METHOD AND APPARATUS FOR SEISMIC-MAGNETIC PROSPECTING

• US 3,621,380 A
• Filed: 01/02/1969
• Issued: 11/16/1971
• Est. Priority Date: 01/02/1969
• Status: Expired due to Term

• Current Assignee: Halliburton Company
• Original Assignee: Carl A. Barlow Jr
• Inventors: Carl, A. Barlow Jr.
• Primary Examiner(s): Gerard R. Strecker
• Application Number:
  US04/788,409
• Time in Patent Office: 1,048 Days
• Field of Search: 324/1,8,6 340/15.5TA
• US Class Current: 324/345
• CPC Class Codes: G01V 1/003 Seismic data acquisition in general, e.g. survey design G01V1/3808, G01V1/42 take precedence
• CPC Class Codes: G01V 11/00 Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
• CPC Class Codes: G01V 3/265 Operating with fields produced by spontaneous potentials, e.g. electrochemicals or produced by telluric currents

Abstract

Seismic disturbances are impinged upon underground magnetic bodies to cause time varying changes in the magnetic field of the bodies. These time varying changes are sensed to provide indications of the magnetization and depth of the bodies. Seismic reflections from the seismic disturbances are also sensed and recorded, with the time varying changes processed in conjunction with the seismic reflections to eliminate noise and otherwise enhance the magnetic data.

Claims

1. The method of seismic exploration comprising:

a. generating a seismic disturbance, b. generating first electrical signals representative of time varying changes in the magnetic field of subsurface structure caused by impingement of said seismic disturbance upon said structure, c. receiving reflections of said seismic disturbance, d. generating second electrical signals representative of said reflections, and e. processing said first signals in conjunction with said second signals to enhance said first signals and produce an output signal representative of the magnetization and depth of said subsurface structure.

2. The method of claim 1 wherein said processing comprises:

cross-correlating said first and second signals.

3. The method of claim 1 and further comprising:

deconvolving said first signals to generate output signals representative of the magnetization and depth of said subsurface structure.

4. The method of claim 1 and further comprising:

generating representations of the time interval between the generation of said seismic disturbance and the impingement of said seismic disturbance on said subsurface structure.

5. Apparatus for detection of a magnetic structure comprising:

a. a source for directing compressional signals toward said magnetic structure, b. means for detecting time varying changes in the magnetic field of said magnetic structure caused by the impingement of said compressional signals, c. means for generating indications of the time intervals between generation of said compressional waves and the impingement thereof on said magnetic structure, and d. means responsive to said detected time varying changes and said indications of time intervals for generating representations of the magnetization and position of said magnetic structure.

6. The apparatus of claim 5 and further comprising:

means for cross-correlating signals representative of said changes in the magnetic field.

7. The apparatus of claim 5 and further comprising:

means for deconvolving said time varying changes in the magnetic field for generating said representations of the magnetization of said magnetic structure.

8. The apparatus of claim 5 wherein said means for detecting comprises at least one magnetometer.

9. The apparatus of claim 5 and further comprising geophone means for generating electrical signals in response to said compressional signals.