CA2019898A1 - Adjustable bent sub - Google Patents
Adjustable bent subInfo
- Publication number
- CA2019898A1 CA2019898A1 CA002019898A CA2019898A CA2019898A1 CA 2019898 A1 CA2019898 A1 CA 2019898A1 CA 002019898 A CA002019898 A CA 002019898A CA 2019898 A CA2019898 A CA 2019898A CA 2019898 A1 CA2019898 A1 CA 2019898A1
- Authority
- CA
- Canada
- Prior art keywords
- mandrel
- housing
- longitudinal
- offset
- axis
- 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.)
- Abandoned
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
- E21B7/06—Deflecting the direction of boreholes
- E21B7/067—Deflecting the direction of boreholes with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub
Abstract
ABSTRACT OF THE DISCLOSURE
An adjustable bent sub for use in earth drilling. The bent sub has a tubular mandrel with an offset axis which is telescopically received in a tubular housing with an offset axis. By rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing. A longitudinal stop limits longitudinal displacement of the mandrel within the housing. The mandrel is longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing. A rotational stop prevents relative rotation between the mandrel and the housing when the mandrel is in the first position and allows such relative rotation when the mandrel is in the second position.
rotator acts between the mandrel and the housing, reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel is displaced from the first position to the second position and returned to the first position. A split ring locks the mandrel in the first position.
An adjustable bent sub for use in earth drilling. The bent sub has a tubular mandrel with an offset axis which is telescopically received in a tubular housing with an offset axis. By rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing. A longitudinal stop limits longitudinal displacement of the mandrel within the housing. The mandrel is longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing. A rotational stop prevents relative rotation between the mandrel and the housing when the mandrel is in the first position and allows such relative rotation when the mandrel is in the second position.
rotator acts between the mandrel and the housing, reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel is displaced from the first position to the second position and returned to the first position. A split ring locks the mandrel in the first position.
Description
T~ preC;erlt invelltiorl relates k~ arl adillcjtable ben-t sub .
BP~C~CCiROUN13 OF THE INVENTIO~
"Berl-t subs" are commorlly used in ear-th drilling in order to deviate the borehole from vertical to a de~ired ang.le. "Subs" are short threaded sections of drill pipe. They are "bent" ei-ther by physical bending or machined -to crea-te an angular offset be-tweerl the lOrespective ends of the sub. Wherl the b~nt sub i~ plac;ed iIl the drill ~trillg, -the bend in the sub causes -the drill string ~o devia-te from vertical as drilling progresses. One drawbac,k in the use of bent subs is that the angle is fixed. This means tha-t numerous bent 15subs must be kept a-t -the drill site -to provide a selection of a range of angles which may be required as drilling progresses. The trend in the indus-try ha~, therefore, been to develop a single bent sub on which the angle can be ad jU5 ted.
SUMMARY OF THE INVENTION
The present invention represents an alternate structure for an adjustable bent sub.
According to the present invention there is provided an adjustable bent sub for use in earth drilliny which is comprised of a tubular housing having a first end, a second end, and a primary axis. Means are provided to offset the second end of the -tubular 30 housing at an angle to the primary a~is -thereby creatiIlg an offset axis. A tubular mandrel is provided having a fir~t end, a second end, and a primary axis. Means are provided to offse-t the first end of the mandrel at an 35 angle to the primary axis thereby creating an offset axis. The first erld of -the mandrel is telescopically ~' .~ 2 received in t~le ~ecorld end of tne -tubular housirl~. By rotation of the mandrel in relation to the housiny an adjustmen-t may be made in ~ berld created by -the cumulative efect of the off~et axis of the ma~ldrel and 5-the offset axis of the housing. A lvngitudiIlal stop limit~ longitudirlal displacemen-t of the mandrel within -the housirlg. T~le mandrel is lorlgitud.inally slidable withirl the housing between a first position whereir fur-ther di~placemerlt -toward the second end of -the lOhousirlg is limited by the longitudirlal atop and a second position wherein the mandrel is displaced toward -the first end of the housirlg. A rotatiorlal s-top prevents relative ro-tation betweerl the mandre:l and the housiny when the mandrel is in the first position and allows 15~uch relative ro-tation wherl the mandrel is in the second position. A rotator acts between -the mandrel and the housing. The rotator reac-ts -to longitudinal displacemerlt between the mandrel and the housing to cause a predetermirled amo-unt of relative rota-tion 20between -the mandrel and the housing when the mandrel is : displaced from -the ~ir~t po~i-tion to the second positior and returned -to the first position. Means is provided for locking the mandrel in the :Eirst posi-tiorl.
' : 25 BRIEF DESCRIPTION OF THE DRAWINGS
.
