US20090139721A1 - Bottom Hole Assembly for Casing Window Milling - Google Patents
Bottom Hole Assembly for Casing Window Milling Download PDFInfo
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- US20090139721A1 US20090139721A1 US12/325,184 US32518408A US2009139721A1 US 20090139721 A1 US20090139721 A1 US 20090139721A1 US 32518408 A US32518408 A US 32518408A US 2009139721 A1 US2009139721 A1 US 2009139721A1
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- window
- mill
- bottom hole
- hole assembly
- bearing
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- 238000003801 milling Methods 0.000 title claims description 15
- 238000005520 cutting process Methods 0.000 claims abstract description 21
- 238000000034 method Methods 0.000 claims description 4
- 230000000717 retained effect Effects 0.000 claims 1
- 238000005553 drilling Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000000452 restraining effect Effects 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 241000219109 Citrullus Species 0.000 description 1
- 235000012828 Citrullus lanatus var citroides Nutrition 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 235000019282 butylated hydroxyanisole Nutrition 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B29/00—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
- E21B29/06—Cutting windows, e.g. directional window cutters for whipstock operations
Definitions
- the invention relates generally to the arrangement of mills on bottom hole assemblies that are used to cut windows in casing strings for the creation of lateral wellbores.
- lateral production wellbores which extend outwardly from a central, generally vertical wellbore.
- a window must be cut into the side of casing in the central wellbore.
- drilling tools are used to form an extended lateral wellbore.
- whipstocks and milling tools are used to create the window in the central wellbore casing wall.
- the invention provides an improved milling bottom hole assembly for use in cutting a window in a wellbore casing wall.
- An exemplary bottom hole assembly (BHA) is described which includes a central shaft. The distal end of the central shaft carries a window mill. A pair of bearing mills is carried by the shaft above the window mill. Placement of the bearing mills permits the bottom hole assembly to cut a window having a greater length and quality (gage width and reduced burrs/slivers) than windows cut by other BHA designs. The above is superior for ingress and egress of long and stiff directional drilling BHAs.
- FIG. 1 is a side, cross-sectional cutaway drawing of an exemplary milling tool bottom hole assembly constructed in accordance with the present invention depicted alongside an associated exemplary whipstock.
- FIG. 2 is a side, cross-sectional view of an exemplary wellbore containing a whipstock, and milling tool bottom hole assembly shown in FIG. 1 , during an initial window cutting stage.
- FIG. 3 is a side, cross-sectional view of the arrangement depicted in FIG. 2 , now with the window cutting operation further advanced.
- FIG. 4 is a side, cross-sectional view of the arrangement depicted in FIGS. 2 and 3 , now with the window cutting operation further advanced.
- FIG. 5 is a graph depicting the correlation of side forces on the window mill with distance of the window mill from the whipstock kick-off point.
- FIG. 1 illustrates an exemplary whipstock 10 and a milling tool bottom hole assembly 12 , which is constructed in accordance with the present invention.
- the bottom hole assembly 12 includes a threaded upper end 14 which is used for securing the bottom hole assembly 12 to a drill string 16 .
- the bottom hole assembly 12 includes a central shaft 17 formed of upper and lower string sections 18 , 20 , which are secured together at threaded joint 22 .
- a window mill 24 is secured to the distal end of the bottom hole assembly 12 .
- a first bearing mill 26 is located on the lower string section 20 above the window mill 24 .
- the first bearing mill 26 preferably presents a rounded, arcuate cross-section.
- a second bearing mill 28 is located on the upper string section 18 .
- the second bearing mill 28 preferably presents a cross-section that is curved and oblong, thereby presenting a substantially flat center segment 30 and arcuately curved end sections 32 .
- the second bearing mill 28 may be of the type generally known in the industry as a “Watermelon mill.” In an alternate embodiment, the second bearing mill 28 presents a cross-section that is arcuately rounded, in the same manner as the first bearing mill 26 .
- the overall length “L” of the bottom hole assembly 12 exceeds the longitudinal length “l” of the ramp 34 of the whipstock 10 (the whipstock ramp length).
