Published: 05/01/2012
Published: 05/01/2012
An operator planning to drill shale oil and shale gas exploratory wells in the Neuquen basin required an 8 1/2-in PDC bit that would drill curve and lateral sections at maximum penetration rates while providing good directional control. Traditionally, bits designed for the curve section have strong build tendencies and predictable toolface control but often deliver low ROP in the lateral. Conversely, bits that target the lateral section are built for aggressive, fast ROP with less directional control. A PDC bit was needed that could be run on a positive displacement motor (PDM) with a lower bend angle, enabling rotation and a high ROP in the lateral. At the same time, the bit had to be capable of producing the required rates.
Using knowledge and experience gained from US shale plays, Smith Bits designed the Spear PDC bit specifically for shale drilling. BHA data, directional profile, mud properties, offset run information, and other application factors were analyzed using several proprietary modeling and database tools:
Based on their analysis, bit design engineers selected an 8 1/2-in SDi513MHPX Spear PDC bit.
The Spear bit on a steerable PDM drilled 1,162 m of curve section in 172.5 h, setting an ROP record of 6.74 m/h in this application. Compared with an offset well, this ROP represented an improvement of 31%. The same bit on a rotary steerable system (RSS) drilled 999 m of lateral section in 105.5 h. Both efforts satisfied drilling performance objectives and saved bit costs and rig time.
The 8 1/2-in Spear bit was run on a steerable PDM in the curve section, with the following operating parameters:
For the lateral section, the bit was run on RSS with the following operating parameters:
Challenge: Drill 8 1/2-in section of a shale gas well with a single bit while maintaining good directional control and high ROP in the section’s curve.
Solution: Run innovative, application-specific Spear shale-optimized steel-body PDC drill bit.
Results: Drilled an 8 1/2-in section of a shale gas well with a single bit for the first time in the field’s history with a 31% faster ROP through the well’s curve section to set a field record.
