US 2013/0153305 A1Published application

Drag Drill Bit With Hybrid Cutter Layout Having Enhanced Stability

AssigneeUlterra Drilling Technologies, L.P.

InventorBenjamin CHREST

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Abstract

A drill bit that provides enhanced stability and a method for manufacturing such bit. In a preferred embodiment, the hybrid drill bit includes a single short driven blade in the shoulder region of the bit having each of its primary cutters plural set, sharing a common radial/elevational position with a primary cutter in an adjacent blade. All other primary cutters of the drill bit are single set at unique radial/elevational positions. The trailing plural-set cutters do less work than the other cutters and disrupt resonance and the feedback mechanism that leads to vibration, instability and whirling. In alternate embodiments, multiple blade pairs or groups may have primary cutters in the shoulder region that are plural set, sharing common radial/elevational positions with other primary cutters.

Claims21

Dependent claims

A drill bit (99) comprising:

a bit body (98) defining a rotational axis (93) and a bit face with a cone region (94), a shoulder region (95), and a gauge region (96);
a driving blade (10) formed on said bit body (98), said driving blade (10) extending from near said rotational axis across said bit face to at least said shoulder region;
first and second driven blades (30, 40) formed on said bit body (98);
and
a plurality of primary cutters disposed along leading edges of said driving blade (10) and said first and second driven blades (30, 40);
wherein
said primary cutters (12, 13) on said driving blade are characterized by having a unique radial/elevational position with respect to all other primary cutters on said bit (99),
each of said primary cutters (31, 32, 33) on said first driven blade (30) are characterized by having a substantially redundant radial/elevational position with one of said primary cutters (41, 42, 43) on said second driven blade (40), and
the remaining of said plurality of primary cutters (44, 45, 46) on said second driven blade (40) that do not have said redundant radial/elevational position with one of said primary cutters (31, 32, 33) on said first driven blade (30) are characterized by having a unique radial/elevational position with respect to all other primary cutters on said bit (99).

6 more elements

Dependencies are inferred from the claim text.