Wellbore drill bit having shear cutters and gouging cutters

Abstract

A fixed cutter drill bit includes a bit body and at least one primary blade formed in the bit body and defining a surface profile on the bit body. The at least one primary blade extends from a first selected radial distance from a center or rotation of the bit body to a gage portion. At least one shear cutter affixed to the at least one blade. At least one gouging cutter affixed to the bit body rotationally ahead of the at least one blade. At least one nozzle is disposed in the bit body in a rotational position between the at least one primary blade and the at least one gouging cutter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT[0003]Not ApplicableBACKGROUND[0004]This disclosure relates generally to the field of wellbore drill bits used for drilling subsurface earthen formations. More particularly, the disclosure relates to fixed cutter wellbore drill bits having shear type cutting elements (“cutters”) and pick or gouging type cutters.[0005]Fixed cutter bits known in the art include polycrystalline diamond compact (“PDC”) bits, wherein a plurality of PDC cutters are affixed to a bit body in a selected arrangement on one or more blades formed in the bit body.[0006]Gouging type cutters are used in drill bits for drilling mine shafts or tunnels, among other uses. Such bits are known in the art as “claw” bits, one example of which is sold under the trademark QUI-KLAW, which is a trademark of Drillhead, Inc. Such bits ar...

AI Technical Summary

Benefits of technology

The patent text describes a new type of wellbore drill bit that combines both shear and gouging cutters. The bit has a unique design that allows for better performance in drilling through subsurface formations. The bit has a bit body with features for connection to drill string or drilling tools, and may also include one or more primary blades that extend radially from the bit body. The design of the bit body and blades helps to prevent premature wear on the cutters and improve drilling rates. The patent also describes a method for manufacturing the drill bit.

Problems solved by technology

It has been observed that such drill bits may exhibit premature wear on the shear cutters disposed on radially outward (from the center of rotation of the bit) portions of blades (the “profile”).

Such wear is believed to be a result of being shielded from high velocity drilling fluid flow by the gouging elements, such that such shear cutter overheat and wear more quickly than expected.

In applications where a drill bit designer would select low cost shear cutters on conventional PDC bits, such gouging and shear cutter bits need cutters made from more heat resistant and therefore more expensive cutters to avoid premature cutter wear due to thermal degradation (i.e., overheating of the cutters).

Such slower drilling rates may also be due to addition of gouging elements to a full shear cutter drill bit cutting structure may add excessive cutter surface area in contact with the earthen formations.

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