Source rock maturity is dependent on temperature, which in turn...

Source rock maturity is dependent on temperature, which in turn is dependent on burial depth. There is quite a bit of 2D data outboard of PEL87 (see first map below), all of which indicate a relatively lesser burial depth than to the east. At Venus and in PEL90, you are seeing the northern extent of the Orange River Basin overburden. The overburden thickness decreases northwards.


The image below is from an old paper (2015, ie pre-Graff etc...). It shows an Aptian source rock maturity model of the Orange River Basin. In the most simplistic description, green means oil-mature, orange and red means gas-mature. You can see however, PEL87, and the area outboard of PEL87 (underneath the word Apto) are modelled as immature. The Graff and Venus discoveries included quite a bit of gas, suggesting a higher heat-flow model and so that the maturity will now map to extend further north than this map below shows. I reckon the Saturn location is probably sitting ok, but the outboard bit is still high-risk. Some of the western extension of the 3D survey area may simply be included as migration aperture (to improve imaging/processing).



GLTAH