RE:RE:RE:dragonfly454 - question for youHi OIL_RUN,
Thanks for clarifying the different horizons and the potential for drilling 2 distinct reservoirs (3 layers but 2 different formations and potentially pressure regimes), because otherwise some of our (my) thinking up to now was missing the bigger picture.
I had so far expected them to set the 13-5/8" x 14" somewhere midway between the 3,300 that they declared in the press release and the 6,300 that is the target reservoir; furthermore, I had expected this settign depth to depend mainly on the PPFG curve evolution and the location of a competent formation; 5,000 to 5,500m seemed, in absence of any further data, like a good guess.
Now, based on the explanations regarding the secondary targets in the +/-5,200m zone, it makes sense that they set the intermediary casing now somewhere around say 4,800-5,000m after having seen the pressure ramp on top of the reservoir. One thing that most drillers do not like is drilling into a reservoir with a 12-1/4" (among other reasons because it is a larger diameter that does not allow as good a dynamic kill as with a 8-1/2" hole, if you have any well control situation), however it is one thing to do it accidentally but a totally different thing if you drill knowingly in the -first- reservoir in 12-1/4" AND your well design has already anticipated it by having a 14" that can take the full displacement to gas from this reservoir, which is the case of the Suriname B58 well where the test is imminent (ref my previous post to anwser Dirk's MW question). In this case, of course you would prefer keeping the options for the upcoming sections open and not "waste a diameter".
In short, based on our common brainstorming, existing B58 architecture & pressure regime and the time/depth curve estimates, I now think it is possible (I have an aversion towards the words "likely" and "probable" in this job so let's keep just possible) that they drill through this first reservoir zone in the coming 10-12 days.
GLTA,