US3727704A

US3727704A - Diamond drill bit

Info

Publication number: US3727704A
Application number: US00125138A
Authority: US
Inventors: T Abplanalp
Original assignee: Christensen Diamond Products Co
Current assignee: Norton Christensen Inc; Baker Hughes Oilfield Operations LLC
Priority date: 1971-03-17
Filing date: 1971-03-17
Publication date: 1973-04-17
Anticipated expiration: 1990-04-17

Abstract

A rotary bit having diamond cutting elements in its drilling face for drilling a bore hole, drilling fluid being pumped from the bit and into primary feeder waterways in the drilling face extending to the outer gauge portion of the bit. Jet passages receive drilling fluid from the interior of the bit, discharging such fluid into secondary waterways in the drilling face in the direction of rotation of the bit and toward the outer gauge portion, to create low pressure regions in the secondary waterways and cause fluid to flow from the relatively high pressure feeder waterways across the intervening bit faces toward the secondary waterways, effecting a cleaning action of the cuttings from the bottom of the hole, the bit faces and the diamonds embedded therein, such cuttings being flushed upwardly around the bit toward the top of the bore hole.

Description

United States Patent 91 Abplanalp DIAMOND DRILL BIT [75] Inventor: Thomas L. Abplanalp, Vernal, Utah [73] Assignee: Christemen Diamond Products Company, Salt Lake City, Utah [22] Filed: Mar. 17, 1971 [21] App1.No.: 125,138

[52] US. Cl ..l75/329 [51] Int. Cl. ..E2lb 9/36 [58] Field of Search 175/329, 330

[56] References Cited UNITED STATES PATENTS 2,371,489 3/1945 Williams ..l75/329 2,493,178 1/1950 Wi11iams.... ....175/329 3,112,803 12/1963 Rowley ....175/329 3,175,629 3/1965 Rowley.... ....175/329 3,135,341 6/1964 Ritter ....l75/329 3,310,126 3/1967 Gstalder et a1. ..175/329 Primary Examiner-David H. Brown Attorney-Bemard Kriegel and Kendrick, Subkow & Kriegel 5 7 ABSTRACT A rotary bit having diamond cutting elements in its drilling face for drilling a bore hole, drilling fluid being pumped from the bit and into primary feeder waterways in the drilling face extending to the outer gauge portion of the bit. Jet passages receive drilling fluid from the interior of the bit, discharging such fluid into secondary waterways in the drilling face in the direction of rotation of the bit and toward the outer gauge portion, to create low pressure regions in the secondary waterways and cause fluid to flow from the relatively high pressure feeder waterways across the intervening bit faces toward the secondary waterways, effecting a cleaning action of the cuttings from the bottom of the hole, the bit faces and the diamonds embedded therein, such cuttings being flushed upwardly around the bit toward the top of the bore hole.

16 Claim, 3 Drawing Figures PATENTEU APR 17 I973 I INVENTO/Q 1140/2495 L 195m RNAZLP DIAMOND DRILL BIT The present invention relates to rotary drill bits, and more particularly to diamond bits used in the drilling of bore holes, such as oil and gas wells.

Diamond drill bits have been provided for drilling comparatively hard formations,- such as sandstone. During the drilling operation drilling' mud or other drilling fluid is pumped down the drill string connected to the bit, discharging from the bit .for the purpose of conveying the formation cuttings to the outer portions of the bit and thence upwardly therearound toward the top of the bore hole being drilled. In addition, the drilling fluid cleans and cools the bit of cuttings, insuring maximum penetration of the cutting elements into the formation.

Prior diamond bits that can drill hard formations effectively slow down upon entering a softer formation, such as shale. lt is believed that the slower rate of drilling the softer formations is due to the inability of the drilling fluid to remove the cuttings effectively from the bit face and the bottom of the borehole, thereby interfering with proper penetration of the diamond cutting elements into the softer formation.

