Negative Planning LL with INEOS

Fat Canyon (6306/3-1 S) – Intermediate section

What happened:

Had two bit trips with very low, down to 1 m/hr ROP

What was planned:

Drill 12 1/4″ hole with 50-60 m/hr ROP in WBM

What was learned:

PDC bit in WBM and low hydraulic horsepower per sq.in did not drill this formation. IN other words, PDC bit nozzled for use in OBM.

What actions are required:

Pay more attention to bit hydraulics when planning to drill in WBM with PDC bit. The HSI needs to be high, between 3 and 5 hp/sq.in. We had HSI as low as 2, since one out of 3 mud pumps broke down, and we had to reduce the flowrate from 3700 to 3100 lpm. This is a common occurrence, so it is better to nozzle bit down a bit, to accommodate good HSI also at the low end of planned flow range.

What Was Done

Ran in with 3 rd bit, and put in smaller nozzles. Reduced TFA from 1,2 to 0,7 sq.in. ROP went from 1 m/hr with 18 MT WOB and 180 rpm, to 10-30 m/hr with 10 MT WOB and same rpm. It must be mentioned that the 3 rd bit run was a more aggressive Hyper Blade bit, with cutters that could protrude deeper into the clay formation. This could also have a positive effect on the ROP.