- the second bearing mill 28 is preferably located at a distance “x” from the window mill 24 that is from about 1.0 to about 1.25 times the length “l” of the ramp 34 . Most preferably, the distance “x” is about 1.15 to about 1.20 times the length “l” of the ramp 34 .
- the first bearing mill 26 is preferably located at a distance “d” from the window mill 24 that is from about one-fifth to about one-half of the length “x”. Most preferably, the distance “d” is about one-third of the length “x”. It is further noted that the spacing (“d 1 ”) between the first and second bearing mills 26 , 28 preferably exceeds the distance “d”.
- FIGS. 2 , 3 and 4 illustrate the bottom hole assembly 12 in operation to create a window 40 in the casing 42 surrounding a primary wellbore 44 .
- FIGS. 2-4 also depict the bottom hole assembly 12 exiting the primary wellbore 44 along a departure path 46 through the surrounding earth 48 .
- the drill string 16 and bottom hole assembly 12 are rotated within the casing 42 , and the bottom hole assembly 12 is lowered within the wellbore 44 until the bottom hole assembly 12 encounters the whipstock 10 proximate the kick-off point 43 .
- the window mill 24 is urged against the casing 42 and begins to cut the window 40 .
- the window mill 24 cuts downwardly from the upper window end 50 to increase the length of the window 40 (as shown in FIGS. 3 and 4 ).
- the incline of ramp 34 urges the window mill 24 laterally outside of the wellbore 44 .
- the lower string section 20 remains substantially rigid between the window mill 24 and the first bearing mill 26 .
- the portion of the lower string section 20 above the first bearing mill 26 and the portion of the upper string section 18 below the second bearing mill 28 will bend and flex.
- the first bearing mill 26 will cut away the upper end 50 of the window 40 during the milling operation, thereby increasing the length of the window 40 . It is noted that, as the milling operation progresses, the first bearing mill 26 will reach the upper end of the whipstock 10 before or at the same time as the mid-point ( 52 in FIGS. 1 and 3 ) of the bottom hole assembly 12 due to the spacing of the first bearing mill 26 proximate to the window mill.
- the design of the bottom hole assembly 12 provides high constraining forces at the window mill 24 while traversing the midsection of the ramp 34 of the whipstock 10 .
- the use of a bottom hole assembly 12 constructed in accordance with the present invention produces a milled window 40 having an extended length, as measured from the upper end 50 to the lower end 52 .
- the proximity of the first bearing mill 26 to the window mill 24 creates restraining forces on the window mill 24 to urge it properly along the departure path 46 from the primary wellbore 44 .
- the proximity of the first bearing mill 26 to the window mill 24 helps in harnessing the efficiency of the cutters of the first bearing mill 26 for is additional cutting of the upper end 50 of the window 40 . This results in a longer window 40 than with many conventional techniques.
- FIG 3 depicts the upper end 50 of the window 40 being milled away by the first bearing mill 26 .
- the first bearing mill 26 is spaced at an optimum distance from the window mill 24 to avoid an early jump-off of the window mill 24 from the casing 42 near the mid-point of the whipstock ramp 34 .
- the first bearing mill 26 preferably has an arcuate cross-section, thereby providing for point-type contact between the bearing mill 26 and the surrounding casing 42 or the whipstock 10 .
- Point-type contact results from the fact that the surface of the curved bearing mill 26 cross-section will contact the surrounding casing 42 or whipstock 10 at a single point.
- FIG. 3 illustrates the mill 26 contacting the casing 42 at point 54 .
- the bottom hole assembly 12 can pivot with respect to the surrounding casing 42 about the point 54 . Binding of the bottom hole assembly 12 as it turns while moving onto the upper end of the whipstock ramp 34 is dramatically reduced as a result of this point-type contact between the first bearing mill 26 and the casing 42 . The combination of these advantages results in a longer service life for the bottom hole assembly 12 .
- FIG. 5 depicts the side forces imparted to the window mill 24 as it is moved along the whipstock ramp 34 from the kick-off point 43 . It can be seen by reference to FIG. 5 that the side forces imparted to the window mill 24 by the bottom hole assembly are kept within a reasonable range throughout the milling operation.
