Hi OldGeo,
Interesting 2D seismic line regards near versus far offset. Need to see more parallel 2D seismic lines, but not really as now have 3D
But need to see the full Saturn 3D data set interpretation of seismic amplitude maps at various offsets to get the full AVO and seismic amplitude map picture. Then see if any mapped seismic amplitude anomalies conform with any of the depth mapped structure/stratigraphic prospects.
AVO's and amplitude maps can be useful as a direct hydrocarbon indicator, but tread cautiously here, as the AVO/amplitude cannot really tell you the thickness of any postulated hydrocarbon reservoir, assuming hydrocarbons are present.
For example see the published 3D Amplitude map for Venus and pre-drill Nara (North Venus/Greater Venus) Prospect attached.
Total had understandably high hopes for Nara-1 testing the major extension of the Venus oil bearing sands extending over the high that formed the initial ponding barrier mechanism for the Venus turbidite sands. These hopes were based on the very large seismic amplitude anomaly extending from Venus over the Nara-1X drill location and surrounds and conforming with the depth mapped structural closure.
I am speculating that Nara-1X encountered oil bearing Cretaceous sands, the overflow to the west from the Venus ponded sand accumulation, but thin at the Nara-1 location with the usual 'the well proved an operating petroleum system'. As though Venus-1X had not proved this already.
So Total plugged and abandoned the well as any hydrocarbon zones were non-commercial.
The take away from this is that DHI's are encouraging for the possible presence of hydrocarbons but can't tell you if a significant hydrocarbon accumulation is present or not.
Having said that, I would rather have AVO/ DHI's present over whatever prospects are defined for Saturn by the 3D, than none, especially as AVO/ DHI's are associated with oil bearing Cretaceous light oil and gas discoveries at Venus and Mopane to the south and southwest. (and I assume also with Graff, Jonkers, Lesidi Shell discoveries but no data released by Shell).
So let us see what WDS/PCL come up with for the final interpretation of the Saturn 3D seismic data and associated seismic amplitude maps.
DYOR.
(20min delay)