CA1042417A - Bit adjacent stabilizer and steel - Google Patents
Bit adjacent stabilizer and steelInfo
- Publication number
- CA1042417A CA1042417A CA254,182A CA254182A CA1042417A CA 1042417 A CA1042417 A CA 1042417A CA 254182 A CA254182 A CA 254182A CA 1042417 A CA1042417 A CA 1042417A
- Authority
- CA
- Canada
- Prior art keywords
- sleeve
- steel
- drill
- box
- thread
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
Abstract of the Disclosure A replaceable stabilizer comprises a steel sleeve with fixed blades adapted to be installed over the reduced lower box end of tubular rotary drill steel member prior to insertion of the taper threaded pin of a drill bit into the taper threaded drill steel box. The drill steel member may be a special sub or a regular length of drill steel with modified lower end. An internal straight thread at the upper end of the sleeve screws onto an external straight thread on the drill steel box. An annular rubber gasket secured to the upper end of the sleeve is clamped between the upper end of the sleeve and a shoulder on the steel between the main body and the reduced box end thereof.
An inturned flange at the lower end of the sleeve is clamped between a shoulder provided by the mouth of the drill steel box and a shoulder on the drill bit around its taper threaded pin. Make up of the pin and box forms a rotary shouldered connection. The outer ends of the blades are provided with tungsten carbide inserts or granular tungsten carbide hard facing is applied to the leading edge and the outer end of each blade.
An inturned flange at the lower end of the sleeve is clamped between a shoulder provided by the mouth of the drill steel box and a shoulder on the drill bit around its taper threaded pin. Make up of the pin and box forms a rotary shouldered connection. The outer ends of the blades are provided with tungsten carbide inserts or granular tungsten carbide hard facing is applied to the leading edge and the outer end of each blade.
Description
11~4Z4~7 This invention relates to drill stoel stabilizers useful in the rotary method of boring ~arth formations.
It is known to provide a rotary drill string with one or more re-placeable sleeve, fixed blade type stabilizers. See for example United States patent 3,754,609 to Garrett, wherein the replaceable sleeve is threaded to a special mandrel and captured between a mandrel shoulder and the shoulder formed by the mouth of a threaded box screwed onto the mandrel. Some of the relevant prior art is discussed in detail in the Garrett patent. See also United States patent number 2,589,534 to Buttolph wherein (Figure 5) a replace-able sleeve 12 is screwed onto a mandrel, the lower end of the sleeve beingprovided with an inturned flange which engages a shoulder on a mandrel, the upper end of the sleeve being connected to the mandrel by companion grooves and locking balls, United States patent number 2,307,688 to Larson shows a combination sucker rod guide and paraffin scraper in which a sleeve around a double pin connector is captured between shoulders on the suckeT rod boxes screwed to the connector and an inturned flange on the upper end of the sleeve engages a shoulder on the connector. United States patent 2,440,441-Hanes shows a replaceable wear sleeve for a tool joint wherein there are cooperating tapers on the sleeve and ~ool joint. United States patent number 2,620,164 to Burris shows a key seat wiper including a sleeve mounted for axial travel on a mandrel between an upper disengaged position and a lower engaged position in which an internal spline on the sleeve engages an external spli~e on the mand-rel. Yancey's United States patent number 2,794,617 shows a "conventional reamer" connected just above a drill bit and just below a circulation booster.
United States patent number 2,869,827 to Cook shows a stabilizer sleeve having a retaining ring screwed into its upper end. The use of tungsten carbide in-serts for wear protection of a drill pipe coupling is shown in United States patent number 3,054,647 to Von Rosenbur. Sintered tungsten carbide hard facing for the outer periphery and leading edge of stabilizer blades is shown in the aforementioned Garrett patent. A stabili~er connected just above a tricone ~ o~z~
rock bit is shown in United States patent number 3,370~657 to Antle. Screwed on stabilizer sleeves are shown in United States patents number 1,607,941 ~Bowser), 1,770,207 (~lelmling), 1,803,267 ~McCloskey~. A rubber buffer at the lower end of a drlll steel guide is shown in United States patent 2,177,300 to Kellegrew, the guide being just above the bit. A directive shell is shown mounted just above ~he drill bit in United States patent number 2,323,027 to Gerstenkorn. Rotary shouldered connections with multiple engaged surfaces are shown in Griffin patent number 2,636,753 and the references cited therein.
