Volumetric and non-volumetric sources-based seismic survey and method

1. A seismic survey system for surveying a subsurface, the system comprising:

a volumetric land source buried underground for generating P-waves;

a non-volumetric land source buried underground for generating P- and S-waves;

plural receivers distributed about the volumetric and non-volumetric land sources and configured to record seismic signals corresponding to the P- and S-waves; and

a controller connected to the volumetric land source and the non-volumetric land source and configured to shoot them in a given pattern,

wherein the plural receivers are arranged so that first receivers among the plural receivers to have a near offset relative to the volumetric land source and/or the non-volumetric land source, and second receivers among the plural receivers to have a far offset relative to the volumetric land source and/or the non-volumetric land source.

2. The system of claim 1 , wherein the volumetric land source is spherical.

3. The system of claim 1 , wherein the volumetric land source is buried in a well below the non-volumetric land source.

4. The system of claim 1 , wherein the volumetric land source includes plural individual volumetric sources placed at first different horizontal-plane positions and the non-volumetric land source includes plural individual non-volumetric sources placed at second different horizontal-plane positions.

5. The system of claim 4 , wherein the plural individual volumetric sources are buried a first depth H 1 and the plural individual non-volumetric sources are buried at a second depth H 2 .

6. The system of claim 5 , wherein the first depth H 1 is larger than the second depth H 2 .

7. The system of claim 5 , wherein the first depth H 1 is smaller than the second depth H 2 .

8. The system of claim 5 , wherein the first depth H 1 is equal to the second depth H 2 .

9. The system of claim 1 , wherein the given pattern includes shooting the volumetric and the non-volumetric sources sequentially or simultaneously.

10. The system of claim 9 , further comprising:

a memory device for storing traces recorded by the plural receivers; and

a processor connected to the memory device and configured to combine first traces corresponding to the volumetric source with second traces corresponding to the non-volumetric source.

11. The system of claim 10 , wherein the processor is further configured to:

separate the first traces corresponding to the volumetric source from the second traces corresponding to the non-volumetric source;

extracting from the first traces third traces that correspond to the near offset reflections and transmissions and contain substantially P-waves;

replacing with the third traces, in the second traces, fourth traces that correspond to the near offset reflections and transmissions; and

using the obtained combination of second traces and third traces to generate a final image of the subsurface.