Abstract:
An isolation device that has a metal bladder that is deformed downhole, such as by hydroforming. Certain aspects of the present invention include methods for implementing and using the isolation device, manufacturing techniques for making the device, sleeve properties and other device components. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Field of Invention. The present invention relates to the field of isolation in a well. More specifically, the invention relates to a device and method for isolating annular portions of a well as well as related systems, methods, and devices.  
       SUMMARY  
       [0002]     One aspect of the present invention is an isolation device or packer that has a metal bladder that is deformed downhole to create a seal. Other aspects are discussed in detail below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0003]     The manner in which these objectives and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:  
         [0004]      FIG. 1  illustrates an embodiment of an isolation device of the present invention.  
         [0005]      FIG. 2  illustrates a portion of the device shown in  FIG. 1 .  
         [0006]      FIG. 3  shows the portion of  FIG. 2  with the sleeve inflated.  
         [0007]      FIG. 4  illustrates a different embodiment of the present invention.  
         [0008]      FIG. 5  shows yet another embodiment of the present invention.  
         [0009]      FIG. 6  illustrates still another embodiment of the present invention having a relief port.  
         [0010]      FIG. 7  shows an embodiment of the present invention in which the inflation fluid is supplied from an exterior of the isolation device and is controlled using a valve.  
         [0011]      FIG. 8  shows an embodiment of the present invention in which the inflation pressure is supplied through a control line.  
         [0012]      FIGS. 9   a - c  illustrate a valve implemented in the present invention.  
         [0013]      FIG. 10  shows another isolation device of the present invention that includes the valve of  FIGS. 8 and 9  implemented in an embodiment of the present invention as well as other components.  
         [0014]      FIG. 11  illustrates another isolation device of the present invention in cross section in which the sleeve is corrugated. 
     
    
       [0015]     It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.  
         [0017]     The present invention relates to various apparatuses, systems and methods for establishing isolation in a well. One aspect of the present invention relates to an isolation device or packer that has a metal bladder that is plastically deformed downhole, such as by hydroforming. A metal sleeve is inflated and plastically deformed to create the isolation seal. Other aspects of the present invention, which are further explained below, relate to methods for implementing and using the isolation device, manufacturing techniques for making the device, sleeve properties and other device components.  
         [0018]     As an example,  FIGS. 1 through 3  illustrate an isolation device  10  having a base pipe  12  which has end connections  14  for connecting to completion or other well tubing, not shown. Positioned about the periphery of the base pipe  12  is a tubular metal sleeve  16 , which has end portions  18 . The base pipe  12  and the sleeve  16  are generally concentric although non-concentric tubes may also be used. Connecting rings  20  sealingly connect the end portions  18  of the sleeve  16  to an exterior of the base pipe  12 . The connections may be welded or connected by other methods. Also, the sleeve  16  may be alternatively connected and sealed directly to the base pipe  12 . The device  10  may employ other types of seals between the sleeve  16  and the base pipe  12 . For example, one or more ends of the sleeve  16  may be free to move longitudinally relative to the base pipe  12  in which case a moving seal is used.  
         [0019]     The sleeve  16  is formed of a metal material capable of withstanding downhole conditions. Materials suitable for the deformation needed (e.g., by hydroforming the sleeve  16 ) are materials with significant plastic strain prior to reaching the tubes ultimate strength (i.e., a plastic strain greater than 10% and more preferably at least 20%). Additionally, the selected material may have a relatively low yield stress between 10 and 60 ksi. Using a material with a yield stress that is sufficiently low is useful so that excessive pressures are not needed to deform the material. The low yield stress may be particularly important in downhole applications where high pressure may damage other well equipment or the well. Examples of materials that may be used include low carbon steels, normalized low alloy steels, austenitic stainless steel alloys in the annealed condition ( 304 ,  316 , etc.), and austenitic nickel alloys such as INCOLOY 825. In addition, the sleeve  16  preferable has a low elastic relaxation so that is maintains its shape after inflation.  
         [0020]     The thickness, material, and other design properties of the sleeve  16  are selected to allow inflation of the sleeve  16 . In the embodiment shown, the sleeve  16  is free of voids or radial passageways therethrough so that the sleeve can hold pressure without relying on additional sealing materials (e.g. without requiring an elastomer or other coating to assist in holding the inflation pressure). The base pipe  12  however is generally designed and selected to withstand the inflation pressures without experiencing significant deformation.  