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, 30 wherein: -FIGVRE 1 is a longitudinal section view of a preferred embodimen-t of the invention.
FIGURE 2 .is a detailed view of a portion of the 35 Adjustable Bent Sub i.llustrated in FIGURE 1.
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_ 3 DETAILED DESCRIPTION OF T~E~ ~R~U ~0 IM~A~
The preferred elslbodimerlt will now be desc~ibed with reference to FIG~R~S 1 and 2. T~le ~referred embodi~nent, generaily de~igna-ted by reference nu~leral 10, is an 5 adjustable berl-t sub for u~e in ear-th drillirly. The primary componen-t~ of adjus-table bent sub 10 are a tubular ho-usirlg l2 alld a tubulal marldrel 1~.
Housing 12 has a fir~t end 16, a second erld 18, and a primary axis (no-t shown). For ease of assembly ho~sing 12 is constructed of two comporlerlts; a sprir1g housing 20 and a ro-ta-tor hou~ing 22. First end 16 of housirlg 12 is equivalerl-t to firs-t end of spring housing 20. Second end 18 of ho-ll~irlg 12 is equivalen-t -to second end of rotator housir1g 22. Sprirlg housing 20 has a second end 24 which -telescopically receives a first end 26 of rotator housing 22 at a threaded connection 28.
Threaded connec-tiorl 28 i~ ~;ealed by an 0 ring seal 30.
Hou~ing 12 has an interior bure 32 which is machined at 20second end 18 a-t an angle -to offset second end 18 of tubular housing 12 at an angle to the primary axis (not shown) creating an off3et axis 34. A -threaded connection 36 is positioned at firs-t end 16 of holl~ing 12. Threaded connection 36 permits hou~ing 12 to be 2s~ecured in the drill string.
Mandrel 14 has a fir~-t end 33, a secorid end 40, and a primary a~is (not shown). A threaded connection 42 is po~itioned at secolld end 40 of mandrel 14. Threaded 30connectiorl 42 permits mandrel 14 to be ~ecured in -the drill string. Mandrel 14 has an armular sho~lder 44, the sîgnificance of which will be hereinafter further described. Fir~-t end 38 of mandrel 14 is machined a-t an 3sangle in ~rder -to offset firs-t end 38 of mandrel 14 at an angle to the primary axi~ (rlot ~howrl) creatirlg an .
, 2 ~
offset axis 46. Fir~-~ end 38 of marldrel 14 i5 telescopicall~ received in secorld end 18 of housirlg 12.
By ro-ta-tion of mand:rel 14 in r~lation -to ho-using 12 arl adjustmerlt may be made in a berld created by a cumulative 5 effect o.C offse-t axi~ 46 of marldrel 14 and off~et axis 34 of housirly 12.
A s-topper 48 is secured to .Eirs-t end 38 of mandrel 14. The connection between stopper 43 arld fir~t end 38 lOof mandrel 14 is sealed by an O ring seal 49. S-topper 48 serves as a longi-tudinal stop -to limit lorlyitudinal displacement of marl~rel 14 within housiIly 12. Mandrel 14 i9 longitudinally slidable within housing 12 between a f.irst p~sition wherein further displacement toward 15second end 18 of housirlg 12 is limited by stopper 48 striking first end 26 of rv-tator ho-us.irlg 22, and a second position whereirl mandrel ls is displaced toward first end 16 of housirly 12. The movemer~t of mandrel 14 in the second position is limi-ted by annular shoulder 44 200f mandrel 14 striking second end 18 of housing 12. A
coil spring 50 is disposed within spring housing 20. A
firs-t end 52 of sp-.ring 50 acts ayainst a shoulder 54 within interior bore 32 at firs-t end 16 of housing 12.
A second end 56 of spring 50 acts against a sealing riny ~558 having an annular seal 60. Sealing ring 58 in turn acts against stopper 48. 0 ring seal~ 62 are positioned where sealing ring 5~ meets stopper 48. The effect of spriny 50 .i5 to apply a bia~ing force be-tween first erld 38 of mandrel 14 and firs-t end 16 of hou~ing 12 which 30uryes mandrel 14 in-to the first po~i-tion.
A rotatiorlal stop in the form of engaying splirle 64 and 66 on housiny 12 and mandrel 14, respectf-ully.
355pline 64 and 66 no~-rotatably couple mandrel 14 -to housiny 1~ when mandrel 14 i5 in -the fir~-t po~ition.
-2 ~
This has -the e:Efe~t of preverltinc3 relative rotatiorl : between mandrel 1~ and hou~irlg 12 wherl mandrel 14 is in -the firs-t po6i-tiorl and allowi.rly such rela-tive :rotatio wherl mandrel 14 i5 in the SeCOrld poYi tion. Splirle 64 5 and 66 are be~-t ill-ustra-ted in FIGURE 2.
