Systems and methods for multiple bandwidth electromagnetic geophysical exploration

Patent metadata

Field	Value
Publication number	US-2019187319-A1
Application number	US-201916273256-A
Country	US
Kind code	A1
Filing date	Feb 12, 2019
Priority date	Apr 23, 2014
Publication date	Jun 20, 2019
Grant date	—

Abstract

An electromagnetic geophysical exploration system includes a first transmitter-receiver pair that includes a first transmitter configured to transmit a first waveform in a first spectrum and a first receiver configured to sense signals in the first spectrum; and a second transmitter-receiver pair that includes a second transmitter configured to transmit a second waveform in a second spectrum, the second spectrum having a frequency higher than a frequency of the first spectrum, and a second receiver configured to sense signals in the second spectrum; and a control portion. The control portion controls the first transmitter to transmit the first waveform with a first given strength or shape in the first spectrum, and controls the second transmitter to transmit the second waveform with a second given strength or shape in the second spectrum, after a specified time delay.

First claim

What is claimed is:

1 . An electromagnetic geophysical exploration system comprising:
a first transmitter-receiver pair that includes a first transmitter configured to transmit a first waveform in a first spectrum and a first receiver configured to sense signals in the first spectrum; a second transmitter-receiver pair that includes a second transmitter configured to transmit a second waveform in a second spectrum, the second spectrum having a frequency higher than a frequency of the first spectrum, and a second receiver configured to sense signals in the second spectrum, wherein the second receiver is configured to be minimum-coupled to the second transmitter, a transmitter coil of the second transmitter is disposed between an inner receiver coil and an outer receiver coil of the second receiver, and the inner receiver coil and the outer receiver coil of the second receiver surround the transmitter coil of the second transmitter; and a control portion configured to:
control the first transmitter to transmit the first waveform with a first given strength or shape in the first spectrum, and
control the second transmitter to transmit the second waveform with a second given strength or shape in the second spectrum, after a specified time delay,
wherein the electromagnetic geophysical exploration system is configured to be airborne.

2 . The system of claim 1 , wherein the control portion is further configured to store the received signals.

3 . The system of claim 2 , wherein the control portion is further configured to process the stored signals to analyze a subsurface formation.

4 . The system of claim 1 , wherein the first waveform includes a different waveform shape from the second waveform.

5 . The system of claim 1 , wherein the first spectrum and the second spectrum include an overlapping bandwidth portion.

6 . The system of claim 1 , wherein the second transmitter is configured to minimize a turn-off time for the second waveform.

7 . The system of claim 1 , wherein the first transmitter is a low-frequency transmitter and the first receiver is a low-frequency receiver.

8 . The system of claim 1 , wherein the second transmitter is a high-frequency transmitter and the second receiver is a high-frequency receiver.

9 . The system of claim 1 , wherein the signals sensed by the first receiver in the first spectrum are sensed during transmission of the first waveform by the first transmitter.

10 . A method of electromagnetic geophysical exploration, comprising:
controlling with a control portion a first transmitter to transmit a first waveform with a first given strength or shape in a first spectrum; controlling with the control portion a second transmitter to transmit a second waveform with a second given strength or shape in a second spectrum, after a specified time delay, the second spectrum having a frequency higher than a frequency of the first spectrum; receiving signals sensed by a first receiver in the first spectrum; and receiving signals sensed by a second receiver in the second spectrum, the second receiver configured to be minimum-coupled to the second transmitter, wherein a transmitter coil of the second transmitter is disposed between an inner receiver coil and an outer receiver coil of the second receiver, and the inner receiver coil and the outer receiver coil of the second receiver surround the transmitter coil of the second transmitter, and wherein the first transmitter, the second transmitter, the first receiver and the second receiver are airborne.

11 . The method of claim 10 , further comprising storing the received signals.

12 . The method of claim 11 , further comprising processing the stored signals to analyze a subsurface formation.

13 . The method of claim 10 , wherein the first waveform includes a different waveform shape from the second waveform.

14 . The method of claim 10 , wherein the first spectrum and the second spectrum include an overlapping bandwidth portion.

15 . The method of claim 10 , wherein the second transmitter is configured to minimize a turn-off time for the second waveform.

Assignees

• Cgg Services Sas

Inventors

• Smiarowski Adam
• Berringer Jason
• Miles Philip

Classifications

• G01V3/16 Primary

  specially adapted for use from aircraft (G01V3/165 - G01V3/175 take precedence) · CPC title

• G01V3/17

  operating with electromagnetic waves {(operating with millimetre waves G01V8/005)} · CPC title