Pgs Geophysical As

Subvision Ab

Per Birger Gunnarsson

Nils Gunnar Olof Kröling

Bo Magnus Bernhardsson

Stig Rune Lennart Tenghamn

Nils Lunde

Jon Falkenberg

Olle Kröling

Techniques are disclosed relating to control of seismic sources such as marine vibrators. According to some embodiments, iterative learning control (ILC) systems may be used to control such seismic sources. According to some embodiments, local sensor(s) placed in, on, or near a seismic source and/or remote sensors placed in the far-field region may be used to determine a transfer function for the seismic source for such ILC control. A sensor is configured to measure the acoustic output of the marine vibrator along with signal pulses from at least one impulsive seismic signal source. The ILC is disabled when it is determined that the impulsive seismic is active based on the sensor measurements.

Control system for marine vibrators operating near impulsive seismic signal sources

Techniques are disclosed relating to control of seismic sources such as marine vibrators. According to some embodiments, iterative learning control (ILC) systems may be used to control such seismic sources. According to some embodiments, local sensor(s) placed in, on, or near a seismic source and/or remote sensors placed in the far-field region may be used to determine a transfer function for the seismic source for such ILC control.

Method for calibrating the far-field acoustic output of a marine vibrator

Techniques are disclosed relating to control of seismic sources such as marine vibrators. According to some embodiments, iterative learning control (ILC) systems may be used to control such seismic sources. According to some embodiments, a control unit provides first input signals to the marine vibrator which include an excitation signal and a high-amplitude, low-frequency signal, the latter is operable to decrease friction effects in the marine vibrator. Furthermore local sensor(s) placed in, on, or near a seismic source and/or remote sensors placed in the far-field region to measure the acoustic output of the marine vibrator. The control unit is further configured to generate initial values for a transfer function of the marine vibrator based on the measured acoustic output.

Control system for marine vibrators to reduce friction effects

A sea bed survey system being configured to be towed by a towing body () is provided. The system comprises at least one sensor carrier () having a plurality of sensors () disposed along its length, and at least one deflector () for controlling the lateral extension and the vertical position of said sensor carrier (), wherein the lateral extension exceeds 25% of the length of sensor carrier, and the vertical height above the sea bed is less than the lateral extension of said sensor carrier.

System and method for sea bed surveying

A system comprises a plurality of acoustic transmitters, mounted inside the streamers, adapted to transmit broadband signals having low cross-correlation between the signals of different transmitters; a plurality of acoustic receivers, mounted inside the streamers, adapted to receive the signals from the transmitters; at least one processor adapted to cross-correlate the signals received at the receivers with copies of transmitter signals to determine identities of the transmitters of the received signals and to determine travel times of the received signals; and a main processor adapted to convert the travel times to distances between the identified transmitters and the receivers and to determine relative positions of the streamers from the distances.

Growing community of inventors

Löddeköpinge, Sweden

Per Birger Gunnarsson