It may be worth a discussion with the DD contractor to determine how far you can reduce the flow rate and retain usable power at the bit. There could be potential to operate the PDM at a lower flow rate than the spec sheet states dependent upon how much grunt you need at the bit.
As a word of caution - if the inclination is hard won, care should be taken that it is not lost while circulating and cleaning up the hole. Keep pipe moving during circulation, rack back stands to minimise undercutting the hole etc. Assess the pros and cons of orienting high side and circulating rather than rotating the string during clean up.
All the best!
Stephen Mann -
Posted from United Kingdom - 2019-09-03 12:31:19replyResponse
CAN technology has been used to establish a conductor base for the well. This permitted a much shallower kick of and a more preferred trajectory to results desired to get to a much shallower reservoir target.
If water depths are quite shallow I would suggest you assess the use a mud recovery system.
The above technologies afford more drillable hole and require less build rates. Drilling with weighted (inhibitive mud if needed) will afford better stability and getting to inclinations desired
We did some shallow directional development work in central North Sea circa . After running and cementing 160-200ft 30in x swedged down conductors We opted to batch drill with the BOP and opted for a slender design vs using a mud recovery system. We opted for a 17 1/2 bi-cone bit (TcTi+cR) S.N PC451, on a motor wit a bent sub as we assessed this would permit easier sliding to get angle required and more rotation. We hopped the SSBOP from well to well using a tool the wellhead manufacture built for us. This saved us a lot of time.
Same bit accumulated 14,609ft of hole to various shoe angle setting depths with on bottom ROP's bit runs varied from 218-440ft/hr per well. ( Lithology was soft drilling with lots of long sand intervals (and why we needed to drill this with a mud system) that made this a lot more treacherous than drilling clay!)
At that time we did not use a mud recovery system because we assessed it as too expensive. Today this may be far more accessible better (there is a new generation of these) and affordable.
Hole opening from 17 1/2 to 26" again should not be an issue as long as best practices are applied. This was common old school 80's 90's practices in many offshore development projects. We had to drill wellbores in two section because drilling a 26" with the mud pumps we had was a tedious and very risk chore. It was therefore delivered in two separate phases.
Wishing you success.
Peter Aird -
Posted from United kingdom - 2019-09-02 14:25:16replyResponse