BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows is a perspective view of a fixed cutter drill bit illustrating general features of a bit.
FIG. 2 shows a plan view of a cutting face for a PDC bit in accordance with one embodiment of the present invention.
FIG. 3 shows a perspective view of the cutting face of the PDC bit shown in FIG. 2.
FIG. 4A-4B shows wear marks on the blades tops of a PDC bit having spiral blades after a drilling run in an unconsolidated, ultra abrasive environment.
FIGS. 5A-5B show a close up view of a blade of a PDC bit used for a drilling run in an unconsolidated, ultra abrasive environment.
FIG. 5C shows a close up view of a blade on another PDC bit used for a drilling run in an unconsolidated, ultra abrasive environment, wherein the blade spiral and spacing between cutters was reduced compared to the bit in FIGS. 5A-5B and resulted in reduced wear of matrix material from around the cutters.
FIG. 6A shows a cross section geometry of a conventional blade for a PDC bit.
FIG. 6B shows a cross section geometry of a blade for a PDC bit in accordance with one embodiment of the invention.
FIG. 7A shows a blade top for a PDC bit without wear resistant material embedded in its blade tops or cutter substrates after a first run in an unconsolidated ultra abrasive environment.
FIG. 7B shows a blade top for a PDC bit similar to the one shown in FIG. 7A but with the addition of wear resistant material embedded in the blade tops and cutter substrates after a first run in an unconsolidated ultra abrasive environment.
FIG. 7C shows the condition of the blade top shown in FIG. 7B after four bit runs.
FIGS. 8A-8C show a cutter oriented on a blade at a selected back rake angle in accordance with one embodiment of the present invention.
FIG. 9 shows one embodiment of a novel abrasive resistant gage pad configuration which may be used on a PDC bit in accordance with one or more embodiments of the present invention.
FIGS. 10A-10B another embodiment of a novel abrasive resistant gage pad configuration which may be used on a PDC bit in accordance with one or more embodiments of the present invention.
FIG. 11 shows a partial view of a heel surface of a bit with back reaming elements positioned on the bit in accordance with an embodiment of the present invention.
FIG. 12 shows one example of a multi-well system used for Steam Assisted Gravity Drainage recovery of heavy oil from a reservoir.