US2776115A - Drill bit - Google Patents

Description

Jan. 1, 1957 E. B. WILLIAMS, JR 2,776,115

DRILL BIT Filed Oct. 29, 1955 2 Sheds-Sheet 1 INVENTOR. 4. Edward B. Wllll'ams, Jr.

BY WW ATTORNEY-5'.

Jan-1, 1957 B. WILLIAMS, JR 2,776,115

DRILL BIT Filed Oct. 29, 1955 2 Sheets-Sheet 2 I N V EN TOR. Edward B. MY/Mms, Jr.

A TTORNE vs.

United States Pater-1t 1 DRILL BIT Edward B. Williams, Jr., Greenville, Tex. Application October 29, 1953, Serial No. 389,037

2 Claims. (Cl. 255-313) This invention relates to rotary drill bits for use in rotary drilling of bore holes in earth formations as, for example, in the exploration for oil, gas and other minerals.

In drilling of this character, the drill bit is rotated by a drill pipe to cut the formation and produce a bore hole while a drilling fluid is being circulated through the bit to serve as a coolant and to carrythe cuttings to the to and out of the bore hole. e

The drilling fluid is pumped into the drill pipe under high pressure and discharges against the bottom of the bore hole where the fluid is diverted outwardly and up wardly for return to the top of the bore hole. Such circulation is intended to keep the bottom of the bore hole clean of cuttings so that the bit is continually cutting a new formation. However, this is not the casebecause the downward discharge of the drilling fluid tends to im-' pact the cuttings against the bottom of the bore hole, and

the velocity thereof is greatly dissipated by opposition of the jet to upward flow, by contact with the cutting elements, by impact with thehole bottom, and by change of direction resulting from such impacts. Consequently, there is insuflicient velocity for the fluid to efficiently pick up the cuttings and carry them to the top of the bore hole. Therefore, the drill bit is acting on the cuttings and it is impossible to obtain full drilling efliciency. 7

With the above in mind, it is the principal object of the present invention to provide a bit with an arrangement of jets that sweep the bottom of the borehole clean of cuttings and provide the upward velocities necessary in carrying the cuttings to the top of the bore hole.

Other objects of the invention are to provide a rotary bit with one or more upward jets to produce eduction at the bottom of the bore hole for increasing the upward velocity of the drilling fluid; to provide a rotary bit with one or more cross jets located near the periphery of the bit for discharge across the bore hole toward the center thereof to sweep the bottom .of the bore hole free of cuttings and to facilitate upward movement of the cuttings; to provide a rotary bit with a plurality of upwardly directed jets acting in combination with one or more of the cross jets thereby keeping the cuttings in movement under high velocity flow and in directions to assure a clean bottom hole and maximum working efiiciency of the bit; and to provide for discharge of the jets so that they do not act in opposition with each other but in directions to promote continuous movement of the cuttings to the top of the bore hole.

In accomplishing these and other objects of the invention, as hereinafter pointed out, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawings wherein:

Fig. 1 is a perspective view of a drill bit constructed and equipped with jets in accordance with the present invention.

Fig. 2 is a bottom plan view of the bit.

Fig. 3 is a vertical section through the bit on a line 3-3 of Fig. 2 and the bottom of the bore hole being drilled thereby and which section has been inverted and rotated 2,776,115 Patented Jan. 1.,

through and particularly illustrating discharge of drilling fluid from upwardly directed jets.

Fig. 4 is a similar section on the line 4-4 of Fig. 2 and which has been inverted and rotated through 180 for particularly illustrating discharge of drilling fluid from the cross jets. v I

Fig. 5 is a diagrammatical view showing the sweep of a single cross jet of the bit illustrated.

Fig. 6 is a similar diagrammatical view showing sweep of dual cross jets for another form of bit.

Referring more in detail to the drawings:

1 designates a rotary bit of the cone type although it is to be understood that the invention may be carried out other types of earth drilling bits that require circulation of a drilling fluid to cool the cutting elements and effect upward movement of the cuttings.

I The bit 1 includes a body portion 2 of a generally cylindrical shape and has an exteriorly threaded pin 3 at one end by which the bit is connected with the box 4 of the lowermost tool joint of a drill pipe 5 when the bit is to be used in drilling a bore hole 6 as shown in Figs. 1, 3, and 4.

Since the bit illustrated has three cutters 7, 8 and 9, the body portion 2 has three outwardly and downwardly extending lugs 10. The lugs 10 are circumferentially spaced apart as indicated at 11 and carry spindles 12 on which i thei cone cutters are rotatably mounted in any suitable manner. The cutters have teeth713 that are adapted to roll upon the bottom 14 of the bore hole 6 to cut and chip the earth formation when the bit is rotated. v

Simultaneously with the rotation of the bit, a drilling fluid is pumped downwardly through the bore 15 of the drill pipe to be discharged through the bit into thebottom of the hole under high pressure for cooling the bit and effecting upward movement of the cuttings.

As above stated, the discharge passageways of such bits have heretofore been directed against the cones of the bit and bottom 14 in such manner that the discharge is in opposition to upward movement of the drilling fluid and cuttings. Consequently, the pressure and velocity of the fluid tends to pack the cuttings against the bottom of the bore hole. Also the direct reversal in direction of the flow results in dissipating the velocity of the fluid, therefore the cuttings are not readily picked up by the fluid and carried from the bore hole, with the result that the cutting elements of the bit are rolling upon cuttings and the teeth thereof are not fully effective in chipping away the formation.

The bit of the present invention avoids this difiiculty in that it is provided with one or more transverse jets that sweep the bottom of the bore hole in combination with upwardly discharging jets that provide the velocities necessary in carrying the cuttings to the top of the bore hole.