According to the present invention there is provided apparatus for use in the rotary system of drilling wherein a length of tubular drill steel having a rotary shouldered connector at one end and a drill bit having a rotary shouldered connector made up with the connector on the drill steel are rotated in a well bore, said apparatus comprising a stabilizer sleeve having an inturned radial flange at one end adapted to be clamped between the shoulders of such connectors of such steel and bit, said sleeve having an internal straight thread and a smooth cylindrical land between the thread and the flange, said sleeve being adapted to screw onto a mating thread on such steel to position the stabilizer sleeve about the end of the drill steel with said smooth cylindrical land fitting snugly about a mating land on such steel.
For a detailed description of a preferred embodiment of the invention reference will now be made to the accompanying drawings wherein Figure 1 is an elevation, partly in axial section through a lower drill stem assembly comprising a drill steel, a stabilizer, and a drill bit, embodying the invention, Figure 2 shows the stabilizer of the Figure 1 assembly, viewed from the direction 2-2 indicated in Figure 1, i.e. a top view;
It is known to provide a rotary drill string with one or more re-placeable sleeve, fixed blade type stabilizers. See for example United States patent 3,754,609 to Garrett, wherein the replaceable sleeve is threaded to a special mandrel and captured between a mandrel shoulder and the shoulder formed by the mouth of a threaded box screwed onto the mandrel. Some of the relevant prior art is discussed in detail in the Garrett patent. See also United States patent number 2,589,534 to Buttolph wherein (Figure 5) a replace-able sleeve 12 is screwed onto a mandrel, the lower end of the sleeve beingprovided with an inturned flange which engages a shoulder on a mandrel, the upper end of the sleeve being connected to the mandrel by companion grooves and locking balls, United States patent number 2,307,688 to Larson shows a combination sucker rod guide and paraffin scraper in which a sleeve around a double pin connector is captured between shoulders on the suckeT rod boxes screwed to the connector and an inturned flange on the upper end of the sleeve engages a shoulder on the connector. United States patent 2,440,441-Hanes shows a replaceable wear sleeve for a tool joint wherein there are cooperating tapers on the sleeve and ~ool joint. United States patent number 2,620,164 to Burris shows a key seat wiper including a sleeve mounted for axial travel on a mandrel between an upper disengaged position and a lower engaged position in which an internal spline on the sleeve engages an external spli~e on the mand-rel. Yancey's United States patent number 2,794,617 shows a "conventional reamer" connected just above a drill bit and just below a circulation booster.
United States patent number 2,869,827 to Cook shows a stabilizer sleeve having a retaining ring screwed into its upper end. The use of tungsten carbide in-serts for wear protection of a drill pipe coupling is shown in United States patent number 3,054,647 to Von Rosenbur. Sintered tungsten carbide hard facing for the outer periphery and leading edge of stabilizer blades is shown in the aforementioned Garrett patent. A stabili~er connected just above a tricone ~ o~z~
rock bit is shown in United States patent number 3,370~657 to Antle. Screwed on stabilizer sleeves are shown in United States patents number 1,607,941 ~Bowser), 1,770,207 (~lelmling), 1,803,267 ~McCloskey~. A rubber buffer at the lower end of a drlll steel guide is shown in United States patent 2,177,300 to Kellegrew, the guide being just above the bit. A directive shell is shown mounted just above ~he drill bit in United States patent number 2,323,027 to Gerstenkorn. Rotary shouldered connections with multiple engaged surfaces are shown in Griffin patent number 2,636,753 and the references cited therein.
According to the present invention there is provided apparatus for use in the rotary system of drilling wherein a length of tubular drill steel having a rotary shouldered connector at one end and a drill bit having a rotary shouldered connector made up with the connector on the drill steel are rotated in a well bore, said apparatus comprising a stabilizer sleeve having an inturned radial flange at one end adapted to be clamped between the shoulders of such connectors of such steel and bit, said sleeve having an internal straight thread and a smooth cylindrical land between the thread and the flange, said sleeve being adapted to screw onto a mating thread on such steel to position the stabilizer sleeve about the end of the drill steel with said smooth cylindrical land fitting snugly about a mating land on such steel.
For a detailed description of a preferred embodiment of the invention reference will now be made to the accompanying drawings wherein Figure 1 is an elevation, partly in axial section through a lower drill stem assembly comprising a drill steel, a stabilizer, and a drill bit, embodying the invention, Figure 2 shows the stabilizer of the Figure 1 assembly, viewed from the direction 2-2 indicated in Figure 1, i.e. a top view;
-2-~:igure 3 is a half sec~ion of an alternate form of th~ stabilizer,and I Figure 4 is a bottom view of the stabilizer shown in Figure 3, Referring now to Figure 1 there is shown a drill stem assembly in-cluding a conventioDal roller cone rock bit 11 comprising a tubular body 13 having a fluid passage lS there~hrough. A plurality of legs 17 extend down-wardly from body 13, Too~hed roller cones 19, providing formation disinteg-rating means, are rotatably mounted on legs 17. A tricone bit is illustrated but two-cone bits and cross section bits (four rollers) or any other form of bit ~e.g. drag, diamond, etc.) could be used, A suitable bit is described in United States Patent number 2,904,374 to Boice, Commercially available bits are disclosed in the 1974-75 edition of the Composite Catalogue of Oil Field Equipment and Services, at pages 4576-4578, referring to bits manufactured by Smith Tool Company. Note that although the Boice patent shows no unthreaded area b0tween pin thread and seal shoulder, the area of unengaged threads need-ed for a rotary shouldered connection can be provided by an unthreaded area on the box to which the pin is connected or by an unthreaded flange as in ~he present invention described hereinafter.
Referring still to Figure 1, the top of body 13 is provided with threaded tool joint means for making a rotary shouldered connection with cor-relative means on th0 lower end of drill steel (pipe~ 21. In the particularexample shown such connection means include on the bit a tapered threaded pin 23 and a seal shoulder 25, and on the drill steel such colmection means com-prises tapered threaded box 27 whose mouth provides a seal shoulder 29. Al-though this is the more usual arrangement, it would be within the scope of the invention to interchange the connection means, providing the box on the bit and the pin on the drill steel.
Stabili~er 31 comprises a tubular steel body or sleeve 33 disposed about the lower end of drill steel 21~ Sleeve 33 is provided with an inturned radial flange 35. The tool jOillt connection between the drill steel 21 and drill bit 11 is characterized by the placement of the inturned seal flznge 35 between the tool joint saal shoulders 25, 29. For ~urther details of rotary shouldered connections, and in particular of sucl- tool joint connections in which an annular member is disposed between the tool joint shoulders, see the aforementioned Garrett pa~ent. The flange 3S is captured between tool joint shoulders 25, 29 and seals therewith when the connection i5 made up tight.
Drill steel 21 is a tubular steel member of any desired length. It may, for example, be of a conventional length of seYenteen or thirty two feet for a two piece drill stem or forty four feet for a single piece drill stem, both of which are typical for blast hole drilling, or it may be a special sub 10 of one or a few feet in length adapted to be used between the bit and drill s~eel. It may also be a drill collar or drill pipe or sub used in oil well drilling. Typically, however, i~ is a joint of regular drill steel modified at its lower end to receive the stabilizer 31. Such a joint of regular drill steel may be distinguished from subs and the mandrels of convention~l repl~ce-able sleeve stabili~ers by its length to diameter ratio, which is at least of the order of 10 feet tlength) divided by 12 inches (diameter) equals 10. This is not a critical ratio but is a descriptive dividing line to distinguish drill steel, drill pipe, and drill collars from subs and mandrels.
