RE: Edison21 Nov 2018 13:23
Actually, the Edison wording is directly from Fastnet's CPR - but seemingly BM has not bothered to read it.
The CPR says; "Years ago, the work by MPE and Onhym with surface geological mapping and 2D seismic revealed a number of leads of which the TE-5 structure was the largest in Tendrara. The 3D seismic survey, acquired in 2004, radically changed the understanding of the structural complexity. Indirectly, it explained the distribution of the Tagi reservoir in Tendrara. I say indirectly, because prediction of good Tagi reservoir does not come directly from the seismic, but rather good, old-fashioned, petroleum geology. TE-9 failed because the reservoir model is faulty.
The TE-5 horst turned out to be a series of half grabens formed as the Tagi basin developed. The 3D seismic area shows faults that have a major control on the post-Palaeozoic history of the area. A series of NE-SW trending second order faults bound smaller structures in the 3D seismic area. All these faults offset the Top Hercynian Unconformity seismic horizon and define the basin geometry during the Triassic rifting phase."
You can see all this on various Fastnet presentations.
As we now know from TE-8 and TE-9, the distribution of Tagi reservoir properties are difficult to predict. We saw at the DD the Tagi alluvial fans from the surrounding ‘hills’ probably merged along downthrown fault scarps. The ‘radius’ of the alluvial fans we saw at the DD were around 1 km; this suggests the good Tagi reservoir facies is confined to a relatively narrow, approximately 1 km wide zone along the downthrown side of faults active during Tagi deposition. The Tagi rocks closest to the fault scarp stand a slightly better chance of being coarser grained, better sorted and less clogged by diagenetic minerals than other rocks further away from the scarp. This is consistent with what has been found in the TE-5 area, not to mention TE-8 and TE-9 which were much further away from active faults.
Drilling TE-10 with a high risk is just going to wipe a huge amout from our value.
Also, most of the TE wells have penetrated the Pz with no shows and few reservoirs.