Data description

The 3-D OBS dataset has been already preprocessed and separated into a PP and a PS section. This thesis focus on the PS section only. The subset of the dataset consists of 250 inline CMPs, 50 crossline CMPs, 200 inline half-offset, and 40 crossline half-offset.

 

shot-rec-nc
Figure 5 Source (a) and receiver (b) distribution for the fraction of OBS dataset in study.

Figure 5 shows the spatial distribution for the shots on the left, and receivers on the right. Notice the gap in the source distribution due to the production platform for the Alba oil field. Additionally, Figure 6 shows the distribution of the CMPs on the left, and the offsets on the right. Remember, the final solution for the inverse problem is a regular common-azimuth cube where all the crossline offsets are collapsed to zero crossline offset. Figure 7 shows a section of the input data. The figure displays the five dimensions of the prestack data cube. The top panel presents the inline-CMP (${\rm CMP}_x$) and crossline-CMP (${\rm CMP}_y$) sections for a constant inline-offset (h_x)=-224 m, and constant crossline-offset (h_y)=-16.5 m. The center panel presents the inline sections for a constant ${\rm CMP}_y$=550 m, and a constant h_y=-16.5 m. The bottom panel presents the crossline sections for a constant ${\rm CMP}_x$=3100 m, and constant h_x=-224 m. Observe the sparsity and the holes of the data due to acquisition problems.

 

cmp-off-nc
Figure 6 CMPs (a) and half-offset (b) distribution for the fraction of OBS dataset in study.

 

data-nc
Figure 7 5-D representation for the real dataset. Top panel, ${\rm CMP}_x$ and ${\rm CMP}_y$ sections for a h_x=-224 m and h_y=-16.5 m. Center panel, ${\rm CMP}_x$and h_x sections for ${\rm CMP}_y$=550 m and h_y=-16.5. Bottom panel, ${\rm CMP}_y$ and h_y sections for ${\rm CMP}_x$=3100 m and h_x=-224 m.