Patent Application
20110120700
In the oil and gas industry, expandable tubing is often used for casing, liners and the like. To create a casing, for example, a tubular member is installed in a wellbore and subsequently expanded by displacing an expansion cone through the tubular member. The expansion cone may be pushed or pulled using mechanical means, such as by a support tubular coupled thereto, or driven by hydraulic pressure. As the expansion cone is displaced axially within the tubular member, the expansion cone imparts radial force to the inner surface of the tubular member. In response to the radial force, the tubular member plastically deforms, thereby permanently increasing both its inner and outer diameters. In other words, the tubular member expands radially. Expandable tubulars may also be used to repair, seal, or remediate existing casing that has been perforated, parted, corroded, or otherwise damaged since installation.
The present disclosure relates to apparatus and methods for expanding a tubular within a wellbore. More specifically, the apparatus includes a resilient launcher with an expansion cone for expanding the tubular within the wellbore.
Referring to
The resilient launcher is configured to withstand internal pressure sufficient to hydraulically drive the expansion cone 110. The pressure necessary varies according to the mechanical properties and the diameter of the tubular being expanded, among various other factors. For an expansion process driven by hydraulic forces with little or no mechanical force applied, the pressure during expansion may range from about 1,000 psi to about 7,000 psi, with the primary factor being the diameter of the tubular being expanded. To withstand higher pressures, the resilient launcher 101 may include mechanical reinforcement 102, which may be, for example, carbon fiber, steel, fabric, and/or a mesh of fiber or metal.
The assembly of the expansion apparatus is illustrated in
Before or after placement of the expansion cone 110, an expandable tubular 140 shown in
Turning to
The additional expandable tubular 240 may further include an upper connection 206 that connects to a lower connection 255 of an end piece 251. The end piece 251 includes an expansion cone catch 256 that will catch the expansion cone 110 after expanding the expandable tubulars 140, 240. The expansion cone catch 256 may be a shoulder or other restriction that prevents further upward axial movement of the expansion cone 110 relative to the end piece 251. In another embodiment, the shoulder 256, or other restriction may be formed integrally within the uppermost expansion sleeve 201. When the expansion cone 110 contacts the expansion cone catch 256, pulling upward on the expansion cone 110 via the support member 120 and the work string will pull the resilient launcher 101 and any other connected resilient sleeves upward to be removed from the wellbore while leaving the expanded tubulars in place. This allows for the expansion process and removal of the entire expansion apparatus in a single trip. Alternatively, without an expansion cone catch 256, the resilient launcher 101 and any other connected resilient sleeves may be left in place and drilled out afterwards.
In
Once the desired fluids are pumped through the port 130, a wiper dart or ball 301 may be dropped from the surface to clean the fluid and plug the port 130 to allow pressure to build in the launcher portion 104 below the expansion cone 110, as shown in
In another embodiment, the expansion cone may be expandable. By using an expandable expansion cone, the expandable tubular may be expanded to a greater diameter while being able to pass through restrictions in the wellbore. The expandable expansion cone may be expanded within the launcher portion of the resilient launcher below the expandable tubular. Actuation of the expandable expansion cone may be carried out hydraulically because the launcher portion made of resilient material requires less force to expand than the metal launchers known in the prior art.
Embodiments of the disclosure allow for hydraulically driven expansion of an expandable tubular in a wellbore using resilient sleeves to expand the expandable tubular to a greater diameter than the outside diameter of the expansion cone. This arrangement allows for a mechanically simple expansion apparatus that has a small pre-expansion outer diameter relative to the inner diameter of the post-expansion tubular. Accordingly, such an expansion apparatus can be deployed below wellbore restrictions while being able to expand the inner diameter of the expandable tubular to be equal or greater than the inner diameter of the wellbore restriction or existing liners.
By driving the expansion process hydraulically, the expansion apparatus disclosed herein may be deployed using smaller rigs because of the low mechanical loads needed for the work string. Additionally, the work string may be tubing instead of drill pipe because of the reduced need for mechanical pull via the work string. This capability allows for the expansion apparatus disclosed herein to be deployed to a wider range of wells.
Although this detailed description has shown and described illustrative embodiments of the invention, this description contemplates a wide range of modifications, changes, and substitutions. In some instances, one may employ some features of the present invention without a corresponding use of the other features. Accordingly, it is appropriate that readers should construe the appended claims broadly, and in a manner consistent with the scope of the invention.
