US3055443A - Drill bit - Google Patents

Description

ept 2 1962 J. H. EDWARDS DRILL BIT 3 Sheets-Sheet 1 Filed May 31, 1960 ZIQ Vm mi Ma A IIIILIIILI Ill {IN s .H llllilllalll JCK H Sept. 25, 1962 Filed May 31, 1960 TRl-CONE BIT 3 s J. H. EDWARDS 3,055,443

DRILL BIT 3 Sheets-Sheet 2 IN VENTOR, JACK H. EDWARDS.

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Se t. 25, 1962 J. H. EDWARDS w il rum/10a JACK H. EDWARDS, BY

3,055,443 DRILL BIT Jaclr I-I. Edwards, Houston, Tex., assignor, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla., a corporation of Delaware Filed May 31, 1960, Ser. No. 32,823 7 Claims. (Cl. 175-330) The present invention is directed to a drill bit for drilling a well bore. More particularly, the invention is concerned with a drill bit provided with abrasive-resistant material on a cutting edge. In its more specific aspects, the invention is concerned with a combination drill bit embodying a cutting edge and coaxial drilling means.

The present invention may be briefly described as a drill bit which comprises a hollow body member having preferably an annular cutting edge on a free end and adapted to be connected to a hollow drill string on its other end. The cutting edge is preferably provided with abrasiveresistant means for drilling through subsurface earth formations which ordinarily rapidly erode usual metallic surfaces. Arranged within and attached to the hollow body member is a rotatable drilling means which assist in drilling operations in penetrating the dense earth formations. The hollow body member is provided with means adapted to deliver drilling fluid separately to the cutting edge and to the rotatable drilling means. The hollow body member forms a shroud which encloses the rotatable drilling means and a window is provided in the wall of the hollow body member for discharge of rock cuttings from the rotatable drilling means to the outside of the shroud.

'When drilling rock with the usual rock bit such as a multicone bit, the fracture effect of loading on the teeth of the rock bit is limited due to the rock matrix surrounding the borehole. Failure of rock is prevented in a large degree by the restraint to movement ofiered by the surrounding rock. Thus, it appears that in usual drilling operations small cracks are created in the rock which return to the surface of the bottom of the well bore creating chips instead of propagating deep into the rock itself. Thus, the bit tooth of the usual rock bit presses on the rock surface, tending to create small cracks which propagate downward but by virtue of the resistance to fracture offered by the surrounding rock matrix, the crack follows the path of least resistance and emerges at the surface on the bottom of the well bore, thus creating the small chips. In the practice of the present invention, the resistance of the rock to fracture is removed or reduced by employing an improved drill bit which destroys the rock rapidly and efficiently. By virtue of providing a hollow cylindrical body having a cutting edge on its lower end and provided with abrasive-resisting material such as diamonds, metal car bides, such as tungsten carbide, boron carbide, titanium carbide, titanium-tungsten carbide, columbium-tantalumtitanium carbide, metal alloys, and cemented carbides known to those schooled in cutting tool manufacture, and the like, the cylinder cuts a small annular portion of the rock, forming a core which is received within the hollow body member. By arranging within the hollow body member vertically spaced from. the cutting edge a drilling means such as a multicone rock bit, it is possible to drill out the core rapidly and efliciently in that the core is no longer laterally restrained. Thus, by combining a cutting edge on a cylindrical member with a rock bit or drilling means enclosed and shrouded by the cylindrical member, it is possible to drill rapidly and efficiently.

In the practice of the present invention, it is necessary to provide a means for egress of the chips formed by destruction of the core. Otherwise, these chips would have to fall to the bottom of the well and be ground substantially to a powder by the annular cutting edge. This Patented Sept. 25, 1962 ice would result in loss of efiiciency and grinding away of material which has already been removed from the bottom of the well. In order to prevent this inefficient result, in the drill bit of the present invention, one or more windows are provided in the shroud adjacent the drilling means for drilling out the core such that the large chips or fragments of the rock formed by destruction of the core are discharged from the inner drilling means to the outside of the shroud to be caught up by and carried to the earths surface with drilling fluid which may be gaseous or liquid drilling fluid supplied separately to the cutting edge and to the inner drilling means in the device of the present invention.

The present invention will be further illustrated by reference to the drawing in which:

FIG. 1 is an elevational view of one embodiment of the present invention;

FIG. 2 is a sectional view of the embodiment of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 3 illustrating a tricone cutting means;

FIG. 5 is a partial sectional View of a preferred embodiment of the present invention illustrating the construction thereof;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5; and

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 5.

Referring now to FIGS. 1, 2, and 3 of the drawing, numeral 11 designates a hollow body member providing a space 12. The hollow body member 1-1 is provided with threaded means 13 on its upper end in the form of the usual pin for attachment to the lower end of a hollow drill string. The hollow body member 11 is provided with windows 14 for discharge of cuttings from the interior space 12 to the exterior of the hollow body member 11.

