STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

798 Drilling and Well Completions
P OF
BC
Bit
Figure 4-150. PDC bit nomenclature. (Courtesy Strata Bit Corp.)
Source: Strata Bit Corporation, 600 Kenrick, Suite A-I, Houston, TX 77060 ph (713) 999-4530.
unknown booklet of the company.
&O 330," 4
Long Cyllndor Cuttor
t--0.624 In 1
Stud Cutter
Figure 4-1 51. Polycrystalline diamond compacts [43A]. (Courtesy Hughes
Christensen.)
diamonds to maintain full gage hole. Matrix body bits generally utilize long
cylinder-shaped cutters secured to the bit by brazing.
Bit frofi/e. Bit profile can significantly affect bit performance based upon the
influence it has on bit cleaning, stability and hole deviation control. The "doublecone"
profile will help maintain a straight hole even in crooked hole country.
The sharp nose will attack and drill the formation aggressively while the apex
and reaming flank stabilize the bit. This sharp profile may be more vulnerable
to damage when a hard stringer is encountered as only the cutters on the sharp
nose will support the impact loading. A shallow cone profile appears to be the
easiest to clean due to the concentration of hydraulics on the reduced surface
area of the bit face. This profile relies heavily upon the gage section for
directional stability. The shallow cone profile will hold direction and angle with
sufficient gauge length and proper stabilization of the bit.