A ~v-tator 68 ac-ts between mandrel 14 and housing 12. Rota-tor 68 react~ to longitudinal displacement be-tween marldrel 14 and housirlg 12 to cause a lOpredetermiIled aMour--t of relative rotation be-tweerl mandrel 14 and housing 12 when mandrel 14 is displaced from -the -first posi-tion to -the second position and returned ta the first position. Referrirlg to ~IG~RE 2, rotator 68 consists of a plurali-ty of generally parallel 15sided depressions on mandrel 1~ defiIling adjacent longitudinal channels 70 and crossover channels ~2.
I,ongi-tudinal charlnels 70 are geIIerally parallel to each other and have a front end 74 and a back end ~6.
Crossover charmels 72 connec-t adjacerl-t longitucliTlal 20channels 70. Crossover chanrlels 72 have an upper end 78 opening into front end ~4 of OTle of lOTlgi tUdirlal channels 70 and a lower end 80 opening into back end ~5 of an adjacen-t one of longi-tudinal cha}lIlels 70. Sl:iders 82 are affixed to housing 12. Sliders 82 erlgage and are 25slidable along channels 70 and 72 on mandrel 14.
A split ring 84 clampingly engages mandrel 14.
Split ring 84 has one peripheral edge 86 which engages second end 18 of housing 12 and an opposed peripheral 30edge 88 which engages annular shoulder 44 on mandrel 14.
Split ring 84 is removably secured -to mandrel 14 by bol-ts 90. When split ring 84 is placed in position as described when mandrel 14 is in the first position 35relative movement of mandrel 14 iII relation to housirlg 12 is prevented, thereby locking mandrel 14 :irl the f.irst ' ~
, ~ 6 pO~i~iOII. Mandrel 1~ iS Ullable to move -tovJaId seco-nd end 18 of housing 1~ due -to ~topper 48. Mandrel 14 is : unable to move ~oward first end 16 of housing 12 du~ -to the imposition of split rin~ ~4 between anrlular shoulder 5 44 of mandrel 14 and second end 18 of nous:irly 12.
An oil filled chamb~r 92 is created between ~andrel 14 and ~lousing 12. Ol:L filled chamber e~-tends from second end 18 of housirlg 12 to anrlular seal 60 on seal ring 58. Second end 18 of housing 12 has a seal 94 to prevent the escape of oil from oll filled chamber 92.
Oil is placed in oil filled chamber 92 after assembly of the tool through oil plug 96.
The use and op~ratioIl of adj-ustable bent sub 10 will now be described with reference to FIG~RES 1 and 2.
In order -to adjust adjustable bent ~ub 10 split ring 84 i5 removed. Once split r;ng 84 is removed mandrel 14 is iongitudirlally slidable within housing 12 from the first 20position to the second position. As mandrel 14 is moved toward the second po~ition coil ~pring 50 is compre~sed.
Wherl Illandrel 14 i5 moved into -the second position spline 64 on housirlg 12 are di~engag~d rom spline 66 on mandrel 14, thereby allvwing relative rotation of mandrel 14 in relation -to housing 12. This relative rotation is control:Led by rotator ~8. ~ach of longitudinal channels 70 represents one incremental adjustmen-t. The displacemen-t of mandrel 14 from the f.irst position to the secorld position, and then the 30return of mandrel 14 to the first posi-tion resul-ts in an adjustment from one on longitudinal channels 70 to an adjacent one of longitudinal chanrlel~ 70. Thi~ i9 due to -the path followed by sliders 82. As mandrel 14 moves 3sfrom the first position tv the ~econd position sliders 82 move via crossover chanrlel~ '72 from frorl-t end '74 of '` `
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` -one vf longi-t-udirlal cha}lrle:l~ 70 to back erld 76 of an adjacent one of longitudirlal chant~ 700 As mandrel 14 moves from -the secorl~ position back to t~le fir~-t position slider~ 82 move from back end 76 to front end 5 ~4 of the adjacen-t one of longi-tudirlal charlrlel~ 70.
. MandLel 14 is displaced betweerl the f irst and ~econd : posi tions as many t:imes as may be required to achiave the desired adjustment. This is due -to t:he ~ac-t -that xot~tion of m~ndrel 14 in rela-tion -to hollsing 12 ad,jus-ts : lOthe bend created by the cumulative offset of offset axis : 46 of m~ndrel 14 and offse-t a~is 34 of housillg 12, and rotator 68 controls the rotation of marldrel 14. Once the desired adjustmen-t has been made ~plit ring 84 is put back in positionO Split riny 84 occupies the space 15between anTIular shoulder 44 on mandrel 14 and Yecond end 18 of housing 12. This maintains stopper 48 against fir~t end 26 of rotator housing 22. Marldrel 14 is ~ therefore maintained in a pos.ition where no longitudinal : movement in relation to housing 12 i5 po~ible. With 20split ring 84 maintainirlg mandrel 14 in the first position, spline 64 on housing 12 are kept enga~ed with spline 66 on mandrel 14. Spline 64 and 66 norl-rota-tably couple mandrel 14 and ho-using 12~
It will be apparent to one skilled in the art how -the structure of -the presen-t invention permits an adjustment to be made of adjustable bent ~ub 10. It will al~o be apparent to one skilled in the art that modifications may be made to the preferred embodiment 30withou-t departing from the spirit and scope of the invention.