By virtue of the present invention, a diamond drill bit has been provided which will drill hard formations efficiently, and which will also drill the softer formations more effectively than heretofore and at faster rates. This is accomplished by providing a rotary diamond drill bit which ensures the flow of the drilling fluid over its diamond set pads or lands. The drilling fluid is caused to discharge intoprimary waterways extending laterally outwardly across the bitface, such fluid being caused to flow from the water ways across the diamond set lands themselves into low pressure areas or waterways in the face of the bit on the opposite sides of the lands. The low pressure in these areas is produced by directing jets of fluid into'such areas, the relatively high velocity of the fluid in the areas, which are preferably placed in advance of the bit lands or pads, reducing the pressure therein, thereby inducing the flow of fluid from the primary or feeder waterways across the pads or lands. Preferably, the primary waterways have a progressively reduced cross-section in the direction of the bit gauge to cause the pressure in such waterways to build up and thereby flow across the padsor lands to the low pressure secondary waterways that extend toward the gauge of the bit.

To enhance the cleaning action effected by the jets issuing from the bit, they are directed toward the bottom of the hole and inclined in a direction in advance of the lands, also being inclined toward the gauge portion of the bit. The jets are caused to discharge at different radial distances from the bit axis to collectively flush substantially the full bottom of the bore hole.

This invention possesses many other advantages, and

has other purposes which may be made more clearly v FIG. 1 is a combined side elevation and longitudinal section of a rotary diamond bit embodying the invention;

FIG. 2 is a bottom plan view of the bit illustrated in FIG. 1; and 2 FIG. 3 is a view similar to FIG. 2 of a modified form of bit.

As disclosed in the drawings, a drill bit is provided for operation upon the bottom of a bore hole and to flush the cuttings from the bottom upwardly around the drill bit and a string of drill pipe (not shown), to which it is secured, to the top of the hole. The drill bit includes a body or shank 10 having an upper threaded pin 11 for threadedly attaching the bit to the string of drill pipe. Circulating drilling fluid pumped down through the drill pipe flows into a central or main passage 12 in the body of the tool, from where it will flow through a plurality of circumferentially spaced longitudinallyextending ports or openings 13 against the bottom of the hole. The lower end of each distribution port 13 communicates with one or a plurality of generally radial primary waterways 14 extending toward the outer gauge portion 15 of the bit, the fluid flowing through such waterways and also across the cutting surface or face 16 of the bit, as described hereinbelow. A relatively short waterway 17 may extend inwardly from one port 13 across the inner portion 18 of the drilling face toward the axis of the bit.

The, body of the bit has diamonds 19, or similar cutting'elements, secured in its formation contacting face 16 within a matrix (not shown separately) of. a suitable type forming a portion of the bit body 10. The central portion 18 of the bit illustrated is generally conical in shape, with the sides of. the cone tapering in an upward and inward direction toward a central core tube portion 20 into which a relatively small diameter core, formed by the bit, will move during the drillingof the hole,'the core moving upwardly until it engages a tapered core breaker face 21 that will break off the core. The broken core can discharge through an ejector passage 22 extending laterally to the outer portion of the bit body above the reaming face 15 of the bit. The arrangement for forming the core, breaking it off, and ejecting it through the lateral passage 22 is known in the art and forms no part of the present invention.

The generally conical central portion 18 of the bit merges into a lowermost bottom contacting portion 23, which, in turn, merges into an upwardly diverging conical face 24 terminating at the generally cylindrical reaming face 15 of the bit.

The drilling portion of the bit is divided into a plurality of diamond set sections, lands, or pads 25 which extend outwardly from the region of the distribution ports 13, and which are defined by the primary feeder waterways 14 extending from each port toward the gauge portion 15 of the bit! Thus, the waterways l4-extend from the outlets 13a of the distribution ports 13 generally radially along the inner conical face portion 18, lowermost face portion 23, and outer conical face portion 24, merging into vertical waterways or grooves 26 in the reaming portion 15 of the bit body.

