Stabilizer with Drilling Fluid Diverting Ports

Abstract

Described are drilling subs that may be connected in a drill string for reducing the accumulation of debris on the exterior of the drill string or otherwise facilitating the return of drilling fluid during drilling operations. A plurality of radially spaced stabilizing blades protrude from an exterior surface of the drilling subs to define exterior flow channels therebetween through which drilling fluid returning to the surface may is directed. Diverting nozzle passages are provided that extend between an inner axial passage of the drilling subs and the exterior surface of the drilling subs. The diverting nozzle passages exhibit a radial spacing corresponding to a radial spacing of the exterior flow channels such that drilling fluid discharged from the diverting nozzle passages is directed toward the exterior flow channels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of co-pending U.S. Provisional Application 61/608,755, filed Mar. 9, 2012. This application also claims priority to and the benefit of co-pending U.S. application Ser. No. 13/341,991, filed Dec. 30, 2011, which claims priority to U.S. Provisional Application 61/430,877, filed Jan. 7, 2011. The full disclosure of each of these applications is hereby incorporated by reference herein for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application relates to earth boring operations, and in particular to upward and outward pointing drilling fluid diverting nozzles located in a drill string above a drill bit.

2. Description of the Related Art

Oil and gas wells are typically drilled with a drill string having a drill bit on bottom that is rotated. One type of drill bit is a drag bit having blades with cutting disks that scrape against and cut the formation. Mud pumps on a drilling rig pump drilling fluid down the drill string and out nozzles on the bit face to sweep formation cuttings from the bit face. The drilling fluid entrains the cuttings and returns up an annulus surrounding the drill string. Particularly for horizontal wells, a mud motor may be provided in the drill string to rotate the drill bit. Drilling fluid pressure powers the mud motor to rotate the drill bit independently of the drill string rotation. The mud motor requires a considerable pressure and flow rate of drilling fluid in order to be able to apply the desired torque to the drill bit.

If the cuttings are not readily removed, the rate of penetration of the drill bit into the earth declines. Drill bits may also plug and ball up while drilling sticky shale formations. If the mud motor is not able to rotate the drill bit at a desired rotational speed, the rate of penetration may decline. Many variations in the bit nozzle diameters, orientation and placement are used in order to more effectively remove cuttings.

SUMMARY OF THE INVENTION

Described herein are methods and apparatuses for reducing and/or preventing the accumulation of cuttings or other debris on a drill string during drilling operations. Drilling subs are provided in a drill string that include diverting fluid passages extending between an interior and exterior thereof. A portion of the drilling fluid being pumped downward through the interior of the drill string is diverted through the passages such that additional turbulence is produced in the flow of the drilling fluid returning upward in the annulus around the drill string. The additional turbulence may dislodge accumulated sediments, e.g., from between stabilizer blades, or prevent the sediment from precipitating from the drilling fluid.

According to one aspect of the disclosure, an apparatus for facilitating the return of drilling fluid through an annulus surrounding a drill string includes a longitudinal body defining an upper end, a lower end and a longitudinal axis extending therebetween. The upper and lower ends include connectors for connecting the longitudinal body into the drill string. An interior axial passage extends between the upper and lower ends of the longitudinal body for conveying drilling fluid through the longitudinal body. A plurality radially spaced blades are provided that protrude from an exterior surface of the longitudinal body and define open exterior flow channels therebetween. A plurality of radially spaced diverting nozzle passages extends between the inner axial passage and the exterior surface of the longitudinal body. The diverting nozzle passages terminate in nozzle openings exhibiting a radial spacing corresponding to a radial spacing of the exterior flow channels. Drilling fluid discharged from the diverting nozzle passages is directed toward the exterior flow channels.

According to another aspect of the disclosure, a wed drilling apparatus includes a body defining a longitudinal body axis, and having a threaded upper end for connection into a drill string and a threaded lower end for connection and rogation with an earth boring bit. An axial passage is provided in the body for conveying drilling fluid to an outlet in the earth boring bit. A plurality of blades extend radially outward from an exterior surface of the body, and are radially spaced to define exterior flow channels therebetween. The plurality of blades is configured for engaging a wall of a borehole formed by the earth boring bit. A plurality of nozzles outlets is defined on the exterior surface of the body and in fluidic communication with the axial passage. Each of the nozzle outlets has a longitudinal position along the body between upper and lower ends of the radially spaced blades.

According to another aspect of the disclosure, a method of drilling a well includes the steps of: (a) providing a drill string having an earth boring device at a lower end thereof, wherein the drill string has a body coupled therein, and wherein the body defines a longitudinal axis and includes a plurality of blades extending radially outward from an exterior surface of the body, and wherein the body further includes a plurality of nozzle outlets defined on the exterior surface of the body between the blades, and an axial passage extending through the body and in fluidic communication with each of the nozzle outlets; (b) lowering the drill string into the well and rotating the earth boring device; (c) pumping drilling fluid down the drill string into the axial passage of the body, and conveying a first portion of the drilling fluid through the axial passage and discharging the first portion of the drilling fluid through an outlet defined in the earth boring device into an annulus surrounding the drill string; and (d) diverting and discharging a second portion of the drilling fluid from the axial passage in the body through plurality of nozzle outlets into the annulus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational and partly sectioned view of a drill string having a drilling fluid diverting sub in accordance with this disclosure.

FIG. 2 is a vertical sectional view of the drilling fluid diverting sub of FIG. 1.

FIG. 3 is a horizontal sectional view of the drilling fluid diverting sub of FIG. 1, taken along the line 3-3 of FIG. 1.

FIG. 4 is a perspective view of one of the nozzles of the drilling fluid diverting sub of FIG. 1.

FIG. 5 is a perspective view of the nozzle of FIG. 4, as seen from a different view point.

FIG. 6 is a sectional view of the nozzle of FIGS. 4 and 5.

FIG. 7 is a perspective view of an alternate embodiment of the drilling fluid diverting sub of FIG. 1.

FIG. 8 is an exploded side view of a stabilizer with a fluid diverting sub.

FIG. 9 is a side view of the stabilizer of FIG. 8 secured to the fluid diverting sub.

FIG. 10 is a side view of the stabilizer and sub of FIG. 9 connected into a drill string.

FIG. 11 is a side view of a stabilizer having integral fluid diverting nozzles.

FIG. 12 is a side view of three of the stabilizers of FIG. 11 connected into a drill string.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring to FIG. 1, a well bore 11 is illustrated being drilled by a drill string 13. Although well bore 11 is shown as being vertical, often it will have a horizontal portion. In this example, drill string 13 includes a mud motor 15, which is a conventional component. Mud motor 15 typically has blades or stabilizers 17 extending from its outer side. A drilling fluid or drilling mud diverting sub 19 is secured to the lower end of mud motor 15. Sub 19 has diverting nozzles 21 in its side wall that have outlets pointing outward and upward. Sub 19 may be joined to an upper end 23 of a conventional earth boring device or bit 25.

In this example, bit 25 is a drag bit having cutting blades 27 extending from a circumference to a lower side or face. Blades 27 have cutting elements 29 mounted thereto for scraping the earth formation as bit 25 rotates. Cutting elements 29 may be formed of a polycrystalline diamond or other materials. Bit 25 also has at least one, and normally several outlets or bit nozzles 31 on its face. Bit outlets 31 receive drilling fluid pumped into a central cavity of bit 25 and discharge the drilling fluid at various angles relative to the face of bit 25. The discharged drilling fluid entrains cuttings of the earth formation and flows up an annulus surrounding drill string 13.

Drilling fluid diverting nozzles 21 in sub 19 discharge a portion of the drilling fluid being pumped down drill string 13 before the drilling fluid reaches bit 25. The flow from nozzles 21 joins the fluid stream of drilling fluid being pumped out of bit nozzles 31. In this embodiment, there are three fluid diverting nozzles 21, these being nozzle 21a, nozzle 21b, and nozzle 21c. Nozzles 21a, 21b and 21c are equally spaced around the side wall of sub 19, 120 degrees apart front each other. More or fewer nozzles 21 is feasible.

Referring to FIG. 2, sub 19 has a tubular body 35 with a threaded upper end 37 for securing to a threaded lower end of mud motor 15 (FIG. 1). Sub 19 may also have a threaded lower end 39 for securing to threaded upper end 23 of bit 25. Alternately, sub 19 could be integrally formed with and be a part of bit upper end 23. An interior axial passage 41 extends through sub body 35 along a longitudinal axis 43. For each nozzle 21, a diverting nozzle passage 45 joins axial passage 41 and extends upward and outward along a nozzle axis 47 to the exterior of sub body 35. In this example, nozzle axis 47 is oriented upward about 45 degrees, but different angles are feasible.

Referring to FIG. 3, an axial or vertical plane 49 is illustrated as emanating from and containing longitudinal axis 43 and also passing through the center of the outlet of each nozzle 21. In this embodiment nozzle axis 47 is not located within axial plane 49, rather it intersects axial plane 49 at the outlet of nozzle 21. The angular difference between nozzle axis 47 and axial plane 49 is referred to herein as an oblique angle and indicated by the numerals 51, 53 and 55 for nozzles 21a, 21b and 21c, respectively. Unlike axial plane 49, a vertical plane containing nozzle axis 47 would not be normal to the cylindrical exterior of body 35. Nozzle axis 47 thus is oblique to the cylindrical exterior of body 35, in addition to pointing upward and outward. Considering the direction of rotation, which is clockwise looking down as shown by the arrow, each nozzle axis 47 lags axial plane 49.

In this embodiment, oblique angle 51 for nozzle 21a is less than oblique angle 53 for nozzle 21b, which in turn may be less than oblique angle 55 for nozzle 21c. In one example, oblique angle 51 is 10 degrees, oblique 53 is 20 degrees, and oblique angle 55 is 30 degrees. Different oblique angles may be employed. Further, it is not essential that each oblique angle differ; rather one oblique angle could differ from only one other oblique angle or all of the oblique angles may be the same.

Also, in this embodiment, each nozzle 21 is at a different elevation than the others. For example, as shown in FIG. 1, nozzle 21a is the lowest, or closest to drill bit 25. Nozzle 21b is farther from drill bit 25 than nozzle 21a. Nozzle 21c is farther from drill bit 25 than nozzle 21c. The difference is distance to drill bit 25 can vary. In one example, the difference is about ⅜ inch from nozzle 21a to nozzle 21b and the same amount form nozzle 21b to nozzle 21c. The lowest nozzle, which is nozzle 21a, may have the smallest oblique angle 51, as shown in FIG. 3. It is not essential that the elevations for each nozzle 21 differ. For example, the distance to bit 25 may differ between only two of the nozzles 21, or all of the elevations could be the same.

Referring again to FIG. 2, a check valve 57 may optionally be inserted into an upper portion of axial passage 41. Check valve 57 may be of various types. In this example, a check valve element is biased by a spring 59 against a seat in a cartridge 61. Cartridge 61 rests on a shoulder in the upper portion of axial passage 41, which is slightly larger in diameter than the central portion that is intersected by nozzle passages 45. Check valve 57 allows down flow of fluid in axial passage 41, but blocks upward blow. When running drill string 13 into the well bore 11, check valve 53 resists silt and cuttings from passing upward through bit outlets 31 to mud motor 15, where damage may occur.

Referring to FIGS. 4-6, each nozzle 21 may have helical grooves 63 formed in its bore or outlet 64. Grooves 63 spiral from one end to the other of outlet 64. The helical angle may vary. Also, FIG. 4 shows that the outer end of each nozzle 21 may have a conical recess 65 that diverges outward. Each nozzle 21 has an O-ring seal groove 67 on its outer diameter for sealing within nozzle passage 45 (FIG. 2). Nozzles 21 may be retained in various conventional manners. A retainer ring shoulder 69 receives a snap ring to retain nozzle 21 in this example.

Referring to FIG. 7, substantially the entire exterior of fluid diverting sub 19′ may have protrusions or dimples 71 formed therein. Dimples 71 serve to enhance turbulence of drilling fluid flowing past sub 19′.

In operation, fluid diverting sub 19 is secured into drill string 13 between drill bit 25 and mud motor 15. Alternately, fluid diverting sub 19 may form an upper part of drill bit 25. If the operator wishes to test mud motor 15 before lowering the string into well bore 11, and if fluid diverting sub 19 is connected between mud motor 15 and drill bit 25, the operator will install blank plugs in nozzle passages 45 in place of nozzles 21. The blank plugs allow the operator to pump drilling fluid through mud motor 15 and out bit outlets 31 to test whether mud motor 15 properly rotates drill bit 25.

After testing, the operator installs nozzles 21 in fluid diverting sub 19. The operator can select different diameters for the bores of diverting nozzles 21 so as to create a desired flow area ratio to the bit nozzles or outlets 31. The total flow areas of the diverting nozzles 21 will be fairly small relative to the total flow areas of the bit outlets 31. Typically, the cumulative diverting nozzle flow area will be only 10 to 20 percent of the cumulative flow area of bit outlets 31.

Once the nozzles 21 are installed, the operator lowers the drill string 13 into well bore 11. When reaching the bottom of well bore 11, the operator rotates drill bit 25 to begin drilling while also pumping drilling fluid down drill string 13. Blades or stabilizers 17 engage a wall of the well bore 11 to stabilize the drill string 13. The operator can rotate drill bit 25 by rotating drill string 13 from the drilling rig. The operator can also hold drill string 13 stationary, and the drilling fluid flowing through mud motor 15 will rotate drill bit 25 and fluid diverting sub 19 in unison with each other. When drilling horizontal wells, the operator may use both procedures at various times. Mud motor 15 is optional for certain drilling operations, such as vertical portions of the well. In those instances, mud motor 15 may be eliminated and fluid diverting sub 19 may connect to a lower end of drill string 13, such as the drill collars.

The drilling fluid flows into bit cavity 33 and out bit outlets 31. The drilling fluid returns back up the annulus surrounding drill string 13, bringing earth formation cuttings. A portion of the drilling fluid is diverted out through diverting nozzles 21. The upward and outward directed drilling fluid mixes with the returning drilling fluid discharged from bit outlets 31, creating turbulence and enhancing the retention of cuttings in the flow stream. The jets of drilling fluid exiting fluid diverting nozzles 21 will swirl due to the helical grooves 63 (FIG. 4).

Referring to the alternate embodiment of FIG. 8, stabilizer sub 73 has a tubular body 75 for connection into a drill string. Tabular body 75 defines a longitudinal axis 76 that extends through an interior axial passage (see FIG. 2) provided for conveying drilling fluid through the tubular body 75.

Several blades 77 are secured of formed on the exterior of body 75 for engaging a borehole wall for stabilizing a drill string. Blades 77 are radially spaced and protrude radially form an exterior surface of body 75 such that open exterior flow channels 77′ are defined between the blades 77. Blades 77 may be inclined relative to the axis 76, as shown in FIGS. 8-10, or they may be parallel to the axis 76, as illustrated in FIG. 1. Blades 77 may be straight or curved. Stabilizer sub 73 has an internally threaded box or upper end 78 for connection to a drill string member. In this embodiment, stabilizer sub 73 also has an internally threaded box or lower end 79 that is located a short distance from the lower ends of blades 77. The lower ends of blades 77 are all located the same distance above the lower end 79 of body 75 in this example. The upper ends of blades 77 are all located the same distance below upper end 78. The distance from lower end 79 to the lower ends of blades 77 is shown much smaller than the distance from the upper ends of blades 77 to upper end 78, but the distances could be the same.

A fluid diverting sub 81 has a tubular body 83 with a plurality of fluid diverting ports or nozzle outlets 85. Tubular body 83 defines a longitudinal axis 84 that extends through an interior axial passage (see FIG. 2) provided for conveying drilling fluid through the tubular body 83. Nozzle outlets 85 are in fluid communication with the interior axial passage through a Respective fluid diverting nozzle passage (see FIG. 2) and point upward and outward to discharge a portion of the drilling fluid being pumped down the drill string. Nozzle outlets 85 may be constructed and oriented the same as nozzles 21a, 21b and 21c in FIG. 1. Three or more nozzle outlets 85 are preferably used in sub body 83.

Sub body 83 has an upper externally threaded pin 87 that secures to the internally threaded lower end 79 of stabilizer sub 73. Sub body 83 has a lower externally threaded pin 89 that secures to another component of the drill string. Flats 91 may be formed on the exterior of sub body 83 for engagement by a wrench to apply torque to secure sub 81 to stabilizer sub 73. When secured as assembly 92 shown in FIG. 9, the axial distance from the uppermost nozzle outlet 85 to the lower ends of blades 77 is quite small, such as three to five inches.

Commercially available stabilizers typically have an externally threaded pin on the lower end, rather than an internally threaded end. Since the externally threaded pin of a commercially available stabilizer would protrude some distance into a sub coupled below the commercially available stabilizer, nozzle outlets 85 provided the sub coupled below the commercially available stabilizer would typically need to be provided at a location below the threaded pin of the commercially available stabilizer. Also, the distance from the upper end of the threaded pin to the lower ends of the blades is farther normally than the distance from internally threaded lower end 79 to the lower ends of the blades 73. Stabilizer sub 73 may be formed by cutting off the lower threaded pin of a commercially available stabilizer and machining an internally threaded lower end 79. Alternately, assembly 92 of FIG. 9 could be integrally formed from a single tubular body.

A radially spacing of the nozzle outlets 85 and corresponding diverting nozzle passages may correspond the radial spacing exhibited by the exterior flow channels 77′ such that drilling fluid discharged from the nozzle outlets 85 is directed toward the exterior flow channels 77′ in some embodiments. Discharging drilling fluid from the nozzle outlets 85 and directing the discharged drilling fluid through the exterior flow channels 77′ facilitates the return of drilling fluid at least by dislodging debris or sediments that accumulates between the blades 77. In some embodiments, each of the nozzle outlets 85 defines a nozzle axis that points upward and outward and also at an oblique angle relative to a vertical plane of the body axis that intersects the nozzle axis at the nozzle outlet in a manner similar to nozzles 21 described above with reference to FIGS. 2 and 3. The plurality of blades 77 are inclined, in some embodiments with respect to the longitudinal axes 76, 84 in the direction of the oblique angle of the nozzle outlets 85.

One manner of utilizing assembly 92 is illustrated in FIG. 10. Drill bit 93 is secured to a fluid diverting sub 95 having nozzles 96 that may be the same as fluid diverting sub 19 of FIG. 1. A mud motor 97, which may the same as mud motor 15, except it may lack stabilizer blades, may be secured to the upper end of fluid diverting sub 95. Fluid diverting sub 95 may have a float or check valve similar to valve 37 (FIG. 2) to impede debris from flowing into mud motor 97 when the drill string is being lowered into the borehole. Other tubular members such as a drill pipe or drill collar may be provided in addition to or as an alternative to mud motor 97 in some embodiments. During drilling, some of the drilling fluid being pumped down the drill string diverts out stabilizer sub nozzle outlets 85 to enhance flow of fluid and cuttings between blades 77. The discharged fluid retards cuttings and debris packing between blades 77 keeping the exterior flow channels 77′ relatively clear. The proximity of the nozzle outlets 85 to the flow channels 77′ allows the fluid discharged from the nozzle outlets to retain sufficient energy to clean the channels 77′. The velocity and force of the fluid discharged from the nozzles 85 facilitates cleaning of the channels 77′ by generating turbulence in the annular flow of drilling fluid returning to the surface. The proximity of the nozzle outlets 85 to the flow channels 77′ ensures that the turbulence is maintained as the drilling fluid passes the through the flow channels 77′, and thereby facilitates cleaning the flow channels 77′. Additional drilling fluid is also diverted through fluid diverter nozzles 96 just above bit 93 in the same manner as discussed in connection with fluid diverter 21 in FIG. 1.

Referring to FIG. 11, stabilizer 99 has a tubular body 101 defining a longitudinal axis 102. An interior axial passage (see FIG. 2) extends through the tubular body 101 for conveying drilling fluid therethrough. The stabilizer 99 includes blades 103 that may be the same as blades 77 of FIG. 8. Exterior flow channels 103′ are defined between the blades 103. In this example, the axial lengths of blades 103 are much closer to the overall length of body 101 than the lengths of blades 77 relative to body 75 of FIG. 8. A number of ports or nozzle outlets 105 are formed in an exterior surface of body 101. The nozzle outlets 105 are in fluid communication with the interior axial passage through a respective fluid diverting nozzle passage (see FIG. 2). Nozzle outlets 105 may be constructed and positioned relative to each other in the same manner as nozzles 21 of FIG. 1. Each of the nozzle outlets 105 is longitudinally positioned between upper and lower ends of blades 103. Optionally a nozzle outlet 105 may be located between each of the blades 103. As illustrated in FIG. 12, a lowermost nozzle outlet 105a may be disposed between two blades 103 near the lower ends of blades 103. A next upward nozzle outlet 105b may be located between two blades 103 about midway along the longitudinal lengths of blades 103. An uppermost nozzle outlet 105c may be located between two of the blades 103 near the upper ends of blades 103. More than three nozzles 105 may be employed.

Stabilizer 99 is illustrated as having an internally threaded lower end or box 107. Stabilizer 99 may have an externally threaded upper end or pin 109. The upper ends of blades 103 are quite close to the base of upper threaded end 109, such as less than two inches. The Lower ends of blades 103 may also be less than two inches from internally threaded lower end 107.

FIG. 12 illustrates one arrangement where stabilizers 99 may be utilized in a drill string. Internally threaded lower end 107 of a lowermost stabilizer 99a is secured to the external threaded pin of a bit 111. One or more drill collars 113 extend upward from lowermost stabilizer 99b. Drill collars 113 are sections of drill pipe with a greater weight and wall thickness than the remaining sections of drill pipe. A next upward stabilizer 99b secures to the upper end of the drill collar or collars 113 connected to stabilizer 99a. An adapter can connect between lower internally threaded end 107 (FIG. 11) and the upper box end of drill collars 113. Alternately, stabilizer 99 could be manufactured with an integral threaded pin on the lower end, similar to pin 89 of diverter sub 81 (FIG. 8). FIG. 12 also shows another stabilizer 99c mounted to drill collars 113 extending upward from stabilizer 99b. Stabilizer 99c may be constructed the same as stabilizers 99a and 99b. Fewer or more stabilizers 99 than three may be used. In FIG. 12, a mud motor isn't used, but it could be. For example, a mud motor may be provided in the drill string tin the place of one of the drill collars 113.

While the disclosure has been shown in only a few of its forms, it should be apparent to those skilled In the art that it is not so limited but is susceptible to various changes without departing from the scope of the disclosure.

Claims

1. An apparatus for facilitating the return of drilling fluid through an annulus surrounding a drill string, the apparatus comprising:

a longitudinal body defining an upper end, a lower end and a longitudinal axis extending therebetween, the upper and lower ends including connectors for connecting the longitudinal body into the drill string;

an interior axial passage extending between the upper and lower ends through the longitudinal body tor conveying drilling fluid therethrough;

a plurality radially spaced blades protruding from an exterior surface of the longitudinal body and defining open exterior flow channels therebetween; and

a plurality diverting nozzle passages extending between the inner axial passage and respective nozzle outlets on the exterior surface of the longitudinal body, the nozzle outlets exhibiting a radial spacing corresponding to a radial spacing of the exterior flow channels such that drilling fluid discharged from the diverting nozzle passages is directed toward the exterior flow channels.