Drill steel 21 is provided with tool joint connectors at its ends for making rotary shouldered connections wi~h other drill stem members. The lower tool joint connection is box 27 and should~r 29 previously described adapted to make up with bit 11. The upper tool joint connection includes tapered thraaded pin 37 and seal shoulder 39. The annular area 41 around shoulder 39 is relieved so as not to interfere with make up with the head of a drill and to prevent the seal area from being so large as to make breakout difficult, In Figure 1 the head 43 of the drill is indicated at dotted lines.
The drill may be of any desired type suitable for rotary drilling with air or water or other fluid, e.g. as shown in United States patent number 31463,252 to Miller et al or at page 5416 of the 1974-75 edi~ion of the Composite Ca~.a~
log of Oil Field Equipmsnt and Services referring to the "Portadrill"made by _4-. , .: . , , ... . . . . . . .
~04~4~
Wlnter-Wels .
Drill steel 21 is shown to be a single piecc ~rill stem adap~ed for connection at i~s lowcr en~ to the bit 11 and at its upper end to the drill head 43, but could be divided into a plurality of joints as is typical for drill stem used in oil well drilling. If a two piece drill stem is used, as is frequent for blast hole drilling, a tool joint connection would be employed between the two pieces as indicated in dotted lines at 51A, 53A~ or at 51B, 53B I~e connection SlA, 53A is similar to that at 37, 43 so that bo~h the upper and lower pieces can be connected to the drill head. The connection at 51B, 53B is similar to that at 23, 27 so that both pieces of drill steel can be connected to the drill bit. A spacer ring 35B is substituted for flange If the drill bit and drill head have like connections, then all the tool joints would be alike, which is the preferred construction. If a connPction of the bit ~ype, 51B, 53B is used in the drill stem, the lower ends of both pieces of the drill stem would be adapted to receive the stabilizer 31.
Drill steel 21 is tubular and its outer periphery is preferably cylindrical. The drill steel is reduced in diameter at its lower end and about box 27 providing a pin 61 adapted to make a rotary shouldered connection with a box 63 formed at the inner periphery of stabilizer sleeve 33. The pin 61 of this connection comprises squ~re end shoulder 29, smooth cylindrical un-threaded area 65, straight ~untapered) thread 67, smooth cylindrical land 69 and square shoulder 71. Box 63 comprises square bottom shoulder 73, smooth cylindrical unthreaded land 75, relief 77 of enlarged diameter, straight (untapered) thread 79, smooth cylindrical unthreaded area 81, and square end shoulder 83~ The bottom shoulderJ land, thread, and unthreaded area of the box 63 are correlative to the end shoulder, unthreaded area, thread, and land of the pin, whereby ~hey fit together tightly with a fluid tight seal between shoulders 29 and 73, ~hen the threads 67, 79 are made up tight the unthreaded portions of the pin and box extending from these threads to the shoulders 29, 73 are stressed so that the connection is tight. A flat elastomeric (e.g.
, .............................. . .
.
rubber) s~al ring 85 of a durom~ter hardness which may be of th~ order of 60 to 90 is clamped bctween shoulders 71, 83 to provide a seal therebetween with-out interfering with sealing engagemen~ of shoulders 29, 73. The seal provided by the rubber rin~ 85 backs up the seal between shoulders 29, 73 and also keeps dir~ and other fo~eign ma~ter out of the threaded ConneGtion between pin 61 on the drill s~eel and box 63 formed in the s~abiliz~r sleeve. This makes it easier to unscrew stabilizer sleeve 33 and replace it when necessary.
