Abstract: An underwater base handles an autonomous underwater vehicle. The underwater base includes a storing part configured to store the AUV; a control part configured to control the storing part; and a support part configured to support the control part and the storing part and to prevent a burial of the underwater base into the ocean bottom. The control part is further configured to guide the AUV while approaching a desired target position on the ocean bottom.

Abstract: A method and apparatus for noise attenuation. The method includes receiving seismic data associated with at least two vintages (di, dj) collected for a same subsurface, wherein the first and second vintages (di, dj) are taken at different times; calculating a set of filters (fi, fj) that minimizes an energy function (E), wherein the energy function (E) includes a term representing a 4D difference between the first and second vintages (di, dj); calculating primaries (pi, pj) corresponding to the first and second vintages (di, dj) based on the set of (fi, fj); and calculating a 4D difference (?ij) based on the primaries (pi, pj). The 4D difference (?ij) is minimized.

Abstract: System, apparatus and method for collecting data from, and providing power to, a geophysical data acquisition device are described herein. The method may include charging a data transfer device comprising a data transfer port, a power transfer port and a battery module, coupling the data transfer device to a geophysical data acquisition device, deploying the geophysical data acquisition device and collecting data therewith, collecting data from the geophysical data acquisition device via the data transfer port and providing power to the geophysical data acquisition device via the power transfer port, replacing the data transfer device with a charged device, coupling the data transfer device to a charging station, transferring data from the data transfer device, and transferring power to the data transfer device via the charging station.

Abstract: A lead-in cable used to tow a streamer behind a vessel includes a replaceable portion removably connected between a portion of the lead-in cable attached to the vessel and the streamer. Alternatively a lead-in additional cable is inserted between a lead-in cable and a towed streamer. The replaceable portion or the lead-in additional cable covers a portion most likely to be damaged between the streamer and the towing vessel.

Abstract: A source element for generating seismic waves includes a housing; a partitioning element placed inside the housing and configured to split the housing in a closed chamber and an opened chamber; and a valve in fluid communication with the closed chamber and configured to supply high-pressure air to the closed chamber to make the partitioning element oscillates. An oscillation of the partitioning element generates low-frequency seismic waves.

Abstract: A towable and steerable elongated float for a marine seismic source arrangement for use in making a seismic survey at sea, having first attachment means at a lower or bottom part of a float body for allowing at least one seismic source to be suspended from the float, and second attachment means on a fore part of the float body for attachment of a strength taking source towing line or umbilical. The float body comprises first and second elongated steering foils being attached to and spaced from respective port and starboard sides of the fore part of said float body by respective support arrangement. The steering foils have respective longitudinal steering foil axes being oriented in a direction substantially perpendicular to a longitudinal axis of the float body and so as to be substantially perpendicular to a sea surface when in use, the elongated steering foils having respective first and second chord axes.

Abstract: A real time deflector monitoring system related to a deflector used in a seismic survey system is provided. The system includes a bridle block configured to connect the deflector to a first rope. The system further includes sensors embedded in the bridle block and configured to measure strength and direction of a tension in at least one of (A) the first rope and/or (B) one of rig ropes connecting the deflector to the bridle block. The system also includes a motion detector configured to acquire information related to deflector's motion.

Abstract: Deflectors configured to be attached to cables towed behind a vessel for performing a marine survey and associated methods are provided. A deflector has a body including a wing portion and a knuckle portion. The wing portion has substantially flat wings extending away from a position where the body is attached to the cable. The knuckle portion is configured to attach the wing portion to the cable so that the wing portion remains able to rotate about three rectangular axes while being towed underwater.

Abstract: Methods and devices for seismic data processing deblend seismic data gathered using simultaneous source acquisition by applying two different deblending techniques. The second deblending technique is applied to residual data obtained after applying the first deblending technique. At least one of these first and second deblending techniques uses a signal-to-noise map.

Abstract: Cooperative attenuation methods are applied to data sets acquired by surveying a same underground formation which therefore include substantially the same primary signal and different individual noise. The data sets are converted in a wavelet basis by applying a high angular resolution complex wavelet transform. When corresponding coefficients of the data set representations in the wavelet basis differ more than predefined thresholds the coefficients are attenuated as corresponding to noise.

Abstract: Methods and systems for separating P-S wave field data are described. Slowness values for the PP mode and the PS mode are estimated and are, typically, unequal based on aliased and/or irregularly sampled data. A calculation, in the space-time domain, based on a matrix of equations, generates separated P-wave and S-wave data. The separated P-wave data and S-wave data are output for further imaging.

Abstract: An autonomous underwater vehicle (AUV) for recording seismic signals during a marine seismic survey. The AUV (200) includes a body (204) having a flush shape; a buoyancy system (202) located inside the body and configured to control a buoyancy of the AUV while traveling underwater; a processor (108) connected to the buoyancy system and configured to select one of plural phases for the buoyancy system at different times of the seismic survey, wherein the plural phases include a neutral buoyancy, a positive buoyancy and a negative buoyancy; and a seismic sensor (110) for recording seismic signals.

Abstract: System and method for monitoring a reservoir underwater. The system includes plural nodes, each having a seismic sensor for detecting seismic waves; a remote operated vehicle (ROV) configured to deploy or retrieve the plural nodes to seabed; and an autonomous underwater vehicle (AUV) configured to monitor and exchange data with the plural nodes. At least one node of the plural nodes has a head that houses the seismic sensor and the head is configured to burrow in the seabed, up to a predetermined depth, and the head remains in electrical contact through a connector with a base of the at least one node.

Abstract: Methods for determining a seismic wave's propagation velocity in water for monitor seismic data of a 4D data set analyze a relationship between seafloor time-shifts and source-receiver offsets. The time-shifts are differences of normal move out corrected seafloor source-receiver travel times for pairs of traces. Each pair includes a base trace extracted from base seismic data of the 4D data set and a monitor trace extracted from the monitor seismic data, the traces corresponding to the same seafloor bin and having the same source-receiver offset.

Abstract: Devices and methods for stabilizing a tailbuoy attached to a streamer towed during a marine survey are provided. The tailbuoy includes a floating body configured to be connected to the streamer, and a keel attached to the floating body. The keel is configured to stabilize a motion of the tailbuoy along a towing direction while in a working state, and to be switched between the working state in which the keel is partially submerged and a retracted state in which the keel is removed from water.

Abstract: A method for attenuating noise in seismic data signals is described wherein seismic signals are transmitted using a pseudo-random frequency sweep signal. Noise is then attenuated from the resulting, acquired seismic data on pre-phase subtraction basis, e.g., before correlating or de-convolving the acquired seismic data. In this way, repetitions associated with, for example, diversity stacking techniques can be avoided.

Abstract: Systems and methods are provided for de-noising seismic data recorded by seismic receivers. A first portion of the seismic data having a first signal-to-noise ratio (SNR) to is processed to generate a de-noising operator or function. The de-noising operator is applied to a second portion of seismic data having a second SNR to remove noise from the second portion of the seismic data, where the first SNR is greater than the second SNR.

Abstract: Method, apparatus and system for calibrating and synchronizing a seismic acoustic source array (50) by taking into account both a time- break signal (500) and a near-field signal (504). A time delay between the time-break signal and the near-field signal is used to calculate an offset for adjusting the shooting of the source elements of the source array.

Abstract: Source signature of a source array is measured using an autonomous underwater vehicle which is not physically connected to surface equipment and uses acoustic signals for communication and/or location. Such measurements may be performed while the source array is towed, the AUV then moving in tandem with the source array.

Abstract: A method for controlling impulsive sources during a geophysical survey includes receiving a set of predetermined shooting times for an impulsive source, receiving a detonation authorization for the impulsive source, and delaying a triggering of the impulsive source until a next available shooting time of the plurality of predetermined shooting times. A corresponding apparatus and system are also disclosed herein.