- FIG. 5 is a chart wherein the amount of side force (in kip-force, or klbf) imparted to the window mill (bit) 24 is represented by curve 60 . As can be seen, the side forces are within an acceptable limit and are higher at locations along the whipstock ramp 34 where the window mill 24 has maximum chances of early jump-offs. In FIG.
- FIG. 5 indicates that areas where the curve 60 presents a positive side force (1, 2, 3, 4, etc.) indicate that the window mill 24 is being urged against the ramp 34 of the whipstock 10 . Conversely, areas where the curve 60 depicts negative side force ( ⁇ 1, ⁇ 2, ⁇ 3, etc.) indicate that the window mill 24 is being diverted away from the ramp 34 of the whipstock 10 .
- FIG. 5 indicates that the BHA 12 causes the window mill 24 to be continually urged against the ramp 34 until point 62 , which generally coincides with the point at which the window mill 24 has moved entirely outside of the casing 42 . As a result of this continuous positive side force, the possibility of the window mill 24 tending to undesirably “jump off” of the ramp 34 during initial phases of window cutting is minimized.
- bottom hole assembly 12 and the whipstock 10 collectively provide a window cutting arrangement that is operable to form a window in surrounding wellbore casing. It should also be understood that the invention provides an improved method for forming a window within wellbore casing.
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- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
- Milling Processes (AREA)
Abstract
A bottom hole assembly for use in cutting a window in a wellbore casing wall. An exemplary bottom hole assembly is described which includes a shaft that carries a window mill. A pair of bearing mills is carried by the shaft above the window mill. Placement of the bearing mills permits the bottom hole assembly to cut a window having a greater length and quality (gage width and reduced burrs/slivers) than windows cut by other bottom hole assembly designs.
Description
- This application claims the priority of U.S. Provisional Patent Application Ser. No. 60/991,432 filed Nov. 30, 2008.
- 1. Field of the Invention
- The invention relates generally to the arrangement of mills on bottom hole assemblies that are used to cut windows in casing strings for the creation of lateral wellbores.
- 2. Description of the Related Art
- In modern hydrocarbon production, it is common to create one or more lateral production wellbores which extend outwardly from a central, generally vertical wellbore. In order to form a lateral production wellbore, a window must be cut into the side of casing in the central wellbore. Thereafter, drilling tools are used to form an extended lateral wellbore. Traditionally, whipstocks and milling tools are used to create the window in the central wellbore casing wall.
- The invention provides an improved milling bottom hole assembly for use in cutting a window in a wellbore casing wall. An exemplary bottom hole assembly (BHA) is described which includes a central shaft. The distal end of the central shaft carries a window mill. A pair of bearing mills is carried by the shaft above the window mill. Placement of the bearing mills permits the bottom hole assembly to cut a window having a greater length and quality (gage width and reduced burrs/slivers) than windows cut by other BHA designs. The above is superior for ingress and egress of long and stiff directional drilling BHAs.
