A nozzle is releasably locked in a drilling fluid passage of a rotary rock bit by a retainer member which bridges between matching grooves in the periphery of the nozzle and in the wall of the passage respectively. The retainer member is introduced to the matching grooves through a first passageway that extends from the surface of the bit to the matching grooves. The grooves lie in a common plane. A second passageway extends at an angle to the common plane from the surface of the bit to the matching grooves. A drive-out tool is inserted through the second passageway to remove the retainer member.
A replaceable fluid nozzle is provided for well hole drill bits. The nozzle includes a main discharge port directed downward between adjacent cutting cones of the drill bit, and two side discharge ports directed toward the leading and trailing cutter cone backfaces, respectively. The side discharge ports direct jets of drilling fluid to wash away formation fines and shale packings from around the cutter cone bearing seals. The side jets of fluid remove abrasive particles to prolong the life of the cutter cone bearings and seals.
A rolling cone rock bit having one or more nozzle retention bodies attached by a single orientation mounting is disclosed, as is the associated method for its manufacture. The upper end of the nozzle retention body has a fluid inlet in communication with the internal fluid plenum of the drill bit, and the lower end of the nozzle retention body includes a fluid outlet that defines an exit flow angle. The fluid outlet is located between two rolling cones, but is positioned closer to one of the cones than the other. Further, the exit flow angle is preferably within 3 degrees of parallel to the drill bit longitudinal axis and, even more preferably, is parallel with the drill bit longitudinal axis.
A drill bit having one or more nozzle retention bodies attached by a single orientation mounting is disclosed, as is the associated method for its manufacture. The upper end of the nozzle retention body has a fluid inlet in communication with the internal fluid plenum of the drill bit, and the lower end of the nozzle retention body includes a fluid outlet that defines an exit flow angle. The exit flow angle is angularly disposed from the longitudinal axis of the drill bit. The nozzle retention body may advantageously be chamfered or the like to provide a reduced cross-sectional area at the lower end of the nozzle retention body. The outer surface of the nozzle retention body (and attached hardened elements) may extend substantially to gage, or may fall short of that diameter.
A non-plugging nozzle and self-cleaning drilling tool incorporating the nozzle is provided. The nozzle has a body that defines a central passageway extending axially from the top to the bottom of the body. The central passageway defines an inlet orifice at the top and an exit orifice at the bottom. A side passageway extends through the side wall of the nozzle and communicates with a cylindrical portion of the central passageway, the intersection of which defines a side inlet orifice that is substantially square. Because the intersection is substantially square, particles may not become trapped within the nozzle and plug the side passageway. When incorporated into a drilling tool, particularly a polycrystalline diamond compact (PDC) bit, the drilling tool becomes self cleaning. The side passageway of the nozzle is directed at the voids formed in the cutting face of the drilling tool creating a cross flow through the voids and preventing accumulation and balling therein.
Subterranean drill bits and particularly to nozzle features to be incorporated in subterranean bits. In one embodiment, the nozzle assembly of the invention defines a wear resistant structure which extends upstream from the terminus of the transition area. In another embodiment, nozzle assemblies are arranged about the transition area at low angles so as to minimize flow turbulence.
