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, 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:
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:
Controller and method for generating a frequency sweep for a seismic survey that uses a seismic source. The method includes receiving specification data about the seismic source; receiving environmental data about an infrastructure affected by the seismic survey; receiving guideline data about the infrastructure; setting a target energy spectrum density to be emitted by the seismic source during the seismic survey; and calculating, in a processor, the frequency sweep based on the specification data, environmental data, guideline data and the target energy spectrum density.
Abstract:
A source element for generating seismic waves includes a housing; a partitioning element placed inside the housing and configured to split the housing in a closed chamber and an opened chamber; and a valve in fluid communication with the closed chamber and configured to supply high-pressure air to the closed chamber to make the partitioning element oscillates. An oscillation of the partitioning element generates low-frequency seismic waves.
Abstract:
Computing device, computer software and methods for generating sweep signals corresponding to plural sources that generate seismic waves. The method includes selecting (502) a nominal sweep signal (S0); applying (512) a perturbation (P) to the nominal sweep signal (S0); and calculating (518) the sweep signals (Sn) by varying the perturbation (P), each sweep signal corresponding to a seismic source.
Abstract:
According to an embodiment, a seismic receiver device is described for use in a borehole surrounded by an ambient material, e.g., rock, mud, etc. The seismic receiver device includes a pressure wave measuring device which is configured to sense pressure changes associated with received seismic waves, a coating layer disposed on the pressure wave measuring device, and an outer layer disposed on the coating layer which is made of a material that is selected to have a bulk modulus number that is substantially similar to a bulk modulus number of the ambient medium. In this way, the acoustic impedance of the device is better matched to the ambient material so that more accurate seismic acquisition may be performed.
Abstract:
A source array generates seismic waves in water during a marine seismic survey. The source array includes a first sub-array including plural source elements; plural acoustic transceivers distributed along the first sub-array; a positioning system; a primary position control device configured to control a position of the first sub-array; and a secondary position control system configured to adjust a depth of the first sub-array.
Abstract:
A source element for generating seismic waves includes a housing; a partitioning element placed inside the housing and configured to split the housing in a closed chamber and an opened chamber; and a valve in fluid communication with the closed chamber and configured to supply high-pressure air to the closed chamber to make the partitioning element oscillates. An oscillation of the partitioning element generates low-frequency seismic waves.
Abstract:
Method and controller 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 first attribute characterizing the source array; and selecting the best distribution from the plural distributions based on a value of the first attribute.