| 摘要 |
A rolling cone drill bit including multiple cones with regions of intermeshing and non-intermeshing cutter elements. In the non-intermeshed regions, an array of cutter elements is disposed about the cone surface in a non-circumferential arrangement with the cutter elements being mounted at differing radial distances from the bit axis. This non-circumferential arrangement, which may be a spiral, multiple spirals, other patterns of offset cutter elements, or a random arrangement, provides a composite cutting profile having substantial width and bottomhole coverage and is free of ridge-producing voids. In certain embodiments, the composite cutting profiles of the arrays at least partially overlap, and may be arranged to cover a portion of or the entire non-intermeshed region on the cones. |
