Method for acquiring and processing of data from two or more simultaneously fired sources

• US 6,545,944 B2
• Filed: 05/30/2001
• Issued: 04/08/2003
• Est. Priority Date: 05/30/2001
• Status: Expired due to Term

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: de Kok, Robbert Jasper
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/870,289
• Publication Number:
  US 20020181328A1
• Time in Patent Office: 678 Days
• Field of Search: 114/242, 367/56, 702/17
• US Class Current: 367/56
• CPC Class Codes: G01V 1/005 with exploration systems emitting special signals, e.g. frequency swept signals, pulse sequences or slip sweep arrangements

Abstract

A method of seismic surveying and seismic data processing using a plurality of simultaneously recorded seismic-energy sources. An activation sequence for each of said plurality of seismic energy sources may be determined such that energy from seismic sources may be recorded simultaneously and seismic energy responsive to individual seismic sources separated into separate source records. The seismic sources are activated using an activation sequence, the recorded seismic energy in the shot recordings may be separated into source recordings responsive to individual seismic sources. The source records may be derived from the shot records using a combination of shot record summations, inversions and filtering.

Claims

1. A method of seismic surveying using simultaneously recorded seismic energy sources, the method comprising:

(a) selecting a plurality of seismic energy sources to be used for surveying, each of said seismic energy sources containing a plurality of source elements;

(b) positioning said plurality of seismic energy sources and associated seismic energy receivers at locations within a seismic survey area;

(c) activating said plurality of source elements of each of said plurality of sources according to an activation sequence wherein said activation sequence is selected to enable separation of simultaneously recorded energy sources into separate source records; and

(d) recording seismic energy generated by the plurality of activated seismic energy sources to form shot recordings.

2. The method of claim 1 further comprising time separating the plurality of activation times of said source elements using at least one predetermined time delay.

3. The method of claim 2 wherein the at least one predetermined time delay is substantially equal to a ghost delay time divided by an integer.

4. The method of claim 2 wherein the at least one predetermined time delay is less than the reciprocal of the maximum frequency of interest.

5. The method of claim 1 wherein said plurality of source elements in a seismic source are vertically separated.

6. The method of claim 1 wherein said source elements are positioned in staggered arrays.

7. The method of claim 1 wherein said source elements are activated to produce directionally enhanced seismic energy.

8. The method of claim 1 further comprising processing said returned seismic energy so that said returned seismic energy may be separated from shot records into separate source records.

9. The method of claim 8 wherein the returned seismic energy from separate source positions is separated using filtering.

10. The method of claim 9 wherein the returned seismic energy from separate source positions is separated using at least one filtering method chosen from the group consisting of i) FK filtering, ii) multi-channel filtering, and iii) radon transform filtering.

11. The method of claim 8 wherein the returned seismic energy is separated into separate source records by summation of shot recordings of returned seismic energy.

12. The method of claim 11 wherein the returned seismic energy from separate source positions is separated by inverting selected shot records to be included in summation of a group of shot recordings.

13. The method of claim 8 wherein the returned seismic energy from separate source positions is separated using filtering of shot records in combination with summation of shot records.

14. The method of claim 8 wherein the returned seismic energy from separate source positions is interpolated between source positions having the same delay sequence and amplitudes.

15. The method of claim 14 wherein the returned seismic energy from separate source positions is interpolated in at lot one data processing domain chosen from the group consisting of i) shot records, ii) CMP gathers, iii) common offset gathers, and iv) common receiver gathers.

16. A method for acquiring and processing seismic data in a seismic survey, the method comprising:

(a) selecting a plurality of seismic energy sources to be used for surveying;

(b) positioning a plurality of seismic energy sources and associated seismic energy receivers at locations within a seismic survey area;

(c) activating said plurality of sources according to an activation sequence wherein at least one predetermined time delay is substantially equal to an integer multiple of a ghost delay time; and

wherein said activation sequence is selected to enable separation of simultaneously recorded energy sources into separate source records; and

(d) recording returned seismic energy generated by the plurality of activated seismic energy sources to form shot recordings.

17. The method of claim 16 wherein said at least one predetermined time delay is less than the inverse of the maximum frequency of interest.

18. The method of claim 16 further comprising processing said returned seismic energy so that said returned seismic energy may be separated from shot records into separate source records.

19. The method of claim 18 wherein the returned seismic energy from separate source positions is separated to individual source records using filtering.

20. The method of claim 19 wherein the returned seismic energy from separate source positions is separated using at least one filtering method chosen from the group consisting of i) FK filtering, ii) multi-channel filtering, and iii) radon transform filtering.

21. The method of claim 18 wherein the returned seismic energy is separated into individual source records by summation of shot recordings of returned seismic energy.

22. The method of claim 21 wherein the returned seismic energy from separate source positions is separated by inverting selected shot records to be included in summation of a group of shot recordings.

23. The method of claim 18 wherein the returned seismic energy from separate source positions is separated using filtering of shot records in combination with summation of shot records.

24. The method of claim 18 wherein the returned seismic energy from separate source positions is interpolated between source positions having the same delay sequence and amplitudes.

25. The method of claim 24 wherein the returned seismic energy from separate source positions is interpolated in at least one data processing domain chosen from the group consisting of i) shot records, ii) CMP gather, iii) common offset gathers, and iv) common receiver gathers.

26. A method for processing seismic data in a seismic survey, the method comprising:

(a) selecting a plurality of seismic shot records from a seismic survey wherein a plurality of impulsive seismic sources activated at separate source positions have been contemporaneously recorded according to an activation sequence containing a delay time substantially equal to an integer multiple of a ghost delay time; and

wherein said activation sequence is selected to enable separation of said contemporaneously recorded energy sources into separate source records, and

(b) separating said seismic shot records into separate source records.

27. The method of claim 26 further comprising separating the seismic shot records into separate source records comprises at least one processing step chosen from the group consisting of i) summation, ii) interpolation, iii) inversion, iv) FK filtering, v) multi-channel filtering, vi) radon transform filtering.

28. The method of claim 27 wherein seismic energy from separate source positions is interpolated between contemporaneously recorded source positions having the same delay sequence and amplitudes.

29. The method of claim 28 wherein the returned seismic energy from separate source positions is interpolated in at least one data processing domain chosen from the group consisting of i) shot records, ii) CMP gathers, iii) common offset gathers, and iv) common receiver gathers.