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BP~C~CCiROUN13 OF THE INVENTIO~
"Berl-t subs" are commorlly used in ear-th drilling in order to deviate the borehole from vertical to a de~ired ang.le. "Subs" are short threaded sections of drill pipe. They are "bent" ei-ther by physical bending or machined -to crea-te an angular offset be-tweerl the lOrespective ends of the sub. Wherl the b~nt sub i~ plac;ed iIl the drill ~trillg, -the bend in the sub causes -the drill string ~o devia-te from vertical as drilling progresses. One drawbac,k in the use of bent subs is that the angle is fixed. This means tha-t numerous bent 15subs must be kept a-t -the drill site -to provide a selection of a range of angles which may be required as drilling progresses. The trend in the indus-try ha~, therefore, been to develop a single bent sub on which the angle can be ad jU5 ted.
SUMMARY OF THE INVENTION
The present invention represents an alternate structure for an adjustable bent sub.
According to the present invention there is provided an adjustable bent sub for use in earth drilliny which is comprised of a tubular housing having a first end, a second end, and a primary axis. Means are provided to offset the second end of the -tubular 30 housing at an angle to the primary a~is -thereby creatiIlg an offset axis. A tubular mandrel is provided having a fir~t end, a second end, and a primary axis. Means are provided to offse-t the first end of the mandrel at an 35 angle to the primary axis thereby creating an offset axis. The first erld of -the mandrel is telescopically ~' .~ 2 received in t~le ~ecorld end of tne -tubular housirl~. By rotation of the mandrel in relation to the housiny an adjustmen-t may be made in ~ berld created by -the cumulative efect of the off~et axis of the ma~ldrel and 5-the offset axis of the housing. A lvngitudiIlal stop limit~ longitudirlal displacemen-t of the mandrel within -the housirlg. T~le mandrel is lorlgitud.inally slidable withirl the housing between a first position whereir fur-ther di~placemerlt -toward the second end of -the lOhousirlg is limited by the longitudirlal atop and a second position wherein the mandrel is displaced toward -the first end of the housirlg. A rotatiorlal s-top prevents relative ro-tation betweerl the mandre:l and the housiny when the mandrel is in the first position and allows 15~uch relative ro-tation wherl the mandrel is in the second position. A rotator acts between -the mandrel and the housing. The rotator reac-ts -to longitudinal displacemerlt between the mandrel and the housing to cause a predetermirled amo-unt of relative rota-tion 20between -the mandrel and the housing when the mandrel is : displaced from -the ~ir~t po~i-tion to the second positior and returned -to the first position. Means is provided for locking the mandrel in the :Eirst posi-tiorl.
' : 25 BRIEF DESCRIPTION OF THE DRAWINGS
.
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, 30 wherein: -FIGVRE 1 is a longitudinal section view of a preferred embodimen-t of the invention.
FIGURE 2 .is a detailed view of a portion of the 35 Adjustable Bent Sub i.llustrated in FIGURE 1.
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.
. :. :
8q~
_ 3 DETAILED DESCRIPTION OF T~E~ ~R~U ~0 IM~A~
The preferred elslbodimerlt will now be desc~ibed with reference to FIG~R~S 1 and 2. T~le ~referred embodi~nent, generaily de~igna-ted by reference nu~leral 10, is an 5 adjustable berl-t sub for u~e in ear-th drillirly. The primary componen-t~ of adjus-table bent sub 10 are a tubular ho-usirlg l2 alld a tubulal marldrel 1~.
Housing 12 has a fir~t end 16, a second erld 18, and a primary axis (no-t shown). For ease of assembly ho~sing 12 is constructed of two comporlerlts; a sprir1g housing 20 and a ro-ta-tor hou~ing 22. First end 16 of housirlg 12 is equivalerl-t to firs-t end of spring housing 20. Second end 18 of ho-ll~irlg 12 is equivalen-t -to second end of rotator housir1g 22. Sprirlg housing 20 has a second end 24 which -telescopically receives a first end 26 of rotator housing 22 at a threaded connection 28.
Threaded connec-tiorl 28 i~ ~;ealed by an 0 ring seal 30.
Hou~ing 12 has an interior bure 32 which is machined at 20second end 18 a-t an angle -to offset second end 18 of tubular housing 12 at an angle to the primary axis (not shown) creating an off3et axis 34. A -threaded connection 36 is positioned at firs-t end 16 of holl~ing 12. Threaded connection 36 permits hou~ing 12 to be 2s~ecured in the drill string.
Mandrel 14 has a fir~-t end 33, a secorid end 40, and a primary a~is (not shown). A threaded connection 42 is po~itioned at secolld end 40 of mandrel 14. Threaded 30connectiorl 42 permits mandrel 14 to be ~ecured in -the drill string. Mandrel 14 has an armular sho~lder 44, the sîgnificance of which will be hereinafter further described. Fir~-t end 38 of mandrel 14 is machined a-t an 3sangle in ~rder -to offset firs-t end 38 of mandrel 14 at an angle to the primary axi~ (rlot ~howrl) creatirlg an .
, 2 ~
offset axis 46. Fir~-~ end 38 of marldrel 14 i5 telescopicall~ received in secorld end 18 of housirlg 12.
By ro-ta-tion of mand:rel 14 in r~lation -to ho-using 12 arl adjustmerlt may be made in a berld created by a cumulative 5 effect o.C offse-t axi~ 46 of marldrel 14 and off~et axis 34 of housirly 12.
A s-topper 48 is secured to .Eirs-t end 38 of mandrel 14. The connection between stopper 43 arld fir~t end 38 lOof mandrel 14 is sealed by an O ring seal 49. S-topper 48 serves as a longi-tudinal stop -to limit lorlyitudinal displacement of marl~rel 14 within housiIly 12. Mandrel 14 i9 longitudinally slidable within housing 12 between a f.irst p~sition wherein further displacement toward 15second end 18 of housirlg 12 is limited by stopper 48 striking first end 26 of rv-tator ho-us.irlg 22, and a second position whereirl mandrel ls is displaced toward first end 16 of housirly 12. The movemer~t of mandrel 14 in the second position is limi-ted by annular shoulder 44 200f mandrel 14 striking second end 18 of housing 12. A
coil spring 50 is disposed within spring housing 20. A
firs-t end 52 of sp-.ring 50 acts ayainst a shoulder 54 within interior bore 32 at firs-t end 16 of housing 12.
A second end 56 of spring 50 acts against a sealing riny ~558 having an annular seal 60. Sealing ring 58 in turn acts against stopper 48. 0 ring seal~ 62 are positioned where sealing ring 5~ meets stopper 48. The effect of spriny 50 .i5 to apply a bia~ing force be-tween first erld 38 of mandrel 14 and firs-t end 16 of hou~ing 12 which 30uryes mandrel 14 in-to the first po~i-tion.
A rotatiorlal stop in the form of engaying splirle 64 and 66 on housiny 12 and mandrel 14, respectf-ully.
355pline 64 and 66 no~-rotatably couple mandrel 14 -to housiny 1~ when mandrel 14 i5 in -the fir~-t po~ition.
-2 ~
This has -the e:Efe~t of preverltinc3 relative rotatiorl : between mandrel 1~ and hou~irlg 12 wherl mandrel 14 is in -the firs-t po6i-tiorl and allowi.rly such rela-tive :rotatio wherl mandrel 14 i5 in the SeCOrld poYi tion. Splirle 64 5 and 66 are be~-t ill-ustra-ted in FIGURE 2.
A ~v-tator 68 ac-ts between mandrel 14 and housing 12. Rota-tor 68 react~ to longitudinal displacement be-tween marldrel 14 and housirlg 12 to cause a lOpredetermiIled aMour--t of relative rotation be-tweerl mandrel 14 and housing 12 when mandrel 14 is displaced from -the -first posi-tion to -the second position and returned ta the first position. Referrirlg to ~IG~RE 2, rotator 68 consists of a plurali-ty of generally parallel 15sided depressions on mandrel 1~ defiIling adjacent longitudinal channels 70 and crossover channels ~2.
I,ongi-tudinal charlnels 70 are geIIerally parallel to each other and have a front end 74 and a back end ~6.
Crossover charmels 72 connec-t adjacerl-t longitucliTlal 20channels 70. Crossover chanrlels 72 have an upper end 78 opening into front end ~4 of OTle of lOTlgi tUdirlal channels 70 and a lower end 80 opening into back end ~5 of an adjacen-t one of longi-tudinal cha}lIlels 70. Sl:iders 82 are affixed to housing 12. Sliders 82 erlgage and are 25slidable along channels 70 and 72 on mandrel 14.
A split ring 84 clampingly engages mandrel 14.
