(02-26-2016, 01:28 AM)sageo Wrote:
(02-26-2016, 01:05 AM)petrengr1 Wrote:Below you will find an excerpt from the OSH call which I think is of some interest- Nik Burns, UBS - Analyst [47]
--------------------------------------------------------------------------------Okay, thanks for that. Just on Antelope you just repeated the interference test between Antelope 5 and 1, are you able to comment at all on whether those results validated the earlier results that were achieved there understanding that there was an issue with the gauge calibration the first time around? Are you able to comment on the results there at all?--------------------------------------------------------------------------------Ian Munro, Oil Search Limited - Executive General Manager [48]--------------------------------------------------------------------------------It's a little too early. We recovered the gauges yesterday from Antelope 1 and Antelope 5 are now both out of the ground. We didn't have topol readouts so the data is now with the operators being calibrated and then we'll get a look at that I'd imagine in the next few days. It was a two week or so flow test and it was around a 10 day build up. We should get some very good data from 5 and the something that the engineers are quite excited to get in.On Antelope 6 we've just taken our fourth core in the reservoir and we're doing an intermediate logging run. We'll test on the way down and then we'll drill out through the reservoir and do a longer term test and also an injectivity test as well.I think once we've got all that data over the next sort of two, three, four weeks I think we're going to have a very good, a good feel for the resource base and all of that data is and will be provided to our certifiers.
Pet - I believe the injectivity test is to keep them from creating the mess that happened with the cement job in the A4 well ...is that the case? Also,if they have taken 4 cores so far in the reservoir,can I assume that we are already into the top 100 ft or so? (of the 450 ft) . " We'll test on the way down" .....dsts maybe ? [ I guess I'm just too doggone anxious to find out more about this eastern part of the reservoir !! ] .
Sageo- They have set the casing above the reservoir. After the cement had time to set they would have run cement bond logs, drilled out the bottom of the casing and done a “leak-off” test of the casing shoe by pressuring the well bore to a pressure of about 1 psi/ft of depth. The cement bond logs and leak-off test were apparently OK indicating the cement bond is good. So they drilled into the reservoir some time before pulling the pressure gauges from Antelope-1 and Antelope-5, based on the progress they have already made, i.e taken 4 cores and now doing an intermediate logging run. It is hard to say how far they have drilled into the reservoir but you would think it would be a significant amount if they have enough open hole to justify an intermediate logging run. It is a bit odd that they took four cores and then also wanted to see a log before drilling ahead.
I don’t think they will be doing any open hole drill stem tests (DST) but they will probably set the packer near the bottom of the casing and test all of the open hole. It could be that they will test as soon as the intermediate logging run is completed.
It will be interesting to see if they drill all the way to the planned TD which, as you know is several hundred feet below the gas/water contact. If they drill all the way down before doing the longer term test they will have to plug off the water zone below the gas/water contact before testing. The other possibility of course would be to drill down to the gas/water contact depth and do the longer term test which I believe will also be done with the packer set in the casing, testing the entire open hole section. They will eventually need to drill below the gas/water contact at least far enough to run a log across the interval where we think the gas/water contact is in order to confirm its location (again), if possible.
The injectivity test on a producing well is new to me. Such tests are usually done on water injection wells or water disposal wells. However such a test could probably be done in conjunction with a Schlumberger logging tool in the hole to see where the fluid is going. The test would be done using fresh water and could be used to locate permeable zones and perhaps to get an estimate of the permeability. They may do the injection at a constant rate and then do a pressure fall off test. Similar to the pressure buildup test after a production test. I would have thought it would be better to run a Schlumberger production log while producing the well to see where the gas is coming from. In either case they will probably be able to locate the permeable zones where the gas is coming from. Most of the gas will probably be coming from a very high porosity zone or a fractured zone.