Abstract:
Drill bit nozzle assemblies and methods of mounting the nozzle assemblies relative to a drill bit for drilling subterranean earth formations are described in which the nozzle assembly provides diverse rotational orientation of the nozzle about at least two axes relative to the drill bit. The nozzle assemblies generally include a nozzle body and an associated, cooperatively-configured nozzle body housing structure to facilitate orientation of the nozzle body within a nozzle orifice of a drill bit body and securement of the nozzle assembly with the nozzle body in a desired orientation.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to nozzles for use in subterranean earth boring drill bits and drill bits so equipped and, more particularly, to nozzles capable of various angles of adjustment to direct drilling fluid to different locations on and around the drilling apparatus. 
     2. State of the Art 
     Subterranean drilling operations generally employ a rotary type drill bit that is rotated while being advanced through rock formations. Elements on the face of the drill bit cut the rock while drilling fluid removes formation debris and carries it back to the surface. The drilling fluid is pumped from the surface through the drill stem and out through one or more, and usually a plurality of, nozzles located on the drill bit. The nozzles direct jets of the fluid to clean and cool cutting surfaces of the drill bit and for the aforementioned debris removal. 
     Because of the importance of the cooling and cleaning functions of the drilling fluid, others in the field have attempted to optimize these benefits by specifically orienting the nozzle exit to direct the drilling fluid to a predetermined location on a cutting surface of the bit. For example, U.S. Pat. No. 4,776,412 describes a nozzle assembly designed to resist rotational forces while directing drilling fluid to a predetermined rotational position. The nozzle&#39;s internal chamber is preformed to direct the fluid at a specific angle. Likewise, in U.S. Pat. No. 4,794,995, a nozzle is disclosed that changes the direction of fluid flow by angling the exit of the nozzle chamber. Again, the angle of exit is predetermined and may only be rotated about its longitudinal axis. U.S. Pat. No. 4,533,005 is another example of an attempt to provide a nozzle that may be reoriented to provide fluid flow in a specific direction. However, similar to other attempts, once the nozzle has been manufactured, the nozzle angle with respect to the longitudinal axis of the nozzle may not be changed. 
     The limited ability to adjust state of the art nozzles of a drill bit to accommodate desired fluid directions necessarily limits the amount of positioning or adjustment that can be attained to accurately establish a desired angle of fluid flow, and therefore limits the potential efficiency of the cleaning and cooling functions of the drilling fluid. The ease of manufacture of such nozzles is also limited because for every desired angle, the prior art systems require manufacture of another nozzle. Thus, it would be advantageous to provide a nozzle for use in subterranean earth boring drill bits which provides variable orientability of the nozzle relative to, but independent of, the orientation of the nozzle assembly in the drill bit. It would also be advantageous to provide a nozzle design that does not require a separately manufactured nozzle for every desired angle of drilling fluid flow. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, a nozzle and a system for mounting the nozzle provide modifiable orientation of the nozzle relative to a drill bit to enable accurate and efficient cleaning and cooling of the bit and its cutting structure by drilling fluid passing through the nozzle during subterranean earth boring operations. 
     According to the invention, a nozzle is structured to be adjustably orientable relative to a surface on a drill bit. The nozzle is thereafter secured into a nozzle orifice on the drill bit. That is, the nozzle orientation may be adjusted relative to the drill bit surface until a desired angle of fluid flow is achieved, then the nozzle is secured into the nozzle orifice of the drill bit. The nozzle is structured to permit a plurality of orientations with respect to the drill bit surface. 
     The nozzle comprises a nozzle body and a housing that secures the nozzle body within the nozzle orifice and provides the orientability feature of the present invention. The nozzle body may be spherical or tapered on its outer surface and includes a fluid passageway formed within. The nozzle may be formed of any suitable material with adequate abrasion and erosion resistance, such as tungsten carbide, or ceramics. Alternatively, the nozzle passage may be lined with such a material. The adjustable nozzle may be preferably removably secured within the nozzle orifice by suitable mechanical means known in the art including threaded sleeves or retainers or permanently secured therein by brazing, adhesive bonding, or welding. Thermally activated adhesives or metal bonding agents may be especially suitable for use, as easily activated by a torch. 
     In one preferred embodiment, the nozzle body is secured to a threaded sleeve at a predetermined angle during the manufacturing process. The may be secured by adhesive bonding, welding, brazing, or other means known in the art. The nozzle&#39;s threaded sleeve may then be inserted into the nozzle orifice with the nozzle positioned toward the cutting surface at the desired angle. A distinct advantage of this configuration is the ease in manufacturing a single nozzle body, rather than complex configurations requiring manufacture of various exit angles within the nozzle body. 
