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11/01/16
14:13
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Originally posted by mandurah
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Hi Denis.
SNE1 had 36m net pay in the oil leg. On the schematic SNE1 only contained the so called
"middle" blocky sand {S520}, S540 still being underwater at this intersection. However, in
this section of the oil leg there are 4 "thinner" sands in the oil leg. Also note that FAR stated
at the IP in Perth {my notes} that there were further interbedded "thin sands" NOT included
in the schematic that were "hoped" could add to net pay.
"Skip" 3km to the left to SNE2 and one would surmise that the Lowest blocky sand {S540}
would now dip clear of the water line into the oil leg. Notice also that probably in
this section of SNE2 that only 2 of the 4 previous "thinner" sands are now located in SNE2
v SNE1 of the oil leg section.
A TOTAL of 27m net pay was tested with 15m proving productive. 11.5/12 + 3.5/15.
The LOWEST {S540} of the blockier sands could not have been included in the 36m
net pay for SNE1 as it was still underwater at this juncture. So, the remaining thin sands
{4} plus 1 blocky sand would constitute this 36m. Be nice to see the actual breakdown of
these 2 sections for real into net pay rather than trying to go by scale or some other method.
At a guess, I would say the S520 thick constitutes 40% of the pay here with the remaining 4
thin sands constituting 60% of the net pay in SNE1. 15m thick sand, 21m thin sands.
Skip to SNE2 ; {extra 8m gross oil column, maybe net pay increases by 3 or 4m}. Now we
should have BOTH blocky sands in the frame {30m} but now only 2 thin sands {10m} for
40m net pay. They tested 15m of the thinner heterolithic sands.....maybe some of that
chunk of "further interbedded thinner sands not included in the schematic" were tested with
the remaining thin sands left in the SNE2 oil leg to arrive at 15m thin sands tested for ONLY
3.5 net or productive. The remaining 11.5m were useless. The blockier sand or primary reservoir
here was almost ENTIRELY productive...11.5/12m. So, 27m tested out of a possible 40m net
pay, still leaves 13m or so 'missing" or untested. 13m or so being approximately the same size
as the "first" blocky sand OR 13m of still further thin sands remaining to be tested. The
reservoir volumetrics don't add up here for mine...28m of thin sands v 12m of thick sands,
unless BOTH blocky sands are contained within this 12m requiring only 1 DST.
Anyway, I think we will have to wait to find out the break ups of net pay thin/thick sands.
8000 bopd is still an excellent result. From 1 thick sand only would open up the possibility
of a few "double yokers" perhaps west of SNE2. I think PJ, you mentioned that CNE only ever
published 1 blocky sand v 2 reported by FAR....can you post their schematic PJ? IF it is
from 1 sand only @11.5m net that is SOME belter of a flow rate on a restricted choke....hence
my confidence in the central structure under the gas cap. Mahogany 1 flowed 5200 bopd
from a 17m interval! Hyedua 2 appraisal well flowed 16 000 bopd from a 41m interval.
DB, it is a very crucial question indeed but that flow rate of 8000 bopd puts less pressure
on the results from SNE3 imo to at least make up the 2C estimate of 330mmboo. We could
just about get there from the central structure alone, particularly if double yokers do in fact
remain a possibility for future producing wells N/W of SNE2. Also, those thin sands should at
least double in extent as we dip further east into the oil leg. They will hopefully be cleaner
and be able to be put on a higher choke than SNE2. They will have to perform better than
those present in SNE2....they probably constituted 35% of the reservoir in SNE2 yet produced
only 11% of the total volume. I am confident they will for the above reasons. 3000-4000 bopd
would be a good result here for mine, considering the excellent result from the central
structure {even if that flow rate is from both sands}.
GLTAH
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Hi Mandurah
Concur with what you have said, indeed I independently arrived at similar in redrafting the speculative net pay translations on the spreadsheet.
Re: "I think PJ, you mentioned that CNE only ever published 1 blocky sand v 2 reported by FAR....can you post their schematic PJ?"
No that's not correct, to all extents and purposes both the schematics of FAR and CNE look exactly the same with respect to the sands and dipping and they both show double blocky sands on the "left". They just have different co-ordinates (W-E vs NW-SE) to confuse us. Also the markedly indented shape of the "wall" structure as illustrated to the left on the "structure maps" also makes it hard or impossible to guess what is actually going on.
In fact the only indication on any images that there might be only one blocky sand at SNE 2 is the N-S artistic seismic from FAR (refer that oft repeated image in the context of my tongue in cheek conspiracy theory post above 1673148 ).
As we and others have both stated previously it would surely beggar belief that Cairn would plan to drill SNE 2 in any position other than one where they expected to encounter the double blocky sands.
pj