Split ring 84 has one peripheral edge 86 which engages second end 18 of housing 12 and an opposed peripheral 30edge 88 which engages annular shoulder 44 on mandrel 14.
Split ring 84 is removably secured -to mandrel 14 by bol-ts 90. When split ring 84 is placed in position as described when mandrel 14 is in the first position 35relative movement of mandrel 14 iII relation to housirlg 12 is prevented, thereby locking mandrel 14 :irl the f.irst ' ~
, ~ 6 pO~i~iOII. Mandrel 1~ iS Ullable to move -tovJaId seco-nd end 18 of housing 1~ due -to ~topper 48. Mandrel 14 is : unable to move ~oward first end 16 of housing 12 du~ -to the imposition of split rin~ ~4 between anrlular shoulder 5 44 of mandrel 14 and second end 18 of nous:irly 12.
An oil filled chamb~r 92 is created between ~andrel 14 and ~lousing 12. Ol:L filled chamber e~-tends from second end 18 of housirlg 12 to anrlular seal 60 on seal ring 58. Second end 18 of housing 12 has a seal 94 to prevent the escape of oil from oll filled chamber 92.
Oil is placed in oil filled chamber 92 after assembly of the tool through oil plug 96.
The use and op~ratioIl of adj-ustable bent sub 10 will now be described with reference to FIG~RES 1 and 2.
In order -to adjust adjustable bent ~ub 10 split ring 84 i5 removed. Once split r;ng 84 is removed mandrel 14 is iongitudirlally slidable within housing 12 from the first 20position to the second position. As mandrel 14 is moved toward the second po~ition coil ~pring 50 is compre~sed.
Wherl Illandrel 14 i5 moved into -the second position spline 64 on housirlg 12 are di~engag~d rom spline 66 on mandrel 14, thereby allvwing relative rotation of mandrel 14 in relation -to housing 12. This relative rotation is control:Led by rotator ~8. ~ach of longitudinal channels 70 represents one incremental adjustmen-t. The displacemen-t of mandrel 14 from the f.irst position to the secorld position, and then the 30return of mandrel 14 to the first posi-tion resul-ts in an adjustment from one on longitudinal channels 70 to an adjacent one of longitudinal chanrlel~ 70. Thi~ i9 due to -the path followed by sliders 82. As mandrel 14 moves 3sfrom the first position tv the ~econd position sliders 82 move via crossover chanrlel~ '72 from frorl-t end '74 of '` `
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` -one vf longi-t-udirlal cha}lrle:l~ 70 to back erld 76 of an adjacent one of longitudirlal chant~ 700 As mandrel 14 moves from -the secorl~ position back to t~le fir~-t position slider~ 82 move from back end 76 to front end 5 ~4 of the adjacen-t one of longi-tudirlal charlrlel~ 70.
. MandLel 14 is displaced betweerl the f irst and ~econd : posi tions as many t:imes as may be required to achiave the desired adjustment. This is due -to t:he ~ac-t -that xot~tion of m~ndrel 14 in rela-tion -to hollsing 12 ad,jus-ts : lOthe bend created by the cumulative offset of offset axis : 46 of m~ndrel 14 and offse-t a~is 34 of housillg 12, and rotator 68 controls the rotation of marldrel 14. Once the desired adjustmen-t has been made ~plit ring 84 is put back in positionO Split riny 84 occupies the space 15between anTIular shoulder 44 on mandrel 14 and Yecond end 18 of housing 12. This maintains stopper 48 against fir~t end 26 of rotator housing 22. Marldrel 14 is ~ therefore maintained in a pos.ition where no longitudinal : movement in relation to housing 12 i5 po~ible. With 20split ring 84 maintainirlg mandrel 14 in the first position, spline 64 on housing 12 are kept enga~ed with spline 66 on mandrel 14. Spline 64 and 66 norl-rota-tably couple mandrel 14 and ho-using 12~
It will be apparent to one skilled in the art how -the structure of -the presen-t invention permits an adjustment to be made of adjustable bent ~ub 10. It will al~o be apparent to one skilled in the art that modifications may be made to the preferred embodiment 30withou-t departing from the spirit and scope of the invention.
