ALgerian Palaezoic17 Nov 2018 15:51
I thought that I would look at the read across to Algeria to see what could be inferred (if anything) from the Upper Carboniferous mudstones.
Firstly (though you will all know this) the sequence from youngest (higher) to oldest (deeper) is: Permian, Carboniferous, Devonian, Silurian, Ordovician and finally Cambrian.
The Palaeozoic source rocks appears to be mainly Silurian and Devonian for the gas in Algeria, though there is some in the Carboniferous. Why did they not drill deeper ? or had they found good enough results to prove the upper Palaeozoic ? ie good gas accumulations from deeper rocks ?
I found an interesting paper on the RKF field in Algeria which is producing from both TAGI and Carboniferous and its not too technical.
https://www.researchgate.net/publication/313351145_Carboniferous_Petroleum_System_in_the_RKF_field_Berkine_Basin_Algeria (sorry don't know how to hyperlink)
It suggests this may also be gas and 'light' oil in the Carboniferous.
As to the Mudstones, I don't know if that is good or bad - it suggests that there could be a highish level of Organic material, but as to the pososity of the mustone I can find nothing, those these can be low. I would have thought that though it may have originally been deposited as a mustone, it would now be some form of shale (is this where the stimulation could play a part, though there is no mention of it in the RKF paper.
All in all only time will tell.