     In another preferred embodiment, the fluid passage of the nozzle is formed into a spherically shaped nozzle body. The spherically shaped nozzle body is then secured into the nozzle orifice by a number of threaded and/or non-threaded sleeves. These sleeves secure the nozzle body into the nozzle orifice at a desired angle. Thus, a single nozzle assembly may be used at several locations on the drill bit, each oriented to better clean and cool the drilling apparatus. 
     Finally, in another preferred embodiment, the nozzle body&#39;s external periphery is tapered toward the exit port of the nozzle body. The nozzle body is then secured in the nozzle orifice by sleeves that orient the nozzle body and thus the direction of fluid flow. That is, the surface of the sleeve that is in contact with the nozzle body provides the desired angle. This embodiment eliminates the costly manufacture of variously angled nozzle passages within the nozzle body. This, and other advantages of the present invention, will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     Methods of orienting and securing nozzle assemblies according to the present invention are also contemplated as included within the invention as well as tools for effecting such orientation and securement. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a drag type drill bit, partially sectioned to expose a nozzle according to the present invention; 
     FIG. 2 is a sectional view taken through the longitudinal center of a nozzle body with a symmetrical fluid passage; 
     FIG. 2A is a sectional view of a nozzle body similar to that of FIG. 2, but with an asymmetrical fluid passage; 
     FIG. 3 is a sectional view taken through the longitudinal center of a pair of sleeves that forms an alternate nozzle body housing; 
     FIG. 4 is a sectional view taken through the longitudinal center of a pair of sleeves that forms an alternate nozzle body housing; 
     FIG. 5 is a sectional view taken through one of the nozzle assemblies of the preferred embodiments of the present invention; 
     FIG. 6 is a sectional view taken through one of the nozzle assemblies of the preferred embodiments of the present invention; 
     FIG. 7 is a sectional view taken through one of the nozzle assemblies of the preferred embodiments depicting the angle of orientation; 
     FIG. 8 is a sectional view taken through one of the nozzle assemblies of the preferred embodiments depicting a tool used to hold the nozzle in the desired position during installation; 
     FIG. 9 is a perspective view of a tool used to rotate and tighten a threaded nozzle assembly; 
     FIG. 10 is a side elevation of a tri-cone drill bit, partially sectioned to expose a nozzle according to the present invention; 
     FIG. 11 is a sectional view taken through one of the nozzle assemblies of the preferred embodiments of the present invention; and 
     FIGS. 12A and 12B are sectional views of further preferred embodiments of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention is illustrated in the drawings with reference to a typical rotary earth boring bit. Referring to FIG. 1, an exemplary drag-type rotary bit  10  is shown, although the present invention possesses equal utility in the context of a tri-cone or “rock” bit  30  (see FIG.  10 ). A plurality of cutting elements  18  is secured to the face of the drill bit for cutting rock as the drill bit is rotated into a subterranean formation. A plurality of nozzles  25  (only one shown for purposes of illustration) according to the present invention is mounted in the face of the drill bit for directing drilling fluid to a desired location at the bottom of the borehole being cut. The drilling fluid is conducted to nozzles  25  through a passage or plenum  26  in the drill bit that communicates with a nozzle orifice  16 . The nozzles  25  are threadedly secured at the outer end of the orifices  16  and include nozzle exits or fluid passages  14  through which the drilling fluid is discharged. The drilling fluid cleans and cools the cutting elements  18  and carries formation cuttings to the top of the borehole via the annular space between the drill string and the borehole wall. It will be understood by those of ordinary skill in the art that a bladed-type bit carrying cutting elements  18  on one or more blades extending below the bit face may also be configured to incorporate the nozzles of the present invention and that the present invention exhibits equal utility with all configurations of drag bits, while demonstrating particular utility with bits wherein precise and diverse orientation of fluid flow is beneficial to the hydraulic performance of the bit. 
     Referring now to FIGS. 2,  2 A and  3 , each of nozzles  25  (as shown in FIG. 1) may comprise a nozzle body  12  having a substantially spherical outer surface  51  of a radius R and a housing  24  (as shown in FIG. 1) for securing the nozzle body  12  into nozzle orifice  16 . The fluid passage  14  in the nozzle body  12  of FIG. 2 is of the type which is symmetrical relative to a longitudinal axis L of the nozzle body  12 , whereby the passage  14  can be oriented by rotating the nozzle body  12  about any axis. That is, the passage  14  may direct a stream of fluid through the nozzle body  12  in a direction coaxial with the longitudinal axis L which is at a desired angle A relative to the longitudinal axis N of the nozzle orifice (see FIG.  7 ). The longitudinal axis L of the nozzle may be changed with respect to the longitudinal axis N of the nozzle orifice  16  by rotating the nozzle body  12  about a horizontal axis and may be rotationally oriented with respect to longitudinal axis N of nozzle orifice  16  as desired. 
     An outlet portion  55  of the nozzle body has a circular passage  59  of smaller inner diameter than a circular passage  57  of an inlet portion  53  of the nozzle body  12 . A beveled or frustoconical transition surface  54  interconnects the two passages  57 ,  59 , the transition surface  54  being oriented concentrically relative to the longitudinal axis L. The nozzle body  12  is preferably formed of tungsten carbide, so as to be resistant to the abrasive and erosive effects of drilling fluid during a drilling operation. Alternatively, passage  14  of nozzle body  12  may be formed of, for example, steel be to lined with an abrasion and erosion-resistant material such as tungsten carbide, ceramics or polyurethanes. 
     FIG. 2A depicts an alternative interior arrangement for nozzle body  12 , wherein a fluid passage  14 ′ is asymmetrically located in nozzle body  12  laterally offset from longitudinal axis L. In this embodiment, circular passage  57  necks down to outlet portion  55  via tapered passage  59 ′, which may be asymmetric as shown or comprise a symmetrical, frustoconical passage. Of course, fluid passage  14 ′ may be of asymmetric cross section throughout its entire extent, or be of symmetric cross section other than circular, such as rectangular, octagonal, etc. 
     The housing  24 , which comprises threaded sleeves  62 ,  84 , encases the outer peripheral surface of the nozzle body  12  so as to allow the nozzle body  12  to be rotatable relative thereto. An outer cylindrical surface of support sleeve  62  is formed with screw threads  76  which are adapted to be threadedly received by internal threads cast or machined in the nozzle orifice  16  of the drill bit. An annular channel  66  in the inner periphery of sleeve  62  is adapted to receive an O-ring seal  68 . The inner periphery of support sleeve  62  also has screw threads on its lower end  65  to receive threaded retention sleeve  84 . 
     Inner surface  64  of support sleeve  62  and inner surface  86  of retention sleeve  84  are shaped complementarily to the outer surface  51  of the nozzle body  12 . That is, the sleeves&#39;respective inner surfaces  64  and  86  have radii to match the outer radius R of nozzle body  12 . The radii of the sleeves&#39; inner surfaces are closely matched and slightly larger than those of the outer surface of the nozzle body so that the nozzle body  12  is freely rotatable on the inner surfaces  64 ,  86  of the sleeves  62 ,  84  but with relatively little play. The curved surfaces  64 ,  86  constitute abutment surfaces of the nozzle which enable the sleeves to displace the nozzle body  12  into the orifice  16  when the assembled housing  24  with nozzle body  12  in place is screwed into the nozzle orifice  16 . 
     Support sleeve  62  includes a fluid passage  82  at its upper end  71  of substantially the same diameter as the nozzle orifice  16  immediately adjacent its outer end where nozzle  25  is secured. At its lower end  65 , support sleeve  62  comprises an inner peripheral surface  70  that is threaded to match the threads  90  on retention sleeve  84 . Retention sleeve  84  includes a fluid exit passage  88  at its lower end  89  that allows unrestricted fluid flow for various orientations of nozzle body  12 . 
     The front end surface  87  of the retention sleeve  84  contains a plurality of bore holes  83  (e.g., six) adapted to receive complementarily shaped protrusions  200  on a tool such as a wrench  190  (FIG. 9) to enable an operator to secure the sleeve  62  and thus the nozzle  25  into the nozzle orifice  16  by means of the wrench  190 . Likewise, the front end surface  85  of the sleeve  62  contains a plurality of bore holes  81  (e.g., six) adapted to receive complementarily shaped protrusions of a wrench similar to that depicted in FIG.  9 . The sleeves may be formed of a softer material (e.g., steel) than the nozzle body to facilitate the cutting of screw threads therein, or of other suitable materials such as ceramics, which may be formed by casting. 
     To install the nozzle  25 , the support sleeve  62  is tightly screwed into the nozzle orifice  16  of the drill bit  10  using a wrench  190  of the type shown in FIG.  9 . The nozzle body  12  is then inserted into support sleeve  62  with outlet portion  55  of nozzle body  12  facing the lower end  65  of support sleeve  62  and held in place by screwing retention sleeve  84  into support sleeve  62 . The protrusions  200  of wrench  190  are inserted into bore holes  83  of sleeve  84  while orientation tool  171  is used to retain the desired angle, as shown in FIG.  8 . By inserting rod  170  into fluid passage  14  and inserting protrusions  181  into holes  182  in the bit face surrounding nozzle orifice  16 , orientation tool  171  will keep nozzle body  12  in position while wrench  190  is rotated to tighten threaded sleeve  84 . 
     Referring now to FIGS. 2,  2 A and  4 , another preferred embodiment is shown similar to the embodiment depicted in FIGS. 2,  2 A and  3 . Housing  32  is similar to housing  24  in that it is comprised of two sleeves  92 ,  100  which encase nozzle body  12  so that the nozzle body  12  may be rotatable relative thereto. Housing  32  differs from housing  24  in that the upper end  103  of the inner periphery  102  of sleeve  100  is of slightly larger diameter outer periphery  98  than sleeve  92  to secure sleeve  92  therein. Sleeve  92  slidably fits within the upper end of sleeve  100  to secure nozzle body  12 . Inner surfaces  96 ,  108  of the sleeves  92 - 100  are shaped complementarity to the outer surface  51  of the nozzle body  12 . Further, sleeve  92  comprises a fluid passage  94  at its upper end  93  that matches the diameter of the nozzle orifice  16  adjacent its outer end. 
     This nozzle assembly is installed in a similar manner to the previously-described embodiment. The nozzle body  12  is inserted into the upper end  103  of the sleeve  100  with front portion  55  of nozzle body  12  facing the front end  109  of sleeve  100 . The lower end  95  of sleeve  92  is then inserted into the upper end  103  of sleeve  100 . The sleeves  92 ,  100  and the nozzle body  12  are then inserted into the nozzle orifice  16  to be screwed into place by use of wrench  190 . The protrusions  200  of wrench  190  are inserted into holes  105  of sleeve  100  while orientation tool  171  is used to retain the desired angle as shown in FIG.  8 . Rod  170  is inserted into fluid passage  14  and protrusions  181  are inserted into holes  182 . Orientation tool  171  is used to keep nozzle body  12  in position while wrench  190  is rotated to tighten threaded sleeve  100 . 
     In yet another preferred embodiment (FIG.  5 ), the nozzle body  151  is similar to nozzle body  12  depicted in FIG. 3 except that the outer surface  158  has been tapered towards the nozzle exit. As with nozzle body  12 , the fluid passage  14  is defined by segments  57 ,  54  and  59 . The housing  134  is comprised of outer sleeve  140  and two inner sleeves  142 ,  150 . The outer sleeve  140  comprises an outer periphery  138  that is threaded to be threadedly attached to nozzle orifice  16 . The inner periphery  139  of sleeve  140  is cylindrical and complementarily sized to receive the inner sleeves  142 ,  150 . Sleeve  140  has holes  148  (e.g. six) formed in its lower surface  147  to receive protrusions  200  of wrench  190 . The sleeves  140 ,  142 ,  150  fit together so that the outer sleeve  140  may be freely rotated with respect to the inner sleeves  142 ,  150 , with relatively little play. 
     The inner sleeve  142  has an internal passage  153  to allow drilling fluid to reach nozzle body  151 . The lower surface  159  of sleeve  142  is angled about the longitudinal axis N to match the angle of the top surface  156  of nozzle body  151  when the latter is placed inside sleeve  150 . The lower surface  159  of the sleeve  142  also provides an orienting abutment for nozzle body  151 . 
     Sleeve  150  has an upper internal periphery  154  sized and shaped to complementarily match the outer surface  158  of nozzle body  151  and to provide an orienting abutment thereto. The upper internal periphery  154  of sleeve  150  is angled about the longitudinal axis N of the nozzle orifice  16  to orient the nozzle body about longitudinal axis L. The lower internal periphery  164  of sleeve  150  provides an exit passage  165  for fluid flow exiting nozzle body  151 . 
     To install nozzle body  151  into nozzle orifice  16 , sleeve  150  is slidably inserted into sleeve  140 . Nozzle body  151  is then placed inside upper internal periphery  154  of sleeve  150 . Sleeve  142  is then slidably inserted into sleeve  140  and placed on top of nozzle body  151  to form an abutment for the nozzle body  151 . The entire nozzle assembly  135  is then threadedly engaged into nozzle orifice  16 . As described in other embodiments, wrench  190  is used to tighten sleeve  140  into nozzle orifice  16  while the direction of the nozzle in the radial plane transverse to longitudinal axis L can be maintained by insertion of a rod in the nozzle passage. Orientation tool  171  is not required. It is apparent that, by use of differently-angled, selected complementary sleeve configurations, a single nozzle body  151  may be oriented at a plurality of preselected angles in nozzle orifice  16  with respect to axis N. 