In carrying outthe invention, the pin 3 of the bit is provided with a drilling fluid passageway 16 that is in connection with the bore 15 of the drill pipe 5 and which supplies drilling fluid through channels 17, 1S and 19 that extend outwardly and downwardly through the body portion of the bit and through outwardly and downwardly extending nozzles 29, 21 and 22 that terminate within the circumferential cutting area of the bit. The terminal ends of the nozzles 21 and 22 thus extend beyond the sides of the body portion 2 of the bit to carry upwardly directed jet orifices 23 for discharging jets of drilling fluid under high velocity upwardly alongside the periphery of the jet and through the annular passageway 24 between the drill pipe and the wall of the bore hole. The nozzle 20 terminates in a downwardly and inwardly directed tip or jet orifice 25 by which a jet of drilling fluid is discharged, as indicated by the arrows in Figs. 4 and 5, at high pressure transversely of the rotational axis of the bit to sweep across the bottom 14 of the bore hole and wash the cuttings outwardly and upwardly through the space 24 as shown by the arrows in Fig. 4. It will be noted that the jet' is discharged at an angle to the bottom of the bore hole and in the direction of the required movement of the cuttings sothat the jet does not interfere with the move.- ment of the cuttings toward the upflow passageway where they arein position to be caught by the educted flow of the drilling fluid as produced by the vertical jets Z3.

In operating a bit constructed as described, the bit is attached to the lower end of the drill pipe and the drilling fluid is circulated under high pressure through the bore of the drill pipe for discharge through the channels 17, 18 and 19 at substantially high velocity whereby the fluid is diverted for discharge through the vertical jet orifices 23, to effect eduction of the drilling fluid and cuttings from the bottom of the bore hole and to maintain velocity of the upflow and prevent settling out of the cuttings.

Simultaneously, a jet of drilling fluid is discharged through the transversely directed jet orifice 25 so that it sweeps transversely across the bottom of the bore hole to wash the cuttings from under the cutters and to effect movement of the cuttings toward the wall of the bore hole as the jets are carried about a circular path within the bore hole under rotation of the bit. In bits employing four cutters, two transverse jets 26 and 27 may be provided with the two vertical jets, the jets being located in the spaces between the cutters as in the above described form of the invention. However, in this instance the transverse jets are arranged in opposed relation and direct substantially parallel jets of drilling fluid on the respective sides of the axis of the bit as diagrammatically indicated in Fig. 6.

From the foregoing, it is obvious that I have provided a rotary bit with upward jets that cooperate with transverse jets in facilitating movement and discharge of the cuttings from the bore hole to enhance the drilling efficiency of the bit.

It is also obvious that the upward jets educe a lifting effect on the transverse or angular jets and facilitate changing direction of flow from near horizontal to vertical. In other words, the flow of the vertical jets assists in changing the direction of the transverse jets so that they maintain the velocity necessary to provide a more effective lift of the cuttings.

What I claim and desire to secure by Letters Patent is:

1. A drill bit for drilling a bore hole into earth formations, said drill bit including a body member having an axis of rotation provided with an axial recess for distribution of a drilling fluid, lug portions spaced apart circumferentially of the body portion and extending downwardly and outwardly therefrom, spindles extending downwardly and inwardly from the lug portions, conical cutters rotatable on the spindles and having teeth arranged for engaging the bottom of the bore hole on substantially radial lines with respect to the axis of rotation, said cutters being of a diameter to cut a bore hole of larger diameter than the body member to provide an upflow passageway surrounding the body member, a jet nozzle extending outwardly and downwardly from said body member within one of said spaces between the lugs to near the outer circumference of the cutters and having a discharge tip facing downwardly and inwardly at an angle to the bottom of the bore hole for directing a stream of drilling fluid across to the opposite side of the bit to sweep the cuttings in one general direction toward the upflow passage, and an eduction nozzle extending downwardly and outwardly of the body member in another of said spaces and having a discharge tip. directed upwardly alongside the body member into the upflow passage for educing an upward flow of the drilling fluid discharged from the first named jet to carry the cuttings upwardly of the bore hole, said nozzles being in communication with said axial recess in the body.

2. A drill bit for drilling a bore hole into earth formations, said drill bit including a body member having an axis of rotation provided with an axial recess for distribution of a drilling fluid, lug portions spaced apart circumferentially of the body portion and extending downwardly and outwardly therefrom, said spaces, on one diametrical side of the body member, being opposite a lug portion on the opposite side, spindles extending downwardly and inwardly from the lug portions, conical cutters rotatable on the spindles and having teeth arranged for engaging the bottom of the bore hole on substantially radial lines with respect to the axis of rotation, said cutters being of a diameter to cut a bore hole of larger diameter than the body member to provide an upflow passageway surrounding the body member, a jet nozzle extending outwardly and downwardly from said body member within one of v the spaces to near the outer circumference of the cuts produced by said teeth of the cutter carried by the opposite lug and having a discharge tip facing downwardly and inwardly toward the opposite side of the axis of rotation for directing a stream of drilling fluid downwardly and inwardly to the opposite side of the axis of rotation to sweep the cuttings in a general direction in parallel relation with the cuts made by the teeth of the opposed cutter, and eduction nozzles extending downwardly and outwardly of the body member in the other of said spaces and having discharge tips directed upwardly into the upflow passage for educing an upward flow of the drilling fluid discharged from the first named jet to carry the cuttings upwardly of the bore hole, said nozzles being in communication with said axial recess in the body.

References Cited in the file of this patent UNITED STATES PATENTS 1,143,273 Hughes June 15, 1915 2,047,110 Reed June 7, 1936 2,184,067 Zublin Dec. 19, 1939 2,200,482 Winslow May 14, 1940 2,201,570 Zublin May 21, 1940 2,634,101 Sloan Apr. 7, 1953

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