The lower free end of the hollow body member 11 is provided with a cutting edge 15 in the form of a matrix 16 in which there is embedded or arranged abrasiveresistant materials such as diamonds, tungsten carbide, and the like. Diamonds and metal carbides may be used simultaneously, if desired.

Arranged within the space 12 and rotatably attached to the hollow body member 11 are cone cutters 17 which are arranged on spindles 18 attached to the body member 11. Drilling fluid is discharged into the hollow body member 11 by means of a passage 19 which connects to the hollow drill string, not shown. This drilling fluid is discharged separately to the cutting edge 15 by fluid passageways 20 and to the conical cutters 17 by passageways 21.

Wherein FIG. 3 illustrates a 2-cone bit arranged in the space v12, FIG. 4 shows the arrangement of a tn'cone bit.

Referring now to FIGS. 5, 6, and 7, a drill bit in accordance with the present invention is comprised of a hollow body member 30 having a free end 31 which is provided with a matrix containing abrasive-resistant material 32 such as diamonds and/or metal carbides and the like. The hollow 'body member 30 is provided with a threaded pin 33 for threadedly attaching the hollow body member 30 to the lower end of a drill string, not shown. The hollow body member 30 is provided with a plurality of ports or windows 34 which may be 3 in number spaced apart Arranged within the space 35 enclosed by the hollow body member 30 is a tricone rock bit 36 which is threadedly attached by a sleeve 37 to the hollow body member 30. The sleeve 37 is provided with radial ports 38 which communicate with an 3 annular space 39 which serve to discharge drilling fluid on bottom through the free end 31 of the hollow body member from the passageway 40 which communicates with the hollow drill string to which the hollow body member 30 is connected by threaded pin 33.

A plate member 41 is threadedly connected to the sleeve 37 and is provided with fluid passageway 42 which communicates with a space 43 and with ports 44 which serve to discharge drilling fluid to the tricone rock bit 36, the tricone rock bit 36 being attached to the sleeve 37 by member 45 which, in turn, is welded to an adapter ring or plate 46.

The hollow body member 30 is provided with splines 47 which cooperatively engage with centering lugs 49 of an annular member 48 to maintain the tricone rock bit 36 coaxially with the hollow body member 30. The body 30 and annular member 48 are slotted to receive rectangular shaped window frames 50 which form windows 34 for the passage of fluids and cuttings from the space 35 to the exterior of the body 30. The body 30 and member 48 together form vertical passages 51 for the flow of fluid to the underside of the lower end 31 of body member 30.

The free end 31, forming the lower end of body member 30, is threadedly attached to the body by mating threads 52, as shown, and is welded to the body member 30 as at 53 and to annular member 48 as at 54. The end 31 of body 30 is provided with spaced-apart vertical passageways 55 which fluidly communicate the lower end of the body 30 with the passages 51, annular space 39, ports 38 and passageway 40.

From the description and the several figures of the drawing, it is apparent that the passageways 21 and ports 44 discharge above and between the rotatable drilling means and are parallel to the longitudinal axis of the hollow body member, the passageways 21 and ports 44 being of constant diameter. Likewise, it is also manifest from the drawing that the openings through the wall of the shroud forming the windows 14 and 34 are at the same level as the level of the rotatable drilling means.

In the several embodiments, the longitudinal axes of the inner drilling means intersect the longitudinal axis of the hollow body member at a common point.

Thus, it will be seen from the description taken with the drawing and especially with reference to FIGS. 5, 6, and 7 that the drilling device of the present invention is easily constructed and is of durable nature.

In operating the device of the present invention, the drilling device is connected to the lower end of a hollow drill string which is rotated. By virtue of the abrasiveresistaut material on the cutting edge, an annular groove is cut causing the hollow body member to enclose a core which is then contacted by the rotating inner rock bit or drilling means causing the destruction thereof and the formation of large chips which are flushed by the drilling fluid through the ports or windows 34 and out into the ascending stream of drilling fluid which flows downwardly through the passageways 4t) and upwardly in the annulus between the drill string and the wall of the borehole.

In order to illustrate the practice of the present invention, a drilling bit was constructed in accordance with the present invention and provided with windows and having diamonds on its lower free end forming a cutting edge. As a result of drilling operations in Indiana limestone while circulating water as the drilling fluid, drilling rates of 14 to 15 feet per hour were obtained. In comparative operations with a conventional rock bit, drilling rates of about feet per hour were obtained.

In drilling operations in Carthage marble, substantial improvements were achieved in the drill bit of the present invention as compared to the conventional rock bit.

In employing the drill bit of the present invention in drilling sandstone, drilling rates of to 18.5 feet per hour were obtained whereas in rock bits of the conventional type, the drilling rate was from about 8.7 to 10 feet per hour.