     The embodiment depicted in FIG. 11 is similar to that shown in FIG. 5 with slight variations. The nozzle assembly  210  is comprised of a nozzle body  212  and a nozzle housing  213  that includes an outer sleeve  214  and two inner sleeves  216 ,  218 . Outer periphery  220  of nozzle body  212 , rather than being tapered along the entire longitudinal length L of the outer surface  158  as shown with regard to nozzle body  151  in FIG. 5, has an upper hemisphere  222  similar to nozzle body  12  (see FIG.  2 ). The lower portion  224 , though, is tapered similar to the nozzle body  151  depicted in FIG.  5 . 
     In this embodiment, the shape of the upper inner sleeve  216  does not need to be altered with a corresponding change in the configuration of the lower inner sleeve  218 . Thus, to adjust the angle of fluid flow from the nozzle orifice  16 , only the lower sleeve  218  needs to be changed. Installation of the nozzle assembly  210  is accomplished in the same manner as that required for the nozzle assembly shown in FIG.  5 . 
     Still another preferred embodiment is shown in FIG.  6 . This nozzle assembly  116  is similar to other embodiments except that it is comprised of a single housing sleeve  120  and nozzle body  12 . In this configuration, nozzle body  12  is attached to housing sleeve  120  by brazing, welding, adhesive bonding or other means known in the prior art. Nozzle body  12  may be oriented at a desired angle relative to longitudinal axis L before or after installation in the drill bit and then permanently attached to housing sleeve  120  thereafter. The installation of nozzle assembly  116  may be achieved using wrench  190 . In lieu of attachment of nozzle body  12  to housing sleeve  120 , it may be adhesively bonded with a weak adhesive and held in place by differential pressure of the drilling fluid. The mating surfaces  51  and  122  of the nozzle body  12  and sleeve  120  may be roughened to enhance their mutual engagement and position retention. As a further alternative, nozzle body  12  may be spring-loaded against housing sleeve  120  as shown in broken lines  124  in FIG.  6 . While a coil-type spring element  124  is shown, it will also be appreciated that a pre-loaded (compressed) elastomeric member may also be employed as a biasing element. A preferred nozzle passage orientation can thus be readily achieved, and maintained by fluid pressure during the drilling operation. 
     FIGS. 12A and 12B depict further embodiments of the present invention. The embodiment of FIG. 12A comprises an even more simplified version of the embodiments of FIGS. 5 and 11, wherein an exteriorly-threaded outer housing sleeve  250  having an inner bore  252  with annular stop  253  at the lower end thereof receives a nozzle body  254  of a slightly smaller outer diameter than that of inner bore  252  and having a fixed-angle fluid passage  256  therethrough oriented at an acute angle to longitudinal axis N of nozzle orifice  16 . Nozzle body  254  is freely rotatable about the longitudinal axis N of nozzle orifice  16  to a selected position until outer housing sleeve  250  is firmly made up in threaded nozzle orifice  16 . Thus, a number of interchangeable nozzle bodies  254  having different, preselected angles may be substituted within outer housing sleeve  250 . The embodiment of FIG. 12B merely comprises a nozzle body  151 ′ being identical on its exterior to nozzle body  151  but having a different interior configuration, nozzle body  151 ′ being substitutable in the embodiment of FIG. 5 for nozzle body  151 . As shown in FIG. 12B, nozzle body  151 ′ defines an asymmetrical interior fluid passage  14 ′ rather than a symmetrical passage as with nozzle body  151 . Such a configuration may permit a more severe angular departure from the longitudinal axis N of nozzle orifice  16  than the symmetrical fluid passage arrangement of nozzle body  151 . The asymmetrical fluid passage may also be employed with the embodiment of FIG. 11 by configuring the upper (inlet) portion of nozzle body  151 ′ substantially as a truncated hemisphere, as shown in broken lines  51 ′. 
     The present invention enables a variably orientable nozzle to be easily and effectively installed in place in proper orientation. The invention also includes tools for holding the position of the nozzle body and tightening the retaining sleeves to secure the nozzle at the desired orientation. 
     While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatus disclosed herein may be made without departing form the scope of the invention, which is defined in the appended claims. For example, multiple nozzle passages may be included in each nozzle; other nozzle body and passage cross-sectional shapes may be employed; and various alternative structures may be used to attach the nozzle body to the bit which allow for nozzle exit angle adjustment.