US 3084751 A
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Description (OCR text may contain errors)
April 9, 1963 W. E. SCARBOROUG H ATTOHNEYJ April 9, 1963 w. E. scARBoRouGH 3,084,751
DRILL BIT'NOZZLE Original Filed July 24, 1957 2 Sheets-Sheet 2 W////0m E. Jaa/'o/az/g INVENTOR 3,084,751 DRILL BIT NZZLE William E. Scarborough, Houston, Tex., assigner, by mesne assignments, to Dresser Industries, Inc., Dallas County, Tex., a corporation of Delaware Continuation or' application Ser. No. 673,923, July 24, 1957. This application Apr. 29, 1%0, Ser. No. 25,623 2 Claims. (Cl. 175-34iti) This invention relates to bits for boring earth formations and more particularly to nozzles in those bits with which drilling fluid is jetted downwardly toward the cutting operation carried on -by the cutters against the bottom of the hole. Even more particularly, the invention relates to the provision of a iiuid nozzle for the drilling fluid which may be easily installed, or replaced by a nozzle of different size or internal contour.
The bit to which the invention relates may be of any conventional form wherein the drilling fluid is pumped to the bit for direction by a nozzle downwardly from the bit. It is customary to provide a nozzle structure which is of different material than that used for the body of the bit itself. The nozzle is usually of material which is highly resistant to wear such as cast tungsten carbide, sintered carbide or a ceramic material. The diiculty solved by the present invention has been found in securing such nozzles in place by welding, brazing, cementing, etc. A well-equipped shop has been necessary, in the past, to install nozzles secured by these methods.
The present invention provides a structure which enables nozzles to be easily installed in the eld. Replacement of nozzles made under the teachings of the present invention may be made with relative ease. A nozzle may thus be readily selected from among various sizes in order that a bit be readily adapted to properly utilize the hydraulic capacity of the drilling rig.
Replaceable nozzles have been developed in they past. These nozzles have been retained in a fluid discharge bore in the bit body by abutting their upper ends against shoulders in the bore and then inserting snap rings into grooves at the lower end ofthe nozzle. The drilling fluid is very abrasive, and the exposure of the snap ring as well as the bit body at the lower end of the nozzle adjacent the snap ring groove `to the wash of the drilling fluid has caused this snap ring as well as the body portion supporting it to erode and fail, permitting the nozzle to be lost into the bottom of `the hole. This structural arrangement, wherein the snap ring and its support are continually exposed to drilling iluid, together with the fact that higher drilling iluid jet velocities and consequently high pressure differentials across the nozzle are being used, combine to make the snap ring somewhat unsatisfactory in many cases for retaining nozzles in the bit body. The present invention provides a retaining and sealing structure for `a drilling bit nozzle which is protected from the abrasive drilling lluid through the bit and which is arranged to utilize the resistance to shear of a body member easily inserted and extracted with common tools from the external surface of the bit body.
A main object of the invention is to provide a nozzle for a well drill bit which may be easily installed or replaced through the use of structure including a solid retainer member inserted and extracted from outside of the bit body and held in shear by forces on the nozzle when in operative position.
Another object is to provide a retaining structure for a nozzle in a drill bit including a solid deformable body held in shear as it bridges between recesses in the nozzle and bit body, isolated from the abrasive action of drilling liuid flowing through the nozzle.
Another object is to provide a retaining structure for a nozzle directing the drilling fluid of a drill bit downward, including a retainer member structure inserted from outside the bit body and into a passageway bridging between the nozzle and body between the ends of the nozzle. The passageway and pin are sealed from the high pressure drilling iluid coming to the nozzle from above and the retaining structure is shielded from the abrasive drilling fluid after it is discharged from the nozzle.