- The advantages and further aspects of the invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout the several figures of the drawing and wherein:
-
FIG. 1 is a side, cross-sectional cutaway drawing of an exemplary milling tool bottom hole assembly constructed in accordance with the present invention depicted alongside an associated exemplary whipstock. -
FIG. 2 is a side, cross-sectional view of an exemplary wellbore containing a whipstock, and milling tool bottom hole assembly shown inFIG. 1 , during an initial window cutting stage. -
FIG. 3 is a side, cross-sectional view of the arrangement depicted inFIG. 2 , now with the window cutting operation further advanced. -
FIG. 4 is a side, cross-sectional view of the arrangement depicted inFIGS. 2 and 3 , now with the window cutting operation further advanced. -
FIG. 5 is a graph depicting the correlation of side forces on the window mill with distance of the window mill from the whipstock kick-off point. -
FIG. 1 illustrates an exemplary whipstock 10 and a milling toolbottom hole assembly 12, which is constructed in accordance with the present invention. Thebottom hole assembly 12 includes a threadedupper end 14 which is used for securing thebottom hole assembly 12 to adrill string 16. Thebottom hole assembly 12 includes acentral shaft 17 formed of upper andlower string sections joint 22. Awindow mill 24, of a type known in the art, is secured to the distal end of thebottom hole assembly 12. - A first bearing
mill 26 is located on thelower string section 20 above thewindow mill 24. The first bearingmill 26 preferably presents a rounded, arcuate cross-section. A second bearingmill 28 is located on theupper string section 18. The second bearingmill 28 preferably presents a cross-section that is curved and oblong, thereby presenting a substantiallyflat center segment 30 and arcuatelycurved end sections 32. The second bearingmill 28 may be of the type generally known in the industry as a “Watermelon mill.” In an alternate embodiment, the second bearingmill 28 presents a cross-section that is arcuately rounded, in the same manner as the first bearingmill 26. - The overall length “L” of the bottom hole assembly 12 (the bottom hole assembly length) exceeds the longitudinal length “l” of the
ramp 34 of the whipstock 10 (the whipstock ramp length). The second bearingmill 28 is preferably located at a distance “x” from thewindow mill 24 that is from about 1.0 to about 1.25 times the length “l” of theramp 34. Most preferably, the distance “x” is about 1.15 to about 1.20 times the length “l” of theramp 34. The first bearingmill 26 is preferably located at a distance “d” from thewindow mill 24 that is from about one-fifth to about one-half of the length “x”. Most preferably, the distance “d” is about one-third of the length “x”. It is further noted that the spacing (“d1”) between the first andsecond bearing mills -
FIGS. 2 , 3 and 4 illustrate thebottom hole assembly 12 in operation to create awindow 40 in thecasing 42 surrounding aprimary wellbore 44.FIGS. 2-4 also depict thebottom hole assembly 12 exiting theprimary wellbore 44 along adeparture path 46 through the surroundingearth 48. - In operation, the
drill string 16 andbottom hole assembly 12 are rotated within thecasing 42, and thebottom hole assembly 12 is lowered within thewellbore 44 until thebottom hole assembly 12 encounters the whipstock 10 proximate the kick-offpoint 43. AsFIG. 2 illustrates, thewindow mill 24 is urged against thecasing 42 and begins to cut thewindow 40. As the milling operation continues, thewindow mill 24 cuts downwardly from theupper window end 50 to increase the length of the window 40 (as shown inFIGS. 3 and 4 ). At the same time, the incline oframp 34 urges thewindow mill 24 laterally outside of thewellbore 44. Thelower string section 20 remains substantially rigid between thewindow mill 24 and the first bearingmill 26. However, due to the substantial distance between the first andsecond bearing mills lower string section 20 above the first bearingmill 26 and the portion of theupper string section 18 below the second bearingmill 28 will bend and flex. The first bearingmill 26 will cut away theupper end 50 of thewindow 40 during the milling operation, thereby increasing the length of thewindow 40. It is noted that, as the milling operation progresses, the first bearingmill 26 will reach the upper end of the whipstock 10 before or at the same time as the mid-point (52 inFIGS. 1 and 3 ) of thebottom hole assembly 12 due to the spacing of the first bearingmill 26 proximate to the window mill. - During the milling operation, as illustrated by
FIG. 4 , theflat portion 30 of the second bearingmill 28 will contact the surroundingcasing 42 and be urged to remain radially inside of thecasing 42. This urging results in additional lateral forces to be imparted to the lower portion of thebottom hole assembly 12, causing thebottom hole assembly 12 to hold against the whipstock 10 for a longer time, thus leading to alonger window 40. - The design of the