The inner conical portion 18 of the bit face has diamonds set therein for operation upon the central portion of .the hole, the central vertical passage 20 having inner gauge stones or diamonds 27 therein for cutting the small diameter core (not shown), which will be broken off by the core breaker face 21, as described above. Similarly, diamonds 19 are set in a predetermined pattern in the faces of all of the lands, the diamonds 19 terminating at the lowermost end of the gauge region where vertical stabilizing ribs 28 are-provided on the bit body, which may, if desired, have diamonds or other suitable cutting and stabilizing elements set therein.

As specifically disclosed in FIGS. 1 and 2, circumferentially spaced low pressure recesses or secondary waterways 30 are formed in the drilling face, each of these recesses extending from an inner or intermediate portion of the lower drilling face, with its sides 31 diverging in a lateral outward direction, these low pressure waterways merging into junk slots 52 in the gauge portion of the bit through which cuttings can be flushed upwardly into the annular space around the smaller diameter bit shank portion a for conveyance by the drilling fluid upwardly around the string of drill pipe to I the top of the bore hole. These low pressure recesses 30 actually dividethe bit face into a plurality of sets of lands 2 5, each set of lands being defined between the low pressure recesses or secondary water-ways 30 and the primary feeder waterways 14, as well as between adjacent primary waterways.

As specifically disclosed in FIG. 2, each set-of lands has three lands a, 25b, 250, a leading land 25a being defined between a secondary waterway and a primary feeder waterway 14, an intermediate land 2512 being b between a pair of adjacent waterways-l4, and a trailing land 25c being defined between a trailing primary waterway l4 and a secondary waterway 30.

During rotation of the bit and the pumping of drilling fluid therethrough, for the purpose of drilling the bore passage inclining in a downward and outward direction toward the bottom of the bit and also beinginclined toward av forward secondary waterway 30 into which its outlet 42 opens. Thus, the fluid discharging from each jet passageway 40. will issue at high velocity into a secondary waterway 30 and, because of such velocity, will reduce the pressure therein below the pressure in the primary feeder waterways 14. As a result, the fluid flowing through such waterways 14 will be caused to flow transversely across the diamond studded

lands'or pads

25a, 25c and into the adjacent secondary waterways 30, covering the full surface of the lands 25a, 250. From thelow pressure secondary waterways 30, the cutting laden drilling fluid will pass outwardly toward the gaugeof the bit and into the junk slots 32, moving upwardly therethrough and around the bit body thereabove. I

For the purpose of insuring transverse flow across the pads from the primary waterways 14 toward the low pressure secondary waterways 30, the cross-sectional area of each primary waterway decreases in a direction toward the gauge of the bit, thereby imposing a restriction to direct generally radial outward flow of the fluid through the primary waterways 14 toward the gauge 15 and into the vertical waterways 26 with which they communicate. The progressively decreasing area of the primary waterways can be achieved, by way of example, by progressively decreasing the'depth of each primary waterway in an outward direction, while maintaining the width uniform.

For the purpose of flushing substantially the full bottom of the bore hole, the outlets '42 of the inclined jets 40 are disposed at different distances from the'bit axis,

'insuring a more thorough sweep of the flushing fluid around the bottom of the bore hole as the drill bit rotates.

In larger bit diameters, the diamond set lands 25 may become too wide for efficient cleaning and cooling when only the specific waterway arrangement disclosed in FIG. 2 is used. Accordingly, as illustrated in FIG. 3, with a drill bit of a larger diameter, a relatively small secondary low pressure area 50'is provided between each set of primary waterways 14, this relatively small secondary low pressure waterway 50 extending from an intermediate point in the bit face and extending to a smaller junk slot or vertical waterway 51, With such design, four lands 25a, 25b1, 25b2, 250 are provided in each set, instead of the three lands shown in FIG. 2, each land being narrower than would be the case if the small secondary waterway 50 were not provided. The drilling fluid flowing through-the primary waterways 14 will not only flow transversely across the

outer lands

25a, 25c toward the low pressure main secondary waterways 30, but it will also flow from the primary waterways 14 transversely acrossthe lands 25b1, 2Sb2' toward the small secondary low pressure waterways S0, insuring the effective cleaning and cooling of all'areas of the drilling face of the drill bit.

With the drill bits illustrated and embodying the invention, hard formations have been drilled effectively, as well as-the softer formations. Moreover, drilling has occurred at faster rates. The relatively high velocity jets 40 reduce the fluid pressure in the secondary waterways 30 and thereby cause the drilling fluid to flow from the primary waterways l4 transversely across the lands 25, for the purpose of cooling and cleaning them of cuttings, as well as flushing the cuttings towards the outer portion of the drill bit and upwardly therearound and around the drill pipe to the top of the bore hole.

lclaim: I I

1. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having first fluid passage means for feeding fluid from the interior of said body'to said primary velocity of the fluid flowing through said primary.

waterways, each of said second fluid passage means extending laterally outwardly of said body and being of the primary waterway substantially inclined substantially to a radial plane passing through the axis of said body. v

2. In a rotary bit as defined in claim 1; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer. ends of said primary and secondary waterways.

3. In a rotary bit: a body having a cuttingface for drilling a bore hole, said face comprising aplurality of spaced lands extending laterally. from an inner portion of the face to the outer portion of thelface, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having first fluid passage means for feeding fluid from the interior of said body to said primary waterways, said body having second fluid passage means for jetting fluid from the interior of said body into said secondary waterways, whereby the jetting fluid decreases the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways to induce flow of fluid from said primary waterways across the larids to said secondary water-- ways; and said second fluid passage means being inclined laterally outwardly and in the direction of rotation of the bit.

4. In a rotary bit as defined in claim 3, said second fluid passage means also being inclined downwardly of the bit.

5. In a rotary bitz-a body having a cutting face for' waterways below the fluid pressure in' said primary" waterways to induce flow of fluid from said primary waterways across the lands to said secondary waterways; said primarywaterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face.

6. In a rotary bit as defined in claim 5; said second fluid passage means being inclined downwardly and laterally outwardly of the bit and also being inclined in the direction of rotation of the bit.

7. In a rotary bit as defined in claim 5; said body having an outer vertical face extending'upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways, said second fluid passage means being inclined downwardly and laterally outwardly of the bit and also being inclined in the direction of rotation of the bit.

8. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having a main fluid passage for receiving fluid from a tubular drilling string to which the body is securable, said body having distribution ports for feeding fluid from said main fluid passage to the inner portions of said primary waterways, said body having jet passages communicating with said main fluid passage and opening into said secondary waterways for jetting fluid underhigh velocity into said secondary waterways to decrease the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways, said jet passages being proportioned to discharge fluid into said secondary waterways at a substantially higher velocity than the velocity of the fluid flowing through said primary waterways, each of said jet passages extending laterally outwardly of said body and being inclined substantially to a radial planepassing through the axis of said body.

9. In a rotary bit as defined'in claim 8; each of said distribution ports feeding fluid into a plurality of primary waterways, said primary waterways diverging from one another in a direction laterally outwardly of the body.

10. In a rotary bit as defined in claim 8; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with andextending upwardly from the outer ends of said primary and secondary waterways.

11. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and second waterways defining said lands and separating said lands from each other, said body having a main fluid passage for receiving fluid from a tubular drilling string to which the body is securable, said body having distribution ports for feeding fluid from said main fluid passage to the inner portions of said primary waterways, said body having jet passages communicating with said main fluid passage and opening into said secondary waterways for jetting fluid under high velocity into said secondary'waterways to decrease the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways; each of said jetpassages being inclined downwardlyand laterally outwardly of the body and also being inclined in the direction of rotation of the bit.

12. In a rotary bit as defined in claim ll; said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face.

13. In a rotary bit as defined in claim -1 1; each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body. 7

14. In a rotary bit as defined in claim 1 1; said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face, each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body.

said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways, said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face, each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body.

15/69) r 1" "'1' r w w "w \I (115R 1 11 16A 1 h 01 CORRILQ l ION Patent No. 3, Z27, 704 Dated April 17 a 1973 lnvcntorkz) THOMAS I ABPLANALP It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 31: "enshres" should be insures- Column 3-, line 32: "b" should be--defined--.