Other objects, features and advantages of the invention will be apparent to one skilled in the art upon consideration of the specification, appended claims and attached drawings, wherein:
FIG. l is a view in vertical cross-section through a well drill bit and replaceable nozzle constructed in accordance with this invention;
I FIG. 2 is a view in vertical cross-section through the part of FIG. 1 in which the replaceable nozzle is held in operative position;
FIGS. 3 and 4 are cross-sections through the nozzle and bit of FIGS. l and 2 showing `different forms for retaining members;
FIG. 5 is similar to FIG. 2, being in vertical crosssection through a portion of the bit, but illustrates another embodiment of the invention;
FIG. 6 is similar to FIG. 2, but illustrates another embodiment of the invention; and
FIG. 7 is a vertical cross-section through a bit portion in which a nozzle of distinctive form is retained in the bit with structure utilizing features of the invention.
In FIG. l of the drawings, a drill bit of the rolling cutter type is illustrated as comprising a head I having downwardly extending legs 2 within which the rolling cutters 3 have an arrangement which is well known. The head 1 has a dome 4 through which extend one or more passages 5 communicating between the interior and exterior of the bit head for the flow of drilling iiuid which emerges from the passage by way of nozzle 6, made of erosion resistant mate-rial such as tungsten carbide, sintered carbide, rubber or ceramic material.
Nozzle y6 is shown in 'greater detail in FIG. 2. It is to be understood that the invention may also be utilized with other types of bits and is not limited to the rolling cutter type shown. Further, the invention comprehends the use of either a single liuid passage in the bit or plurality of passages in which nozzles are to be positioned to direct drilling iiuid. Fur-ther, the invention comprebends the use of nozzles in body passages which direct the drilling iiuid in jets against either the cutters or against the bottom or sides of the hole being drilled by the cutters.
Passage 5 is counterbored to form a shoulder 7 which faces downwardly and to which the upper end of the nozzle is adjacent. The internal diameter of the counterbore is slightly larger than the outer diameter of the nozzle in order that the nozzle may be readily .slid into the coun-terbore, or removed, without rotation.
The nozzle 6 is releasably secured within the counterbore of passage `5 by means of a peripheral groove 8 formed in the wall of the `counterbore and a matching groove 9 formed in the external -wall of the nozzle forming a passageway in-to rwhich a retainer member is forced to bridge across the grooves. The axis of this passageway 8, 9 is circular, about the nozzle. Retainer member 10, as an elongated solid body, is forced along the axis of this passage and thereby deformed, or distorted, int-o the shape of the passage. The retainer member is forced into passageway 8, 9 from a passageway 11 through the body of the bit. This passageway 11 extends from the external surface of the bit and is brought into passageway 8, 9 tangentiallly. The registration of these passageways in this manner enables the retainer member to slide around 8, 9 smoothly in locking the nozzle into the bit body.
FIGS. 3 and 4 show the relation between the locking passageways and retainer member most clearly. These views are sections taken through that portion of the bit holding the nozzle and in a plane common to the passageway and retainer member. lFIG. 3 shows the retainer member in a solid cylindrical form which can be a nail or the like, while FIG. 4 shows a erinkled, wavy, or wiggly form 10A. Both forms have a head which is driven below `the bit body surface into counterbore 12 on the external end of passageway 11. A simple grasping tool, such as pliers, can be used to extract the retainer member manually. A hammer will drive the retainer member into locking position.
The crinkled retainer member 10A is more easily forced into passageway 11 than the solid -form of FIG. 3. This wavy form will permit use of metals for retainer member 16A which, in the solid `formt of FIG. 3 would prove too brittle to deform into the circular path formed by 8, 9.
Retainer member 10 must be made of substantially nonresilient material which can be deformed into passageway S, 9 but which is tough and strong enough to hold the nozzle against the forces placed on it. In position within its passageway, the body of the retainer member is placed in shear along its entire length. The wiggly form of retainer member `10A is also placed in shear Within its passageway, but not continuously along its length. The choice of for-m and material for this retainer member depends upon the `subjective factors of a particular design problem to which -the invention is applied. However, with the materials normally available at present, the solid, continuous form of the retainer member of lFIG. 3 offers greater resistance to the shear Iforces than the crinkled form because more of its material is placed in shear.