         [0021]     Stiffening rings  22  surround each of the end portions  18  of the sleeve  16 . The stiffening rings  22  restrict outward radial movement of the end portions  18  (i.e., during inflation of the sleeve). The stiffening rings  22  thereby protect the connections of the sleeve  16  to the connecting rings  20 , and the base pipe  12 , by preventing bending at the connection. An optional jacket  24  is placed on the sleeve  16 , such as by bonding. The jacket  24  may be formed of an elastomer, resin, or other material. The jacket  24  may be used to improve the seal between the sleeve  16  and the well  25  (see  FIG. 3 ), to protect the device  10 , or for other purposes.  
         [0022]     A fluid passageway  26 , or inlet, extends between an interior of the base pipe and a cavity  28  formed between the base pipe  12 , sleeve  16 , and connecting rings  20 . The fluid passageway  26  in the figure ports to the base pipe interior and thereby communicates the tubing pressure to the cavity  28 . In alternate designs the fluid passageway  26  may communicate with the well annulus or with a control line that extends to the surface or to some other region in the well (e.g., an annulus above a packer).  
         [0023]     In one method of manufacturing the isolation device  10 , a metal plate is formed into a tubular sleeve  16  (e.g., by rolling and then welding the abutting ends). Note that the sleeve  16  could also be machined or cold drawn. The sleeve  16  is placed on the base pipe  12  by sliding the sleeve  16  onto the base pipe  12 . Finally, the sleeve  16  is connected and sealed to the base pipe  12 .  
         [0024]     In operation, pressure applied to the cavity  28  through the fluid inlet  28  deforms the sleeve  16  causing it to expand outward against the surrounding well conduit  25 .  FIG. 3  illutrates the sleeve  16  in the inflated state. During expansion, the sleeve undergoes significant plastic deformation so that the sleeve  16  remains in the inflated state. Note that the end portions  18  remain undeformed because the stiffening rings  22  restrain them. Outward expansion of the sleeve  16  is constrained by the well conduit  25  and the sleeve  16  tends to conform to the contour of the abutting well conduit  25 . The conformance of the sleeve  16  to the well conduit  25  helps to improve the seal of the isolation device  10 .  
         [0025]      FIG. 4  illustrates another embodiment of the present invention in which the central portion  30  of the sleeve  16  has a smaller diameter than the end portions  18  when in the contracted state. In the figure, the central portion  30  of the sleeve  16  is shown as abutting or nearly abutting the base pipe  12 . The jacket  24  placed on the central portion  30  is thus protected when the device is in the retracted state (e.g., when the device  10  is run into the well).  
         [0026]     In addition, one of the connecting rings  20   a  shown in  FIG. 4  is free to move longitudinally relative to the base pipe  12 . The other connecting ring  20   b  is fixed relative to the base pipe  12 . As the sleeve  16  inflates, the connecting ring  20   a  is free to slide on the base pipe  12  to accommodate axial length changes of the sleeve  16 . A seal  32  (such as an elastomeric seal, a seal stack, or other seal) provides a seal between the movable connecting ring  20   a  and the base pipe  12 .  
         [0027]     In  FIG. 5 , an inflation material  34  is placed within the cavity  28 . In one embodiment, the inflation material  34  is a swellable elastomer. During the initial inflation, the fluid pressure inside the bladder (sleeve  16 ) provides the isolation contact stress with the formation. Over time, the swelling elastomer inside the bladder  16  swells to take up the internal volume and supply long-term support for the sealing bladder  16 . With this method, if the metal bladder  16  looses pressure integrity for some reason, the swelling elastomer inflation material  34  has filled the majority of the volume, maintaining the formation sealing force. In addition, the swelling elastomer may assist in the inflation of the sleeve  16 .  