The fact that flange 35 on the stabilizer sleeve extends under the lower end of the drill steel far enough to be clamped between the drill steel and drill bit is important since it makes it possible to use the entire radial thickness of the drill steel box as a shoulder against which the flange can bear, and a~ the same time the area for engagment by bit shoulder 25 is not reducedJ in fact ths area of the shoulder 89 provided by the lower face of flange 35 ~or engag~men~ with bit shoulder 25 is larger than the area of shoulder 29 at the lower end of the drill s~eel box. As a measure of the large inward radial extent of flange 35 and its shoulder 73 it may be noted that the radial extent of shoulde~ 89 may be over three times the height of the threads -~ -79 on the stabilizer sleeve, and the radial extent of shoulder 73 is at leasS
about twice the height of threads 79. As shown in the dr~wing, the inner dia-meter of flange 35 is about the same as the root diameter of the thread at the mouth of box 27, being largeronly by the clearance necessary to receive the pin 23.
Referring now also to Figure 2, stabilizer sleeve 33 is provided with a plurality, e.g. four, o~ radial blades 91 for engaging the side of the hole being bored, the:reby to centralize bit 11. The outer paripheries 93 of the blades and the leading edges 95 (for clockwise rotation viewed from the top) are coated with wear resistant material in the form of tungsten carbide granules. Alternatively, as shown in Figures 3 and 4, the blades can be pro-vided with cylindrical tungsten carbide bodies 97 pressed into radial cylindri-30 A cal holes 99 in the s~abilizer blades.
:~4~ L7 ~ b L~hc~ kxcept for this diffarence the stabilizer of Figures 3 and 4 is the same as that of Figures 1 and 2 and lik~ parts ar~ given like reference numbers. I`he upper and lower ends of the blades in both embodiments are be-veled at 101, 103 (see Figure 3) and the lower outer periphery of flange 35 is beveled at 105.
Sumn~rizing, a drill stem assembly is provided including a stabili-zer sleeve having an inturned radial flange clamped between the lower end of the drill steel and the drill bit shoulder. The sleeve can be replaced on the drill steel during a bit change without the need for special tools or additional personnel. The sleeve can be screwed on and off the drill steel using the usual tongs, wrenches, chains and the like used for making up the bit and drill steel. It is not even necessary that the stabilizer be made up on the drill steel more than hand tight since make up of the bit with the drill s~eel clamps the stabilizer sleeve therebetween and turning of the bit on the steel causes the sleeve to turn with the bit until the sleeve is tight on the steel. Effective stabilization is maintained at a lower cost through replacement of the sleeve alone. The support for the replaceable sleeve can be formed on the lower end of the drill steel itself eliminating the need for additional steel stock (sub) and eliminating one threaded connection (between sub and steel). The stabilization is placed directly at the bit.
While a preferred embodiment of ~he invention and one modification thereof have been shown and described many other modifications of the inven-tion can be made by one skilled in the art without departing from the spirit of the invention.
"'~'' ' '
Referring still to Figure 1, the top of body 13 is provided with threaded tool joint means for making a rotary shouldered connection with cor-relative means on th0 lower end of drill steel (pipe~ 21. In the particularexample shown such connection means include on the bit a tapered threaded pin 23 and a seal shoulder 25, and on the drill steel such colmection means com-prises tapered threaded box 27 whose mouth provides a seal shoulder 29. Al-though this is the more usual arrangement, it would be within the scope of the invention to interchange the connection means, providing the box on the bit and the pin on the drill steel.
Stabili~er 31 comprises a tubular steel body or sleeve 33 disposed about the lower end of drill steel 21~ Sleeve 33 is provided with an inturned radial flange 35. The tool jOillt connection between the drill steel 21 and drill bit 11 is characterized by the placement of the inturned seal flznge 35 between the tool joint saal shoulders 25, 29. For ~urther details of rotary shouldered connections, and in particular of sucl- tool joint connections in which an annular member is disposed between the tool joint shoulders, see the aforementioned Garrett pa~ent. The flange 3S is captured between tool joint shoulders 25, 29 and seals therewith when the connection i5 made up tight.
