US3765487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for releasing differentially stuck pipe
Assignee: Shell USA Inc
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Filing: 1972-06-16
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Granted: 1973-10-16
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Expires: 1992-06-16
Abstract
Abstract Pipe stuck in a well by pressure differential sticking is recovered by swabbing the well to reduce pressure around the point of differential sticking and then exerting an upward pull on the stuck pipe. The method is practiced with an apparatus comprising a swabbing tool connected to a well jar or bumper sub.
Inventors
- 👤 Ever J Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:10
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/12; E21B31/00; E21B37/00; E21B37/10
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
106 words
A method of freeing a segment of pipe stuck in a fluid-filled well borehole by pressure differential sticking comprising the steps of: packing off a compressed-liquid filled portion of the borehole adjacent the stuck pipe; expanding compressed-liquid in the packed-off portion of the borehole while maintaining the borehole above the packed-off portion substantially full of fluid across the entire width of the borehole, the expansion of the compressed liquid causing a reduction in pressure in the borehole adjacent the stuck pipe; and exerting an upwardly directed force on the stuck pipe while maintaining the liquid in the packed-off portion of the borehole in the expanded condition.
Claim 2
Independent Claim
106 words
A method of freeing a segment of pipe stuck in a fluid-filled well borehole by pressure differential sticking comprising the steps of: packing off a compressed-liquid filled portion of the borehole adjacent the stuck pipe; expanding compressed-liquid in the packed-off portion of the borehole while maintaining the borehole above the packed-off portion substantially full of fluid across the entire width of the borehole, the expansion of the compressed liquid causing a reduction in pressure in the borehole adjacent the stuck pipe; and exerting an upwardly directed force on the stuck pipe while maintaining the liquid in the packed-off portion of the borehole in the expanded condition.
Claim 3
Dependent Claim
62 words
The method of claim 1 wherein the step of packing off a liquid filled borehole portion comprises packing off a borehole portion of variable volume; and wherein the step of expanding liquid in the packed-off portion comprises increasing the volume of the packed-off portion while preventing movement of fluid into the packed-off portion from portions of the borehole above the packed-off portion.
Claim 4
Dependent Claim
49 words
The method of claim 2 wherein the step of packing off a borehole portion of variable volume comprises positioning a swab means in the borehole; and wherein the step of increasing the volume of the packed-off portion of the borehole comprises moving the swab means upwardly in the borehole.
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the step of expanding compressed liquid in the packed-off portion of the borehole comprises pumping fluid out of the packed-off portion while maintaining the volume of the packed-off portion substantially constant.
Claim 6
Independent Claim
195 words
A method of recovering a well drill-string having a portion thereof stuck in a fluid-filled borehole by pressure differential sticking comprisIng the steps of: detaching the free portion of the drill-string above the stuck portion and removing it from the well borehole; lowering a string of pipe capable of being attached to the upper end of the stuck portion of the drill-string into the borehole; attaching the string of pipe to the stuck portion of the drill-string; closing the interior of the string of pipe and the space between the exterior of the string of pipe and the walls of the borehole to fluid flow at a point in the borehole above the stuck drill-string to form a packed-off borehole portion adjacent the stuck drill-string, the packed-off portion having an upper boundary; moving at least a portion of the upper boundary of the packed-off portion of the borehole upwardly to increase the volume of the packed-off portion while simultaneously preventing the flow of fluid into the packed-off portion from portions of the borehole above the packed-off portion; and thereafter moving the pipe string upwardly to exert an upwardly directed force on the stuck drill-string portion.
Claim 7
Independent Claim
195 words
A method of recovering a well drill-string having a portion thereof stuck in a fluid-filled borehole by pressure differential sticking comprisIng the steps of: detaching the free portion of the drill-string above the stuck portion and removing it from the well borehole; lowering a string of pipe capable of being attached to the upper end of the stuck portion of the drill-string into the borehole; attaching the string of pipe to the stuck portion of the drill-string; closing the interior of the string of pipe and the space between the exterior of the string of pipe and the walls of the borehole to fluid flow at a point in the borehole above the stuck drill-string to form a packed-off borehole portion adjacent the stuck drill-string, the packed-off portion having an upper boundary; moving at least a portion of the upper boundary of the packed-off portion of the borehole upwardly to increase the volume of the packed-off portion while simultaneously preventing the flow of fluid into the packed-off portion from portions of the borehole above the packed-off portion; and thereafter moving the pipe string upwardly to exert an upwardly directed force on the stuck drill-string portion.
Claim 8
Dependent Claim
48 words
The method of claim 5 wherein the step of moving the upper boundary of the packed-off portion of the borehole to increase the volume of the packed-off portion comprises moving the upper boundary a sufficient distance to increase the volume of the packed-off portion at least 1 percent.