         [0028]     Another inflation material  34  that may be used in the present invention is a two-part foam (e.g., silicone foam, elastomer foam, urethane foam). The foam components are combined as they are injected and swell the element until it touches the formation. The foam would cure into a solid mass, keeping the element engaged to the formation. A service or running tool or a control line may be used to inject the materials into the cavity. Alternatively, the materials may be stored in the cavity and kept separate until a predetermined time and then combined (e.g., as by opening a valve or rupturing a container). The isolation device  10  may employ other types of inflation materials  34  as well.  
         [0029]      FIG. 6  shows schematically a sleeve  16  that has a pressure relief port  36 , or passageway, built into the expanded metal bladder  16  to achieve equilibrium from the high-pressure zone (P 1 ). The relief port  36  may include a valve to permit one-way flow into the bladder  16 . In the illustration below, if the pressure at P 1  is larger than the pressure at P 2 , the internal pressure of the metal bladder, P 3 , will become equal to the pressure at P 1 .  
         [0030]      FIG. 7  shows an embodiment of the present invention in which the inflation fluid is supplied from an exterior of the isolation device  10  and is controlled using a valve  38 . In this embodiment, the fluid inlet  26 , or passageway, within the base pipe  12  communicates with the cavity  28  and an exterior of the isolation device  10  (e.g., with the well annulus). The valve  38  allows fluid pressure to enter the bladder  16  during inflation of the isolation device  10 , and maintains the fluid pressure within the bladder  12  once the inflation is complete.  
         [0031]     For example, the valve  38  may restrict or prevent fluid from exiting the cavity  28  through the fluid passageway  26 . The valve  38  may take many forms, including a check valve or an inflation valve. Inflation valves, such as those used in inflation packers, use pistons controlled by springs and shear pins with the intent of permanently trapping a pressurized fluid inside the bladder. The design of these valves generally allows control of the pressure at which inflation begins, pressure at which inflation ends, and permanently closing of the bladder communication at inflation end. Examples of some ECP-type valves are shown in U.S. Pat. Nos. 4,776,396, 4,711,301, and 4,260,164 and in U.S. patent application No. 2003/0183398. Other types of valves  38  may also be used in the present invention. The sleeve  16  may be designed to inflate at reasonable pressures within the wellbore. Maintaining the pressure within the bladder  16  will support the bladder  16  and improve its resistance to collapse and its ability to hold pressure and better perform the isolation function of the isolation device  10 . Thus, the valve  38  performs an important step of maintaining a pressure within the bladder  16  to support the bladder  16  and improve its collapse resistance.  
         [0032]      FIG. 8  shows an embodiment of the present invention in which the inflation pressure is supplied through a control line  40 . In this embodiment, the fluid inlet  26  within the base pipe  12  communicates with the cavity  28  and a control line  40 . The control line  40  may extend to the surface of the well or to some other region in the well (e.g., an annulus above a packer). In one embodiment, pressure is maintained in the bladder  16  through the control line  40 . In the event of a leak, for example, additional pressure is applied through the control line  40  to maintain the pressure. As discussed previously, maintaining the pressure within the bladder  16  improves the collapse resistance of the bladder  16  and improves its performance.  
         [0033]     Note also that in the embodiments of  FIGS. 7 and 8 , no jacket is applied to the sleeve  16 . The sleeve  16  directly seals against the well conduit  25 . As discussed previously, the jacket  24  is optional in some embodiments.  
         [0034]      FIGS. 9   a - c  illustrate a portion of an isolation device  10  of the present invention in which the base pipe  12  defines a plurality of fluid passageways  42  therein. A valve  44  controls the flow through the passageways  42 . The valve  44  and passageways  42  provide a similar function to the relief ports  36  discussed in connection with  FIG. 6 . Specifically, the valve  44  allows selective unidirectional communication from the annulus (i.e. high pressure side) to the interior cavity  28  of the bladder  16 . The valve shown in the figures is used in an isolation device  10  that is inflated using tubing pressure. Other valves may be used and the configuration may change depending upon the inflation mode, or the source of inflation fluid or pressure (e.g., the use of control line inflation or annulus inflation). A first passageway  42   a  communicates with the cavity  28  and tubing port  46 , which communicates tubing pressure into the first passageway  42   a  and, thus, into the bladder cavity  28 . Piston  48  positioned in first passageway  42   a  has a J-slot  50  and a set of seals  52 . The J-slot  50  operates to position the piston  48  in either a retracted, open position ( FIG. 9   b ), or an extended, closed position. A spring  54  biases the piston  48  to the closed position ( FIG. 9   c ). As shown in the figures, in the open position, the first passageway  42   a  communicates with the tubing port  46 ; in the closed position, the piston  48  covers the tubing port  46  and the seals  52  prevent communication with the first passageway  42   a.    
