3D SEISMIC ACQUISITION

• US 20170090053A1
• Filed: 09/26/2016
• Published: 03/30/2017
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: Shearwater Geoservices Software Incorporated
• Original Assignee: Conocophillips Company (ConocoPhillips)
• Inventors: MOSHER, Charles Clinton, EICK, Peter M., BREWER, Joel D.
• Granted Patent: US 10,267,939 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01V 1/302 in 3D data cubes
• CPC Class Codes: G01V 1/345 Visualisation of seismic data or attributes, e.g. in 3D cubes
• CPC Class Codes: G01V 1/36 Effecting static or dynamic corrections on records, e.g. correcting spread; Correlating seismic signals; Eliminating effects of unwanted energy
• CPC Class Codes: G01V 1/3808 Seismic data acquisition, e.g. survey design
• CPC Class Codes: G01V 2210/45 F-x or F-xy domain
• CPC Class Codes: G01V 2210/51 Migration
• CPC Class Codes: G01V 2210/57 Trace interpolation or extrapolation, e.g. for virtual receiver; Anti-aliasing for missing receivers
• CPC Class Codes: G01V 2210/74 Visualisation of seismic data

Abstract

Disclosed are methods of marine 3D seismic data acquisition that do not require compensation for winds and currents.

Claims

1. ) A method of imaging a marine 3D survey area, comprising:

a) obtaining or developing a geology model of a marine survey area;

b) determining a bin size and orientation based on a smallest feature to be mapped and a shape of said marine geology model;

c) determining a stability of a compressed seismic imaging source and receiver station and sampling design (“

CSI design”

), and if unstable modify said bin size or orientation and re-determine said stability iteratively to produce a stable CSI design;

d) establishing a set of sampling rules or criteria for coverage of said marine survey area to assure that appropriate data is recorded so said stable CSI design can be properly reconstructed;

e) acquiring 3D seismic data traces over said marine survey area using said stable CSI design until said rules or criteria are met, wherein wind and current are not compensated for but allowed to direct vessel travel;

f) reconstructing a wavefield and regularizing the traces using the appropriate reconstruction techniques to produce seismic data; and

g) processing the seismic data and imaging the survey area.

4. ) The method of claim 3, including the further step of processing the seismic data using conventional techniques and imaging said survey area. 5) The method of claim 1, wherein said CSI design is determined by a method comprising:

i) constructing an optimization model, via a computing processor, given by minu∥

Su∥

₁s.t.∥

Ru−

b∥

₂≦

σ

wherein S is a discrete transform matrix, b is seismic data on an observed grid, u is seismic data on a reconstruction grid, and matrix R is a sampling operator;

b) defining mutual coherence as;

6. ) The method of claim 4, wherein the sample grid is determined via a randomized greedy algorithm method.

7. ) The method of claim 4, wherein the sample grid is determined via a randomized greedy algorithm method and the randomized greedy algorithm method finds local minimum.

8. ) The method of claim 4, wherein the sample grid is determined via a stochastic global optimization method.

9. ) The method of claim 4, wherein r*=arg minr μ

(r) is non-convex.

10. ) The method of claim 4, wherein the mutual coherence proxy is derived using a fast Fourier transform.

11. ) The method of claim 1, wherein data is analyzed in real time or near real time to confirm sufficient coverage and that said rules or criteria have been met.

12. ) The method of claim 1, wherein an actual pathway travelled is mapped and used to thereby confirm sufficient coverage and that said rules or criteria have been met.

13. ) A non-transitory machine-readable storage medium, which when executed by at least one processor of a computer, performs the steps of the method of any of claims 12.

14. ) A non-transitory machine-readable storage medium containing or having saved thereto the seismic data or imaging of claims 1.

2. ) A method of acquiring marine 3D seismic data comprising:

a) acquiring 3D seismic data of an marine area to be surveyed without compensating for wind and current, but instead allowing wind and current to direct >

25% of said travel;

b) collecting data positioning data while acquiring 3D data; and

c) continuing said acquiring step a) until said collected positioning data indicates that sufficient coverage of said marine area has been obtained such that a seismic map of said marine area can be constructed from said 3D seismic data.

3. ) The method of claim 2, wherein sufficient coverage is determined by the following steps:

a) obtaining or developing a geology model of a marine survey area;

b) determining a bin size and orientation based on a smallest feature to be mapped and a shape of said geology model;

c) determining a stability of a CSI design and if unstable modify said bin size or orientation to produce a stable CSI design;

d) establishing a set of sampling rules or criteria for coverage of said survey area to assure that appropriate data is recorded so the stable CSI design can be properly reconstructed; and

e) acquiring 3D seismic data traces over said marine survey area until said rules or criteria are met, wherein wind and current are not compensated for but allowed to direct vessel travel; and

f) reconstructing a wavefield and regularizing said traces using appropriate reconstruction techniques to produce seismic data.