Method and marine seismic acquisition system that includes an acoustic source towed along an overlapping curved sail path and configured to generate acoustic waves; a first underwater vehicle, UV, that moves along a receiver straight path; and a first seismic receiver attached to the first UV and configured to record the acoustic waves generated by the acoustic source. A receiver position along the straight path is substantially coincident with the overlapping curved sail path at given times.

Method and marine seismic acquisition system that includes an acoustic source towed along an overlapping curved sail path and configured to generate acoustic waves; a first underwater vehicle, UV, that moves along a receiver straight path; and a first seismic receiver attached to the first UV and configured to record the acoustic waves generated by the acoustic source. A receiver position along the straight path is substantially coincident with the overlapping curved sail path at given times.

A reaction mass seismic survey source that is located in an underground casing. The seismic source includes a non-planar base plate; a reaction mass located on the non-planar base plate; and a flextensional element housed in a recess of the reaction mass and configured to vibrate the non-planar base plate when actuated, to generate seismic waves underground.

A reaction mass seismic survey source that is located in an underground casing. The seismic source includes a non-planar base plate; a reaction mass located on the non-planar base plate; and a flextensional element housed in a recess of the reaction mass and configured to vibrate the non-planar base plate when actuated, to generate seismic waves underground.

Methods of designing seismic survey and acquisition of seismic data with reduced noise using equally or optimally irregularly spaced sources or receivers are described. Specifically, prime number ratios for the station to line spacing is used to prevent harmonic leakage and other noise contaminations in the acquired seismic data.

A method for generating acoustic waves under water includes actuating first and second pistons with an actuator system provided inside an enclosure of a source element, to generate a wave having a first frequency, and actuating the first and second pistons with a pressure mechanism attached to the enclosure, to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure. The enclosure has first and second openings and the first and second pistons are configured to close the first and second openings.

A method for generating acoustic waves under water includes actuating first and second pistons with an actuator system provided inside an enclosure of a source element, to generate a wave having a first frequency, and actuating the first and second pistons with a pressure mechanism attached to the enclosure, to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure. The enclosure has first and second openings and the first and second pistons are configured to close the first and second openings.

Disclosed are dipole sources and associated methods. An example system may include a dipole source a first marine seismic vibrator and a second marine seismic vibrator. The first marine seismic vibrator may include two or more sound radiating surfaces. The second marine seismic vibrator may also include two or more sound radiating surfaces. A relative position of the second marine seismic vibrator to the first marine seismic vibrator may be fixed. The first marine seismic vibrator may be positioned above the second marine seismic vibrator in a towing configuration. The system may further include a control system operable to control the dipole source such that the first marine seismic vibrator is operating substantially 180 out of phase with the second marine seismic vibrator.

Disclosed are dipole sources and associated methods. An example system may include a dipole source a first marine seismic vibrator and a second marine seismic vibrator. The first marine seismic vibrator may include two or more sound radiating surfaces. The second marine seismic vibrator may also include two or more sound radiating surfaces. A relative position of the second marine seismic vibrator to the first marine seismic vibrator may be fixed. The first marine seismic vibrator may be positioned above the second marine seismic vibrator in a towing configuration. The system may further include a control system operable to control the dipole source such that the first marine seismic vibrator is operating substantially 180 out of phase with the second marine seismic vibrator.

Processes and systems described herein are directed to performing marine surveys with marine vibrators that emit orthogonal coded pseudo-random sweeps. In one aspect, coded pseudo-random signals are generated based on coded pseudo-random sequences. The coded pseudo-random sequences are used to activate the marine vibrators in a body of water above a subterranean formation. The activated marine vibrators generate orthogonal coded pseudo-random sweeps. A wavefield emitted from the subterranean formation in response to the orthogonal coded pseudo-random sweeps is detected at receivers located in a body of water. Seismic signals generated by the receivers may be cross-correlated with a signature of one of the orthogonal coded pseudo-random sweeps to obtain seismic data with incoherent residual noise.