Drill steel 21 is a tubular steel member of any desired length. It may, for example, be of a conventional length of seYenteen or thirty two feet for a two piece drill stem or forty four feet for a single piece drill stem, both of which are typical for blast hole drilling, or it may be a special sub 10 of one or a few feet in length adapted to be used between the bit and drill s~eel. It may also be a drill collar or drill pipe or sub used in oil well drilling. Typically, however, i~ is a joint of regular drill steel modified at its lower end to receive the stabilizer 31. Such a joint of regular drill steel may be distinguished from subs and the mandrels of convention~l repl~ce-able sleeve stabili~ers by its length to diameter ratio, which is at least of the order of 10 feet tlength) divided by 12 inches (diameter) equals 10. This is not a critical ratio but is a descriptive dividing line to distinguish drill steel, drill pipe, and drill collars from subs and mandrels.
Drill steel 21 is provided with tool joint connectors at its ends for making rotary shouldered connections wi~h other drill stem members. The lower tool joint connection is box 27 and should~r 29 previously described adapted to make up with bit 11. The upper tool joint connection includes tapered thraaded pin 37 and seal shoulder 39. The annular area 41 around shoulder 39 is relieved so as not to interfere with make up with the head of a drill and to prevent the seal area from being so large as to make breakout difficult, In Figure 1 the head 43 of the drill is indicated at dotted lines.
The drill may be of any desired type suitable for rotary drilling with air or water or other fluid, e.g. as shown in United States patent number 31463,252 to Miller et al or at page 5416 of the 1974-75 edi~ion of the Composite Ca~.a~
log of Oil Field Equipmsnt and Services referring to the "Portadrill"made by _4-. , .: . , , ... . . . . . . .
~04~4~
Wlnter-Wels .
Drill steel 21 is shown to be a single piecc ~rill stem adap~ed for connection at i~s lowcr en~ to the bit 11 and at its upper end to the drill head 43, but could be divided into a plurality of joints as is typical for drill stem used in oil well drilling. If a two piece drill stem is used, as is frequent for blast hole drilling, a tool joint connection would be employed between the two pieces as indicated in dotted lines at 51A, 53A~ or at 51B, 53B I~e connection SlA, 53A is similar to that at 37, 43 so that bo~h the upper and lower pieces can be connected to the drill head. The connection at 51B, 53B is similar to that at 23, 27 so that both pieces of drill steel can be connected to the drill bit. A spacer ring 35B is substituted for flange If the drill bit and drill head have like connections, then all the tool joints would be alike, which is the preferred construction. If a connPction of the bit ~ype, 51B, 53B is used in the drill stem, the lower ends of both pieces of the drill stem would be adapted to receive the stabilizer 31.
Drill steel 21 is tubular and its outer periphery is preferably cylindrical. The drill steel is reduced in diameter at its lower end and about box 27 providing a pin 61 adapted to make a rotary shouldered connection with a box 63 formed at the inner periphery of stabilizer sleeve 33. The pin 61 of this connection comprises squ~re end shoulder 29, smooth cylindrical un-threaded area 65, straight ~untapered) thread 67, smooth cylindrical land 69 and square shoulder 71. Box 63 comprises square bottom shoulder 73, smooth cylindrical unthreaded land 75, relief 77 of enlarged diameter, straight (untapered) thread 79, smooth cylindrical unthreaded area 81, and square end shoulder 83~ The bottom shoulderJ land, thread, and unthreaded area of the box 63 are correlative to the end shoulder, unthreaded area, thread, and land of the pin, whereby ~hey fit together tightly with a fluid tight seal between shoulders 29 and 73, ~hen the threads 67, 79 are made up tight the unthreaded portions of the pin and box extending from these threads to the shoulders 29, 73 are stressed so that the connection is tight. A flat elastomeric (e.g.
, .............................. . .
