A dip angle-steering median filtering method based on a niche differential evolution algorithm, comprising the following steps: dividing a data to be processed into a series of overlapping time-space windows; obtaining an event energy curve in a time-space window and obtaining an event position according to a local maximum value of the event energy curve; obtaining event dip angles and coherence values of the event dip angles through the niche differential evolution algorithm at the event position; filtering the event dip angles according to the event dip angles and the coherence values of the event dip angles; and performing a median filtering sequentially along a filtering dip angle. The disclosure can simultaneously obtain all dip angles of intersecting events and a true three-dimensional feature enable the present disclosure to obtain a better filtering effect.

A towed array ballasting unit includes a canister, an internal bladder, an external bladder, a motor valve, fluid, a shroud, and printed circuit boards. The canister includes a head endcap and an aft endcap with the internal bladder located within and attached to an internal end of a fluid channel. An external bladder is located outside the canister and attached to an external end of the fluid channel. The motor valve is attached to the aft endcap of the canister and the internal end of fluid channel. The fluid moves between the internal bladder and external bladder via the fluid channel. The shroud forms a shell around the canister, external bladder, and a connector that connects the towed array ballasting system to an array tail. The printed circuit boards execute instructions provided by a computer.

A marine seismic acquisition system includes a frame that includes a central longitudinal axis and members that define orthogonal planes that intersect along the central longitudinal axis; a data interface operatively coupled to the frame; hydrophones operatively coupled to the frame; a buoyancy engine operatively coupled to the frame where the buoyancy engine includes at least one mechanism that controls buoyancy of at least the frame, the hydrophones and the buoyancy engine; and at least one inertial motion sensor operatively coupled to the frame that generates frame orientation data, where the hydrophones, the buoyancy engine and the at least one inertial motion sensor are operatively coupled to the data interface.

The present invention relates to the field of marine towing operations for marine seismic survey systems and seismic data gathering. More specifically, the present invention relates to seismic sources and receiver sensor cables, streamers, floats etc., that have means for adjusting and keeping a desired position in an array during a tow behind a vessel. The apparatus comprises a body (10) with means for being towed behind a vessel, means for connecting with and supporting and steering submerged marine seismic equipment laterally in the water and means for remote control from vessel. The body (10) of the apparatus has a forward positioned float unit (16) with an elongated rear float (12) hinged at the rear of the forward float. The forward float unit has vertical wings (18, 18′) with means for adjusting angle of attack in water.

Techniques are disclosed relating to performing marine surveys with non-uniform spacing of survey elements in a cross-line direction. This may include, for example, performing a survey pass in a multi-pass survey by towing a plurality of sources and sensors in a towing pattern with non-uniform spacing between adjacent ones of the sources. In some embodiments, the non-uniform spacing between adjacent ones of the sources is determined based on a common mid-point (CMP) spacing parameter for the survey pass in the cross-line direction. The spacing parameter may relate, for example, to difference in average CMP spacing for different parts of the survey spread, variance in CMP spacing, and/or width of the survey spread for which a threshold CMP spacing distance is satisfied. In various embodiments, the disclosed techniques may improve survey resolution and/or accuracy and may require a smaller number of survey passes and/or a reduced amount of survey equipment relative to traditional techniques.

A dip angle-steering median filtering method based on a niche differential evolution algorithm, comprising the following steps: dividing a data to be processed into a series of overlapping time-space windows; obtaining an event energy curve in a time-space window and obtaining an event position according to a local maximum value of the event energy curve; obtaining event dip angles and coherence values of the event dip angles through the niche differential evolution algorithm at the event position; filtering the event dip angles according to the event dip angles and the coherence values of the event dip angles; and performing a median filtering sequentially along a filtering dip angle. The disclosure can simultaneously obtain all dip angles of intersecting events and a true three-dimensional feature enable the present disclosure to obtain a better filtering effect.

The present invention relates to the field of marine towing operations for marine seismic survey systems and seismic data gathering. More specifically, the present invention relates to seismic sources and receiver sensor cables, streamers, floats etc., that have means for adjusting and keeping a desired position in an array during a tow behind a vessel. The apparatus comprises a pulley apparatus, being a kind of miming block (1), connected with and supporting marine equipment (3, 3′). The miming block (1) is configured to attach to the deflected lead wire or tow wire (2, 9). It has means for traveling along the wire (2, 9).

In a first embodiment the invention comprises a method for gathering geophysical data, including towing geophysical data gathering equipment behind a survey vessel in a body of water, said equipment including an array of sensor streamers extending behind said vessel, and determining a geodetic location of a streamer steering reference point at a forward end of the sensor streamers and a reference direction. At least one sensor streamer included in said array of sensor streamers is laterally deflected in response to the determined geodetic location of said streamer steering reference point and the determined reference direction.

The invention relates to an arrangement for seismic acquisition the spacing between each adjacent pairs of receiver and sources lines is not all the same. Some receiver and/or source lines and/or receiver and/or source spacings are larger and some are smaller to provide a higher quality wavefield reconstruction when covering a larger total area or for a similar total area of seismic data acquisition while providing a wavefield that is optimally sampled by the receivers and sources so that the wavefield reconstruction is suitable for subsurface imaging needs.

Disclosed are methods and systems for using tension feedback from steerable deflectors. In one example, a method may comprise: towing sensors streamers in a body of water from a survey vessel, wherein each of the sensor streamers comprises geophysical sensors at spaced apart locations; towing steerable deflectors in the body of water from the survey vessel, wherein the steerable deflectors are used to provide a lateral component of force to the sensors streamers as the steerable deflectors are towed through the body of water; turning the survey vessel; measuring tension at the steerable deflectors during the step of turning the survey vessel; and in response to the step of measuring tension, determining at least one of a reduced vessel operating speed, an increased vessel operating speed, a reduced angle of attack for at least one of the steerable deflectors, an increased angle of attack for at least one of the steerable, an increased vessel turn radius, or a decreased vessel turn radius.