Random Sampling for Geophysical Acquisitions

• US 20110158041A1
• Filed: 12/28/2010
• Published: 06/30/2011
• Est. Priority Date: 12/30/2009
• Status: Active Grant

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: Otnes, Einar, Quigley, John, Moldoveanu, Nicolae
• Granted Patent: US 8,711,654 B2
• Time in Patent Office: Days
• US Class Current: 367/14
• 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 1/3808 Seismic data acquisition, e.g. survey design
• CPC Class Codes: G01V 99/00 Subject matter not provided for in other groups of this subclass

Abstract

The presently disclosed technique includes a method for geophysical survey having at least one source and one receiver, wherein the survey has two sets of survey locations within the survey area, one set of survey locations for the source(s) and the other set of survey locations for the receiver(s), wherein the survey locations in one set are randomized.

Claims

1. A method for geophysical survey having at least one source and one receiver, wherein the survey has two sets of survey locations within the survey area, one set of survey locations for the source(s) and the other set of survey locations for the receiver(s), the method comprising:

randomizing the survey locations in a first set of survey locations.

2. The method of claim 1, further comprising:

randomizing survey locations in a second set of survey locations.

3. The method of claim 1, further comprising:

setting survey locations in a second set of survey locations in non-random pattern.

4. The method of claim 1,

wherein the first set of survey locations are for receiver locations.

5. The method of claim 1,

wherein the first set of survey locations are for source locations.

6. The method of claim 1, wherein the geophysical survey is selected from one or more from the group of marine survey;

land survey, transitional zone survey;

seismic survey;

Controlled Source Electromagnetic (CSEM) survey, borehole seismic survey, Vertical Seismic Profile (VSP) survey.

7. The method of claim 1, wherein the randomized survey location is determined using a method from the group of Hamersley and Halton point method, jittering method and Poisson sampling method.

8. The method of claim 1,

wherein the geophysical survey system includes a cabled system where the distance between two adjacent survey locations is limited by the cable distance d1;

and

wherein the distance between two adjacent randomized survey locations is less than d1.

9. The method of claim 1,

wherein the geophysical survey system includes a node system;

and

wherein average number of survey locations per unit survey area is a predetermined survey density.

10. The method of claim 1,

wherein the randomized survey locations is determined to be positions on overlapping circles, wherein the centers of the circles are randomized locations within the survey area.

11. The method of claim 1, further comprising:

acquiring from the receivers data of the subsurface earth structure of the survey area.

12. The method of claim 11, further comprising:

processing data acquired to determine the subsurface earth structure of the survey area.

13. The geophysical surveying dataset acquired indicative of the subsurface earth structure using the method as in claim 1.

14. The geophysical surveying dataset acquired indicative of the subsurface earth structure using the method as in claim 11.

15. A geophysical survey system, comprising:

a plurality of sources;

a plurality of receivers;

at least one controller controlling the sources and receivers;

that, in operation, controls two set of survey locations, one set for sources and one set for receivers, wherein the survey locations in a first set is randomized locations within a survey area.

16. The geophysical survey system as in claim 15,

wherein the survey locations in a second set are in non-random pattern.

17. The geophysical survey system as in claim 15,

wherein the survey locations in a second set are randomized.