Multi-sensor system for airborne geophysical prospecting and method
AssigneeCgg Services SAS
InventorPhilip Miles
Life of this patent
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Abstract
A multi-sensor electromagnetic (EM) system and method for measuring gradients of EM signals. The multi-sensor EM system includes a frame; a transmitter device attached to the frame and configured to generate a primary EM field; a receiver device attached to the frame and configured to record a secondary EM field generated by the earth after being excited by the primary EM field; and a gradient sensor device attached to the frame and configured to record a gradient of the secondary EM field.
Claims19
A multi-sensor electromagnetic (EM) system for measuring earth EM response to an EM excitation while the multi-sensor EM system is flown over a surveyed area, the multi-sensor EM system comprising:
- a transmitter device configured to generate the EM excitation;
- a receiver device configured to detect and record an EM field generated by the earth in response to the EM excitation;
- a gradient sensor device configured to record a gradient of the EM field,
- wherein a transmitter coil of the transmitter device and at least one receiver coil of the receiver device are arranged substantially in a plane, and the gradient sensor device includes two coils placed out of the plane.
A multi-sensor electromagnetic (EM) system for measuring earth EM response to an EM excitation while the multi-sensor EM system is flown over a surveyed area, the multi-sensor EM system comprising:
- a transmitter device configured to generate the EM excitation;
- a receiver device configured to detect and record an EM field generated by the earth in response to the EM excitation;
- a gradient sensor device configured to record a gradient of the EM field,
- wherein the transmitter device, the receiver device and the gradient sensor device are configured to generate the EM excitation, detect the EM field and the gradient of the EM field on three non-coplanar directions,
- wherein, for at least one of the three directions, coils of the transmitter device and of the receiver device are coplanar and two coils of the gradient sensor device are placed symmetrically on either side and parallel with a plane of the coils of the transmitter device and of the receiver device.
A method of geophysical exploration using a multi-sensor electromagnetic (EM) system for measuring earth EM response to an EM excitation, the method comprising:
- flying a multi-sensor EM system over a surveyed area;
- controlling a transmitter device of the multi-sensor EM system to generate an EM excitation;
- recording an EM field generated by the earth in response to the EM excitation, using with a receiver device of the multi-sensor EM system;
- and
- recording a gradient of the EM field with a gradient sensor device of the multi-sensor EM system,
- wherein the transmitter device, the receiver device and the gradient sensor device are configured to generate the EM excitation, to detect the EM field and the gradient of the EM field, respectively, on three directions perpendicular to one another,
- wherein, for at least one of the three directions, coils of the transmitter device and of the receiver device are coplanar and two coils of the gradient sensor device are placed symmetrically on either side and parallel with a plane of the coils of the transmitter device and of the receiver device.
Dependencies are inferred from the claim text.