         [0035]     Each of the passageways  42   a - c  communicates with the well annulus. A lateral passageway  55  provides communication between passageway  42   b  and passageway  42   a  at the backside of the piston  48  (distal the tubing port  46 ). The piston  48  uses the annulus or well pressure as a reference pressure and the communication between passageways  42   a  and  42   b  as shown helps to ensure that the reference pressure is supplied to the back side of the piston  48 .  
         [0036]     Passageway  42   c  is in fluid communication with passageway  42   a.  Check valve  56  allows fluid to enter the bladder cavity  28  via the passageways  42   c  and  42   a,  but prevents fluid from exiting the cavity  28 .  
         [0037]     A rupture disk  58  in passageway  42   b  restricts the flow of fluid from the annulus to the bladder cavity  28  until after the disk  58  is ruptured (e.g., as by supplying a sufficient rupture pressure).  
         [0038]     Thus, the valve  44  has (1) a piston  48  that closes communication between the tubing and inflated bladder  16 , (2) a rupture disk  58  that opens bladder  16  to unidirectional annulus pressure, (3) a check valve  56  that protects the rupture disk  58  from hydrostatic pressure during RIH (“run in hole”) and prevents an atmospheric chamber in the bladder cavity  28 , and a spring  54  and J-slot  50  that change the piston  44  position from open to closed. In operation, the valve  44  shown follows a specific series of events relating to the pressure applied to the inflating bladder  16 . Initially, the J-slot  50  holds the piston  48  in the open position during RIH and as shown in  FIG. 9   b.  Once the isolation device  10  is in the desired location, the pressure in the tubing is increased to inflate the bladder  16 . During inflation, the pressure from the tubing moves the piston  44  against the  54  spring as the pressure increases. At a critical pressure, the piston  48  fully compresses the spring and the J-slot rotates to the next position. The bladder  16  is fully inflated. When the pressure reaches the rupture pressure, the rupture disk  58  breaks and opens the bladder cavity  28  to the annulus pressure (e.g., on the high pressure side of the isolation device  10 ). With the rupture disk  58  open, the bladder pressure decreases and the spring  54  moves the piston  48  to the closed position ( FIG. 9   c ) isolating the bladder-cavity  28  from the tubing pressure. With the rupture disk  58  blown (open) and the tubing port closed, the bladder cavity  28  is free to communicate with one side of the wellbore annulus (e.g., the high pressure side). Exposing the cavity  28  to the high-pressure side of the annulus creates a energized seal.  
         [0039]      FIG. 10  shows an isolation device  10  of the present invention having a valve  44  (discussed above in connection with  FIGS. 9   a - c ) provided in the base pipe  12  thereof. One of the connecting rings  20   a  is free to move longitudinally relative to the base pipe  12 . As the sleeve  16  inflates, the connecting ring  20   a  is free to slide on the base pipe  12  to accommodate axial length changes of the sleeve  16 . A seal  32  provides a seal between the movable connecting ring  20   a  and the base pipe  12 . A ratchet  60  of the device  10  allows the connecting ring  20   a  to move one direction relative to the base pipe  12  (i.e., toward the other connecting ring  20   b  as a result of sleeve inflation) and prevents movement in the opposite direction. The ratchet  60  thereby helps to lock the sleeve  16  in the inflated position and further resist collapse.  
         [0040]      FIG. 11  illustrates yet another embodiment of the present invention in which the sleeve  16  is corrugated when in the contracted state. The corrugations, or folds, increase the expansion range of the sleeve  16 .  
         [0041]     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. For example, although the above description discusses hydraulic and mechanical systems for maintaining the pressure in the bladder  16  and for establishing fluid communication between the bladder cavity  28  and the high pressure side of the annulus, the isolation device  10  could employ electrical systems such as electric valves and solenoid valves or chemical or explosive systems (which could also be used for inflating the bladder  16 ). In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.