To illustrate the effect of drilling unrestrained rock, the core resulting from these drilling operations was drilled at a rate 2- to 3-fold the rate achieved with the conventional rock bit in restrained rock such as at the bottom of a hole. In other words, the practice of the present invention allows the achievement of rapid drilling since the major portion of the rock is placed in an unrestrained condition which allows it to be rapidly drilled out. The present invention is therefore quite important and useful.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and secure by Letters Patent is:

l. A drill bit which comprises a hollow body member having a cutting edge on a free end and adapted to be connected to a hollow drill string on its other end, a plurality of drilling means attachedly arranged within said hollow body member for rotation relative to said body member, the longitudinal axes of said drilling means intersecting the longitudinal axis of said body member at a common point, and means in said hollow body member adapted to deliver drilling fluid separately to said cutting edge and to said rotatable drilling means, said means adapted to deliver drilling fluid forming separate passageways discharging separately above and between said drilling means and through said cutting edge, the passageways discharging above and between said drilling means being parallel to the longitudinal axis of said body member and having a constant diameter throughout the length thereof, said hollow body member forming a shroud enclosing said rotatable drilling means and having a window in its wall adjacent said drilling means, said window being formed for lateral discharge of cuttings from said rotatable drilling means to the outside of the shroud, said window being formed by an opening through the wall of said shroud at the same level as the level of said rotatable drilling means in said shroud.

2. A drill bit in accordance with claim 1 in which the drilling means is a tricone rock bit.

3. A drill bit which comprises a hollow body member having a cutting edge on a free end and adapted to be connected to a hollow drill string on its other end, abrasive-resistant means on said cutting edge, a plurality of drilling means attachedly arranged within said hollow body member for rotation relative to said body member, the longitudinal axes of said drilling means intersecting the longitudinal axis of said body member at a common point, and means in said hollow body member adapted to deliver drilling fluid separately to said cutting edge and to said rotatable drilling means, said means adapted to deliver drilling fluid forming separate passageways discharging separately above and between said drilling means and through said cutting edge, the passageways discharging above and between said drilling means being parallel to the longitudinal axis of the body member and having a constant diameter throughout the length thereof, said hollow body member forming a shroud enclosing said rotatable drilling means and having a window in its wall adjacent said rotatable drilling means, said window being formed for lateral discharge of said outtings from said rotatable drilling means to the outside of said shroud, said window being formed by an opening through the wall of said shroud at the same level as the level of said rotatable drilling means in said shroud.

4. A .drill bit in accordance with claim 3 in which the abrasive-resistant means comprises diamonds.

5. A drill bit in accordance with claim 3 in which the abrasive-resistant means comprises metal carbide.

6. A drill bit in accordance with claim 3 in which the abrasive-resistant means comprises tungsten carbide.

7. A drill bit which comprises a hollow body member having an annular cutting edge on a free end and adapted to be connected to a hollow drill string on its other end, abrasive-resistant means on said cutting edge, a plurality of drilling means attachedly arranged within said hollow body member for rotation relative to said body member, the longitudinal axes of said drilling means intersecting the longitudinal axis of said body member at a common point, and means in said hollow body member adapted to deliver drilling fluid separately to said cutting edge and to said rotatable drilling means, said means adapted to deliver drilling fluid forming separate passageways discharging separately above and between said drilling means and through said cutting edge, the passageways discharging above and between said drilling means being parallel to the longitudinal axis of the body member and having a constant diameter throughout the length thereof, said hollow body member forming a shroud enclosing said rotatable drilling means and having a window in its Wall adjacent said rotatable 6 drilling means, said window being formed for lateral discharge of cuttings from said rotatable drilling means to the outside of said shroud, said window being formed by an opening through the wall of said shroud at the same level as the level of said rotatable drilling means in said shroud.

References Cited in the file of this patent UNITED STATES PATENTS 839,837 Guttzeit Jan. 1, 1907 2,022,101 Wright Nov. 26, 1935 2,034,073 Wright Mar. 17, 1936 2,587,429 Arutunofi Feb. 26, 1952 2,667,334 Ortlofl Jan. 26, 1954 2,708,103 Williams May 10, 1955 2,738,166 Koch Mar. 13, 1956 2,854,219 MacNeil Sept. 30, 1958 2,975,849 Stuart Mar. 21, 1961 UNITED STATES PATENT OFFICE CERTIFICATE QT CORRECTIN Patent N00 s oss aae September 25, 1962 Jack H. Edwards hat error appears in the above numbered pat=- It is hereby certified t hat the said Letters Patent should read as ent requiring correction and t corrected below.

In the drawings Sheet 2 FIG, 5, part 36 thereof for "TRI-CONE BIT read e THREE CONE BIT column 2 lines 21,- 55 and ()9 column 3, lines 9 and 15 and column 4, line 41, for 'tricone" read three cone u Signed and sealed this 12th day of March 1963 EAL) Atte t:

' DAVID L. LADD Commissioner of Patents ESTON Go JOHNSON Attesting Officer

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