Published: 08/01/2014
Published: 08/01/2014
An operator in North Dakota wanted to access an unconventional reservoir in the Bakken shale by drilling an 8 3/4-in vertical borehole followed by a curve, landing the wellbore horizontally at the producing formation. The shale play was characterized by Mississippian-age carbonates usually with an unconfined compressive strength (UCS) of 10,000–20,000 psi, peaking at 26,000 psi. In previous runs, the interbedded formations caused downhole harmonics that significantly reduced drilling efficiency.
To produce a high-quality wellbore, the operator needed a bit that could deliver vibration-free drilling performance. In addition, the operator sought to improve drilling ROP and cutter durability to reduce drill time to section TD.
Smith Bits recommended RockStorm wear-resistant high-impact PDC cutter technology for improved protection from the impact and wear damage typically seen on offset bits. The RockStorm technology was added onto the base drill bit, an 8 3/4-in MDSi616 PDC bit. PDC cutters manufactured with RockStorm technology deliver superior wear and impact resistance in interbedded formation applications. RockStorm PDC technology combines synthetic diamond and tungsten carbide, resulting in PDC cutters that are more durable and impact-resistant to retain sharp edges for increased drilling efficiency.
RockStorm PDC technology enabled the 8 3/4-in PDC bit to drill 2,010 ft at an average ROP of 98 ft/h, which, when compared with bits used in offset runs, resulted in a 23% increase in average ROP.
Challenge: Reduce drilling time to section TD in an 8 3/4-in curve in Bakken shale while delivering a smooth, vibration-free drilling operation to increase the lateral’s contact with the shale reservoir.
Solution: Reconfigured the 8 3/4-in MDSi616 PDC bit with RockStorm wear-resistant high-impact PDC cutter technology to increase durability, improve ROP, and ensure a full-gauge borehole.
Results: