High fidelity vibratory source seismic method using a plurality of vibrator sources

• US 5,715,213 A
• Filed: 11/13/1995
• Issued: 02/03/1998
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Allen, Kenneth Paul
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/555,654
• Time in Patent Office: 813 Days
• Field of Search: 364/421, 181/111, 367/46, 367/48, 367/49, 367/189
• US Class Current: 367/48
• CPC Class Codes: G01V 1/04 Details
• CPC Class Codes: G01V 1/28 Processing seismic data, e.g. for interpretation or for event detection G01V1/48 takes precedence
• CPC Class Codes: G01V 2210/20 Trace signal pre-filtering to select, remove or transform specific events or signal components, i.e. trace-in/trace-out removing noise G01V2210/32

Abstract

A method for recording and pre-processing high fidelity vibratory seismic data includes the steps of measuring the motion of the vibrator which is related to the vibrator applied force times a transfer function of minimum phase, causal, linear system relating the actual vibrator output with the measured vibrator motion, separation of signals according to generating source, determining a ratio by dividing the vibratory seismic data by the measured motion of the vibrator to remove the unknown applied force leaving the earth reflectivity times a time derivative divided by a minimum phase function, minimum phase band pass filtering the resulting ratio and performing minimum phase deconvolution to remove the time derivative divided by the transfer function of minimum phase. The method may also include shot ensemble deconvolution, receiver ensemble deconvolution, statics correction, F-K filtering for noise, zero phase spiking deconvolution and model dephasing. A signal directly proportional to the actual signal that the vibrator is sending into the ground is used in pre-processing. The vibrator motion is measured to provide a signal that is used to process the data. The data is divided by the relative of the actual transmitted signal in frequency domain.

Claims

1. A method for recording high resolution vibroseis data comprising the steps of:

receiving electrical signals representing received seismic information generated by multiple vibrators;

receiving measured signals representing transmitted seismic waves from each of said multiple vibrators;

separating said electrical signals corresponding to each of said multiple vibrators;

performing an inversion function on said separated electrical signals with said corresponding measured signals to obtain inversion electrical signals; and

performing minimum phase deconvolution on said inversion electrical signals.

2. The method according to claim 1 also including the steps of:

generating a model trace with a spike of said inverted electrical signals;

shot deconvolving said inversion electrical signals;

performing statics correction on said deconvolved inversion electrical signals;

filtering said statics corrected electrical signals;

performing receiver deconvolution on said filtered electrical signals;

performing zero phase spiking deconvolution on said receiver deconvolved signals;

dephasing said zero phase deconvolved signals with said model trace.

3. The method according to claim 1 wherein said separating step includes the step of:

varying the generation sequence of each of said multiple vibrators.

4. The method according to claim 1, wherein said receiving measured signals step includes the steps of:

measuring the seismic signal actually transmitted into the earth'"'"'s surface; and

converting said measured seismic signals into a measured electrical signal.

5. The method according to claim wherein said separating step includes the step of:

varying the generation sequence of each of said multiple vibrators.

6. An apparatus for recording high resolution vibroseis data comprising:

means for receiving electrical signals representing received seismic information from multiple vibrators and measured signals representing transmitted seismic waves from each of said multiple vibrators;

separating means for separating said electrical signals according to Said measured signals;

means for performing an inversion function on said separated electrical signals with said corresponding measured signals to obtain inversion electrical signals; and

means for minimum phase deconvolving said inversion electrical signals.

7. The apparatus according to claim 6 also including:

correction means for performing statics correction on said deconvolved inversion electrical signals;

filtering means for said statics corrected electrical signals;

summing means for said filtered statics corrected electrical signals;

recording means for said summed electrical signals; and

display means for displaying said recorded summed signals.

8. The apparatus according to claim 6 wherein said separating means includes:

means for varying the generation sequence of each of said multiple vibrators.

9. The apparatus according to claim 6 wherein said means for receiving measured signals includes:

means for measuring the seismic signal actually transmitted into the earth'"'"'s surface; and

means for converting said measured seismic signals into a measured electrical signal.

10. The apparatus according to claim 9 wherein said means for separating includes:

means for varying the generation sequence of each of said multiple vibrators.

12. The method according to claim 10 also including the steps of:

performing shot ensemble deconvolution on said minimum phase band pass filtered ratio.

13. The method according to claim 10 also including the steps of:

performing receiver ensemble deconvolution on said minimum phase band pass filtered ratio.

14. The method according to claim 10 also including the steps of:

performing statics correction on said minimum phase band pass filtered ratio.

15. The method according to claim 10 also including the steps of:

performing F-K filtering for noise on said minimum phase band pass filtered ratio.

16. The method according to claim 10 also including the steps of:

performing zero phase spiking deconvolution on said minimum phase band pass filtered ratio.

17. The method according to claim 10 also including the steps of:

generating a model trace from said vibratory seismic data signals generated by a plurality of vibratory seismic sources; and

performing model dephasing using said model trace on said minimum phase band pass filtered ratio.

11. A method for recording and pre-processing high fidelity vibratory seismic data signals generated by a plurality of vibratory seismic sources comprising the steps of:

measuring the motion of each of the vibratory sources which is related to the vibrator applied force times a transfer function of minimum phase, causal, linear system;

relating actual vibrator output with said measured vibrator motion;

separating of the vibratory seismic data signals according to generating source;

determining a ratio by dividing the separated vibratory seismic data signals by said measured motion of each corresponding vibratory source to remove the unknown applied force leaving the earth reflectivity times a time derivative divided by a minimum phase function;

minimum phase band pass filtering said resulting ratio; and

performing minimum phase deconvolution on said minimum phase band pass filtered ratio to remove the time derivative divided by the transfer function of minimum phase function.