bottom hole assembly 12 provides high constraining forces at thewindow mill 24 while traversing the midsection of theramp 34 of the whipstock 10. The use of abottom hole assembly 12 constructed in accordance with the present invention produces amilled window 40 having an extended length, as measured from theupper end 50 to thelower end 52. The proximity of the first bearingmill 26 to thewindow mill 24 creates restraining forces on thewindow mill 24 to urge it properly along thedeparture path 46 from theprimary wellbore 44. Additionally, the proximity of the first bearingmill 26 to thewindow mill 24 helps in harnessing the efficiency of the cutters of the first bearingmill 26 for is additional cutting of theupper end 50 of thewindow 40. This results in alonger window 40 than with many conventional techniques.FIG. 3 depicts theupper end 50 of thewindow 40 being milled away by the first bearingmill 26. At the same time, the first bearingmill 26 is spaced at an optimum distance from thewindow mill 24 to avoid an early jump-off of thewindow mill 24 from thecasing 42 near the mid-point of the whipstockramp 34. - As noted, the first bearing
mill 26 preferably has an arcuate cross-section, thereby providing for point-type contact between thebearing mill 26 and the surroundingcasing 42 or the whipstock 10. Point-type contact results from the fact that the surface of the curved bearingmill 26 cross-section will contact the surroundingcasing 42 or whipstock 10 at a single point.FIG. 3 illustrates themill 26 contacting thecasing 42 atpoint 54. In addition, thebottom hole assembly 12 can pivot with respect to the surroundingcasing 42 about thepoint 54. Binding of thebottom hole assembly 12 as it turns while moving onto the upper end of thewhipstock ramp 34 is dramatically reduced as a result of this point-type contact between thefirst bearing mill 26 and thecasing 42. The combination of these advantages results in a longer service life for thebottom hole assembly 12. -
FIG. 5 depicts the side forces imparted to thewindow mill 24 as it is moved along thewhipstock ramp 34 from the kick-off point 43. It can be seen by reference toFIG. 5 that the side forces imparted to thewindow mill 24 by the bottom hole assembly are kept within a reasonable range throughout the milling operation.FIG. 5 is a chart wherein the amount of side force (in kip-force, or klbf) imparted to the window mill (bit) 24 is represented bycurve 60. As can be seen, the side forces are within an acceptable limit and are higher at locations along thewhipstock ramp 34 where thewindow mill 24 has maximum chances of early jump-offs. InFIG. 5 , areas where thecurve 60 presents a positive side force (1, 2, 3, 4, etc.) indicate that thewindow mill 24 is being urged against theramp 34 of thewhipstock 10. Conversely, areas where thecurve 60 depicts negative side force (−1, −2, −3, etc.) indicate that thewindow mill 24 is being diverted away from theramp 34 of thewhipstock 10.FIG. 5 indicates that theBHA 12 causes thewindow mill 24 to be continually urged against theramp 34 untilpoint 62, which generally coincides with the point at which thewindow mill 24 has moved entirely outside of thecasing 42. As a result of this continuous positive side force, the possibility of thewindow mill 24 tending to undesirably “jump off” of theramp 34 during initial phases of window cutting is minimized. More specifically, when the gage O.D. of thewindow mill 24 clears thecasing 42, because of which thecasing 42 no longer provides a restraining force urging thewindow mill 24 against theramp 34, side forces are maximized. A thorough finite element analysis of the proposed design predicts the trajectory of the lateral bore hole created in the surroundingearth formation 48 after thewindow mill 24 has moved past the ramp 34 (i.e., beyondpoint 62 of curve 60). This analysis shows that thewindow mill 24 and hence thebottom hole assembly 12 will tend to desirably hold or build an angle that is more normal to thecasing 42 than with other bottom hole assembly designs, which tend to drop angle. This improved trajectory is desirable for the creation of a lateral wellbore using drilling assembly. - It can be seen that the
bottom hole assembly 12 and thewhipstock 10 collectively provide a window cutting arrangement that is operable to form a window in surrounding wellbore casing. It should also be understood that the invention provides an improved method for forming a window within wellbore casing. - The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope and the spirit of the invention.
Claims (20)
1. A bottom hole assembly for use in milling a window in a wellbore casing in association with a whipstock with an angled ramp having a whipstock ramp length, the bottom hole assembly having a bottom hole assembly length and comprising:
a central shaft;
a window mill located proximate a lower end of the shaft;
a first bearing mill upon the shaft;
a second bearing mill upon the shaft;
the window mill and the second bearing mill being spaced from each other by a first distance; and
the first bearing mill being spaced from the window mill at a second distance that is from about one-fifth to one-half of the first distance.
