Method of conditioning seismic data for first-break picking using nonlinear beamforming

1. A method, comprising:

obtaining a pre-stack seismic dataset, wherein the pre-stack seismic dataset comprises a plurality of pre-stack traces;

generating, using a computer processor, a pre-processed seismic dataset and an initial refraction velocity model, based, at least in part, on the pre-stack seismic dataset;

generating, using the computer processor, a first-break energy-enhanced seismic dataset using nonlinear beamforming based, at least in part, on the pre-processed seismic dataset and the initial refraction velocity model;

estimating, using the computer processor, a refined refraction velocity model based, at least in part, on the first-break energy-enhanced seismic dataset;

generating, using the computer processor, a post-processed seismic dataset based, at least in part, on the refined refraction velocity model and the first-break energy-enhanced seismic dataset;

determining, using the computer processor, a first-break time for each pre-stack trace based, at least in part, on the refined refraction velocity model and the post-processed seismic dataset;

generating, using the computer processor, a seismic image based, at least in part, on the first-break time for each pre-stack trace; and

determining a location of a hydrocarbon reservoir based, at least in part, on the seismic image.

2. The method of claim 1 , wherein pre-processing comprises noise attenuation, frequency filtering or amplitude balancing.

3. The method of claim 1 , wherein nonlinear beamforming comprises:

determining an initial refraction velocity model based on the pre-stack seismic dataset;

forming a moveout-correct seismic dataset based on the pre-stack seismic dataset and the initial refraction velocity model using moveout correction;

determining a beamformed seismic dataset based on the moveout-correct seismic dataset by performing beamforming over at least one spatial direction; and

determining a first-break energy-enhanced seismic dataset from the beamformed seismic dataset by reversing the moveout correction.

4. The method of claim 1 , wherein estimating the refined refraction velocity model comprises moveout correction, cross-correlation, or interpolation.

5. The method of claim 1 , wherein post-processing comprises linear moveout correction, noise attenuation, frequency filtering, or amplitude balancing.

6. The method of claim 1 , wherein determining the first-break time for each pre-stack trace comprises performing automatic picking on linear moveout corrected data using the refined refraction velocity model.

7. The method of claim 1 , further comprising:

planning a wellbore path to intersect the hydrocarbon reservoir; and

drilling a wellbore guided by the wellbore path.

8. A non-transitory computer readable medium storing a set of instructions, executable by a computer processor, the set of instructions comprising functionality for:

receiving a pre-stack seismic dataset, wherein the pre-stack seismic dataset comprises a plurality of pre-stack traces;

generating a pre-processed seismic dataset and an initial refraction velocity model based, at least in part, on the pre-stack seismic dataset;

generating a first-break energy-enhanced seismic dataset using nonlinear beamforming based, at least in part, on the pre-processed seismic dataset and the initial refraction velocity model;

estimating a refined refraction velocity model based, at least in part, on the first-break energy-enhanced seismic dataset;

generating a post-processed seismic dataset based, at least in part, on the refined refraction velocity model and the first-break energy-enhanced seismic dataset;

determining a first-break time for each pre-stack trace based, at least in part, on the refined refraction velocity model and the post-processed seismic dataset;

generating a seismic image based, at least in part, on the first-break time for each pre-stack trace; and

determining a location of a hydrocarbon reservoir based, at least in part, on the seismic image.

9. The non-transitory computer readable medium of claim 8 , wherein pre-processing comprises noise attenuation, frequency filtering or amplitude balancing.

10. The non-transitory computer readable medium of claim 8 , wherein nonlinear beamforming comprises:

determining an initial refraction velocity model based on the pre-stack seismic dataset;

forming a moveout-correct seismic dataset based on the pre-stack seismic dataset and the initial refraction velocity model using moveout correction;

determining a beamformed seismic dataset based on the moveout-correct seismic dataset by performing beamforming over at least one spatial direction; and

determining a first-break energy-enhanced seismic dataset from the beamformed seismic dataset by reversing the moveout correction.

11. The non-transitory computer readable medium of claim 8 , wherein estimating the refined refraction velocity model comprises moveout correction, cross-correlation, or interpolation.

12. The non-transitory computer readable medium of claim 8 , wherein post-processing comprises linear moveout correction, noise attenuation, frequency filtering, or amplitude balancing.

13. The non-transitory computer readable medium of claim 8 , wherein determining the first-break time for each pre-stack trace comprises performing automatic picking on linear moveout corrected data using the refined refraction velocity model.

14. The non-transitory computer readable medium of claim 8 , the set of instructions further comprising planning a wellbore path to intersect the hydrocarbon reservoir.

15. A system, comprising:

a seismic acquisition system configured to acquire a pre-stack seismic dataset, wherein the pre-stack seismic dataset comprises a plurality of pre-stack traces; and

a seismic processor, configured to:

generate a pre-processed seismic dataset and an initial refraction velocity model based, at least in part, on the pre-stack seismic dataset;

generate a first-break energy-enhanced seismic dataset using nonlinear beamforming based, at least in part, on the pre-processed seismic dataset and the initial refraction velocity model;

estimate a refined refraction velocity model based, at least in part, on the first-break energy-enhanced seismic dataset;

generate a post-processed seismic dataset based, at least in part, on the refined refraction velocity model and the first-break energy-enhanced seismic dataset;

determine a first-break time for each pre-stack trace based, at least in part, on the refined refraction velocity model and the post-processed seismic dataset;

generate a seismic image based, at least in part, on the first-break time for each pre-stack trace; and

determine a location of a hydrocarbon reservoir based, at least in part, on the seismic image.

16. The system of claim 15 , wherein nonlinear beamforming comprises:

determining an initial refraction velocity model based on the pre-stack seismic dataset;

forming a moveout-correct seismic dataset based on the pre-stack seismic dataset and the initial refraction velocity model using moveout correction;

determining a beamformed seismic dataset based on the moveout-correct seismic dataset by performing beamforming over at least one spatial direction; and

determining a first-break energy-enhanced seismic dataset from the beamformed seismic dataset by reversing the moveout correction.

17. The system of claim 15 , wherein estimating the refined refraction velocity model comprises moveout correction, cross-correlation, or interpolation.

18. The system of claim 15 , wherein post-processing comprises linear moveout correction, noise attenuation, frequency filtering, or amplitude balancing.

19. The system of claim 15 , wherein determining the first-break time for each pre-stack trace comprises performing automatic picking on linear moveout corrected data using the refined refraction velocity model.

20. The system of claim 15 , further comprising:

a wellbore path planning system configured to plan a wellbore path to intersect the hydrocarbon reservoir; and

a wellbore drilling system configured to drill a wellbore guided by the wellbore path.