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Claims (5)
1. An adjustable bent sub for use in earth drilling, comprising:
a. a tubular housing having a first end, a second end, and a primary axis, means being provided to offset the second end of the tubular housing at an angle to the primary axis thereby creating an offset axis;
b. a tubular mandrel having a first end, a second end, and a primary axis, means being provided to offset the first end of the mandrel at an angle to the primary axis thereby creating an offset axis, the first end of the mandrel being telescopically received in the second end of the tubular housing such that by rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing;
c. a longitudinal stop to limit longitudinal displacement of the mandrel within the housing, the mandrel being longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing;
d. a rotational stop preventing relative rotation between the mandrel and the housing when the mandrel is in the first position and allowing such relative rotation when the mandrel is in the second position;
e. a rotator acting between the mandrel and the housing, the rotator reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel displaced from the first position to the second position and returned to the first position;
and f. means for locking the mandrel in the first position.
a. a tubular housing having a first end, a second end, and a primary axis, means being provided to offset the second end of the tubular housing at an angle to the primary axis thereby creating an offset axis;
b. a tubular mandrel having a first end, a second end, and a primary axis, means being provided to offset the first end of the mandrel at an angle to the primary axis thereby creating an offset axis, the first end of the mandrel being telescopically received in the second end of the tubular housing such that by rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing;
c. a longitudinal stop to limit longitudinal displacement of the mandrel within the housing, the mandrel being longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing;
d. a rotational stop preventing relative rotation between the mandrel and the housing when the mandrel is in the first position and allowing such relative rotation when the mandrel is in the second position;
e. a rotator acting between the mandrel and the housing, the rotator reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel displaced from the first position to the second position and returned to the first position;
and f. means for locking the mandrel in the first position.
2. The adjustable bent sub as defined in Claim 1, the means for locking the mandrel in the first position being a split ring which clampingly engage the mandrel, the split ring having one peripheral edge which engages the second end of the housing and and opposed peripheral edge which engages a shoulder on the mandrel to prevent relative movement of the mandrel in relation to the housing.
3. The adjustable bent sub as defined in Claim 1, the rotator being comprised of:
a. a plurality of generally parallel sided depressions on the mandrel defining at least two adjacent longitudinal channels and at least one crossover channel, the longitudinal channels being generally parallel to each other, the longitudinal channels having a front end and a back end, the crossover channel connecting adjacent longitudinal channels having an upper end opening the front end of one of the longitudinal channels and a lower end opening into the back end of an adjacent one of the longitudinal channels; and b. at least one slider affixed to the housing, the slider engaging and being slidable along the channels on the mandrel.
a. a plurality of generally parallel sided depressions on the mandrel defining at least two adjacent longitudinal channels and at least one crossover channel, the longitudinal channels being generally parallel to each other, the longitudinal channels having a front end and a back end, the crossover channel connecting adjacent longitudinal channels having an upper end opening the front end of one of the longitudinal channels and a lower end opening into the back end of an adjacent one of the longitudinal channels; and b. at least one slider affixed to the housing, the slider engaging and being slidable along the channels on the mandrel.
4. An adjustable bent sub as defined in Claim 1, the rotational stop being engaging spline on the housing and the mandrel which non-rotatably couple the mandrel to the housing.
5. An adjustable bent sub for use in earth drilling, comprising:
a. a tubular housing having a first end, a second end, and a primary axis, means being provided to offset the second end of the tubular housing at an angle to the primary axis thereby creating an offset axis;
b. a tubular mandrel having a first end, a second end, and a primary axis, means being provided to offset the first end of the mandrel at an angle to the primary axis thereby creating an offset axis, the first end of the mandrel being telescopically received in the second end of the tubular housing such that by rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing;
c. a longitudinal stop to limit longitudinal displacement of the mandrel within the housing, the mandrel being longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing;
d. biasing means disposed between the first end of the mandrel and the first end of the housing thereby urging the mandrel into the first position;
e. a rotational stop comprising engaging spline on the housing and the mandrel which non-rotatably couple the mandrel to the housing when the mandrel is in the first position, thereby preventing relative rotation between the mandrel and the housing when the mandrel is in the first position and allowing such relative rotation when the mandrel is in the second position;
f. a rotator acting between the mandrel and the housing, the rotator reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel is displaced from the first position to the second position and returned to the first position, the rotator being comprised of:
i. a plurality of generally parallel sided depressions on the mandrel defining at least two adjacent longitudinal channels and at least one crossover channel, the longitudinal channels being generally parallel to each other, the longitudinal channels having a front end and a back end, the crossover channel connecting adjacent longitudinal channels having an upper end opening the front end of one of the longitudinal channels and a lower end opening into the back end of an adjacent one of the longitudinal channels; and ii. at least one slider affixed to the housing, the slider engaging and being slidable along the channels on the mandrel; and g. a split ring which clampingly engages the mandrel, the split ring having one peripheral edge which engages the second end of the housing and an opposed peripheral edge which engages a shoulder on the mandrel to prevent relative movement of the mandrel in relation to the housing, thereby locking the mandrel in the first position.
