Patent Application
20090294134
When an existing safety valve in a well becomes inoperable, operators must take measures to rectify the problem by either working over the well to install an entirely new safety valve on the tubing or deploying a safety valve within the existing tubing. In the past, operators may have simply deployed a subsurface controlled subsurface safety valve in the well. The subsurface controlled valves could be a velocity valve or Protected Bellows (PB) pressure actuated valve. However, regulatory requirements and concerns over potential blowout have prompted operators to work over the well rather than deploying such subsurface controlled valves. As expected, working over a well can be time consuming and expensive. Therefore, operators would prefer to deploy a surface controlled safety valve in the tubing of the well without having to work over the well.
Current technology primarily allows surface controlled safety valves to be deployed in wells that have either an existing tubing-mounted safety valve or a tubing-mounted safety valve landing nipple. In French Patent No. FR 2734863 to Jacob Jean-Luc, for example, a surface controlled safety valve device 100 is disclosed that can be landed in an existing landing nipple from which the original safety valve has been removed. This safety valve device 100 reproduced in
When deployed in the landing nipple 10, a conduit (not shown) communicated through the tubing connects to the device 100 to operate the flapper 104. This conduit conveys hydraulic fluid to the connector 120 connected to a fixed portion 123 in the device 100. This fixed portion 123 in turn communicates the fluid to the intermediate tubing 130 that is movable in the fixed portion 123. A cross port 132 from the intermediate tubing 130 communicates the fluid so that it fills a space 133 and moves a sleeve 134 connected to the intermediate tubing 130. As the sleeve 134 moves down against the bias of a spring, it opens the flapper 104. Because the mechanisms for operating the device 100 are exposed and involve several moving components, the mechanical operation of this device 100 is less than favorable. Moreover, the exposed mechanisms that operate the device 100 with their several moving parts can become damaged.
In U.S. Pat. No. 7,040,409 to Sangla, another safety valve device for wells is disclosed that can be deployed in tubing without the need for an existing landing nipple. This device 200 is reproduced in
To position the device 200 in tubing 20, the lower part of the device 200 as shown in
To create a seal in the tubing 20, the device 200 uses a pile of eight cups 230 that position between the device 200 and the tubing 20. These cups 230 have a general herringbone U or V shape and are symmetrically arranged along the device's central axis. Hydraulic pressure present in a sealing assembly chamber 234 displaces a piston 232 that activates the cups 230 against the tubing 20. Locks 236 hold this piston 232 in place even without pressure in the chamber 234.
Hydraulic pressure communicated from the surface operates the device 200. In particular, rods (not shown) from the surface connect to a connector 240 that communicates with internal line 242. This internal line 242 communicates with an interconnecting tube 250 to distribute hydraulic pressure to the valve opening chamber 234 via a cross port 243, to the anchor chamber 224a-b via cross ports 244a-b, and to the sealing assembly chamber 218 via the tube 250. A hydraulic pressure rise in line 242 transmits the pressure to all these chambers simultaneously. When the hydraulic pressure drops in line 242, the device 200 closes but remains in position, anchored and sealed. A special profile 204 arranged at the top of the device 200 can be used to unanchor the device 200 by traction and jarring with a fishing tool suited to this profile 202. By jarring on the device 200, a series of shear pins are broken, thus releasing anchor pistons 222a-b and the sealing piston 232. The released device 200 can then be pulled up to the surface.
As with the valve 100 of
Accordingly, a need exists for more effective subsurface safety valves that can be deployed in a well.
Capillary hanger arrangements allow operators to deploy a capillary string through the bore of an existing wellhead so the string can communicate hydraulic fluid with a safety valve or other hydrauilic tool downhole. For example, operators tap a control port and a retention port in the side of the wellhead, such as in an adapter between a casing hanger and a gate valve or elsewhere. After the hydraulic tool has been deployed downhole, operators then connect the capillary string to a first port of an internal passage in a capillary hanger and install the capillary string through the wellhead. Eventually, the capillary hanger is installed in the wellhead, for example, by landing a distal end of the capillary hanger on a tubing hanger in the wellhead. Once installed, a side port of the internal passing in the capillary hanger can communicate with the control line port tapped in the side of the wellhead. Because the side port's location may not align with the control port, operators may need to measure how long the capillary hanger should be and either modify its length or design it with the appropriate length. Once the hanger is installed, operators insert retention rods in the retention port to support the capillary hanger. Then, operators connect a control line to the control port in the wellhead's side so hydraulic fluid can communicate with the capillary line through the internal passage in the capillary hanger. Eventually, fluid flow in the wellhead is allowed to flow through an axial flow passage in the capillary hanger. These and other embodiments are disclosed herein.
As disclosed herein, a surface controlled subsurface safety valve apparatus can be installed in a well that either has or does not have existing hardware for a surface controlled valve. Coil tubing communicates the hydraulic fluid to the apparatus to operate the valve. One disclosed valve apparatus deploys in a well that has an existing safety valve nipple and is retrievable therefrom. Another disclosed valve apparatus deploys in tubing of a well with or without a safety valve nipple.
A retrievable surface controlled subsurface safety valve 300 illustrated in
The safety valve 300 has a housing 302 with a landing portion 310 and a safety valve portion 360. The landing portion 310 best shown in
To operate the landing portion 310, an upper sleeve 320 shown in
To operate the valve portion 360, a lower sleeve 380 shown in
With a basic understanding of the operation of the valve 300, discussion now turns to a more detailed discussion of its components and operation.
In deploying the valve 300, a conventional wireline tool (not shown) couples to the profile in the upper end of the valve's housing 302 and lowers the valve 300 to the landing nipple 50. While it is run downhole, trigger dogs 322 on the upper sleeve 320 remain engaged in lower grooves 312 in the housing 302, while the upper sleeve 320 allows the locking dogs 332 to remain disengaged. When in position, the tool actuates the landing portion 310 by moving the upper sleeve 320 upward against the bias of spring 324 and disengaging the trigger dogs 322 from the lower grooves 312 so they engage upper grooves 314. With the upward movement of the sleeve 320, the sleeve's distal end 326 pushes out the locking dogs 332 from the housing 302 so that they engage the landing nipple's groove 52 as shown in
With the valve 300 landed in the nipple 50, operators lower a capillary string 304 down hole to the valve. This capillary string 304 can be hung from a capillary hanger (not shown) at the surface. The capillary string 304 may include blade centralizers 305 to facilitate lowering the string 304 downhole. The string 304's distal end passes into the valve's housing 302, and a hydraulic connector 350 is used to couple the string 304 to the valve 300. In particular, a female member 352 of the hydraulic connector 350 on the distal end mates with a male member 354 on the valve 300.
Briefly,
Once the members 352/354 are connected as shown, the capillary string 304 communicates with an internal port 372 defined in a projection 370 within the valve 300 as shown in
From the annular space 375, the fluid reaches a passage 365 in the valve portion 360 and engages an internal piston 382. Hydraulic pressure communicated by the fluid moves this piston 382 downward against the bias of a spring 386 at the piston's end 384. The downward moving end 384 moves the inner sleeve 380 connected thereto so that the inner sleeve 380 forces open the flapper 390. In this way, the valve portion 360 can operate in a conventional manner. As long as hydraulic pressure is supplied to the piston 382 via the capillary string 304, for example, the inner sleeve 380 maintains the flapper 390 open, thereby permitting fluid communication through the valve's housing 302. When hydraulic pressure is released due to an unexpected up flow or the like, the spring 386 moves the inner sleeve 380 away from the flapper 390, and the flapper 390 is biased shut by its torsion spring 394, thereby sealing fluid communication through the valve's housing 302.
Retrieval of the valve 300 can be accomplished by uncoupling the hydraulic connector 350 and removing the capillary string 304. Then, a conventional wireline tool can engage the profile in valve's upper end, disengage the locking dogs 332 from the nipple's slot 52, and pull the valve 300 up hole.
As opposed to prior art subsurface controlled safety valves, the disclosed valve 300 has a number of advantages, some of which are highlighted here. In one advantage, the valve 300 deploys in a way that lessens potential damage to the valve's components, such as the male member 354 and movable components. In addition, communication of hydraulic fluid to the safety valve portion 360 is achieved using an intermediate projection 370 and a single port 372 communicating with an annular space 375 and piston 382 without significantly obstructing the flow passage through the valve 300. Furthermore, operation of the valve portion 360 does not involve a number of movable components exposed within the flow passage of the valve 300, thereby reducing potential damage to the valve portion 360.
The previous embodiment of safety valve 300 lands into an existing landing nipple 50 downhole. By contrast, a surface controlled subsurface safety valve 400 in
For the pack-off portion 410, the valve 400 has a packing element 420 and slips 430 disposed thereon. The packing element 420 is compressible from an uncompressed condition to a compressed condition in which the element 420 engages an inner wall of a surrounding conduit (not shown), such as tubing or the like. The slips 430 are movable radially from the housing 402 from disengaged to engaged positions in which they contact the surrounding inner conduit wall. The slips 430 can be retained by a central portion (not shown) of a cover 431 over the slips 430 and may be biased by springs, rings or the like.
For the valve portion 460, the valve 400 has a flapper 490 rotatably disposed on the housing 402 by a pivot pin 492 and biased by a torsion spring 494 to a closed position. The flapper 3490 can move relative to the valve's internal bore between opened and closed positions to either permit fluid communication through the valve's bore 403 or not.
To operate the packer portion 410, hydraulic fluid moves an upper sleeve 440 moves within the housing's bore. In one position as shown in
To operate the valve portion 460, a lower sleeve 480 shown in
With a basic understanding of the operation of the valve 400, discussion now turns to a more detailed discussion of its components and operation.
The valve 400 is run in the well using capillary string technology. For example, a capillary string 404 connects inside the valve housing 400 with a hydraulic connector 450 having both a male member 454 and female member 452 similar to that disclosed in
Once positioned, both the packer portion 410 and the safety valve portion 460 are hydraulically set by control line pressure communicated via the capillary string 404. In particular, the capillary string 404 communicates with the sleeve's internal port 472 defined in a projection 470 positioned internally in the housing 402. Operators then inject pressurized hydraulic fluid through the capillary string 404. When the fluid reaches the internal port 472 as shown in
From the intermediate annular space 475, the fluid communicates via an upper passage 445 to an upper annular space 444 near the upper sliding sleeve 440.
As discussed below, fluid communicated via this passage 445 operate the valve's packer portion 410. From the intermediate annular space 475, the fluid also communicates via a lower passage 465 in the valve portion 460 and engages a piston 480. As discussed below, fluid communicated via this passage 465 operates the valve portion 460.
In operating the valve's packer portion 410, the fluid communicated by upper passage 445 fills the upper annular space 444 which is best shown in
As the sleeve 440 moves downward, it moves not only upper and lower members 422/424 but also moves an upper wedged member 432 toward a lower wedged member 434 fixed to lower housing members 440 and 442. As the sleeve 440 moves downward, therefore, the wedged members 432/434 push the slips 430 outward from the housing 402 to engage the inner conduit wall (not shown) surrounding the housing 302. Eventually, as the sleeve 440 is moved downward, outer serrations or grooves 441 on the sleeve 440 engage locking rings 443 positioned in the housing 402 to prevent the sleeve 440 from moving upward.
Simultaneously, the communicated hydraulic fluid operates the safety valve portion 460. Here, hydraulic pressure communicated by the fluid via passage 465 moves the piston 482 downward against the bias of spring 486. The downward moving piston 482 also moves the inner sleeve 480, which in turn forces open the rotatable flapper 490 about its pin 392. In this way, the valve portion 460 can operate in a conventional manner. When hydraulic pressure is released due to an unexpected up flow or the like, the spring 486 moves the inner sleeve 484 away from the flapper 490, and the flapper 490 is biased shut by its torsion spring 494.
Retrieval of the safety valve 400 can use the capillary string 404. Alternatively, retrieval can involve releasing the capillary string 404 and using standard wireline procedures to pull the safety valve 400 from the well in a manner similar to that used in removing a downhole packer.
As opposed to the prior art surface controlled subsurface safety valves, the disclosed valve 400 has a number of advantages, some of which are highlighted here. In one advantage, the valve 400 uses a solid packing element and slip combination to produce the pack-off in the tubing. This produces a more superior seal than found in the prior art which uses a pile of packing cups. Second, the flapper 490 of the valve 400 is operated using an annular rod piston arrangement with the components concealed from the internal bore of the valve 400. This produces a more reliable mechanical arrangement than that found in the prior art where rod, piston, and tubing connections are exposed within the internal bore of the prior art valve. Third, the packing element 420 and the rod piston 482 in the valve are actuated via hydraulic fluid from one port 472 communicating with the coil tubing 404. This produces a simpler, more efficient communication of the hydraulic fluid as opposed to the multiple cross ports and chambers used in the prior art.
Finally, the disclosed valve 400 can be deployed using a capillary string or coil tubing ranging in size from 0.25″ to 1.5″ and can be retrieved by either the capillary string or by standard wireline procedures. Deploying the valve 400 (as well as valve 300 of
For example,
Initially, the surface controlled safety valve (400;
As shown in
As shown in
Finally, as shown in
In each of these arrangements, the surface controlled safety valve (e.g., 400;
After tapping the wellhead components, operators drift either a suitably sized conduit or the capillary hanger 600 itself through the gate valve 540 and land it in the tubing hanger 620. Operators then measure the axial distance between the control line port (532 or 542) and the landing position on the tubing hanger 620. Using that measured distance, operators then remove any excess length from the end of the capillary hanger 600 so that once the hanger 600 is installed in the wellhead and landed on the landing position, the hanger's side port will be at the needed level to communicate with the control line port (532 or 534).
Having a properly sixed hanger 600, operators then secure the capillary string 550 onto the hanger 600 and pass the string 550 through the assembly 500. The hanger 600 then seats on the tubing hanger 520 to support the string 550 downhole. With the hanger 600 seated, first seals on the hanger 600 can seal inside the gate valve 540, and second seals on the hanger 600 can seal inside the adapter 530. For example, the hanger's seals in
Finally, operators insert and lock one or more retention rods (not shown) in the one or more retention ports 534 and/or 544 so that the rods engage in the peripheral slot 634 around the hanger 600 to hold it in the assembly 500. With the hanger 600 secured, operators connect a control line fitting 570 to the control line port 532 or 542 to communicate hydraulic fluid with the capillary string 550 through the capillary hanger 600. Eventually, wellbore fluid can pass through a flow passage 620 in the hanger 600.
In yet another alternative, a capillary string can be deployed through the wellhead and used for a downhole safety valve or other hydraulic tool without the need for hot-tapping the wellhead components as in previous arrangements. In this technique, the existing gate valve's seat and bonnet are modified to accept a control line. This eliminates the need to drill holes in an adapter, in a gate valve flange or body, or in another wellhead component to install and secure a capillary hanger.
As shown in
At this point, operators can install the capillary hanger 600. In this arrangement, the required length of the hanger 600 may be known because the axial distance between the gate valve's seat 545 and the tubing hanger 520 may be known. Alternatively, operators may drift the hanger 600 itself or some other suitably sized conduit through the wellhead and land it on the tubing hanger 520. Then, operators can measure the axial distance from this tubing hanger's seating location to the valve seat's aperture 547. This measured distance can then be used to modify the length of the hanger 600 or to design a new hanger 600 with the appropriate axial length from the side port 632 to the landing end on the hanger 600.
With a properly sized hanger 600, operators install the safety valve or other hydraulic tool downhole using capillary string procedures. Then, operators attach the capillary string 550 to the inner port end of the capillary hanger 600 and install the string 550 through the wellhead. Eventually, operators seat the distal end of the capillary hanger 600 in the tubing hanger 520. In seating, the hanger 600 may thread into the bore of the tubing hanger 620. Also, a seal (not shown) may be provided in a surrounding notch on the hanger's landing end so it can seal against the inside of the tubing hanger 620.
As shown in more detail in
The control line port 548 can be angled as in
Finally, a control line 575 connected to the fitting 570 at the port 548 on the bonnet 546 can communicate with the capillary string 550 via control line 555, aperture 547, and hanger 600 so that the downhole safety valve or other hydraulic tool can be hydraulically operated. Eventually, fluid in the wellhead assembly 500 can pass through the axial flow passage 620 in the hanger 600.
To install this arrangement, a replacement seat 545 and bonnet 546 can be provided for the particular installation, and the modified replacement parts can be installed at the wellsite to adapt the assembly 500 for deploying the capillary string 500. Alternatively, operators can directly modify the existing seat 545 and bonnet 546 at the installation. Making modifications to the bonnet 546 and seat 545 is preferred over hot-tapping the gate valve or any other components of the assembly 500. The needed modifications will depend on the particular gate valve 540. Likewise, the required length of the hanger 600 may vary depending on the implementation and may be already known or determined during installation.
An alternative arrangement shown in
Here, however, the hanger 600 does not extend down through the wellhead to seat in the tubing hanger 620 as in
In yet another alternative shown in
To install this replacement element 600′, operators remove the gate valve mechanism 541, connect the capillary string 550 to the inner port end of the element 600′ with a fitting 552, and deploy the string 550 through the wellhead. As they deploy the string, operators eventually position the hanger-seat element 600′ in the gate valve 540 below the location where the gate mechanism 541 situates. Then, operators thread the end of the line 555 to the side port 602 in the element 600′, fit the gate valve mechanism 541 back in the gate valve's housing, and fit a redesigned or modified bonnet (e.g. 546;
Another alternative for deploying the surface controlled safety valve (400;
The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. Although the capillary hanger arrangements have been described for use with a surface controlled subsurface safety valve, it will be appreciated with the benefit of the present disclosure that the disclosed arrangements can be used with any other downhole tool that uses a control line for operation. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.
This application is a continuation-in-part of U.S. appl. Ser. No. 12/128,811, filed 29 May 2008, to which priority is claimed and which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12128811 | May 2008 | US |
| Child | 12408527 | US |
