how accurate is figure 1, page-6

Stoops.

I see your point , and I have resurrected a drilling report schematic from 12.01.02.

Reported total vertical depth (final)was 2534m.

2834m. including the horizontal section.

This schematic shows final angle to horizontal at about 2542m. with the horizontal actually rising somewhat from this point.

This is indicated as being in the lower part of the LOWER STAIRWAY SST which ends at 2560m.

The HVS is shown on this schematic to be starting at 2560m. and still continuing to the end of the schematic which is 2600m.

Of course , they have had access to new 3D seismic in the intervening period.

Hope this helps.