Positive Bit LL with INEOS

Fat Canyon (PL937) – Intermediate section

What happened:

ROP in 12 1/4″ section dropped to almost nothing at +/- 1900 m. Drilling parameters were varied, and two different PDC bits were used with no noticeable improvement.
It was decided to run the 3rd bit with much higher HSI (4-6, as opposed to the +/- 3 on the previous runs). Schlumberger’s PowerDrive is not rated for the pressure that the required nozzle configuration would give, so it was decided to lay down the PD and go in with a rotary assembly.

What was planned:

Section to be drilled with 12 1/4″ RSS BHA with Schlumberger’s PowerDrive.

What was learned:

ROP improved significantly (from +/- 1 m/hr to 10-20 m/hr) with the higher HSI. However, building tendency with the rotary assembly means that WOB needed to be limited, and thus give somewhat lover ROP.

What actions are required:

Need to choose an RSS that can tolerate higher pressure to accommodate for the required HSI at the bit.