Extend run life and reduce trips in unconventional gas play
Schlumberger was working with Encana to drill directional wells from
pads in an unconventional gas play in the Horn River basin of British Columbia,
Canada. Temperatures that sometimes exceeded 150 degC [302 degF] limited the
run life of the downhole equipment. To extend run life and reduce the number of
trips needed to reach TD, Encana and Schlumberger jointly designed a drilling
system engineered to deliver maximum performance.
Design a fit-for-purpose integrated drilling system to reduce
trips
The BHA included a 7-in-OD PowerPak HR hard rubber motor lined with
Dyna-Drill NBR-HR elastomer that powered a SHARC drill bit, the TeleScope
service, directional drilling services, and the Slider system.
The PowerPak HR motor drilled 4,650 m of the 8¾-in hole in the
first well and 5,258 m in the second well in one run. The BHA with the SHARC
PDC bit and PowerPak HR motor began drilling at 754-m MD, drilled the build
section to land the well, and continued drilling in the lateral section.
After staying in the hole for 255 circulating hours and spending 170
hours drilling at an average ROP of 27.3 m/h, the BHA was pulled out of the
hole for a pipe swap.
In a subsequent well, a PowerPak HR motor and SHARC bit drilled 5,258 m
of the 8¾-in hole at an average ROP of 25.9 m/h, setting another
worldwide run length record for 8¾-in hole size and a North America
record for all hole sizes. The run totaled 203 drilling hours and 303
circulating hours at temperatures exceeding 150 degC.