Claim 9
Dependent Claim
50 words
The method of claim 5 including the steps of after freeing the stuck drill-string, opening the interior of the string of pipe and the space between the exterior of the string of pipe and the well borehole to fluid flow; and withdrawing the string of pipe from the well borehole.
Claim 10
Dependent Claim
74 words
Apparatus for freeing pipe stuck in a well borehole by pressure-differential sticking, comprising: means for packing off a fluid filled borehole portion adjacent the stuck pipe; means for increasing the volume of the packed-off borehole portion to a selected increased volume while preventing fluid flow into the packed-off borehole portion; and means for exerting an upwardly directed force on the stuck pipe while the pipe is in the packed-off borehole portion of increased volume.
Claim 11
Dependent Claim
74 words
Apparatus for freeing pipe stuck in a well borehole by pressure-differential sticking, comprising: means for packing off a fluid filled borehole portion adjacent the stuck pipe; means for increasing the volume of the packed-off borehole portion to a selected increased volume while preventing fluid flow into the packed-off borehole portion; and means for exerting an upwardly directed force on the stuck pipe while the pipe is in the packed-off borehole portion of increased volume.
Claim 12
Dependent Claim
56 words
The apparatus of claim 8 wherein the means for increasing the volume of the packed-off portion comprises a connecting member having upper and lower portions telescopingly connected for limited movement between a closed position and a fully expanded position; and wherein the pack-off means comprises swab means connected to the upper portion of the connecting member.
Claim 13
Dependent Claim
37 words
The apparatus of claim 9 wherein the connecting member is hollow; and wherein the packed-off means further comprises a valve positioned to control flow through the hollow connecting member; and means for opening and closing the valve.
Claim 14
Dependent Claim
62 words
The apparatus of claim 10 wherein the means for opening and closing the valve comprises first and second axially slideably connected tubular members operatively connected to the valve and to the means for exerting an upwardly directed force on the stuck pipe, the valve being opened by relative axial motion of the tubular members in response to an upwardly directed axial force.
Claim 15
Dependent Claim
37 words
The apparatus of claim 11 wherein the means for opening and closing the valve further comprises hydraulic motion damper means for retarding the relative axial motion of the slidably connected members in response to an axial force.
Claim 16
Dependent Claim
166 words
Apparatus for recovering a pipe segment stuck in a partially cased well borehole by differential sticking comprising: means for engaging stuck pipe; a pipe string; a bumper sub connecting the pipe string to the means for engaging stuck pipe, said bumper sub including a top portion and a bottom portion telescopingly connected for movement between a closed position and a fully expanded position, said bumper sub having an interior flow passage in fluid communication with the pipe string for carrying fluid through the telescoping connecting member; pack-off means, including swab means connected to the toP portion of the telescoping connecting member, for packing off and swabbing the cased borehole above the stuck pipe segment to reduce pressure in the borehole adjacent the stuck pipe as the top portion of the telescoping connecting member is moved upwardly in the borehole; and valve means positioned in the pipe string adjacent the telescoping connecting member for selectively opening and closing the interior of the pipe string to fluid flow.
Claim 17
Dependent Claim
166 words
Apparatus for recovering a pipe segment stuck in a partially cased well borehole by differential sticking comprising: means for engaging stuck pipe; a pipe string; a bumper sub connecting the pipe string to the means for engaging stuck pipe, said bumper sub including a top portion and a bottom portion telescopingly connected for movement between a closed position and a fully expanded position, said bumper sub having an interior flow passage in fluid communication with the pipe string for carrying fluid through the telescoping connecting member; pack-off means, including swab means connected to the toP portion of the telescoping connecting member, for packing off and swabbing the cased borehole above the stuck pipe segment to reduce pressure in the borehole adjacent the stuck pipe as the top portion of the telescoping connecting member is moved upwardly in the borehole; and valve means positioned in the pipe string adjacent the telescoping connecting member for selectively opening and closing the interior of the pipe string to fluid flow.
Claim 18
Dependent Claim
16 words
the apparatus of claim 13 including bypass means for allowing fluid to bypass the swab means.
Claim 19
Dependent Claim
55 words
The apparatus of claim 13 wherein the valve means comprises first and second axially slideably connected tubular members operatively connected to the pipe string and the bumper sub, the interior of the pipe string being opened to flow by relative axial motion of the tubular members in response to upward motion of the pipe string.
Claim 20
Dependent Claim
37 words
The apparatus of claim 15 wherein the means for opening and closing the valve further comprises hydraulic motion damper means for retarding the relative axial motion of the slidably connected members in response to an axial force.
Claim 21
Dependent Claim
79 words
The apparatus of claim 16 wherein the hydraulic motion damper means comprises: a chamber containing viscous fluid; means for restricting the flow of viscous fluid from a first portion of the chamber to a second portion of the chamber; and means connected to one of the tubular members for forcing viscous fluid to flow from the first chamber portion to the second chamber portion through the flow restricting means in response to relative axial movement of the tubular members.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |