Reduce impact damage in horizontal shale well
Statoil was experiencing high levels of lateral vibration while drilling a horizontal unconventional well through the Bakken Shale in the Williston basin of North Dakota. The target formation has an unconfined compressive strength (UCS) of between 15,000 and 21,000 psi [103.4 and 144.8 MPa]; the instability generated by conventional PDC bits while penetrating the target formation was causing downhole tool failures and impact-induced cutter damage.
To reduce drilling time and costs, Statoil required a PDC bit that would remain dynamically stable to increase borehole quality and to reduce the number of trips for changing out the bit and BHA components.