Hybrid pdc bit

Abstract

A bladeless polycrystalline diamond compact (PDC) drill bit includes a head having a plurality of knots protruding from a drilling face of the head. Each of the plurality of knots includes a single cutter. Each of the cutters is arranged about a central axis of the head such that each cutter has a unique radial position and angular position relative to the central axis. The head defines at least one fluid port extending through the drilling surface.

What is claimed is: 
     
         1 . A polycrystalline diamond compact (PDC) drill bit, comprising:
 a head comprising:
 a first plurality of cutters arranged on a plurality of blades arranged proximate a center of the head; and 
 a second plurality of cutters arranged on a plurality of knots that protrude from a drilling face of the head, wherein:
 each of the second plurality of cutters is arranged about a central axis of the head such that each of the second plurality of cutters has a unique radial position and at least a substantial number of the second plurality of cutters have unique angular positions relative to the central axis; and 
 the head defines at least one fluid nozzle extending through the drilling surface. 
 
   
     
     
         2 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 the angular position of each successive one of the second plurality of cutters is incremented by between about 131 and 143 degrees starting from an innermost cutter of the second plurality of cutters relative to the central axis.   
     
     
         3 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 the at least one fluid nozzle extends through the drilling surface between bases of at least two of the plurality of blades.   
     
     
         4 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 a diameter of an opening of each of the at least one fluid nozzle is adjustable.   
     
     
         5 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 the angular position of each of the first plurality of cutters and the second plurality of cutters are incremented by between about by between about 109 to 132.5 degrees starting from an innermost cutter of each of the first plurality of cutters and the second plurality of cutters relative to the central axis.   
     
     
         6 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 spacing between adjacent ones of the second plurality of cutters is equal in all angular directions.   
     
     
         7 . The polycrystalline diamond compact (PDC) drill bit of  claim 1 , wherein:
 the plurality of knots cover substantially an entirety of the drilling surface of the head that is positioned outward of the plurality of blades.   
     
     
         8 . A polycrystalline diamond compact (PDC) drill bit, comprising:
 a head comprising:
 a first plurality of cutters arranged on a plurality of blades arranged proximate a center of the head; and 
 a second plurality of cutters arranged on a plurality of knots that protrude from a drilling face of the head, wherein:
 each of the second plurality of cutters is arranged about a central axis of the head such that each of the second plurality of cutters is has a unique radial position and a unique angular position relative to the central axis; 
 an angular position of each successive one of the first plurality of cutters following an innermost one of the first plurality of cutters is incremented approximately by a first angle selected from a first range of between 109 to 132.5 degrees, a second range of between about 156 to 180 degrees, or a third range of between about 81.5 to 97.5 degrees starting from an innermost cutter of the first plurality of cutters relative to the central axis the golden angle; 
 the angular position of each successive one of the second plurality of cutters following an innermost one of the second plurality of cutters is incremented approximately by a second angle selected from the first range of between 109 to 132.5 degrees, the second range of between about 156 to 180 degrees, or the third range of between about 81.5 to 97.5 degrees starting from an innermost cutter of the second plurality of cutters relative to the central axis; and 
 the head defines at least one fluid nozzle extending through the drilling surface. 
 
   
     
     
         9 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , wherein:
 at least some of the knots comprise multiple ones of the second plurality of cutters.   
     
     
         10 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , wherein:
 each of the second plurality of cutters comprises a generally flat leading edge; and   each of the generally flat leading edges is oriented in a different angular direction.   
     
     
         11 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , further comprising:
 webbing extending between and connecting at least some adjacent one of the knots.   
     
     
         12 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , further comprising:
 at least one fluid port extending between at least some of the knots.   
     
     
         13 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , wherein:
 the first angle and the second angle are different.   
     
     
         14 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , wherein:
 the second angle is closer to a boundary of the selected one of the first range, the second range, or the third range than the first angle.   
     
     
         15 . The polycrystalline diamond compact (PDC) drill bit of  claim 8 , wherein:
 the first plurality of cutters are positioned more linearly in a radial direction than the second plurality of cutters.   
     
     
         16 . A method of using a polycrystalline compact (PDC) drill bit, comprising:
 coupling a PDC drill bit to a drill string, the PDC drill bit comprising:
 a head comprising:
 a first plurality of cutters arranged on a plurality of blades arranged proximate a center of the head; and 
 a second plurality of cutters arranged on a plurality of knots that protrude from a drilling face of the head, wherein:
 each of the second plurality of cutters is arranged about a central axis of the head such that each of the second plurality of cutters has a unique radial position and at least a substantial number of the second plurality of cutters have unique angular positions relative to the central axis; and 
 the head defines at least one fluid nozzle extending through the drilling surface; 
 
 
   rotating the drill string and the PDC drill bit; and   engaging the PDC drill bit with a material to be excavated.   
     
     
         17 . The method of using a polycrystalline compact (PDC) drill bit of  claim 16 , further comprising:
 supplying a cooling fluid to the drilling face of the PDC drill bit via the at least one fluid nozzle such that the cooling fluid engages multiple of the second plurality of cutters wholly laterally.   
     
     
         18 . The method of using a polycrystalline compact (PDC) drill bit of  claim 16 , wherein:
 the angular position of each successive one of the second plurality of cutters is incremented by between about 131 and 143 degrees starting from an innermost cutter of the second plurality of cutters relative to the central axis.   
     
     
         19 . The method of using a polycrystalline compact (PDC) drill bit of  claim 16 , further comprising:
 adjusting a diameter of the at least one fluid nozzle.   
     
     
         20 . The method of using a polycrystalline compact (PDC) drill bit of  claim 16 , wherein:
 an angular position of each successive one of the first plurality of cutters following an innermost one of the first plurality of cutters is incremented approximately by a first angle selected from a first range of between 109 to 132.5 degrees, a second range of between about 156 to 180 degrees, or a third range of between about 81.5 to 97.5 degrees starting from an innermost cutter of the first plurality of cutters relative to the central axis the golden angle; and   the angular position of each successive one of the second plurality of cutters following an innermost one of the second plurality of cutters is incremented approximately by a second angle of about 81.8, 84, 96.9, 109.6, 111.8, 127.7, 129.6, 132.1, 156.6, 158.4, 161.5, 162.5, 165, 167.2, or 168.9 degrees.