STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Drilling Bits and Downhole Tools 803
Five letters are presently defined: D-natural diamond/matrix body, M-PDC/
matrix body, S-PDC/steel body, T-TSP/matrix body, 0-other.
The term PDC is defined as “polycrystalline diamond compact.” The term
TSP is defined as “thermally stable polycrystalline” diamond. TSP materials are
composed of manufactured polycrystalline diamond which has the thermal
stability of natural diamond. This is accomplished through the removal of trace
impurities and in some cases the filling of lattice structure pore spaces with a
material of compatible thermal expansion coefficient.
The distinction of primary cutter types is made because fixed cutter bits often
contain a variety of diamond materials. Typically one type of diamond is used
as the primary cutting element while another type is used as backup material.
Profile. The numbers 1 through 9 in the second character of the fixed cutter
classification code refer to the bit’s cross-sectional profile (Figure 4-158). The
BIT PROFILE CODES
WILL BIT
CORE BIT
0: 00-10
-
G-GAGE WEIGHT ’
HIM Q>3/80
UED 1/80 S G S JMO
LOW 0 < 1/80
C -CONE HEIGHT
WlOW UEDIVY LOW
c > 1/40 1/80 S C 6 1/40 C < I/8D
1 2 3
4 5
6 9
Figure 4-158. Bit profile codes for fixed cutter bits [54]. (Courtesy SPE.)