The force of the large pressure drop across the nozzle will, of course, tend to drive iluid between the outer cylindrical surface of the nozzle and the wall of -the counterbore `of passageS. `If the highly abrasive drilling uid were allowed to wash down between these two surfaces, it would erode the locking structure and cause its evenftual failure. If a seal were effected between Ithe nozzle and counterbore at a point below the retainer member 10, drilling iluid could still flow between the nozzle and counterbore and then out retainer member passage 11 unless the latter were sealed. Sealing of passage 11 complicates the use of the bit. Therefore, itt is simpler to provide the seal above the locking structure and thus isolate and protect it from the abrasion `of the drilling huid. The specific form of seal structure utilized in the preferred embodiment of the invention includes an annular groove about the nozzle, in the bit body passage, and resilient seal body in the groove to bear against the nozzle surface to provide resistance to leakage.
IFIGS. l and 2 show sealing groove 13 in the wall of the counterbore of passage 5 in the bit body, above the locking structure. Seal ring 114 is arranged in groove 13 and compressed against the nozzle lto form the seal. Seal ring 14 is of deformable material such as rubber and normally has an oval or circular radial cross-section. It is to be understood that seal ring 14 may be of any suitable ilexible deformable material and that the dimensions of the 4ring with relation -to the groove 13 is such that the ring 4is under initial compression when installed in the groove and the nozzle is in position within the counterbore of passage 5.
Referring to FIG. 3, it will Ibe seen that when the straight retainer member or pin lll is inserted through passageway or counterbore 11 -to be driven into position, its inner end will Contact the bit :body at a point along the Wall of passageway portion 8. At a point (called herein a fulcrum point) spaced from the point of contact of its inner end `and toward its outer end, the retainer member will contact the nozzle and at a point still closer to the nozzle can move back to a centered position.
the -outer end of the retainer member, it will again contact the bit body. Of course, the two points of contact with the bit body are on the side of the retainer member opposite `the point of contact with the nozzle. Thus, the retainer member is similar to a ulcrumed lever. As -the retainer -member is driven into position, it pushes the nozzle laterally 'away from the `fulcrurn point, thereby increasing the clearance between the nozzle and the wall of passage 5 in the vicinity of .the `fulcrum point. This increased clearance is maintained as the retainer member is driven toward its :fully inserted position. As a result, it is possible within manufacturing tolerances, that the clearance is so great that the seal ring d4 loses its effectiveness on one side of the nozzle, namely, on the side of the fulcrum point. Also, the increased clearance may be great enough that at high pressure differentials across the nozzle and hence across the seal ring, the latter may be extruded into the clearance so as to destroy its sealing ability.
In order that the nozzle can be re-centered after the retainer member has been driven into position, counterbore 11 is given a lateral dimension in the plane of line 3-3 of FIG. l such that the retainer member as a whole can be rotated about the longitudinal axis of the nozzle suificiently that the nozzle is free to move bacii to a position coaxial with passage 5. Stated in another manner, the head of the retainer member would move upwardly in FIG. 3 in an are about the nozzle axis. As a result, the fulcruming action of the retainer member tending to hold the nozzle to one side, is removed so that In fact, once the fulcruming action is removed, the natural resiliency of the seal ring will re-center the nozzle, thereby re-establishing the maximum sealing efhciency of the rmg.
The exact lateral dimension required in counterbore 11 to permit recentering of the nozzle will be dependent upon a number of design factors such as the relative diameters of the retainer member and passageway 8, 9, etc. but the dimensions can be determined by a routine designer lfor any particular bit.
FIG. 5 illustrates how a seal groove 15 can be periphorally formed in a nozzle. Seal ring 14 can be arranged in nozzle groove 15. rl`he result is to bring the seal ring up against the surface of the passage in the bit body in a sealing function similar to that produced by bringing the seal ring up against the external surface of nozzle 6 in FIGS. l and 2.
The shoulder provided by the counterbore of passage 5 in FIGS. l and 2 is aligned with the nozzle bore to give a smooth ow of drilling fluid from the body and into `the nozzle. The nozzle need not abut the shoulder in the sense of performing a sealing function with it. The seal structure between the upper end of the nozzle and the locking structure performs this function. Further, the two members need not abut to prevent movement of the nozzle because the locking structure prevents movement of the nozzle in either direction. I-Iowever, the stream of fluid is guided smoothly into the nozzle by properly sizing the nozzle and body passages so they align and the shoulder 7 helps prevent erosionof the bit body in the passage 5 adjacent the upper end Vof the nozzle.
In FIG. 5, it is to be noted that the nozzle 16 is fixed in operable position within a body passage 17 which has no counterbore `to provide a protecting shoulder at the upper end of nozzle 16. While present day nozzle manufacturing techniques and materials make it desirable that the walls of the nozzle at its upper end have some thickness (ie. terminate in a shoulder although it can be a rounded one and not terminate in a thin edge), it has been found that erosion of the bit body adjacent the upper end of the nozzle is usually negligible even in the absence of the protecting shoulder. Hence the shoulder can be eliminated and the use of matching grooves which are similar to 8 and 9, along with a retainer member within the passageway so formed, is effective to fix the position of nozzle 16 in passage 17 against movement in either direction. This disclosure of FIG. 5 emphasizes that the combination of retainer member and matching grooves in body and nozzle is sufficient -to fix nozzle 16 against movement in either direction within passage 17 under the urging of vforces from either direction Without employment of a shoulder structure in the passage 17.
Another aspect of the invention is shown in FIG. 6 as providing a plurality of combinations of matching body and nozzle grooves with retainer members deformed into them. As shown in FIG. 6, -the nozzle of the FIGS. l and 2 has been modified to form a passage retainer member combination 18, similar to that in which body passageway 11 is included. The result is a series of locking structures for nozzles in passages of bit bodies. A number of locking means may be utilized as required, under the teachings of the invention, to resist any anticipated value of shear imposed upon the retainer member by the forces developed across the bit body passage in which a nozzle is positioned.
FIG. 7 is utilized to illustrate another form of passage with which a retainer member also acts to fix a nozzle into position within a bit body passage. A bit body portion 2) has been illustrated in vertical cross-section, as well as a nozzle 21 in a passage 22. Passage 22 has been counterbored to provide a shoulder 23 against which nozzle 21 is caused to abut. A groove 24 has been formed peripherally about nozzle 21 in the material of body 20 below shoulder 23. Within groove 24 is arranged an O-ring seal 25 compressed against the external wall of nozzle 21.
The external surface of nozzle 21 has been reduced in diameter below its seal structure at 24, 25 to form a shoulder 26. With the top of nozzle 21 abutting shoulder 23, nozzle shoulder 26 is caused to register with the top of a groove 27 formed in lthe wall of the counterbore of passage 22. A retainer member 28 is forced Iinto the space formed by groove 27 and the space under shoulder 26 of nozzle 21. It is clear that nozzle 21 is thus held in abutment against body shoulder 23 by the resistance of retainer member 28 to the shear force exerted by shoulder 26. The result is a positional location of nozzle 21, or a locking thereof, within the counterbore of passage 22.
One advantage of the FIG. 7 arrangement lies in the fact :that the positional locking provision has been obtained with a relatively cheaper form `for nozzle 21. Thus, a finite amount of valuable nozzle material is saved by the simple extension of the reduced diameter of the nozzle the remainder of its length below shoulder 26. The wear resistant materials of which Ithese nozzles must be formed is quite expensive, and any saving of this material becomes quite important commercially.
All disclosure of nozzles in the vanious figures of the drawing has utilized internal configurations in which the internal diameter below the top of the nozzle is materially reduced toward the nozzle bottom. These streamlined reductions in cross-section increase the velocity of the drilling fluid greatly. However, it must be emphasized that these configurations are only representative of many variations possible. For example, it may be required that the nozzle be simply cylindrical. Whatever the configuration used internally of the nozzle, it must not be construed as limiting the scope of invention embodied in the locking and sealing combination disclosed.
From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense;
This application is a continuation of my copending application Serial No. 673,923, filed Iuly 24, 1957.
The invention having been described, what is claimed is:
l. A rotary drill bit including a body having a cutter means mounted thereon and a passage for discharging drilling fluid downwardly from the body; a replaceable, hard, brittle nozzle of circular cross-section adapted to be slipped upwardly into the body passage for controlling the discharge of fluid from the body; a circumferential groove in the outer wall of the nozzle; a circumferential groove in the inner wall of the body passage surrounding the nozzle and spaced vertically in the body passage to match the circumferential groove in the nozzle so that the body and nozzle grooves together form a first passageway whose walls are longitudinally divided between the nozzle and body; a second passageway extending from the exterior of the body to the first passageway; an elongate, stiff, bendable but non-resilient retainer member having portions thereof disposed in the first and second passageways with the portion in the rst passageway bridging between the grooves in the nozzle and body and preventing endwise displacement of the nozzle from the body; the nozzle and body grooves and the retainer member portion therein being vertically spaced `below the upper end of the nozzle and sufhciently far above the lower end of the nozzle that they are isolated from impingement by turbulent drilling fluid with abrasive particles therein Which is discharged from the nozzle; and a resilient fluid energized seal means of the 0- ring type between the nozzle and body above the nozzle and body grooves preventing drilling fiuid from fiowing downwardly between the nozzle and body; said second passageway having a lateral dimension sufficiently larger than the corresponding lateral dimension of the retainer member portion in the second passageway such that the retainer member can be rotated about the longitudinal axis of the nozzle to eliminate the fulcruming action exerted on the nozzle by the retainer member as the latter is driven into place, thereby permitting the nozzle to be recentered in the body passage by the seal means.
v2. A rotary drill bit including a body having a cutter means mounted thereon and a passage for discharging drilling fluid downwardly from the body; a replaceable, hard, brittle nozzle of circular cross-section adapted to be slipped upwardly into the body passage for controlling the discharge of fluid from the body; a circumferential groove in the outer wall of the nozzle, a circumferential fgroove in the inner wall of the body passage surrounding the nozzle and spaced vertically in the body passage to match the circumferential groove in the nozzle so that the body and nozzle grooves together form a yfirst passageway whose walls are longitudinally divided between the nozzle and body; a counterbore extending from the exterior of the body to the `first passageway; a metal retaining member of stiff, bendable but non-resilient material and having portions thereof disposed in the first passageway and in the counterbore with the portion in the first passageway bridging between the grooves in the nozzle and body and preventing endwise displacement of the nozzle from the body; the nozzle and body grooves and the pin therein being vertically spaced below the upper end of the nozzle and sufficiently far above the lower end of the nozzle that they are isolated from impingement by turbulent drilling fiuid with abrasive particles therein which is discharged from the nozzle; and an O-ring seal between the nozzle and body above the nozzle and body grooves preventing drilling uid from owing downwardly between the nozzle and body; said counterbore being of suiiciently larger diameter than that of the pin portion disposed therein such that the pin, after being driven into place, can be rotated about the nozzle axis to eliminate the fulcrurning action of the pin on the nozzle, thereby permitting the nozzle to be recentered in the body passage by the O-ring.
References Cited in the le-of this patent UNITED STATES PATENTS Mackey et al Feb. 28, 1933 Howard et al Apr. 13, 1937 Melsonl Feb. 9, 1943 Mahoney Jan. 1l, 1949 Payne Oct. 7, 1958 Hammer May 5, 1959 Sherman Dec. 8, 1959