2. The bottom hole assembly of claim 1 wherein the second distance is about one-third of the first distance.
3. The bottom hole assembly of claim 1 wherein the first and second bearing mills are separated from each other by a third distance that is at least as great as the second distance.
4. The bottom hole assembly of claim 1 wherein the first distance is greater than the whipstock ramp length.
5. The bottom hole assembly of claim 1 wherein the first bearing mill presents a rounded, arcuate cross-section.
6. The bottom hole assembly of claim 1 wherein the second bearing mill presents a cross-section having a substantially flat bearing surface.
7. The bottom hole assembly of claim 1 wherein the second bearing mill presents a rounded, arcuate cross-section.
8. The bottom hole assembly of claim 1 wherein the bottom hole assembly length has a midpoint and wherein the first bearing mill reaches an upper end of a whipstock during a milling operation before the midpoint of the bottom hole assembly length reaches the upper end of the whipstock.
9. A window cutting arrangement for forming a window within a wellbore casing, the window cutting arrangement comprising:
a whipstock to be disposed within the wellbore casing, the whipstock presenting an angled ramp and having a whipstock ramp length;
a bottom hole assembly for contacting the angled ramp and cutting a window within the wellbore casing, the bottom hole assembly having a bottom hole assembly length and comprising:
a central shaft;
a window mill proximate a lower end of the shaft and operable for cutting a window in the wellbore casing;
a first bearing mill upon the shaft;
a second bearing mill upon the shaft;
the window mill and the second bearing mill being spaced from each other by a first distance; and
the first bearing mill being spaced from the window mill at a second distance that is from about one-fifth to one-half of the first distance.
10. The window cutting arrangement of claim 9 wherein the second distance is about one-third of the first distance.
11. The window cutting arrangement of claim 9 wherein the first and second bearing mills are separated from each other by a third distance that is at least as great as the second distance.
12. The window cutting arrangement of claim 9 wherein the first distance is equal to or greater than the whipstock ramp length.
13. The window cutting arrangement of claim 9 wherein the first bearing mill presents a rounded, arcuate cross-section.
14. The window cutting arrangement of claim 9 wherein the second bearing mill presents a cross-section having a substantially flat bearing surface.
15. The window cutting arrangement of claim 9 wherein the second bearing mill presents a rounded, arcuate cross-section.
16. The window cutting arrangement of claim 1 wherein the bottom hole assembly length has a midpoint and wherein the first bearing mill reaches an upper end of the whipstock during a milling operation before the midpoint of the bottom hole assembly length reaches the upper end of the whipstock.
17. The window cutting arrangement of claim 12 wherein the first distance is from about 1.0 to about 1.25 times the whipstock ramp length.
18. The window cutting arrangement of claim 17 wherein the first distance is from about 1.15 to about 1.20 times the whipstock ramp length.
19. A method of forming a window in wellbore casing, the method comprising the steps of:
disposing a bottom hole assembly within a wellbore, the bottom hole assembly comprising:
a shaft;
a window mill mounted upon the shaft and located proximate a lower end of the shaft;
a first bearing mill carried by the shaft;
a second bearing mill carried by the shaft;
contacting a whipstock ramp within the wellbore casing with the window mill so that the window mill cuts a window in the wellbore casing;
milling away an upper portion of the window with the first bearing mill; and
contacting the wellbore casing with the second bearing mill so that the first bearing mill and the window mill are retained against the whipstock ramp.
