Presented are methods and systems for collecting marine seismic data. The collected seismic data can be low frequency (e.g., less than 10 Hz) or it can be a full seismic bandwidth (1-200 Hz) depending on if the low frequency tuned sources and tuned receivers are combined with conventional sources and receivers. The low frequency sources can be towed or they can be autonomous and positioned in the survey area by tether, drifting or self-propelled. The tuned low frequency receivers are towed at a depth greater than conventional receivers and the sources can be fired independently or simultaneously.

Presented are methods and systems for collecting marine seismic data. The collected seismic data can be low frequency (e.g., less than 10 Hz) or it can be a full seismic bandwidth (1-200 Hz) depending on if the low frequency tuned sources and tuned receivers are combined with conventional sources and receivers. The low frequency sources can be towed or they can be autonomous and positioned in the survey area by tether, drifting or self-propelled. The tuned low frequency receivers are towed at a depth greater than conventional receivers and the sources can be fired independently or simultaneously.

A method for seismic surveying comprises deploying a plurality of seismic receivers proximate an area of subsurface to be surveyed. At least one seismic energy source moves in a path that circumscribes a center, wherein positions of the plurality of seismic receivers remain fixed. At least one of a distance between the path and the center changes monotonically as seismic energy source traverses the path, or the center moves in a selected direction as the seismic energy source traverses the path. The source is actuated at selected times as the at least one seismic energy source traverses the path, such that a spacing between positions of the source along the source path and transverse to the source path varies between successive actuations of the source. Seismic energy is detected at the plurality of seismic receivers resulting from actuating the at least one seismic energy source.

A method for seismic surveying comprises deploying a plurality of seismic receivers proximate an area of subsurface to be surveyed. At least one seismic energy source moves in a path that circumscribes a center, wherein positions of the plurality of seismic receivers remain fixed. At least one of a distance between the path and the center changes monotonically as seismic energy source traverses the path, or the center moves in a selected direction as the seismic energy source traverses the path. The source is actuated at selected times as the at least one seismic energy source traverses the path, such that a spacing between positions of the source along the source path and transverse to the source path varies between successive actuations of the source. Seismic energy is detected at the plurality of seismic receivers resulting from actuating the at least one seismic energy source.

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.

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.

Marine seismic data recording employs airgun sources which are usually arrays of airguns of various sizes towed behind a seismic vessel. The seismic airgun pulses are omni-directional except for some cancellation of horizontal waves by the geometry of the array. The Airgun Pulse Amplifier Cone is an invention that can be used with a commercially available airgun mounted at or near the top of the cone which will increase the amplitude of the down-going pulses and reduce the amplitude of the horizontally traveling pulses. Multiple airgun cones can be constructed into a steel box-structure for towing, to provide the tuning benefits of airgun arrays and the box itself. Using the Airgun Pulse Amplifier Cone can reduce the impact on marine life and the environment near a seismic survey and can also result in lower airgun volume requirements and lower airgun costs.

Marine seismic data recording employs airgun sources which are usually arrays of airguns of various sizes towed behind a seismic vessel. The seismic airgun pulses are omni-directional except for some cancellation of horizontal waves by the geometry of the array. The Airgun Pulse Amplifier Cone is an invention that can be used with a commercially available airgun mounted at or near the top of the cone which will increase the amplitude of the down-going pulses and reduce the amplitude of the horizontally traveling pulses. Multiple airgun cones can be constructed into a steel box-structure for towing, to provide the tuning benefits of airgun arrays and the box itself. Using the Airgun Pulse Amplifier Cone can reduce the impact on marine life and the environment near a seismic survey and can also result in lower airgun volume requirements and lower airgun costs.

An unmanned vessel system can include a hull system configured to provide buoyancy, one or more seismic sources configured to generate seismic energy, and a deployment apparatus configured to deploy the seismic sources from the hull system to a water body or water column. A control system can be configured to operate the deployment apparatus, in order to deploy the one or more seismic sources so that the seismic energy propagates through the water column. A compressed air source can be provided on board the unmanned vessel system, with a source line configured to provide compressed air to the seismic sources.

An unmanned vessel system can include a hull system configured to provide buoyancy, one or more seismic sources configured to generate seismic energy, and a deployment apparatus configured to deploy the seismic sources from the hull system to a water body or water column. A control system can be configured to operate the deployment apparatus, in order to deploy the one or more seismic sources so that the seismic energy propagates through the water column. A compressed air source can be provided on board the unmanned vessel system, with a source line configured to provide compressed air to the seismic sources.