.
rubber) s~al ring 85 of a durom~ter hardness which may be of th~ order of 60 to 90 is clamped bctween shoulders 71, 83 to provide a seal therebetween with-out interfering with sealing engagemen~ of shoulders 29, 73. The seal provided by the rubber rin~ 85 backs up the seal between shoulders 29, 73 and also keeps dir~ and other fo~eign ma~ter out of the threaded ConneGtion between pin 61 on the drill s~eel and box 63 formed in the s~abiliz~r sleeve. This makes it easier to unscrew stabilizer sleeve 33 and replace it when necessary.
The fact that flange 35 on the stabilizer sleeve extends under the lower end of the drill steel far enough to be clamped between the drill steel and drill bit is important since it makes it possible to use the entire radial thickness of the drill steel box as a shoulder against which the flange can bear, and a~ the same time the area for engagment by bit shoulder 25 is not reducedJ in fact ths area of the shoulder 89 provided by the lower face of flange 35 ~or engag~men~ with bit shoulder 25 is larger than the area of shoulder 29 at the lower end of the drill s~eel box. As a measure of the large inward radial extent of flange 35 and its shoulder 73 it may be noted that the radial extent of shoulde~ 89 may be over three times the height of the threads -~ -79 on the stabilizer sleeve, and the radial extent of shoulder 73 is at leasS
about twice the height of threads 79. As shown in the dr~wing, the inner dia-meter of flange 35 is about the same as the root diameter of the thread at the mouth of box 27, being largeronly by the clearance necessary to receive the pin 23.
Referring now also to Figure 2, stabilizer sleeve 33 is provided with a plurality, e.g. four, o~ radial blades 91 for engaging the side of the hole being bored, the:reby to centralize bit 11. The outer paripheries 93 of the blades and the leading edges 95 (for clockwise rotation viewed from the top) are coated with wear resistant material in the form of tungsten carbide granules. Alternatively, as shown in Figures 3 and 4, the blades can be pro-vided with cylindrical tungsten carbide bodies 97 pressed into radial cylindri-30 A cal holes 99 in the s~abilizer blades.
:~4~ L7 ~ b L~hc~ kxcept for this diffarence the stabilizer of Figures 3 and 4 is the same as that of Figures 1 and 2 and lik~ parts ar~ given like reference numbers. I`he upper and lower ends of the blades in both embodiments are be-veled at 101, 103 (see Figure 3) and the lower outer periphery of flange 35 is beveled at 105.
Sumn~rizing, a drill stem assembly is provided including a stabili-zer sleeve having an inturned radial flange clamped between the lower end of the drill steel and the drill bit shoulder. The sleeve can be replaced on the drill steel during a bit change without the need for special tools or additional personnel. The sleeve can be screwed on and off the drill steel using the usual tongs, wrenches, chains and the like used for making up the bit and drill steel. It is not even necessary that the stabilizer be made up on the drill steel more than hand tight since make up of the bit with the drill s~eel clamps the stabilizer sleeve therebetween and turning of the bit on the steel causes the sleeve to turn with the bit until the sleeve is tight on the steel. Effective stabilization is maintained at a lower cost through replacement of the sleeve alone. The support for the replaceable sleeve can be formed on the lower end of the drill steel itself eliminating the need for additional steel stock (sub) and eliminating one threaded connection (between sub and steel). The stabilization is placed directly at the bit.
While a preferred embodiment of ~he invention and one modification thereof have been shown and described many other modifications of the inven-tion can be made by one skilled in the art without departing from the spirit of the invention.
"'~'' ' '
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for use in the rotary system of drilling wherein a length of tubular drill steel having a rotary shouldered connector at one end and a drill bit having a rotary souldered connector made up with the connector on the drill steel are rotated in a well bore, said apparatus comprising a stabilizer sleeve having an inturned radial flange at one end adapted to be clamped between the shoulders of such connectors of such steel and bit, said sleeve having an internal straight thread and a smooth cylindrical land between the thread and the flange, said sleeve being adapted to screw onto a mating thread on such steel to position the stabilizer sleeve about the end of the drill steel with said smooth cylindrical land fitting snugly about a mating land on such steel.