20. The method of claim 19 wherein the bottom hole assembly is disposed within the wellbore casing on a drill string.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/325,184 US20090139721A1 (en) | 2007-11-30 | 2008-11-29 | Bottom Hole Assembly for Casing Window Milling |
US13/021,726 US20110174477A1 (en) | 2007-11-30 | 2011-02-05 | Full Gauge Milling Bottom Hole Assembly with Optimal Contact Force and Build Rate Capability |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US99143207P | 2007-11-30 | 2007-11-30 | |
US12/325,184 US20090139721A1 (en) | 2007-11-30 | 2008-11-29 | Bottom Hole Assembly for Casing Window Milling |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/021,726 Continuation-In-Part US20110174477A1 (en) | 2007-11-30 | 2011-02-05 | Full Gauge Milling Bottom Hole Assembly with Optimal Contact Force and Build Rate Capability |
Publications (1)
Publication Number | Publication Date |
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US20090139721A1 true US20090139721A1 (en) | 2009-06-04 |
Family
ID=40674566
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/325,184 Abandoned US20090139721A1 (en) | 2007-11-30 | 2008-11-29 | Bottom Hole Assembly for Casing Window Milling |
Country Status (2)
Country | Link |
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US (1) | US20090139721A1 (en) |
WO (1) | WO2009073585A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012106044A2 (en) * | 2011-02-05 | 2012-08-09 | Baker Hughes Incorporated | Full gauge milling bottom hole assembly with optimal contact force and build rate capability |
US20160010412A1 (en) * | 2014-07-09 | 2016-01-14 | Baker Hughes Incorporated | Casing exit mills and apparatus and methods of use |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5109924A (en) * | 1989-12-22 | 1992-05-05 | Baker Hughes Incorporated | One trip window cutting tool method and apparatus |
US5445222A (en) * | 1994-06-07 | 1995-08-29 | Shell Oil Company | Whipstock and staged sidetrack mill |
US5657820A (en) * | 1995-12-14 | 1997-08-19 | Smith International, Inc. | Two trip window cutting system |
US5769166A (en) * | 1996-01-24 | 1998-06-23 | Weatherford/Lamb, Inc. | Wellbore window milling method |
US6102123A (en) * | 1996-05-03 | 2000-08-15 | Smith International, Inc. | One trip milling system |
US7207401B2 (en) * | 1996-05-03 | 2007-04-24 | Smith International, Inc. | One trip milling system |
US20070261840A1 (en) * | 2006-05-15 | 2007-11-15 | Stowe Calvin J | Exit window milling assembly with improved restraining force |
-
2008
- 2008-11-29 US US12/325,184 patent/US20090139721A1/en not_active Abandoned
- 2008-11-30 WO PCT/US2008/085090 patent/WO2009073585A2/en active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5109924A (en) * | 1989-12-22 | 1992-05-05 | Baker Hughes Incorporated | One trip window cutting tool method and apparatus |
US5445222A (en) * | 1994-06-07 | 1995-08-29 | Shell Oil Company | Whipstock and staged sidetrack mill |
US5657820A (en) * | 1995-12-14 | 1997-08-19 | Smith International, Inc. | Two trip window cutting system |
US5769166A (en) * | 1996-01-24 | 1998-06-23 | Weatherford/Lamb, Inc. | Wellbore window milling method |
US6102123A (en) * | 1996-05-03 | 2000-08-15 | Smith International, Inc. | One trip milling system |
US7207401B2 (en) * | 1996-05-03 | 2007-04-24 | Smith International, Inc. | One trip milling system |
US20070261840A1 (en) * | 2006-05-15 | 2007-11-15 | Stowe Calvin J | Exit window milling assembly with improved restraining force |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012106044A2 (en) * | 2011-02-05 | 2012-08-09 | Baker Hughes Incorporated | Full gauge milling bottom hole assembly with optimal contact force and build rate capability |
WO2012106044A3 (en) * | 2011-02-05 | 2012-10-18 | Baker Hughes Incorporated | Full gauge milling bottom hole assembly with optimal contact force and build rate capability |
GB2500535A (en) * | 2011-02-05 | 2013-09-25 | Baker Hughes Inc | Full gauge milling bottom hole assembly with optimal contact force and build rate capability |
US20160010412A1 (en) * | 2014-07-09 | 2016-01-14 | Baker Hughes Incorporated | Casing exit mills and apparatus and methods of use |
US9945198B2 (en) * | 2014-07-09 | 2018-04-17 | Baker Hughes, A Ge Company, Llc | Casing exit mills and apparatus and methods of use |
Also Published As
Publication number | Publication date |
---|---|
WO2009073585A3 (en) | 2009-09-17 |
WO2009073585A2 (en) | 2009-06-11 |
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Owner name: BAKER HUGHES INCORPORATED, TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VERMA, SUHAS S.;REEL/FRAME:022138/0574 Effective date: 20081223 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |