Progressive 3D vertical seismic profiling method

1 . A method comprising:

providing a first data set representative of a first 3D VSP of a first region of a subterranean formation;

providing a second data set representative of a second 3D VSP of a second region of the subterranean formation;

wherein the first data set and the second data set define a common region of the subterranean formation;

merging the first data set and the second data set within the common region to produce a third data set representative of a third 3D VSP of the first and second regions of the subterranean formation; and

storing the third data set on a computer readable medium.

2 . The method of claim 1 wherein the second data set is obtained later in time than the first data set.

3 . The method of claim 1 wherein merging the first data set and the second data set within the common region comprises averaging data from the first and second data sets which is representative of the common region.

4 . The method of claim 3 wherein the first and second data sets are migrated prior to merging.

5 . The method of claim 1 wherein the first data set comprises the first data set edge data, the second data set comprises second data set edge data, and the common region is defined by is defined by the first and second edge set edge data, and further wherein merging the first data set and the second data set within the common region comprises interpolating the first and second edge set edge data into the common region.

6 . The method of claim 1 and further comprising, prior to merging the first data set and the second data set within the common region, verifying that the first and second data sets comprise data representative of common geologic events.

7 . The method of claim 1 and further comprising, after merging the first data set and the second data set within the common region, identifying data representative of events within the first and second regions and verifying essential continuity of data representative of the events across the common region.

8 . The method of claim 1 and wherein merging the first data set and the second data set within the common region comprises selecting data from one of the first or second data sets to be used as data representative of the common region.

9 . The method of claim 8 wherein the data representative of the common region is migrated after the merging.

10 . The method of claim 1 further comprising, following the merging of the first data set and the second data set within the common region, extrapolating data representative of the common region into the first data set outside of the common region.

11 . The method of claim 1 further comprising, following the merging of the first data set and the second data set within the common region, extrapolating data representative of the common region into a third region not represented by either the first or second data sets.

12 . The method of claim 1 further comprising providing a fourth data set representative of a third VSP of a third region of the subterranean formation, wherein the fourth data set defines at least a portion of the common region, and further comprising merging the fourth data set and the third data set within the portion of the common region to produce a fifth data set representative of a fourth VSP of the first, second and third regions of the subterranean formation, and storing the fifth data set on a computer readable medium.

13 . The method of claim 12 wherein the second data set is obtained later in time than the first data set, the fourth data set is obtained later in time than the second data set, and the fourth data set is merged with the third data set following merging of the first and second data sets.

14 . A computer readable medium comprising a series of computer-executable program steps configured to perform the method of claim 1 .

15 . A computer readable medium comprising the third data set produced by the method of claim 1 .