Column 6, line 36': "secondWshould be secondary.

Signed and sealed this 18th day of December 19-73.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER v Attesting Officer Acting Commissioner of Patents

Claims

1. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having first fluid passage means for feeding fluid from the interior of said body to said primary waterways, means for decreasing the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways to induce flow of fluid from said primary waterways across the lands to said secondary waterways, comprising second fluid passage means communicating with the interior of said body and proportioned to discharge fluid into said secondary waterways at a substantially higher velocity than the velocity of the fluid flowing through said primary waterways, each of said second fluid passage means extending laterally outwardly of said body and being inclined substantially to a radial plane passing through the axis of said body.

2. In a rotary bit as defined in claim 1; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways.

3. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having first fluid passage means for feeding fluid from the interior of said body to said primary waterways, said body having second fluid passage means for jetting fluid from the interior of said body into said secondary waterways, whereby the jetting fluid decreases the fluid pressure in said secondary waterways beloW the fluid pressure in said primary waterways to induce flow of fluid from said primary waterways across the lands to said secondary waterways; said second fluid passage means being inclined laterally outwardly and in the direction of rotation of the bit.

5. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having first fluid passage means for feeding fluid from the interior of said body to said primary waterways, said body having second fluid passage means for jetting fluid from the interior of said body into said secondary waterways, whereby the jetting fluid decreases the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways to induce flow of fluid from said primary waterways across the lands to said secondary waterways; said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face.

7. In a rotary bit as defined in claim 5; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways, said second fluid passage means being inclined downwardly and laterally outwardly of the bit and also being inclined in the direction of rotation of the bit.

8. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having a main fluid passage for receiving fluid from a tubular drilling string to which the body is securable, said body having distribution ports for feeding fluid from said main fluid passage to the inner portions of said primary waterways, said body having jet passages communicating with said main fluid passage and opening into said secondary waterways for jetting fluid under high velocity into said secondary waterways to decrease the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways, said jet passages being proportioned to discharge fluid into said secondary waterways at a substantially higher velocity than the velocity of the fluid flowing through said primary waterways, each of said jet passages extending laterally outwardly of said body and being inclined substantially to a radial plane passing through the axis of said body.

9. In a rotary bit as defined in claim 8; each of said distribution ports feeding fluid into a plurality of primary waterways, said primary waterways diverging from one another in a direction laterally outwardly of the body.

10. In a rotary bit as defined in claim 8; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways.

11. In a rotary bit: a body having a cutting face for drilling a bore hole, said face comprising a plurality of spaced lands extending laterally from an inner portion of the face to the outer portion of the face, said cutting face having primary and secondary waterways defining said lands and separating said lands from each other, said body having a main fluid passage for receiving fluid from a tubular drilling string to which the body is securable, said body having distribution ports for feeding fluid from said main fluid passage to the inner portions of said primary waterways, said body having jet passages communicating with said main fluid passage and opening into said secondary waterways for jetting fluid under high velocity into said secondary waterways to decrease the fluid pressure in said secondary waterways below the fluid pressure in said primary waterways; each of said jet passages being inclined downwardly and laterally outwardly of the body and also being inclined in the direction of rotation of the bit.

12. In a rotary bit as defined in claim 11; said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face.

13. In a rotary bit as defined in claim 11; each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body.

14. In a rotary bit as defined in claim 11; said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face, each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body.

15. In a rotary bit as defined in claim 11; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways, said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face.

16. In a rotary bit as defined in claim 11; said body having an outer vertical face extending upwardly from said cutting face, said vertical face having vertical grooves therein communicating with and extending upwardly from the outer ends of said primary and secondary waterways, said primary waterways being of progressively decreasing cross-sectional area in a direction laterally outwardly of the cutting face, each of said distribution ports feeding fluid into a plurality of primary waterways which diverge from one another in a direction laterally outwardly of the body.