| 摘要 |
A drill bit for obtaining core sample fragments from a subterranean formation includes a bit body having a bit centerline and a bit face, a plurality of blades extending radially along the bit face, including a coring blade, a plurality of cutting elements on the blades, and a non-planar insert embedded in the bit body proximate the bit centerline. One of the cutting elements is a first cutting element on the coring blade at a first radial position from the bit centerline, and at least a portion of the coring blade is radially outward from a most radially interior cutting part of the first cutting element. |
