Method and system of subsurface horizon assignment

1. A method comprising:

obtaining, by a computer system, a seismic data volume;

identifying, by the computer system, a plurality of patches in the seismic data volume, and the identifying thereby creating a patch volume, the patch volume distinct from the seismic data volume; and then

displaying, on a display device, at least a portion of the seismic data volume, and simultaneously displaying on a display device the plurality of patches of the patch volume;

assigning a patch of the plurality of patches to a subsurface horizon of the seismic data volume by selecting from a display device a first patch of the patch volume and designating the first patch to be a portion of a first subsurface horizon; and

discarding a patch from the patch volume by selecting from a display device a second patch of the patch volume, identifying the second patch as not belonging to a subsurface horizon, and removing the second patch from the patch volume.

2. The method of claim 1 wherein identifying the plurality of patches further comprises:

applying the seismic data volume to a horizon tracking algorithm; and

creating the patch volume based on patches identified by the horizon tracking algorithm.

3. The method of claim 2 wherein creating the patch volume further comprises creating the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume upon which the seismic data volume is based.

4. The method of claim 2 wherein creating the patch volume further comprises creating the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume upon which the seismic data volume is based, and each memory location stores an indication of the presence or absence of a portion of a patch at the corresponding physical volume.

5. The method of claim 4 wherein the correspondence between the physical volumes considered together corresponds one-to-one with the volume spanned by the seismic data volume.

6. The method of claim 1 further comprising, prior to the identifying, setting a range of values that, when found within the seismic data volume, represent a subsurface horizon in the seismic data volume.

7. The method of claim 1 wherein assigning further comprises creating a horizons file comprising a plurality of indications of location of a horizon, and where the locations do not represent physical volumes of the hydrocarbon bearing formation upon which the seismic data volume is based.

8. A system comprising:

a processor;

a memory coupled to the processor;

a display device coupled to the processor; and

a user interface device coupled to the processor;

wherein the memory storing a program that, when executed by the processor, causes the processor to:

read a seismic data volume from a storage location;

identify a plurality of patches in the seismic data volume;

create a patch volume based on the plurality of patches, the patch volume distinct from the seismic data volume;

display on the display device at least a portion of the seismic data volume, and simultaneously display on the display device the plurality of patches of the patch volume; and

receive a first indication from the user interface of selection of a first patch of the patch volume, and identify a first patch based on location of a pointing feature displayed on a display device when the first indication is received;

receive a second indication from the user interface of selection of a first subsurface horizon of the seismic data volume, and identify the first subsurface horizon based on location of a pointing feature displayed on a display device when the second indication is received; and then

assign the first patch to be a portion of the first subsurface horizon.

9. The system of claim 8 wherein when the program identifies, the program causes the processor to:

perform a horizon tracking algorithm; and

create the patch volume based on patches identified by the horizon tracking algorithm.

10. The system of claim 9 wherein when the processor creates the patch volume, the program causes the processor to create the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume upon which the seismic data volume is based.

11. The system of claim 9 wherein when the processor creates the patch volume, the program causes the processor to create the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume upon which the seismic data volume is based, and the memory locations considered together correspond to a volume spanned by the seismic data volume.

12. The system of claim 9 wherein when the processor receives indications, the program causes the processor to:

receive an indication of selection of a first patch of the patch volume; and then

assign the first patch to be a portion of a first subsurface horizon.

13. The system of claim 12 wherein when the processor receives indications, the program causes the processor to:

receive an indication of selection of a second patch of the patch volume; and then

assign the second patch as not belonging to a subsurface horizon; and

remove the second patch from the patch volume.

14. The system of claim 9 wherein when responsive to the processor's receipt of indications, the program further causes the processor to create a horizons file comprising a plurality of indications of location of a horizon, and where the locations do not represent physical volumes of the hydrocarbon bearing formation upon which the seismic data volume is based.

15. A non-transitory computer-readable medium storing a program that, when executed by a processor, causes the processor to:

read a seismic data volume from a storage location;

identify a plurality of patches in the seismic data volume;

create a patch volume based on the plurality of patches, the patch volume distinct from the seismic data volume;

display on a display device at least a portion of the seismic data volume, and simultaneously display the plurality of patches of the patch volume on a display device;

receive an indication from a user interface of selection of a first patch of the patch volume;

assign the first patch to be a portion of a first subsurface horizon;

receive an indication from the user interface of selection of a second patch of the patch volume;

receive an indication from the user interface that the second patch does not belong to a subsurface horizon; and responsive to the indication that the second patch does not belong

remove the second patch from the patch volume.

16. The non-transitory computer-readable medium of claim 15 wherein when the program identifies, the program causes the processor to:

perform a horizon tracking algorithm; and

create the patch volume based on patches identified by the horizon tracking algorithm.

17. The non-transitory computer-readable medium of claim 16 wherein when the processor creates the patch volume, the program causes the processor to create the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume of a hydrocarbon formation upon which the seismic data volume is based.

18. The non-transitory computer-readable medium of claim 16 wherein when the processor creates the patch volume, the program causes the processor to create the patch volume organized as an array of memory locations, each memory location corresponding to a physical volume of the hydrocarbon formation upon which the seismic data volume is based, and the memory locations considered together correspond to a volume spanned by the seismic data volume.

19. The non-transitory computer-readable medium of claim 15 wherein when the processor assigns, the program further causes the processor to create a horizons file comprising a plurality of indications of location of a horizon, and where the locations do not represent physical volumes upon which the seismic data volume is based.

20. The method of claim 1 :

wherein selecting the first patch further comprises choosing the first patch using a pointing feature displayed on the display device; and

wherein designating the first patch to be a portion of the first subsurface horizon further comprises choosing the first subsurface horizon using a pointing feature displayed on the display device.

21. The non-transitory computer-readable medium of claim 15 :

wherein when the processor receives the indication of selection of the first patch, the program further causes the processor to identify the first patch based on location of a pointing feature displayed on a display device; and

wherein when the processor assigns the first patch, the program further causes the processor to identify the first subsurface horizon based on location of a pointing feature displayed on a display device.