information from seismic information. Flexural wave information removal includes receiving the seismic information using an information processing device interface, the seismic information having a plurality of directional components acquired using a multi-axis motion sensor coupled to ice floating on a body of water, the seismic information including desired seismic information and the flexural wave information. A noise model of the flexural wave information may be generated using at least one of the plurality of seismic information directional components using an information processing device. The noise model is improved using an adaptive correction filter, and the improved noise model is applied to at least one directional component of the received seismic information to attenuate the flexural wave information wave in the seismic information.

Abstract: An arrangement for conducting a seismic survey and methods for operating a vibrator array in a seismic survey. A signal source coupled to an array of vibrators drives the vibrators with a set of signals to generate seismic signals into a survey area. Each of the signals of the set has an autocorrelation function and a cross correlation function with the other signals of the set that decays faster with time than reflections of the seismic signals from the survey area. One such set of signals includes a linear FM sweep phase-modulated by a maximal-length sequence code shifted a different number of chips for each signal.

Abstract: An exemplary system for managing the deployment of a seismic data acquisition system uses a module configured to execute a plurality of task in the field by receiving one or more seismic devices. The module may include a power source that provides electrical power to the seismic devices. The module may also include a processor programmed to retrieve data stored in the seismic devices, perform diagnostics, facilitate inventory and logistics control, configure seismic devices and update data or pre-programmed instructions in the seismic device.

Abstract: A method and system for acquiring seismic data from a seismic survey plan is provided. A survey area is selected in which the seismic data will be acquired. A coordinate for at least one point of interest within the survey area is determined and input into a portable navigation device. A navigation solution is determined between a GPS-determined location of the portable navigation device and the determined coordinate and thereupon presented in a human cognizable media. A seismic device may be positioned at the determined coordinate to insonify a subterranean formation with seismic energy or for detecting reflected seismic energy. Data may be periodically entered into and retrieved from the portable navigation device by an in-field operator. 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.

Abstract: An underwater ocean bottom cable constructed of a series of axially aligned cable segments alternately arranged with sensor units. The sensor units include an outer housing with an interior cavity in which a sensor module is suspended by a cradle. Vanes on the sensor module protrude through axially elongated openings in the outer housing to dig into the seabed to provide good seismic coupling between the seabed and pressure sensors and motion sensors housed in the sensor module. The outer sensor housing is split into complementary portions that clamp firmly onto the ends of adjacent cable segments. Stress members, such as high modulus fiber ropes, extend out the ends of adjacent cable segments. Axial channels formed in the intervening outer sensor housing on opposite sides of the sensor module receive the stress members, which, along with the cradle, provide seismic isolation between the cable segments and the sensor modules.

Abstract: A seismic information processing method and apparatus includes attenuating flexural wave noise information from seismic information. Flexural wave information removal includes receiving the seismic information using an information processing device interface, the seismic information having a plurality of directional components acquired using a multi-axis motion sensor coupled to ice floating on a body of water, the seismic information including desired seismic information and the flexural wave information. A noise model of the flexural wave information may be generated using at least one of the plurality of seismic information directional components using an information processing device. The noise model is improved using an adaptive correction filter, and the improved noise model is applied to at least one directional component of the received seismic information to attenuate the flexural wave information wave in the seismic information.

Abstract: An apparatus for in-field configuration of a seismic device such as a seismic sensor may include a memory module having data for configuring the seismic device, a location sensor determining a location parameter for the seismic sensor, an alignment member aligning the location sensor with the seismic sensor, and a communication device transmitting the determined location parameter to a selected external device.