Analytically generated shooting schedules for use with patterned and simultaneous source acquisition

Patent metadata

Field	Value
Publication number	US-10024989-B2
Application number	US-201514603117-A
Country	US
Kind code	B2
Filing date	Jan 22, 2015
Priority date	Dec 9, 2010
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

According to an embodiment, there is provided a system and method of collecting seismic data using a predetermined pattern of source activations that is intended to control the properties of the resulting seismic signal. One embodiment utilizes a seismic source array (or, more generally, any collection of controllable sources) to create a series of spaced apart in time source activations, with the spacing and number of such activations being used to shape the resulting signal. In one method of building sweeps, the guns are fired at an increasing rate (decreasing time separation) as time goes by. Other patterns may be generated by decreasing the firing rate as time goes by, or some combination of the foregoing. In an embodiment, the rate of the increase or decrease in the firing rate will change from pattern to pattern.

First claim

What is claimed is:

1. A method of seismic exploration for hydrocarbons within a region of the subsurface of the earth, wherein there is provided a set of seismic sources, said set of seismic sources comprising a plurality of subarrays, each of said subarrays having one or more seismic sources associated therewith, the method comprising:
(a) selecting an analytic firing pattern;
(b) assigning each of said plurality of subarrays a different firing time within said analytic firing pattern, thereby forming a firing schedule having a corresponding plurality of firing intervals associated therewith, wherein said plurality of firing intervals monotonically vary in length based on a number of seismic sources in the set of seismic sources and a size of each of the seismic sources in the set of seismic sources;
(c) positioning said set of seismic sources at a first location proximate to the region of the subsurface of the earth;
(d) activating each of said subarrays according to said firing schedule;
(e) recording seismic data as each of said plurality of subarrays is activated;
(f) performing steps (d) and (e) at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a Popcorn seismic survey;
(g) reconstructing said recorded seismic data from said Popcorn seismic survey, thereby obtaining a plurality of seismic traces; and,
(h) using said plurality of seismic traces to image at least a portion of the subsurface of the earth.

2. The method of claim 1 , wherein at least one of said subarrays comprises a single one of said set of seismic sources.

3. The method of claim 1 , wherein at least steps (c) through (g) are performed a plurality of times at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a seismic survey proximate to the region of the subsurface of the earth.

4. The method of claim 1 , wherein at least steps (a) through (g) are performed a plurality of times at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a seismic survey proximate to the region of the subsurface of the earth.

5. The method of claim 1 , wherein said firing time duration is between one second and ten seconds.

6. The method of claim 1 , wherein step (g) is performed by solving:
d=Am,
where m is said plurality of seismic traces obtained by reconstruction, d is said recorded seismic data, and A is a set of Popcorn signatures corresponding to said firing schedule.

7. The method of claim 1 , wherein step (g) is performed by solving:
d=ACm,
where m is said plurality of seismic traces obtained by reconstruction, d is said recorded seismic data, A is a set of Popcorn signatures corresponding to said firing schedule, and C is a matrix of coherency conditions.

8. The method of claim 1 wherein said plurality of firing intervals are either monotonically increasing in length or monotonically decreasing in length.

9. The method of claim 1 wherein step (a) comprises the steps of:
(a1) generating a plurality of candidate analytic firing patterns;
(a2) determining a maximum amplitude of each of said plurality of candidate analytic firing patterns;
(a3) determining which one of said candidate analytic firing patterns has a smallest maximum amplitude;
(a4) selecting as said analytic firing pattern said determined one of said candidate analytic firing patterns which has said smallest maximum amplitude.

10. A method of seismic exploration for hydrocarbons within a region of the subsurface of the earth, wherein there is provided a set of seismic sources, said set of seismic sources comprising a plurality of subarrays, each of said subarrays having one or more seismic sources associated therewith, the method comprising:
(a) determining an analytic firing pattern having a plurality of firing intervals associated therewith;
(b) assigning each of said plurality of subarrays a different firing time within said analytic firing pattern, thereby forming a firing schedule, wherein said plurality of firing intervals monotonically vary in length based on a number of seismic sources in the set of seismic sources and a size of each of the seismic sources in the set of seismic sources;
(c) positioning said set of seismic sources at a first location proximate to the region of the subsurface of the earth;
(d) activating each of said subarrays according to said firing schedule;
(e) recording seismic data as each of said plurality of subarrays is activated;
(f) performing steps (d) and (e) at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a Popcorn seismic survey;
(g) reconstructing said recorded seismic data from said Popcorn seismic survey, thereby obtaining a plurality of seismic traces; and,
(h) using said plurality of seismic traces to image at least a portion of the subsurface of the earth.

11. The method according to claim 10 where said firing intervals are either monotonically increasing or monotonically decreasing.

12. The method according to claim 10 where said firing intervals are piecewise monotonic.

13. The method of claim 10 , wherein at least one of said subarrays comprises a single one of said set of seismic sources.

14. The method of claim 10 , wherein at least steps (a) through (f) are performed a plurality of times at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a seismic survey proximate to the region of the subsurface of the earth.

15. The method of claim 10 , wherein said firing pattern has a firing time duration associated therewith, and wherein said firing time duration is between one second and ten seconds.

16. The method of claim 10 , wherein step (g) is performed by solving:
d=Am,
where m is said plurality of seismic traces obtained by reconstruction, d is said recorded seismic data, and A is a set of Popcorn signatures corresponding to said firing schedule.

17. The method of claim 10 , wherein step (g) is performed by solving:
d=ACm
where m is said plurality of seismic traces obtained by reconstruction, d is said recorded seismic data, A is a set of Popcorn signatures corresponding to said firing schedule, and C is a matrix of coherency conditions.

18. A method of seismic exploration for hydrocarbons within a region of the subsurface of the earth, wherein there is provided a set of seismic sources, said set of seismic sources comprising a plurality of subarrays, each of said subarrays having one or more seismic sources associated therewith, the method comprising:
(a) selecting a firing pattern, said firing pattern specifying an activation order for each of said subarrays and a time separation between each successive subarray activation, wherein said time separations between each successive subarray activation are either monotonically increasing in length or monotonically decreasing in length based on a number of seismic sources in the set of seismic sources and a size of each of the seismic sources in the set of seismic sources;
(b) positioning said set of seismic sources at a first location proximate to the region of the subsurface of the earth;
(c) activating each of said subarrays according to said firing pattern;
(d) recording seismic data as each of said plurality of subarrays is activated;
(e) performing steps (c) and (d) at a plurality of different locations proximate to the region of the subsurface of the earth, thereby acquiring a Popcorn seismi

Assignees

• Abma Raymond Lee
• Ross Allan
• Bp Corp North America Inc

Inventors

• Abma Raymond Lee
• Ross Allan

Classifications

• G01V1/006

  generating single signals by using more than one generator, e.g. beam steering or focusing arrays (G01V1/13, G01V1/3861 take precedence) · CPC title

• G01V1/003 Primary

  Seismic data acquisition in general, e.g. survey design (G01V1/3808, G01V1/42 take precedence) · CPC title