2. The apparatus according to claim 1, wherein each diverting nozzle passage is oriented upward and outward with respect to the longitudinal axis.

3. The apparatus according to claim 2, wherein each of the each of the nozzle outlets is longitudinally spaced from the plurality of blades and disposed below the plurality of blades.

4. The apparatus according to claim 3, wherein the longitudinal body comprises:

a stabilizer sub supporting the plurality of radially spaced blades thereon and including a first sub connector at a lower end thereof; and

a first fluid diverting sub having a second sub connector at an upper end thereof for coupling to the first sub connector of the stabilizer sub, the first fluid diverting sub supporting the plurality of diverting nozzle passages.

5. The apparatus according to claim 4, wherein the first sub connector of the stabilizer sub comprises an internally threaded box for receiving a threaded pin comprising the second sub connector of the fluid diverting sub.

6. The apparatus according to claim 4, wherein a longitudinal spacing between an uppermost nozzle outlet and a lower end of the plurality of blades is in the range of three to five inches.

7. The apparatus according to claim 4, wherein the longitudinal body further includes a mud motor coupled to a lower end of the first fluid diverting sub and a second fluid diverting sub coupled to a lower end of the mud motor.

8. The apparatus according to claim 1, wherein at least one of the nozzle outlets has a longitudinal position along the longitudinal body between upper and lower ends of the radially spaced blades.

9. The apparatus according to claim 1, wherein the blades are inclined with respect to the longitudinal axis.

10. The apparatus according to claim 1, wherein the plurality of radially spaced blades and the plurality of diverting nozzle passages are integrally formed together on a single tubular body.

11. A well drilling apparatus, comprising:

a body defining a longitudinal body axis, and including a threaded upper end for connection into a drill string and a threaded lower end for connection and rotation with an earth boring bit;

an axial passage in the body for conveying drilling fluid to an outlet in the earth boring bit;

a plurality of blades extending radially outward from an exterior surface of the body and radially spaced to define exterior flow channels therebetween, the plurality of blades configured for engaging a wall of a borehole formed by the earth boring bit; and

a plurality of nozzles outlets defined on the exterior surface of the body and in fluidic communication with the axial passage, each of the nozzle outlets having a longitudinal position along the body between upper and lower ends of the radially spaced blades.

12. The apparatus according to claim 11, wherein each of the nozzle outlets defines a nozzle axis that points upward and outward and also at an oblique angle relative to a vertical plane of the body axis that intersects the nozzle axis at the nozzle outlet.

13. The apparatus according to claim 12, wherein the plurality of blades is are inclined with respect to the longitudinal axis in the direction of the oblique angle.

14. The apparatus according to claim 11, wherein at least one nozzle outlet is positioned within in each of the exterior flow channels defined between the blades.

15. The apparatus according to claim 11, further comprising a tubular member coupled to a lower end of the body, wherein the tubular member comprises at least one of a mud motor, a drill pipe and a drill collar.

16. A method of drilling a well, the method comprising:

(a) providing a drill string having an earth boring device at a lower end thereof, the drill string having a body coupled therein that defines a longitudinal axis, the body including a plurality of blades extending radially outward from an exterior surface of the body, a plurality of nozzle outlets defined on the exterior surface of the body between the blades, and an axial passage extending through the body and in fluidic communication with each of the nozzle outlets;

(b) lowering the drill string into the well and rotating the earth boring device;

(c) pumping drilling fluid down the drill string into the axial passage of the body, conveying a first portion of the drilling fluid through the axial passage and discharging the first portion of the drilling fluid through an outlet defined in the earth boring device into an annulus surrounding the drill string; and

(d) diverting and discharging a second portion of the drilling fluid from the axial passage in the body through the plurality of nozzle outlets into the annulus.

17. The method of claim 16, further comprising:

(e) engaging a wall of the annulus with the plurality of blades to stabilize the drill String.

18. The method of claim 16, wherein step (a) comprises providing the drill string with a tubular member coupled therein, the tubular member comprising at least one of a mud motor, a drill pipe and a drill collar, and providing the body in the drill string above the tubular member.