Hybrid drill bit and method of using tsp or mosaic cutters on a hybrid bit

Abstract

An earth boring drill bit comprising: a bit body; a plurality of fixed blades extending downwardly from the bit body, each blade having a leading edge; a plurality of fixed-blade cutting elements arranged on the leading edge of the fixed blades; at least one rolling cutter mounted for rotation on the bit body; and wherein the rolling cutter is configured to act as a depth-of-cut limiter, thereby reducing the risk of damage to the fixed-blade cutting elements. The fixed-blade cutting elements may include thermally stable polycrystalline diamond wafers mounted on tungsten carbide substrates and/or a mosaic of geometrically-shaped thermally stable diamond elements cooperatively arranged and bonded to form a unitary cutting surface. The rolling cutter may be positioned, relative to the fixed blades, to also limit rate of penetration and/or exposure of the fixed-blade cutting elements.

1 . An earth boring drill bit comprising:
 a bit body;   a plurality of fixed blades extending downwardly from the bit body, each blade having a leading edge and a trailing edge;   a plurality of fixed-blade cutting elements arranged on the leading edge of the fixed blades;   at least one rolling cutter mounted for rotation on the bit body; and   wherein the rolling cutter is configured to act as a depth-of-cut limiter, thereby reducing the risk of damage to the fixed-blade cutting elements.   
   
   
       2 . The bit as set forth in  claim 1 , wherein the fixed-blade cutting elements include thermally stable polycrystalline diamond wafers mounted on tungsten carbide substrates. 
   
   
       3 . The bit as set forth in  claim 1 , wherein the fixed-blade cutting elements include mosaic cutters formed of a plurality of geometrically-shaped thermally stable diamond elements cooperatively arranged and bonded to form a unitary cutting surface. 
   
   
       4 . The bit as set forth in  claim 1 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements and the fixed-blade cutting elements cooperate up to a maximum depth-of-cut. 
   
   
       5 . The bit as set forth in  claim 1 , wherein the rolling cutter is positioned, relative to the fixed blades, to limit rate of penetration. 
   
   
       6 . The bit as set forth in  claim 1 , wherein the rolling cutter is positioned, relative to the fixed blades, to prevent overexposure of the fixed-blade cutting elements. 
   
   
       7 . The bit as set forth in  claim 1 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements extend beyond the fixed blades. 
   
   
       8 . The bit as set forth in  claim 1 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements extend beyond the fixed-blade cutting elements. 
   
   
       9 . The bit as set forth in  claim 1 , wherein the rolling cutter is aligned with the fixed-blade cutting elements. 
   
   
       10 . The bit as set forth in  claim 1 , wherein the rolling cutter is aligned between the fixed blades and the fixed-blade cutting elements. 
   
   
       11 . An earth boring drill bit comprising:
 a bit body;   a plurality of fixed blades extending downwardly from the bit body, each blade having a leading edge and a trailing edge;   a plurality of fixed-blade cutting elements arranged on the leading edge of the fixed blades;   at least one rolling cutter mounted for rotation on the bit body; and   wherein the rolling cutter is configured to act as a rate of penetration limiter, thereby reducing the risk of damage to the fixed-blade cutting elements.   
   
   
       12 . The bit as set forth in  claim 11 , wherein the fixed-blade cutting elements include thermally stable polycrystalline diamond wafers mounted on tungsten carbide substrates. 
   
   
       13 . The bit as set forth in  claim 11 , wherein the fixed-blade cutting elements include mosaic cutters formed of a plurality of geometrically-shaped thermally stable diamond elements cooperatively arranged and bonded to form a unitary cutting surface. 
   
   
       14 . The bit as set forth in  claim 11 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements and the fixed-blade cutting elements cooperate up to a maximum depth-of-cut. 
   
   
       15 . The bit as set forth in  claim 11 , wherein the rolling cutter is positioned, relative to the fixed blades, to prevent overexposure of the fixed-blade cutting elements. 
   
   
       16 . The bit as set forth in  claim 11 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements extend beyond the fixed blades. 
   
   
       17 . The bit as set forth in  claim 11 , wherein the rolling cutter is positioned, relative to the fixed blades, such that a plurality of rolling-cutter cutting elements extend beyond the fixed-blade cutting elements. 
   
   
       18 . The bit as set forth in  claim 11 , wherein the rolling cutter is aligned with the fixed-blade cutting elements. 
   
   
       19 . The bit as set forth in  claim 11 , wherein the rolling cutter is aligned between the fixed blades and the fixed-blade cutting elements. 
   
   
       20 . An earth boring drill bit comprising:
 a bit body;   a plurality of fixed blades extending downwardly from the bit body, each blade having a leading edge and a trailing edge;   a plurality of fixed-blade cutting elements arranged on the leading edge of the fixed blades, wherein the fixed-blade cutting elements include thermally stable polycrystalline diamond elements mounted on tungsten carbide substrates;   at least one rolling cutter mounted for rotation on the bit body;   a plurality of rolling-cutter cutting elements arranged on the rolling cutter; and   wherein the rolling-cutter cutting elements are positioned, relative to the fixed-blade cutting elements, to limit depth-of-cut, rate of penetration, and exposure of the fixed-blade cutting elements, thereby reducing the risk of damage to the fixed-blade cutting elements.