The field of the invention is swages that adjust in diameter for expanding tubulars and more particularly that have the ability to collapse if an obstruction is encountered to clear past it.
Swages are used to expand downhole diameter of tubulars. They can be fixed conical shapes or they can be adjusted to change diameter downhole. The swages that can change diameter can be more versatile in that they can do expansion of a given tubular in stages to avoid overstressing. They can be collapsed after the expansion is complete to facilitate removal.
There are concerns when using adjustable swages that involve a plurality of segments that do the expansion. Gaps between the segments can cause lines of stress concentration that can ultimately create a fracture longitudinally. An adjustable swage design is disclosed in U.S. Publication Number 2003/01558118 A1 that involves wedge shaped segments that translate with respect to each other. Alternating wedges are held fixed while the movable segments are powered by a hydraulic piston. Applied pressure moves the movable segments into alignment with the stationary segments so that their high spots align to create the swaging diameter. The segments are dovetailed on an incline so that as they move relatively into alignment they also move radially into a larger radius. A ratchet system is incorporated to hold the position of the segments attained in response to applied hydraulic pressure to the piston. The discussion below of the basic components of this adjustable swage gives the general starting point for the present invention.
Additional flexibility can be achieved by using flexible swage 138.
Segments 140 have a wide top 150 tapering down to a narrow bottom 152 with a high area 154, in between. Similarly, the oppositely oriented segments 142 have a wide bottom 156 tapering up to a narrow top 158 with a high area 160, in between. The high areas 154 and 160 are preferably identical so that they can be placed in alignment, as shown in
Segments 140 have a preferably T shaped member 166 engaged to ring 168. Ring 168 is connected to mandrel 144 at thread 170. During run in a shear pin 172 holds ring 168 to mandrel 144. Lower segments 142 are retained by T shaped members 174 to ring 176. Ring 176 is biased upwardly by piston 178. The biasing can be done in a variety of ways with a stack of Belleville washers 180 illustrated as one example. Piston 178 has seals 182 and 184 to allow pressure through opening 186 in the mandrel 144 to move up the piston 178 and pre-compress the washers 180. A lock ring 188 has teeth 190 to engage teeth 192 on the fixed swage 134, when the piston 178 is driven up. Thread 194 connects fixed swage 134 to mandrel 144. Opening 186 leads to cavity 196 for driving up piston 178. Preferably, high areas 154 and 160 do not extend out as far as the high area 198 of fixed swage 134 during the run in position shown in
The operation of the method using the flexible swage 138 will now be described. The swage 134 makes contact with an obstruction. At first, an attempt to set down weight could be tried to see if swage 134 could go through the damaged portion of the casing. If this fails to work, pressure is applied from the surface. If the fixed swage 134 goes through the obstruction, the flexible swage could then land on the obstruction and then be expanded and driven through it. Pressure from the surface enters opening 186 and forces piston 178 to compress washers 180, as shown in
What the above description from the original disclosure didn't go into much detail about is what happens when segments 140 and 142 are in alignment and encounter an obstruction through which the fixed cone 134 has already cleared. Two things can happen. If the adjustable swage is to clear the obstruction, it needs to get smaller in diameter by moving from the
What the present invention attempts to do is to enhance the radial force that urges collapse of the adjustable swage when it gets stuck on an obstruction that the fixed swage 134 has already passed. The invention seeks to redirect the longitudinal loading force to create an additional radial component when the adjustable swage is stuck. One way this is accomplished is to alter the loading angles on the mounts for the segments so as to create additional radial load component when the adjustable swage sticks in the tubular on an obstruction. Those skilled in the art will better appreciate the full scope of the invention from the claims below. The detailed description and drawings illustrate the concept of the invention by showing the preferred embodiment.
An adjustable swage features an ability to enhance a radial collapse force when an obstruction in a tubular is encountered to allow radial contraction so that the obstruction can be cleared. The movable segments are configured to elastically bend on high loading so as to create additional radial component force to aid the adjustable swage in reducing its size to clear the obstruction.
a-2c are a prior art section view of the adjustable swage in the
a-3c are the view of
Segments 20 and 22 and the other similarly situated segments that are not shown preferably have a flexible flange 26 spaced apart from base surface 28. Retainer 30 has an inner recess 32 that holds a guide flange 34 that is part of the segment 20 or 22 or the other similarly situated segments that are not shown. Retainer 30 has a bearing surface 36 that contacts surface 38 on flexible flange 26. Surface 38 is part of an inwardly oriented ring 40 that defines circular recess 32. The connection arrangement for the oppositely oriented segments is substantially the same with ring 42 having a bearing surface 44 to contact surface 46 on flexible flange 48 on segment 24 and the others that are similarly oriented and not shown.
When the segments that make up the adjustable swage hit an obstruction the contact location is still on steep surface 50 as shown in
The present invention addresses this situation as the loading increases when an obstruction is hit.
Those skilled in the art will appreciate that both ends can have the same treatment to create a radial component force at both ends even though only one end has been described. While the creation of the additional radial force has been accomplished with bending load surfaces other ways to create a radial force when an obstruction is hit are also within the scope of the invention. In the preferred embodiment the additional radial force is not created until an obstruction is hit so that in normal expansion operation the operation of the adjustable swage described is similar to the prior art operation. In that sense a radial collapsing force is not created during normal operations when it is not needed. Rather, it is when an obstruction is encountered and the adjustable swage needs to get smaller in diameter to get past that obstruction that the bending takes place and the collapse force comes into play to get the adjustable swage past the obstruction.
Additionally, the size of gap 58 adjacent flexible flange 26 is sized such that even when flange 26 closes gap 58, the bending is still in the elastic range.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.
Number | Name | Date | Kind |
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4842082 | Springer | Jun 1989 | A |
20030155118 | Sonnier et al. | Aug 2003 | A1 |
20040168796 | Baugh et al. | Sep 2004 | A1 |
20050161213 | Sonnier et al. | Jul 2005 | A1 |
Number | Date | Country |
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1640560 | Mar 2006 | EP |
02059456 | Aug 2002 | WO |
2007017355 | Feb 2007 | WO |
Number | Date | Country | |
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20070277971 A1 | Dec 2007 | US |