Abstract: 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.

Abstract: Methods of compensating for source signature effects in seismic data are described. One method includes a step of receiving seismic data recorded with a receiver; a step of receiving source data of the seismic waves generated by the moving source; a step of receiving position data of the source while generating the seismic waves; a step of determining a transform operator using the source data, the position data, and a selected domain-transform operator; a step of determining a seismic model by mathematically optimizing a relationship between the transform and the seismic data; and a step of compensating for the source signature effects in the seismic data using the seismic model. A method for generating an image of a subsurface of a geographical area using seismic data includes compensating the seismic data for source signature effects using a model which assumes a moving, non-impulsive source.

Abstract: Controller and method for adapting a frequency sweep for a vibro-acoustic source element that is configured to generate acoustic waves during a seismic survey. The method includes driving a seismic source element to generate a current frequency sweep; recording seismic data with plural seismic sensors in response to the current frequency sweep; selecting, during the seismic survey, a data subset of the seismic data, wherein the data subset has a size less than 10% of the seismic data; calculating with a processing device an attribute based on the data subset; and calculating a new frequency sweep based on the attribute.

Abstract: A system and method for performing a marine seismic survey of a subsurface. The method includes deploying under water, from a deploying vessel, an autonomous underwater vehicle (AUV); recording with seismic sensors located on the AUV seismic waves generated by an acoustic source array; instructing the AUV to surface at a certain depth relative to the water surface; recovering the AUV by bringing the AUV on a recovery vessel; and transferring recorded seismic data to the recovery vessel.

Abstract: Method, source array and seismic vibro-acoustic source element for seismic data acquisition. The method includes storing in a controller a library of beam form factor sets associated with a source array and corresponding regions to be surveyed; towing the source array along survey lines over the regions to be surveyed; selecting a beam form factor set from the library to be applied to the source array for each region; and actuating the source array based on the selected set of beam form factors and a position of the source array relative to the regions. Each set of beam form factors maps to a corresponding region of an area to be surveyed.

Abstract: Method, source array and source element that generate seismic waves. The source element includes an enclosure having an opening covered by a piston; a local supply accumulator fluidly communicating with an interior of the enclosure, a pressure of the fluid inside the local supply accumulator being larger than a pressure of the fluid inside the enclosure; a local supply valve located between the local supply accumulator and the enclosure and configured to control a flow of the fluid from the local supply accumulator to the interior of the enclosure; and a controller configured to control the local supply valve such that the pressure inside the enclosure does not fall below a first preset value based upon an ambient pressure of the enclosure while seismic waves are generated.

Abstract: Method and marine acoustic source array for generating an acoustic wave in a body of water. The marine acoustic source array includes a first depth sub-array set of first acoustic source points configured to be provided at a first depth (z1), the first acoustic source points having different inline first locations along a longitudinal axis (X); and a second depth sub-array set of second acoustic source points configured to be provided at a second depth (z2), the second acoustic source points having different inline second locations along the longitudinal axis (X). The first locations do not coincide along the longitudinal axis (X) with any of the second locations.

Abstract: Method and marine acoustic source array for generating an acoustic wave in a body of water. The marine acoustic source array includes at least one sub-array. The at least one sub-array includes a float from which plural source points are attached. The source points may be provided on a curved line, straight line, or other desired shape so that a variable-depth source is obtained with a single float. The source points may be divided into groups and the groups may be provided on the curved line, straight line or other desired shape.

Abstract: A method and source element for generating seismic waves in water. The source element includes a housing having an opening; an acoustic piston closing the opening; an actuating mechanism located inside the housing and configured to actuate the acoustic piston; and a decoupling mechanism interposed between the acoustic piston and the actuating mechanism. The decoupling mechanism allows the acoustic piston to move substantially independent of the actuating mechanism for a first frequency range.

Abstract: An autonomous underwater vehicle (AUV) for recording seismic signals during a marine seismic survey. The AUV includes a body having a flush shape; an intake water element located on the body and configured to take in water; at least one propulsion nozzle located on the body and configured to eject the water from the intake water element for actuating the AUV; at least one guidance nozzle located on the body and configured to eject water to change a traveling direction of the AUV; and a seismic payload located on the body of the AUV and configured to record seismic signals.

Abstract: A marine seismic source includes source elements configured to emit waves having different frequencies while the source elements are towed at different predetermined depths, respectively. The predetermined depths are calculated such that water-surface reflections of the waves generated by a source element among the source elements interfere constructively with the waves generated by the source element and propagating toward an explored structure under the seafloor. The waves combine to yield a spike-like signature of the source.

Abstract: Method for generating an excitation signal for a first vibratory seismic source so that the first vibratory seismic source is driven with no listening time. The method includes a step of determining a first target spectrum for the first vibratory seismic source; a step of setting a first group of constraints for the first vibratory seismic source; and a step of generating a first excitation signal for the first vibratory seismic source based on the first group of constraints and the first target spectrum. The first seismic traces recorded with plural receivers can be identified when the first vibratory seismic source is driven with no listening time, based on the first excitation signal.

Abstract: A resonant source element is configured to generate seismic waves in water. The resonant source element includes a housing having two openings covered by first and second pistons, wherein the first and second pistons are configured to freely translate relative to the housing to generate the seismic waves; and a high-pressure system configured to discharge inside the housing and to actuate the first and second pistons. The first and second pistons are configured to oscillate after the high-pressure system is fired to generate low-frequency seismic waves.

Abstract: A low-frequency source element is configured to generate seismic waves in water. The low-frequency source element includes includes a hydraulic reservoir configured to hold a given fluid volume; a compliant chamber configured to hold a given gas volume and to accommodate volume changes of the given fluid volume; a rotational kinetic energy actuator configured to impart rotational kinetic energy to the fluid volume; and a flow modulator device configured to transform part of the rotational kinetic energy of the fluid volume into translational energy to generate an acoustic signal.

Abstract: Method and dynamically-adjusted marine acoustic source array for generating an acoustic wave in a body of water. The acoustic source array includes a float; plural actuation devices, each actuation device having corresponding cables; and plural source points connected to the float through the corresponding cables. The plural actuation devices dynamically adjust corresponding lengths of the corresponding cables to achieve a desired variable-depth profile for the plural source points.

Abstract: There is a method for finding a best distribution of source elements that form a vibratory source array. The method includes inputting plural constraints for the source elements; generating plural distributions of the source elements that fulfill the plural constraints; calculating for each distribution a performance index characterizing the source array; and selecting the best distribution from the plural distributions based on a value of the performance index.

Abstract: 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.

Abstract: A resonant source element configured to generate seismic waves. The resonant source element includes a housing; a high-pressure system configured to be discharged inside the housing; and a first conduit attached to an opening of the housing, wherein a distal end of the first conduit freely communicates with an ambient.

Abstract: Method, source array and source element that generate seismic waves. The source element includes an enclosure having an opening covered by a piston; a local supply accumulator fluidly communicating with an interior of the enclosure, a pressure of the fluid inside the local supply accumulator being larger than a pressure of the fluid inside the enclosure; a local supply valve located between the local supply accumulator and the enclosure and configured to control a flow of the fluid from the local supply accumulator to the interior of the enclosure; and a controller configured to control the local supply valve such that the pressure inside the enclosure does not fall below a first preset value based upon an ambient pressure of the enclosure while seismic waves are generated.

Abstract: 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.