a. a tubular housing having a first end, a second end, and a primary axis, means being provided to offset the second end of the tubular housing at an angle to the primary axis thereby creating an offset axis;
b. a tubular mandrel having a first end, a second end, and a primary axis, means being provided to offset the first end of the mandrel at an angle to the primary axis thereby creating an offset axis, the first end of the mandrel being telescopically received in the second end of the tubular housing such that by rotation of the mandrel in relation to the housing an adjustment may be made in a bend created by the cumulative effect of the offset axis of the mandrel and the offset axis of the housing;
c. a longitudinal stop to limit longitudinal displacement of the mandrel within the housing, the mandrel being longitudinally slidable within the housing between a first position wherein further displacement toward the second end of the housing is limited by the longitudinal stop and a second position wherein the mandrel is displaced toward the first end of the housing;
d. biasing means disposed between the first end of the mandrel and the first end of the housing thereby urging the mandrel into the first position;
e. a rotational stop comprising engaging spline on the housing and the mandrel which non-rotatably couple the mandrel to the housing when the mandrel is in the first position, thereby preventing relative rotation between the mandrel and the housing when the mandrel is in the first position and allowing such relative rotation when the mandrel is in the second position;
f. a rotator acting between the mandrel and the housing, the rotator reacting to longitudinal displacement between the mandrel and the housing to cause a predetermined amount of relative rotation between the mandrel and the housing when the mandrel is displaced from the first position to the second position and returned to the first position, the rotator being comprised of:
i. a plurality of generally parallel sided depressions on the mandrel defining at least two adjacent longitudinal channels and at least one crossover channel, the longitudinal channels being generally parallel to each other, the longitudinal channels having a front end and a back end, the crossover channel connecting adjacent longitudinal channels having an upper end opening the front end of one of the longitudinal channels and a lower end opening into the back end of an adjacent one of the longitudinal channels; and ii. at least one slider affixed to the housing, the slider engaging and being slidable along the channels on the mandrel; and g. a split ring which clampingly engages the mandrel, the split ring having one peripheral edge which engages the second end of the housing and an opposed peripheral edge which engages a shoulder on the mandrel to prevent relative movement of the mandrel in relation to the housing, thereby locking the mandrel in the first position.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002019898A CA2019898A1 (en) | 1990-06-26 | 1990-06-26 | Adjustable bent sub |
| EP19910305677 EP0465072A3 (en) | 1990-06-26 | 1991-06-24 | Adjustable bent sub |
| AU79321/91A AU7932191A (en) | 1990-06-26 | 1991-06-25 | An adjustable bent sub |
| NO91912480A NO912480L (en) | 1990-06-26 | 1991-06-25 | ADJUSTABLE BOEYD SUBB. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002019898A CA2019898A1 (en) | 1990-06-26 | 1990-06-26 | Adjustable bent sub |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2019898A1 true CA2019898A1 (en) | 1991-12-26 |
Family
ID=4145345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002019898A Abandoned CA2019898A1 (en) | 1990-06-26 | 1990-06-26 | Adjustable bent sub |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0465072A3 (en) |
| AU (1) | AU7932191A (en) |
| CA (1) | CA2019898A1 (en) |
| NO (1) | NO912480L (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2063161A1 (en) * | 1992-03-16 | 1993-09-17 | Lennard Sihlis | Adjustable bent housing ii |
| GB9210846D0 (en) * | 1992-05-21 | 1992-07-08 | Baroid Technology Inc | Drill bit steering |
| GB9222298D0 (en) * | 1992-10-23 | 1992-12-09 | Stirling Design Int | Directional drilling tool |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4303135A (en) * | 1977-08-18 | 1981-12-01 | Benoit Lloyd F | Directional drilling sub |
| US4596294A (en) * | 1982-04-16 | 1986-06-24 | Russell Larry R | Surface control bent sub for directional drilling of petroleum wells |
| US4745982A (en) * | 1986-11-28 | 1988-05-24 | Wenzel Kenneth H | Adjustable bent sub |
| US4884643A (en) * | 1989-01-17 | 1989-12-05 | 392534 Alberta Ltd. | Downhole adjustable bent sub |
| CA2022452C (en) * | 1990-08-01 | 1995-12-26 | Douglas Wenzel | Adjustable bent housing |
| US5117927A (en) * | 1991-02-01 | 1992-06-02 | Anadrill | Downhole adjustable bent assemblies |
-
1990
- 1990-06-26 CA CA002019898A patent/CA2019898A1/en not_active Abandoned
-
1991
- 1991-06-24 EP EP19910305677 patent/EP0465072A3/en not_active Withdrawn
- 1991-06-25 AU AU79321/91A patent/AU7932191A/en not_active Abandoned
- 1991-06-25 NO NO91912480A patent/NO912480L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU7932191A (en) | 1992-01-02 |
| EP0465072A2 (en) | 1992-01-08 |
| NO912480L (en) | 1991-12-27 |
| NO912480D0 (en) | 1991-06-25 |
| EP0465072A3 (en) | 1992-12-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |