Patent Application
20170218737
The field of the invention is liner hanger systems and more particularly where the liner hanger is set with an inflatable and a liner top packer is set with setting down weight after liner cementing.
In the completion process a liner string is run into the hole through an existing tubular so that the liner top overlaps with the lower end of the existing tubular. A running string delivers the liner using a running tool that ultimately releases from the liner once a liner hanger on the liner string is set against the existing tubular. One system that sets the liner hanger with swaging is used in the TORX® system offered by Baker Hughes Incorporated of Houston, Tex. USA and described broadly in in US 2010/0044029. Briefly this system has a leading swage, a stroker and a releasable anchor. A ball is seated and pressuring up sets the anchor to brace the stroker, which is then extended to move a swage through a liner hanger to expand it into a gripping relation with the existing tubular. The liner hanger can be a tubular structure made of segments initially held together for running in with the segments separating on expansion with a swage as illustrated in U.S. Pat. No. 7,607,476. After the liner hanger supports the liner string the running tool is released and picked up to extend dogs so that on subsequent setting down weight the liner top packer is set and the running tool pulled out of the hole. When the well is ready for production a production string and packer are run in and the production packer is set to allow production to begin.
Other systems have been developed where the tubular is expanded in spaced location to leave gaps in between. The expansion anchors the liner string to the surrounding tubular so that a cement job can be run and fluid displaced by the cement can travel through the gaps between the support locations for the liner string. A second expansion then closes the gaps as the seal for the liner string. This technique is shown in U.S. Pat. No. 6,598,677.
A combination hanger and seal can be expanded with a swage or an inflatable to act as a backup to a main liner hanger for additional support capacity. The device is an expandable ring with spikes inside sealing material so that on expansion the spikes extend through the seal material and into the surrounding tubular as the seal material is also force against the surrounding tubular. This device is shown in U.S. Pat. No. 7,784,797.
While these past techniques were workable, they also involved the use of complex equipment that drove up cost and created risks for performance of the required functions in the needed sequence. The present invention seeks to simplify the operation with the use of an inflatable for setting the liner hanger. The inflatable can be run in at the same time as the hanger already sitting in alignment with it so that when placed at the proper depth pressure can be directed to the inflatable to reliably set the hanger. A cement job can proceed in the known manner followed by running tool manipulation after its release from the liner string to set the liner top packer. These and other features of the invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawing while recognizing that the full scope of the invention is to be determined by the appended claims.
An assembly and method for hanging, cementing and sealing a liner to an existing tubular uses an inflatable to set the hanger. The running tool then releases the liner string and a cement job can take place. The Cement is pushed with darts out of the liner into the surrounding annulus to set up. Displaced fluids are pushed through the liner hanger as the cement advances. The running tool is picked up to land on a setting sleeve for a liner top packer so that set down weight can be applied to set the liner top packer. The running string then pulls out the running tool out of the hole.
The FIGURE shows the component layout in a borehole for practicing the method.
A liner string 10 is located below a hanger 12 with a liner top packer 14 located further uphole. The running string 16 supports a packer setting tool 18 which can be one or more dogs 20 that extend out and are set down on a setting sleeve 22 for the packer 14 after the inflatable 24 inflates to set the hanger 12. The hanger 12 can be fully set with a single inflation of the inflatable 24 or the hanger 12 can be expanded in stages with the inflatable 24 inflated, then deflated and repositioned to complete the setting of the hanger 12. The running tool can be released after the first inflation of the inflatable 24 to allow the inflatable to be repositioned to finish setting the liner hanger 12. Hanger 12 has spaced slips to allow fluid flow when expanded radially by the inflatable 24 against an existing tubular that is not shown. With the slips of the hanger 12 extended to support the liner string 10 from the existing tubular, the running string 16 with the packer setting tool 18 are released from the liner string 10 that is now independently supported.
At this point there are two options. If the liner string 10 is part of an open hole completion, then the inflatable 24 is deflated and the completion fluid is displaced with circulation. The running string 16 is picked up and the dogs 20 are allowed to spring out radially so that on setting down weight the dogs 20 land on sleeve 22 to set the liner top packer 14 against the surrounding tubular that is not shown.
On the other hand if the liner string 10 is to be cemented, the inflatable 24 is deflated and cement is pumped through the running string 16 and the liner string 10. One or more wiper darts that are not shown are released from the lower end of the packer setting tool to displace cement out a shoe on the lower end of the liner string 10 in a known manner. The packer setting tool 18 is raised to extend the dogs 20 out so that on setting down weight on the running string 16 the dogs 20 push on the setting sleeve 22 to set the liner top packer 14. Those skilled in the art will appreciate that the liner hanger 12 and the inflatable 24 that sets it are run in together and in alignment. The setting of the hanger 12 can happen quickly and reliably with pumping fluid into the inflatable which preferably can run the length of the hanger 12. In that manner the inflatable 24 does not need to be repositioned to fully expand the liner hanger 12. Release of the inflatable can also be quickly accomplished with deflation. The pressure buildup during inflation can be seen at the surface as a signal that the liner hanger has been set. Another signal that the hanger 12 is set is that the amount of hanging weight declines as the weight of the liner string 10 is taken up by the existing tubular that is not shown. The assembly of an anchor, stroker and swage that was used before to set the liner hanger is far more expensive to supply and operate. Frequently several cycles of anchoring and stroking to move the swage were needed to fully expand the liner hanger and release the running string from the liner string.
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:
