Abstract: Methods and systems to separate seismic data associated with impulsive and non-impulsive sources are described. The impulsive and non-impulsive sources may be towed through a body of water by separate survey vessels. Receivers of one or more streamers towed through the body of water above a subterranean formation generate seismic data that represents a reflected wavefield produced by the subterranean formation in response to separate source wavefields generated by simultaneous activation of the impulsive source and the non-impulsive source. Methods and systems include separating the seismic data into impulsive source seismic data associated with the impulsive source and non-impulsive source seismic data associated with the non-impulsive.

Abstract: Embodiments related to a sound source that comprises a base plate configured to bend and generate acoustic energy; a spring coupled to the base plate; and a mass element coupled to the spring, wherein the sound source is operable to produce at least two resonance frequencies in the sound source.

Abstract: Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

Abstract: Methods and systems to separate seismic data associated with impulsive and non-impulsive sources are described. The impulsive and non-impulsive sources may be towed through a body of water by separate survey vessels. Receivers of one or more streamers towed through the body of water above a subterranean formation generate seismic data that represents a reflected wavefield produced by the subterranean formation in response to separate source wavefields generated by simultaneous activation of the impulsive source and the non-impulsive source. Methods and systems include separating the seismic data into impulsive source seismic data associated with the impulsive source and non-impulsive source seismic data associated with the non-impulsive.

Abstract: Methods and systems to separate seismic data associated with impulsive and non-impulsive sources are described. The impulsive and non-impulsive sources may be towed through a body of water by separate survey vessels. Receivers of one or more streamers towed through the body of water above a subterranean formation generate seismic data that represents a reflected wavefield produced by the subterranean formation in response to separate source wavefields generated by simultaneous activation of the impulsive source and the non-impulsive source. Methods and systems include separating the seismic data into impulsive source seismic data associated with the impulsive source and non-impulsive source seismic data associated with the non-impulsive.

Abstract: Embodiments relate to coupling a heading sensor to a deflector surface reference for obtaining the deflector heading which can be used in estimation of the deflector angle of attack. A method may comprise: towing a plurality of streamers behind a survey vessel in a body of water, wherein at least one deflector provides a lateral component of force to the streamers; determining a deflector heading over ground using at least measurements from a heading sensor on a surface reference corresponding to the deflector; determining a deflector velocity over ground using at least measurements from a position sensor on the surface reference; determining a water current of the body of water; and estimating a deflector angle of attack based on inputs comprising the deflector heading, the deflector velocity over ground, and the water current.

Abstract: 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.

Abstract: Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

Abstract: Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

Abstract: Embodiments related to a sound source that comprises a base plate configured to bend and generate acoustic energy; a spring coupled to the base plate; and a mass element coupled to the spring, wherein the sound source is operable to produce at least two resonance frequencies in the sound source.

Abstract: Embodiments related to a piezoelectric bender that comprises a spring and mass element to provide additional constructive resonance. An embodiment provides an apparatus comprising: a base plate; a piezoelectric body coupled to the base plate; a spring coupled to the base plate; and a mass element coupled to the spring, wherein the base plate, the piezoelectric body, the spring, and the mass element are operable to produce at least two resonance frequencies in the apparatus.

Abstract: Methods and systems to separate seismic data associated with impulsive and non-impulsive sources are described. The impulsive and non-impulsive sources may be towed through a body of water by separate survey vessels. Receivers of one or more streamers towed through the body of water above a subterranean formation generate seismic data that represents a reflected wavefield produced by the subterranean formation in response to separate source wavefields generated by simultaneous activation of the impulsive source and the non-impulsive source. Methods and systems include separating the seismic data into impulsive source seismic data associated with the impulsive source and non-impulsive source seismic data associated with the non-impulsive.

Abstract: 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.

Abstract: Embodiments relate to coupling a heading sensor to a deflector surface reference for obtaining the deflector heading which can be used in estimation of the deflector angle of attack. A method may comprise: towing a plurality of streamers behind a survey vessel in a body of water, wherein at least one deflector provides a lateral component of force to the streamers; determining a deflector heading over ground using at least measurements from a heading sensor on a surface reference corresponding to the deflector; determining a deflector velocity over ground using at least measurements from a position sensor on the surface reference; determining a water current of the body of water; and estimating a deflector angle of attack based on inputs comprising the deflector heading, the deflector velocity over ground, and the water current.

Abstract: Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

Abstract: Disclosed are methods and systems for using tension feedback from steerable deflectors to adjust vessel turn time. In one example, a maximum tension for a second steerable first towed on a first side of the survey vessel may be determined. A radius of a turn of the vessel at a preselected speed may further be selected such that the tension on the first steerable deflector is less than the maximum tension. The vessel may be turned while moving at the preselected speed, wherein the turning of the vessel has the selected radius. Tension may be measured on the first steerable deflector during the step of turning the vessel.

Abstract: Embodiments related to a piezoelectric bender that comprises a spring and mass element to provide additional constructive resonance.

Abstract: Disclosed are methods and systems for using tension feedback from steerable deflectors to adjust vessel turn time. In one example, a maximum tension for a second steerable first towed on a first side of the survey vessel may be determined. A radius of a turn of the vessel at a preselected speed may further be selected such that the tension on the first steerable deflector is less than the maximum tension. The vessel may be turned while moving at the preselected speed, wherein the turning of the vessel has the selected radius. Tension may be measured on the first steerable deflector during the step of turning the vessel.