A method of seismic exploration above a region of the subsurface of the earth containing structural or stratigraphic features conducive to the presence, migration, or accumulation of hydrocarbons comprises setting a tow depth of a resonant seismic source, producing a resonant frequency at a first amplitude with the resonant seismic source at the tow depth, detecting a depth excursion from the tow depth, reducing an amplitude of the mass from the first amplitude to a second amplitude, preventing the mass from contacting at least one of the first end stop or the second end stop based on reducing the amplitude to the second amplitude, correcting the depth excursion to return the resonant seismic source to the tow depth, and increasing the amplitude from the second amplitude to produce the resonant frequency with the resonant seismic source at the tow depth.

A marine seismic data acquisition system may include first and second containers deployable in a body of water. The first container includes a first seismic data acquisition channel capable of transducing seismic energy in the body of water having a first maximum amplitude, and the second contain includes a second seismic data acquisition channel capable of transducing seismic energy in the body of water having a second maximum amplitude. The first seismic data acquisition channel is associated with at least a first seismic sensor, and the second seismic data acquisition channel is associated with at least a second seismic sensor. The second sensor corresponds to a same sensor type as the first seismic sensor, and the first maximum amplitude is higher than the second maximum amplitude.

A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

A method of seismic exploration above a region of the subsurface of the earth containing structural or stratigraphic features conducive to the presence, migration, or accumulation of hydrocarbons comprises setting a tow depth of a resonant seismic source, producing a resonant frequency at a first amplitude with the resonant seismic source at the tow depth, detecting a depth excursion from the tow depth, reducing an amplitude of the mass from the first amplitude to a second amplitude, preventing the mass from contacting at least one of the first end stop or the second end stop based on reducing the amplitude to the second amplitude, correcting the depth excursion to return the resonant seismic source to the tow depth, and increasing the amplitude from the second amplitude to produce the resonant frequency with the resonant seismic source at the tow depth.

In some examples, the disclosure provides a method for deploying a plurality N of seismic sensors, wherein each seismic sensor is adapted to measure seismic energy with at least one gain, within a survey area, the method comprising: obtaining a plurality M of gains from which the at least one gain may be selected; configuring the plurality N of seismic sensors such that, for each given gain of the obtained plurality M of gains, at least N/M seismic sensors are adapted to measure the seismic energy with at least one corresponding gain; and deploying the plurality N of configured seismic sensors on the survey area.

A system, method, and circuit for determining signals. A bridge output is received from a Wheatstone bridge sensing a slow signal and a fast signal. A slow output associated with the slow signal and a fast output associated with the fast signal are determined from the bridge output utilizing a microcontroller. The microcontroller generates the offset signal in response to the slow output. Other systems, methods, and circuits are disclosed.

A system and method for detecting underground infrastructure that include generating analog transmit signals, receiving analog receive signals, and digitizing and recording the receive signals; amplifying analog transmit signals, converting the amplified analog transmit signals into acoustic signals, and adjusting a power and coupling of the acoustic signals to the ground; and combining the digitized and recorded receive signals to generate position data of the detected underground infrastructure.

A method of detecting subsurface conditions conducive to fluid transfer can include obtaining microseismic resonance signals from multiple surface locations over a subsurface region of interest using a resonance sensor, wherein for at least a plurality of the multiple surface locations, multiple microseismic resonance signals are obtained at different times to generate signal stacks. In some examples, the method can also include amplifying the microseismic resonance signals, filtering out the high frequencies at least above about 7,500 Hz leaving low frequencies at least as low as about 4 Hz for evaluation, and using these low frequencies to identify subsurface fracture zones where subsurface fluid may be present. In some examples, subsurface fluids can be detected and/or mapped using gamma radiation count and/or magnetometric density data collected using appropriate equipment.

A system, method, and circuit for determining signals. A bridge output is received from a Wheatstone bridge sensing a slow signal and a fast signal. A slow output associated with the slow signal and a fast output associated with the fast signal are determined from the bridge output utilizing a microcontroller. The microcontroller generates the offset signal in response to the slow output. Other systems, methods, and circuits are disclosed.