Improve ROP while drilling an S-type well through a high-risk
environment
Saka Indonesia Pangkah needed to drill an S-type well offshore Indonesia
in a difficult environment. The well (UPB-12) was planned to be the first
S-type well to drill to 9,618-ft TVD (Ngimbang carbonate formation) with a
61° inclination in Ujung Pangkah field. It was also going to be the field's
deepest well—nearly double the depth at TD. However, the drilling
environment posed high erratic torque and stick/slip risks.
Mitigate risks using a customised PDC bit and an RSS
Schlumberger suggested using the PowerDrive vorteX system to mitigate
these risks while improving ROP and reducing the friction factor. The
PowerDrive vorteX system is made up of a PowerDrive Xceed RSS and a PowerPak
motor and is extremely reliable in abrasive, hot, and high-shock
environments.
Saka Indonesia Pangkah planned to use the PowerDrive vorteX system,
combined with a customized PDC bit as torque risk prevention, to drill the 8
1/2-in section of the well. The plan entailed dropping the angle from 43°
at 7,944-ft MD (5,685-ft TVD) to vertical with a 2.6° dogleg severity until
planned TD at 11,900-ft MD (9,618-ft TVD).
Increased ROP 130% compared to the ROP achieved by the previous
BHA
Drilling torque ranged from 5,000 to 7,000 ft.lbf with a consistent WOB
throughout the process. The stick/slip ratio was reduced to a maximum of 100%,
which enables the operator to mitigate stick/slip even when using a more
aggressive bit. The average friction factor during rotation was reduced by 18%
from 0.28 to 0.23.
By using the PowerDrive vorteX system, Saka Indonesia Pangkah was able
to increase ROP by 130% compared with ROP from a standalone BHA and 154%
compared with the well plan. The PowerDrive vorteX system significantly
improved drilling efficiency, saving rig time and reducing overall cost.