2. Apparatus according to claim 1 wherein said flange extends radially inwardly from said sleeve at least about twice the height of said straight thread.
3. Apparatus according to claim 1 wherein said sleeve has a further smooth cylindrical land on the side of the thread opposite from the first said land and adapted to engage another smooth cylindrical land on the steel.
4. Apparatus according to claim 1 including such steel, said connector on the steel being provided with a shoulder thereabout opposite the end of said sleeve, with an elastomeric seal ring clamped between said end of the sleeve and the last said shoulder.
5. Apparatus according to claim 4 wherein the rotary shouldered connector at the end of the drill steel to which the bit is connected is a box, said thread on the steel to which the thread of said stabilizer sleeve is screwed being formed on the exterior of said box.
6. Apparatus according to claim 5 wherein said drill steel is a tube having a length to diameter ratio of at least ten, the other end of said drill steel being pro-vided with means for making connection with a drill head.
7. Apparatus according to claim 6 including such drill bit, wherein said drill bit is a roller cone bit and said stabilizer sleeve has a plurality of radial blades with tungsten carbide wear resistant material on the outer periphery of each blade, the radial extent of the outer peripheries of the blades being substantially equal to the radius of the hole bored by said bit.
8. Apparatus according to claim 1 including such drill steel, said drill steel comprising a tube, having a rotary shouldered connector at its other end for making connection with another drill stem member, said connector at said one end being a tool joint box for making connection with such a drill bit whose connector is a tool joint pin, said thread on the steel to which the thread on said stabilizer sleeve is screwed being formed on the exterior of said box.
9. Apparatus according to claim 8 wherein said tube has a length to maximum outer diameter ratio of at least ten.
10. Apparatus according to claim 1 wherein said sleeve has an internal relieved area of greater diameter than said land lying between said land and said thread.
11. Apparatus according to claim 8 wherein the mouth of said box is a square shoulder of the same radial extent approximately as the radial extent of said flange inwardly from said sleeve.
12. Apparatus according to claim 10 wherein said sleeve has a plurality of radial blades with tungsten carbide wear resistant material on the outer peripheries of the blades.
13. Apparatus according to claim 8,said radial flange having an inner diameter about equal to the thread root diameter of said box but large enough to receive said pin of the drill bit, said sleeve having a smooth cylindrical internal land between said internal thread and said flange, said drill steel having a smooth cylindrical land between said straight thread on the exterior of the box and the mouth of the box.
14. Apparatus according to claim 2, said stabilizer sleeve comprising an elongated tubular body whose length is greater than its outer diameter, said body having on its outer periphery a plurality of azimuthally spaced apart radial blades protected with tungsten carbide wear resistant material on the outer peripheries of the blades, said blades having a lesser axial extent than said body leaving an unbladed neck at one end forming the upper end of the stabilizer sleeve, the upper end of said neck being adapted to engage an elastomeric seal ring, said body having on its inner periphery underlying said carbide pro-tected blades a cylindrical relieved area of greater inner diameter than the inner diameter of the remainder of said inner periphery and extending axially over half the length of the body, said straight thread being formed on said inner periphery between said relieved area and said neck, said smooth cylindrical land being formed on said inner periphery immediately below said relieved area, and said inturned radial flange being formed at the lower end of said body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA254,182A CA1042417A (en) | 1976-06-07 | 1976-06-07 | Bit adjacent stabilizer and steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA254,182A CA1042417A (en) | 1976-06-07 | 1976-06-07 | Bit adjacent stabilizer and steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1042417A true CA1042417A (en) | 1978-11-14 |
Family
ID=4106142
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA254,182A Expired CA1042417A (en) | 1976-06-07 | 1976-06-07 | Bit adjacent stabilizer and steel |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1042417A (en) |
-
1976
- 1976-06-07 CA CA254,182A patent/CA1042417A/en not_active Expired
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