Dr has authorised doubling of Lyrica dose starting immediately with some effect, so have found myself able to put the following together – this is just my own personal attempt at reconciling the different 2C resource estimates between FAR’s
pre SNE2 RISC estimate of 485mmbls and Cairns
post SNE2 estimate of 385mmbls then adding a bit more comment on SNE3. Sorry if it’s not my most lucid effort, I’m too whacked for more than the most cursory proof read.
1. Looking at SNE2 again first:
CN from the current presentation transcript: “you can see here that on SNE-2 we flow-tested our big, thick units at the base, and a couple of our shallower units”
@mandurah, I and others have been grappling in the past with whether both blocky sands (Mandurah’s “double yoker”) were in the oil window at the SNE2 location, and that surely pre-drill they would have had an expectation of that. For a moment I thought CN had given us the answer here, but on reflection still not clear: the SNE1 logs indicated the upper blocky sand to be split so CN’s use of the plurality could be referring to that feature, so from that, again not clear.
The flow testing bars in FAR’s accompanying diagram does indicate only one blocky sand as being tested, but does include half the lower blocky in the oil window, suggesting both sands were present but only one was tested.
But now Cairn have provided us with the log charts for all three wells as below, and hey it looks like
all the really yummy yellow lower blockies are below the water line. Surely these are not artistic license as well... so that settles that then – no double yoker at SNE2.
View attachment 156734
So although there was a coincident fall in the oil price when the SNE2 result was announced that the time, perhaps the impression that in some ways the SNE2 result was not all it was cranked up to be might well have contributed to the fall in share price of both Cairn and FAR at that time. I mean if the good stuff is the yummy yellow stuff (which I am assuming it is) then even to the most casual eye SNE2 doesn’t look as good as SNE1 in terms of pay does it? And we were expecting it to be better weren’t we? So in terms of net pay, although we don’t have the official version, although the block sand flow rates were brilliant, the net pay contribution to recoverable volume adjustments must have been disappointing.
Trying to be more exact, looking at SNE2 from the logs leaves me with a tentative conclusion that tested net pay may in fact be close to the actual net pay of 11.5m blocky and 3.5m thin sands as productive = 15m definite net pay at this extreme West central location, add another possible say 10m not tested ....say 25m max????
The next thing to note is that we don’t know exactly how the blocky sand dips away over the N/E part of the central structure, but CN has stated they fall away from the crest and the thin sands become more important, so any reduction in thin sand net pay that does not include dipping gas sands (see below) reduces the average net pay over the central/east areas. So where has the increase in Cairn’s net pay come from? Well the revised seismic increase in total central “gas cap” area of more than 100% would certainly do it wouldn’t it, but it does spread a thinner net pay over a larger area which can’t be quite so efficient.
So on this basis of all that reasoning the RISC post SNE2 estimates (if we ever see them before SNE3 RISC update becomes available) could well come down closer towards the Cairn number.
2. CN on SNE 3 “And indeed we’ve flowed some of these units that sat in gas at SNE-2, and we’ve flowed them for oil at SNE-3”
CN confirms that what looks like a major contribution to the productive flows from the SNE3 well come from the “Gas sands”. This I have, along with Ya quite separately, mentioned as likely in several previous posts, as deduced from the infamous N/S artistic seismic image to which I am told by some I must pay no attention to and draw no conclusions from.
The productiveness of the upper thin sand sand present at the top of the SNE1 column not quite so good as hoped for perhaps, a possible problem here is that, as illustrated as present these “gas sands” only dip into the oil leg towards the perimeter of the structure leaving the more central parts relatively bare. Certainly like the margin round the page of a book can account a relatively thin perimeter can account for more area than is first apparent and I haven’t yet done any calculations on that but more spread out means more wells than would otherwise have been the case? Whatever, I certainly expect SNE3 to increase Cairn’s current 385 number significantly as these results were definitely better than expected at the post SNE2 stage I think.
Second problem is that the productive gas sands at SNE3 are shown in FAR’s N-S artistic seismic image to continue to dip away south to the illustrated nearby oil water contact limit and not spread out to the Soleil prospect as illustrated in their latest areal images. Sorry to harp on about that but as I stated in previous posts it really does require an explanation – its kilometres in difference for the illustrated oil zone limits.
OK having said all that, some will say that its not
what we are shown, but
what is being said that matters so I will finalise with the full context of the extracts I presented above:
CN para 17 full transcript
“We then headed South and drilled our second appraisal well that we’ve just completed and flow-tested, and you can see here that on SNE-2 we flow-tested our big, thick units at the base, and a couple of our shallower units. Our big, thick units are dropping into the water as we get further South, and we’re relying on our thinner units to be containing oil, to reach perhaps our 3C number. We get more confidence in saying we’ve got a billion barrels of oil rather than half a billion barrels of oil. And indeed we’ve flowed some of these units that sat in gas at SNE-2, and we’ve flowed them for oil at SNE-3. Again we got almost twice the flow rates that we were expecting, and again world class type reservoirs that we have in terms of their deliverability”
pj
(20min delay)