Patent Application
20080251256
Tieback seals are commonly used to seal a tieback to a downhole tubular such as a liner. Seal integrity and durability are desirable characteristics for such seals, as once set, tieback seals are often kept in place for long periods of time, often multiple years.
Typical tieback seals incorporate elastomers at the seal interface. Caustic fluids, high temperatures and high pressures encountered downhole often precipitate degradation of elastomeric seals. Degraded seals can develop leaks that can be costly to an operation whether left in place or replaced. When left in place, the quality of a production stream can suffer. When replaced, the cost of equipment and labor as well as costs of lost production, during replacement down-time, will accumulate. Accordingly, there is a need in the art for highly durable tieback seals.
Disclosed herein is a tieback seal system. The system includes, a tubular receptive of a tieback seal assembly. The tieback seal assembly includes, a body, a sleeve in radial alignment with the body, a ratcheting member, a shoulder within the tubular, and at least one deformable metal member in operable communication with the sleeve and the body. The operable communication is such that movement of the sleeve in a first axial direction causes deformation of at least one of the at least one deformable metal member and sealing with the tubular in response to being in a deformed position. The ratcheting member is engaged between the body and the sleeve such that the sleeve is movable in the first axial direction relative to the body and is not movable in a second axial direction that is opposite to the first axial direction. The shoulder is contactable with the sleeve such that contact of the sleeve and the shoulder causes axial motion of the sleeve relative to the body.
Further disclosed herein is a method of sealing a tieback to a tubular. The method includes, positioning a metal deformable member of the tieback within a tubular and contacting the tubular with a sleeve of the tieback. Moving the sleeve in a first axial direction thereby contacting and radially deforming a first portion of the deformable member by axially compressing the deformable member and sealably engaging the tubular with the radially deformed first portion.
Further disclosed herein is a method of sealing a tieback to a tubular. The method includes, positioning each of a plurality of metal radially deformable members of a tieback within a tubular, moving the tieback into functional contact with the tubular, actuating a sleeve of the tieback through the functional contact with the tubular and selectively deforming at least one of the plurality of metal radially deformable members with the actuation of the sleeve. The method further includes maintaining the plurality of metal radially deformable members in deformed positions with a ratcheting member.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of several embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
Movement of the sleeve 222, relative to the body 214, occurs when an end surface 238 of the sleeve 222 contacts a shoulder 242 of a downhole tubular with which the tieback assembly will seal herein referred to as liner 246. Downhole movement of the tieback assembly 210 into the stationary liner 246 causes the end surface 238 to contact the shoulder 242. The uphole directed force on the sleeve 222 increases until an optional shear screw 250, axially locking the sleeve 222 to the body 214 is sheared, after which the sleeve 222 is able to stop moving in a downhole direction with the body 214.
As the tieback seal assembly 210 continues moving in a downhole direction the body 214, collar 230 and deformable member 218 continue to move downhole while the sleeve 218 remains stationary due to contact with the shoulder 238 of the liner 246. Continued movement causes the deformable member 218 to compress axially between the sleeve 222 and the collar 230. In this embodiment, the axial compression of the deformable member 218 causes a first portion 254 to extend radially outwardly and a second portion 258 to extend radially inwardly. The radially outwardly deformation of the first portion 254 causes the first portion 254 to sealably engage with an inner surface 262 of the liner 246. Similarly, the radially inwardly deformation of the second portion 258 causes the second portion 258 to sealably engage with an outer surface 266 of the body 214. Thus the deformable member 218 when in a deformed configuration is sealable engaged with both the body 214 and the liner 246 simultaneously. Maintaining the deformable member 218 in axial compression can help assure that the sealing function performed by the deformable member 218 is maintained. The ratcheting member 226 is, therefore, functionally engaged with the body 214 and the sleeve 222 to allow movement of the sleeve 222 in one direction relative to the body 214 while preventing movement of the sleeve 222 in the opposite direction. A review of the deformable member 218 is described in more detail below.
Referring to
Reconfigurability of the deformable member 218 between the non-deformed configuration and the deformed configuration is effected by and is enabled by the construction thereof. The deformable member 218 is formed from a tubular member 286 that has four lines of weakness, specifically located both axially of the tubular member 286 and with respect to an inside surface 290 and an outside surface 292 of the tubular member 286. In one embodiment, a first line of weakness 300 and a second line of weakness 302 are defined in this embodiment by diametrical grooves formed in the outside surface 292 of the tubular member 286. A third line of weakness 304 and a fourth line of weakness 306 are defined in this embodiment by a diametrical grooves formed in the inside surface 290 of the tubular member 286. The four lines of weakness 300, 302, 304, 306 each encourage local deformation of the tubular member 286 in a radial direction that tends to cause the groove to close. It will be appreciated that in embodiments where the line of weakness is defined by other than a groove, the radial direction of movement will be the same but since there is no groove, there is no “close of the groove.” Rather, in such an embodiment, the material that defines a line of weakness will flow or otherwise allow radial movement in the direction indicated. The four lines of weakness 300, 302, 304, 306 together encourage deformation of the tubular member 286 in a manner that creates a feature such as the deformed configuration. The feature is created, then, upon the application of an axially directed mechanical compression of the tubular member 286 such that the deformed configuration is formed as the tubular member 286 is compressed to a shorter overall length.
Referring to
The ratcheting member 326 has a movable portion 346, attached to the sleeve 322, and a stationary portion 350, attached to the body 314. The movable portion 346 moves with the sleeve 322 in an uphole direction relative to the body 314 in this embodiment (although other embodiments could have the sleeve 322 move in a downhole direction relative to the body 314). Movement of the sleeve 322 causes the deformable members 318, 319, 320 to deform from the non-deformed positions 340 to the deformed positions 338. It should be noted that in this embodiment the body 314 is actually moving in a downhole direction and the sleeve 322 is stationary due to contact of an end 354 of the sleeve 322 with a shoulder 358 on the stationary liner 344. The ratcheting member 326 allows movement of the sleeve 322 relative to the body 314 in one direction while not permitting relative movement in the opposite direction. In so doing, the ratcheting member 326 locks the deformable members 318, 319, 320 in the deformed position 338. The deformable members 318, 319, 320 are prevented from moving relative to the body 314 by a shoulder 362 on the third deformable member 320 that engages with a stop surface 366 on the body 314.
The three deformable members 318, 319, 320 are structurally similar to one another and are described in detail with reference to
Alternatively, sequential control of actuation of the three deformable members 318, 319, 320 can be by incorporating a series of force failing members, disclosed herein as shear screws, between components. For example, four shear screws 370, 371, 372, and 373 (shown intact in
Referring to
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.
