Abstract:
A method and apparatus includes providing an element formed of a superplastic material to perform a predetermined downhole task. In another arrangement, a method and apparatus includes a flowable element and a deformable element that can be expanded by flowing the flowable element.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit under 35 U.S.C. § 119 to U.S. Provisional Patent Application Serial No. 60/208,671, entitled “EXPANDABLE ELEMENTS,” filed on Jun. 1, 2000. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The invention relates to expandable elements for performing various operations.  
         BACKGROUND  
         [0003]    Many different tasks may be performed in a wellbore. For example, perforating guns may be shot to create perforations in a target formation to produce well fluids to the surface. Different zones in a wellbore may be sealed with packers. Plugs may be set at desired depths to isolate portions of a wellbore. A casing patch may be activated to patch openings in a casing or other type of liner. Sand screens may be installed to control production of sand. In addition to completion equipment, other tools for use in wellbores may include drilling equipment, logging equipment, and so forth.  
           [0004]    The tools for performing the various operations may include many different types of elements. For example, the tools may include explosives, sealing elements, expandable elements, tubings, casings, and so forth. Operation, translation, actuation, or even enlargement of such elements may be accomplished in a number of different ways. For example, mechanisms that are electrically triggered, fluid pressure triggered, mechanically triggered, and explosively triggered may be employed. Although improvements in downhole technology has provided more reliable and convenient mechanisms for operating, translating, actuating, or performing other tasks with downhole elements, a need continues to exist for further improvements in such mechanisms.  
         SUMMARY  
         [0005]    In general, according to one embodiment, an apparatus for use in a wellbore, comprises an element formed of a superplastic material to perform a predetermined downhole task.  
           [0006]    In general, according to another embodiment, an apparatus comprises a flowable element and a deformable element adapted to be expanded by flowing the flowable element.  
           [0007]    In general, according to yet another embodiment, a method of installing a tubular structure into a wellbore comprises running the tubular structure having a reduced diameter into the wellbore, and activating a heating element to heat at least a portion of the tubular structure to enable the tubular structure to exhibit a highly deformable characteristic while maintaining structural integrity. The diameter of the tubular structure is expanded.  
           [0008]    Other features and embodiments will become apparent from the following description, from the drawings, and from the claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 illustrates an embodiment of a plug tool in a run-in position.  
         [0010]    [0010]FIG. 2 illustrates the plug tool of FIG. 1 in a set position.  
         [0011]    [0011]FIGS. 3 and 4 illustrate a release mechanism in the plug tool of FIG. 1 in accordance with an embodiment.  
         [0012]    FIGS.  5 - 7  illustrate a pipe fishing tool in accordance with an embodiment.  
         [0013]    [0013]FIG. 8 illustrates a packer in accordance with an embodiment.  
         [0014]    [0014]FIG. 9 illustrates an expandable casing assembly in accordance with an embodiment.  
         [0015]    [0015]FIG. 10 illustrates an expandable screen assembly in accordance with an embodiment.  
         [0016]    [0016]FIG. 11 illustrates a junction seal assembly in accordance with an embodiment for use in a lateral junction.  
         [0017]    [0017]FIG. 12 illustrates a tool string having a shock absorber in accordance with an embodiment.  
         [0018]    [0018]FIG. 13 illustrates a releasable connector assembly in accordance with an embodiment.  
         [0019]    [0019]FIG. 14 illustrates a removable plug in accordance with an embodiment.  
         [0020]    [0020]FIG. 15 is a cross-sectional view of shaped charge in accordance with an embodiment.  
         [0021]    [0021]FIG. 16 illustrates a tool string including a weak point connector in accordance with an embodiment. 
     
    
     DETAILED DESCRIPTION  
       [0022]    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. For example, although the described embodiments include equipment for use in downhole applications, further embodiments may include equipment for surface applications.  
         [0023]    As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.  
         [0024]    In accordance with some embodiments of the invention, tools containing an expandable element are used to perform various operations or tasks. For example, the expandable element may be used to provide a seal, a plug, a packer, a patch, an expandable tubing or casing, an anchor, a tubing hanger, and so forth. In one embodiment, the expandable element includes a highly deformable material that in one embodiment is made of a superplastic material. A superplastic material exhibits high elongation or deformation without fracturing or breaking. The superplastic material may be a metal (such as aluminum, titanium, magnesium, or other light metals), a ceramic, or some other suitable material. Some superplastic materials may exhibit superplastic characteristics at about 95% to 100% of the melting temperature of the material. Other superplastic materials may exhibit superplastic characteristics at other temperature ranges, such as grater than about 50% of the melting temperature. Thus, depending on the desired application, the superplastic material selected may be one that exhibits superplastic characteristics at a desired temperature range. In further embodiments, other highly deformable materials that exhibit the desired deformation characteristics at a selected temperature while still maintaining structural integrity (e.g., without breaking or fracturing) may be used.  
         [0025]    A superplastic material is a polycrystalline solid that has the ability to undergo large uniform strains prior to failure. For deformation in uni-axial tension, elongation to failure in excess of 200% are usually indicative of superplasticity. For superplastic behavior, a material must be capable of being processed into a fine equi-axed grain structure that will remain stable during deformation. The grain size of superplastic materials are made as small as possible, normally in the range of 2 to 10 micrometers, although materials with larger grain sizes may also exhibit superplasticity.  
         [0026]    Referring to FIG. 1, in one embodiment, an expandable plug  10  includes a “flowable” element  12  and an expandable element  14  formed at least in part of a superplastic material. The flowable element  12  is initially in solid form inside a housing  16  of the expandable plug  10 . When heated, the flowable element  12  transitions to a molten or liquid state. The expandable element  14  is in the form of a sleeve attached to the housing  16  at the upper and lower ends of the sleeve  14 .  
         [0027]    In one embodiment, the flowable element  12  may include a eutectic material. In other embodiments, the flowable element  12  may include a solder, a fusible alloy, or a blocking alloy. A fusible alloy is a low melting temperature composition containing bismuth, lead, tin, cadmium, or indium. A blocking alloy is a high purity, low melting temperature alloy. The eutectic material, solder, fusible alloy, and blocking alloy exhibit volume expansion when transitioning from a molten or liquid state to a solid state. A eutectic material generally melts and solidifies at the same temperature. On the other hand, some of the other types of materials may have a first temperature at which they transition from a solid state to a molten or liquid state and a second temperature at which they transition from a molten or liquid state to a solid state. Generally, the first temperature is higher than the second temperature. Due to desired characteristics of bismuth, many of the alloys used to form the flowable element  12  that may be used in various applications may contain bismuth along with other elements. The flowable element  12  can also be formed entirely of bismuth. Possible flowable materials are listed in the attached Appendix A.  
         [0028]    The flowable element  12  has a predetermined temperature at which it transitions from the solid to a molten or liquid state. To actuate the plug  10 , the flowable element  12  is raised to above this predetermined temperature. To allow cooperation between the flowable element  12  and the expandable element  14 , the expandable element  14  is made of a superplastic material that exhibits superplastic characteristics at about the same temperature as the predetermined flow temperature of the flowable element  12 . This allows the flowable element  12  to be displaced to deform the superplastic sleeve  14  to form the desired plug inside a casing, liner, tubing, or pipe  40 .  
         [0029]    As further shown in FIG. 1, the expandable plug  10  includes a cap  100  defining an atmospheric chamber  18  through which electrical wiring  20  is routed. The electrical wiring  20  is connected through a sealed adapter  22  to an igniter  24 . The adapter  22  provides a sealed path through a bulkhead of the expandable plug  10 . The igniter  24  is fitted with an O-ring seal to isolate the atmospheric chamber  18 . A thermosensor  46  is also attached through the bulkhead to sense the temperature of the flowable element  12 . A connector  42  attached to the thermosensor  46  may be connected to electrical wiring (not shown) that extends to the surface so that a well surface operator can monitor the temperature of the flowable element  12 .  
         [0030]    In the illustrated embodiment, the igniter  24  is placed in the upper portion of a tube  26 , which may be formed of a metal such as steel. Below the igniter  24  is a propellant stick  28  that can be initiated by the igniter  24 . The propellant stick  28  runs along the length the tube  26  into a chamber  30  formed inside a power piston  32 .  
         [0031]    The power piston  32  is moveable inside the housing  16  of the expandable plug  10  in response to pressure generated in the chamber  30 . The power piston  32  is moveable in an upward direction to apply pressure against the flowable element  12 . The lower end of the housing  16  terminates in a bull plug bottom  34 . When in solid form, the flowable element  12  prevents movement of the power piston  32 .  
         [0032]    A sealing element  42  is formed on the outside surface of the superplastic sleeve  14 . The sealing element  42 , which may be formed of an elastomer, is designed to engage the inner wall of the casing, liner, tubing, or pipe  40  to isolate the wellbore above and below the expandable plug  10 .  
         [0033]    In operation, to set the expandable plug  10 , a survey may be initially performed with a surveying tool (not shown) to determine the temperature and pressure of the wellbore at the desired depth. Once the temperature and pressure has been determined, the surveying tool may be pulled out of the hole and the expandable plug  10  lowered into the wellbore. When the expandable plug  10  is lowered to a desired depth, some time is allowed for the plug  10  to equalize to the temperature of the wellbore. The setting process is then started by firing the igniter  24 , which initiates the propellant stick  28  to create heat and to generate gas in the chamber  30 . The increase in pressure in the chamber  30  creates a differential pressure across the power piston  32 , whose other side is at atmospheric chamber. Due to the increased heat, the expandable element  12  becomes molten. As a result, the resistance against movement of the power piston  32  is removed so that the gas pressure in the chamber  30  pushes the power piston  32  upwardly. The molten element  12  is displaced and expands to deform the sleeve  14 , which due to the increased temperature is now exhibiting superplastic characteristics. As best shown in FIG. 2, the sleeve  14  radially deforms outwardly by force applied by the power piston  32  so that the sealing element  42  is pressed against the inner wall of the casing  40 .  
         [0034]    After full displacement, the power piston  32  engages a ratchet lock (not shown) to maintain its up position as shown in FIG. 2. Some amount of the flowable element  12  still remains above the power piston  32 . At this point, the propellant stick  28  has burned out, so that the temperature within the expandable plug  10  starts to decrease. The temperature of the flowable element  12  as monitored by the thermosensor  46  is communicated to the surface. The surface operator waits until the temperature stabilizes in the expandable plug  10 .  
         [0035]    As the flowable element  12  cools and transitions from a molten or liquid state to a solid state, the element  12  expands in volume during the phase change. The volume expansion creates a radially acting force to increase the force applied against the sealing element  42  that is in contact with the casing inner wall of the casing, liner, tubing, or pipe  40 .  
         [0036]    The volume expansion of the flowable element  12  that is located above the power piston  32  inside the cap  100  also applies a radial force against the inner wall of the cap  100 . As further described below in connection with FIGS. 3 and 4, this outward radial force applied against the cap  100  causes a release of the cap  100  from the rest of the expandable plug  10 . This allows the cap  100  and the carrier line attached to the cap  100  to be retrieved from the well after the plug  10  has been set.  
         [0037]    Referring to FIGS. 3 and 4, the release mechanism of the expandable plug  10  is illustrated. The upper cap  100  is attached to a collet  102 . The collet  102  has a protruding portion  104  that is engaged in a groove  106  of the housing  16 . The collet  104  is maintained in engagement in the groove  106  by a frangible ring  108 , which may be formed of a ceramic or other suitably frangible material.  
         [0038]    When the flowable element  12  in the upper portion of the housing  16  cools and transitions from a molten or liquid state to a solid state, it expands in volume to create an outward radial force against the inner wall of the housing  16 . Application of a sufficient force pushes the housing  16  and the collet  102  radially outwardly so that the frangible ring  108  breaks. When the frangible ring  108  breaks, the collet  102  can disengage from the groove  106  so that the upper head of the expandable plug  10  can be retrieved to the well surface, leaving the plug  10  formed of the flowable element  12  and superplastic sleeve  14  behind.  
         [0039]    In accordance with some embodiments of the invention, to achieve a material having superplastic characteristics, an extrusion process may be performed on the material. Extrusion refers to a process in which a large plastic deformation is induced in the material without changing the size or general shape of the material. In one embodiment, the desired material, which in this case may be a sleeve, is passed through two intersecting channels of only slightly larger dimensions. The angle can be chosen between 0 and 90° to provide a varied amount of strain. As the material passes the turn between the intersecting channels, the material must shear. Extrusion allows the grain size of the material to be reduced to a micron or submicron range to enhance the elasticity of the material. One example material that may be subjected to the extrusion process to achieve superplastic characteristics is AZ91, which includes a composition of magnesium, aluminum and zinc. The formula for AZ91 is 90Mg9Al1Z. In addition to reducing grain size, the grain size also becomes more uniform after the extrusion process, which enables a processed metal to distort and flow without splitting or fracturing due to stress concentrations.  
         [0040]    Referring to FIGS.  5 - 7 , another application of a highly deformable material such as a superplastic material is in downhole fishing operations. As shown in FIG. 5, a tubing or pipe  200  is to be retrieved to the well surface. A fishing tool, which may be lowered by a wireline, slickline, or coiled tubing  202 , is lowered into the inner bore of the tubing or pipe  200 . The carrier line  202  is attached to a cable head  204 , which in turn is coupled to a fishing head  206  that is attached to a firing head  208 . A detonating cord  210  extends from the firing head  208  into a sleeve  212 , which may be perforated. The sleeve  212  may be formed of a highly expandable metal alloy that exhibits superplastic behavior at an elevated temperature.  
         [0041]    An internal upset  214  is provided in the inner wall of the tubing or pipe  200 . In operation, the fishing tool is lowered into the inner bore of the tubing or pipe  200  to a position proximal the upset  214 , as shown in FIG. 5. The firing head  208  is then activated to ignite the detonating cord  212 . Heat and pressure generated by initiation of the detonating cord  210  causes the sleeve  212  to expand. A portion of the sleeve  212  expands into the upset  214  to provide a move secure engagement of the sleeve  212  with the tubing or pipe  200 . Once the sleeve  212  has been expanded into engagement with the tubing or pipe  200 , the cable head  204  is detached from the fishing head  206  and raised by the carrier line  202 , as shown in FIG. 6.  
         [0042]    Next, as shown in FIG. 7, a work string having a stinger  220  is lowered into the wellbore. The stinger  220  is passed into the bore of the tubing or pipe  200  for engagement with the fishing head  206 . Once engaged, the work string can be raised to raise the entire assembly including the fishing tool and the tubing or pipe  200 .  
         [0043]    Referring to FIG. 8, a packer  300  in accordance with one embodiment is illustrated. The packer  300  includes an anchor slip or element  302  and a sealing element  304 , which may be formed of an elastomeric material. Both the sealing element  304  and the anchor element  302  may be translated radially into engagement with an inner wall of a casing or liner  310 . This isolates an annular region formed between an inner tubing or pipe  306  of the packer  300  and the casing  310 . However, flow through the packer  300  is still possible through an inner bore  308  of the tubing or pipe  306 .  
         [0044]    The anchor element  302  is attached on the outside of a highly deformable sleeve  312 , and the sealing element  304  is formed on the outside of a highly deformable sleeve  314 . Each of the highly deformable sleeves  312  and  314  may be formed of a superplastic material that exhibits a superplastic behavior in a predetermined temperature range. The highly deformable sleeves are attached to the housing  316  of the packer  308 .  
         [0045]    A space is defined inside the housing  316  of the packer  300  in which a flowable element  318  may be located. The flowable element, initially in solid form, is in contact with the inner surfaces of both expandable sleeves  312  and  314  in the illustrated embodiment. An annular tube  320  runs in the region formed inside the housing  316  of the packer  300 . A propellant  322  (or multiple propellants) may be placed inside the annular tube  300 .  
         [0046]    The propellant  322  extends into an annular space  324  defined within a piston  326 . The piston  326  is movable upwardly by application by pressure inside the chamber  324  once the flowable element  318  transitions from a solid to a molten or liquid state.  
         [0047]    In an activating mechanism that is similar to that of the plug  10  in FIGS. 1 and 2, the propellant  322  may be ignited to generate heat to melt the flowable element  318  and to create high pressure inside the chamber  324 . Once the flowable element  318  melts, the pressure inside the chamber  324  pushes the power piston  326  upwardly to displace the highly deformable sleeves  312  and  314 , which pushes the anchor elements  302  and the sealing element  304  into contact with the inner wall of the casing  310 .  
         [0048]    Once the propellant  322  has burned out, the temperature of the flowable element  318  starts to cool, which enables the flowable element  318  to transition from a molten or liquid state back to a solid state. The transition back to the solid state causes the volume of the flowable element  318  to expand, which applies a further radial force against the highly deformable sleeves  312  and  314  to further engage the anchor element  302  and the sealing element  304  against the inner wall of the casing  310 .  
         [0049]    Once set, the packer  300  isolates the annular region between a pipe or tubing and the casing  310 . The pipe or tubing maybe arranged concentrically within the casing  310 , and may include a production tubing or injection tubing.  
         [0050]    In another application, a tool similar in design to that of the packer  300  may be employed as a patching tool. A patching tool is used to patch portions of a casing or liner that may have been damaged or that may have been previously perforated. In one example, a formation that was previously producing hydrocarbons may start to produce water or other undesirable fluids. When that occurs, a patching tool may be used to patch the perforations formed in the casing or liner to prevent further production of fluids from the formation.  
         [0051]    To implement such a patching tool in accordance with some embodiments of the invention, the tool  300 , shown in FIG. 8, may be modified to include a patch in place of the anchor element  302  and the sealing element  304 . The patch may be formed of an elastomer, which is similar to the sealing element  304  of FIG. 8. However, to provide a larger coverage area, the patch may be formed of a larger piece of material. The patch may be arranged on the outer surface of a highly deformable sleeve, which may be made of a superplastic material. The patching tool may include an inner bore much like the inner bore  308  shown in FIG. 8 to allow fluid flow even after the patch has been set in the wellbore.  
         [0052]    Another embodiment may include a patching tool used in open holes rather than cased or lined holes. Such a patching tool may include a patch made of a metal or other suitable material that can be pressed into contact with the inner wall of the open hole.  
         [0053]    Referring to FIG. 9, an expandable casing or liner assembly  400  is illustrated. The expandable casing or liner assembly includes a casing or liner  402  that is formed of a highly deformable material, which may be a superplastic material. The casing or liner  402  may be run into a wellbore with a diameter that is smaller than the inner diameter of the wellbore. To expand the diameter of the casing or liner  402 , an expander tool  404  may be run into the inner bore of the casing or liner  402 . The outer diameter of the expander tool  404  is the desired inner diameter of the casing or liner  402 . The expander tool  404  may be pushed downwardly by a carrier line  408 . To provide structural rigidity, the carrier line  408  may be tubing or pipe.  
         [0054]    The highly deformable casing or liner  402  exhibits superplastic behavior at a predetermined temperature range. Thus, to ease the expansion of the casing or liner  402 , the expander tool  404  contains a heating element, which may include resistive heating elements  406 , to heat the adjacent casing or liner  402  to a desired temperature range. Thus, when the expander tool  404  heats the adjacent casing or liner  402  to a sufficiently elevated temperature, the casing or liner  402  becomes superplastic, making the expansion process more convenient. Further, due to the superplasticity of the casing or liner  402 , likelihood of breakage or fractures of the casing or liner  402  is reduced.  
         [0055]    A similar process may be applied to expanding a tubing or pipe formed of a superplastic material or other highly deformable material that exhibits high deformability at an elevated temperature while still maintaining structural integrity.  
         [0056]    In another embodiment, instead of running the expander tool  404  downwardly, the expander tool  404  may be positioned at the lower end of the casing or liner  402  and run with the casing or liner  402  into the wellbore. To perform the expansion process, the expander tool  404  may be raised through the inner bore of the casing or liner  402  to expand the casing or liner  402 .  
         [0057]    Referring to FIG. 10, an expandable screen assembly  500  is shown. The screen assembly  500  may include a screen  502  that is used for sand control, as an example. A screen  502  typically includes a pattern of openings to provide the desired flow characteristics so that sand may be blocked while desired hydrocarbons are produced into the wellbore.  
         [0058]    In the embodiment of FIG. 10, the screen  502  is formed of a highly deformable material, such as a superplastic material. The screen assembly  500  may be installed inside a wellbore with an expander tool  504  positioned below the expandable screen  502 . When the screen assembly  500  is positioned at a desired depth, an electrical signal may be run through an electrical cable in the carrier line  506  to heat up resistive heating elements  508 . This allows the expander tool  504  to heat the adjacent portion of the expandable screen  502  to a temperature at which the screen  502  exhibits superplastic behavior. This enables the expander tool  504  to be raised to expand the diameter of the screen  502 , which may bring it into contact with the inner wall of an open hole. By bringing the sand screen  502  into closer proximity to the inner wall of an open hole, better sand control may be provided. Also, by employing a superplastic material that is heated to enable expansion of the screen  502 , the likelihood of damage to the screen  502  during the expansion process may also be reduced because of the superior structural integrity of superplastic materials.  
         [0059]    Referring to FIG. 11, a multi-lateral junction assembly  600  is illustrated. The lateral junction assembly  600  includes a tubing  602  that is formed of a highly deformable material that may be inserted through a window  604  milled through the side of a casing or liner  606  to expose the main wellbore  608  to a lateral wellbore  610 .  
         [0060]    Conventionally, tubings have been inserted through such milled openings of a casing into a lateral bore. The tubing typically has a smaller diameter than the lateral wellbore. Cement may be formed around the annulus region of the tubing inserted into lateral wellbore; however, an optimal seal is not always provided. In accordance with some embodiments of the invention, the highly deformable tubing or pipe  602  may be formed of a superplastic material that exhibits superplastic behavior at a desired elevated temperature. The tubing or pipe  602  having an initial reduced diameter is run through the window  604  of the casing or liner  606  into the lateral wellbore  610 . Once properly positioned, an expander tool  612  may be run on a carrier line  614  into the inner bore of the tubing or pipe  602 . The expander tool  612  is heated to an elevated temperature to heat the tubing or pipe  602  to a temperature at which the tubing or pipe  602  exhibits superplastic behavior. This makes expansion of the tubing or pipe  602  much easier, with structural integrity of the tubing or pipe  602  maintained because of the characteristics of a superplastic material. Once the tubing or pipe  602  in the lateral wellbore  610  has expanded to contact the inner surface of the lateral wellbore  610 , a good seal may be provided at the junction of the main wellbore  608  and the lateral wellbore  610 .  
         [0061]    Referring to FIG. 12, in another embodiment, a highly deformable material may be used to form part of a shock absorber  702  in a tool string  704 . The tool string  704  may include a first component  706  and a second component  708 . It may be desirable to protect the first component  706  (which may be a gyroscope or some other sensitive equipment) from shock generated by the second component  708  (which may be an explosive device, such as a perforating gun). The shock absorber  702  includes a heating element  710  that is activated to an elevated temperature to cause a material in the shock absorber  702  to become highly deformable, which in one embodiment becomes superplastic.  
         [0062]    Thus, in operation, the tool string  704  is lowered to a desired depth at which the second component  708  is to be activated. For example, if the second component  708  is a perforating gun, then a perforating operation may be performed at the desired depth to create openings in the surrounding casing and formation. Before activation of the perforating gun  708 , the heating element  710  is activated, such as by an electrical signal conducted through a cable  712 . This causes a superplastic material in the shock absorber  702  to exhibit superplastic characteristics, which provides superior shock absorbing characteristics to protect the sensitive components  706  from shock generated when the perforating gun  708  is activated.  
         [0063]    In another embodiment, as shown in FIG. 13, a release mechanism  800  includes a connector sub  802  that may be formed at least in part of a highly deformable material, such as a superplastic material. The connector member  802  includes a protruding portion  804  that is adapted to be engaged to another member  806 . The strength of the connector member  802  when it is at a lower temperature is sufficient to maintain connection between the connector member  802  and the member  806 , despite the presence of a spring  808  applying a radially outward force against the inner walls of the connector member  802 . However, when release of the connector member  802  and the member  806  is desired, a resistive heating element  810  may be activated to heat up the connector member  802 . If the connector member  802  includes a superplastic material, heating of the material to an elevated temperature may cause the connector member  802  to exhibit superplastic behavior. As a result, the force applied by the spring  808  becomes sufficient to push the connector member  802  apart to release the member  806 .  
         [0064]    Referring to FIG. 14, a removable isolation plug  900  in accordance with an embodiment is illustrated. As shown in FIG. 14, the removable plug  900  is adapted for use at the lower end of a tubing  914 , which may be a production tubing, as an example, which is positioned inside a casing or liner  910 . First and second O-ring seals  916  and  918  may be placed around the plug  900  to isolate one side of the plug  900  from the other side in the bore of the tubing  914 . A packer  912  is placed between the tubing  914  and the casing or liner  910  to isolate an annulus region  908 . Fluid pressure in the annulus region  908  may be communicated through a port  906  to an activating mechanism  904 . The activating mechanism  904  is associated with a local heat source  902 , which may be an exothermic heat source.  
         [0065]    The plug  900  may be formed of a highly deformable material when its temperature is raised to an elevated level. In one example, such a highly deformable material includes superplastic material. To remove the plug  900 , fluid pressure is applied in the annulus region  908  and communicated through the port  906  to the activating mechanism  904 . This activates the exothermic heat source  902 , which heats up the plug  900  to a predetermined temperature range. When that occurs, the plug  900  begins to exhibit superplastic behavior, which enables the elevated fluid pressure communicated through the port  906  to deform the plug  900  radially inwardly. Deformation of the plug  900  in a radially contracting fashion allows the plug  900  to drop through the tubing  914  to the lower end of the wellbore. An isolation plug that can be removed using an interventionless technique may thus be employed.  
         [0066]    Referring to FIG. 15, a shaped charge  1000  includes a liner  1002  that is formed of a highly deformable material, which may be a superplastic material. The liner  1002  is placed adjacent an explosive charge  1004 , which is contained inside a container  1006 . A detonation wave traveling through a detonating cord  1008  is communicated through a primer  1010  to the explosive charge  1004 . Detonation of the explosive charge  1004  causes the liner  1002  to collapse into a perforating jet that is useful for creating perforations in the surrounding casing or liner and the formation.  
         [0067]    Referring to FIG. 16, a tool  1100  in accordance with another embodiment includes a weak point connector  1104  formed at least in part of a highly deformable material such as a superplastic material. The weak point connector  1104  is connected to an adapter  1105 , which in turn is coupled to a carrier line  1102 . The weak point connector  1104  is connected to a string of perforating guns  1106 ,  1108 , and so forth.  
         [0068]    The weak point connector  1104  is provided in case the gun string  1100  is stuck as it is being lowered into or removed from the wellbore. Conventionally, a weak point is provided to enable retrieval of at least a part of the run-in tool string when it becomes stuck. When the weak point breaks, the perforating guns (or other tools) drop to the bottom of the wellbore while the carrier line can be retrieved from the surface. However, such weak points may also break during perforating operations due to the shock generated by perforating guns.  
         [0069]    By using a weak point connector  1104  that is formed of a highly deformable material, superior structural integrity may be provided so that the gun string does not break when the perforating guns are fired. In operation, a heating element  1107  in the weak point connector  1104  is activated to heat the weak point connector  1104  so that it exhibits superplastic behavior. The perforating guns  1106  and  1108  are then fired, which may cause a shock that may deform or bend the weak point connector  1104  without breaking it. As a result, the whole string of guns may be retrieved back to the surface, with some components re-used.  
         [0070]    While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention.  
                                                                                                                                         THIS IS THE GENERAL LIST OF ARCONIUM ALLOYS. CUSTOM ALLOYS/FORMULATIONS       ARE AVAILABLE TO SUIT YOUR SPECIAL REQUIREMENTS.            Ostalloy   Temperature ° F.   Temperature ° C.       Density            Number   Solidus       Liquidus   Solidus       Liquidus   Alloy   lb · in −3     g · cm −3                        51    51   E    51   10.7   E   10.7   62.5 Ga, 21.5 In, 16 Sn   .2348   6.50         60    60   E    60   15.7   E   15.7   75.5 Ga, 24.5 In   .2294   6.35         117   117   E   117   47   E   47   44.7 Bi, 22.6 Pb, 19.1 In   .3307   9.16                                   8.3 Sn, 5.3 Cd       129133   129       133   54       56   49.3 Bi, 20.8 In, 17.9 Pb,    .3253   9.01                                   11.5 Sn, .5 Cd       134149   134       149   57       65   47.5 Bi, 25.4 Pb, 12.6 Sn,    .3419   9.47                                   9.5 Cd, 5 In         136   136   E   136   58   E   58   49 Bi, 21 In, 18 Pb, 12 Sn   .3253   9.00       136156   136       156   58       69   49 Bi, 18 Pb, 18 In, 15 Sn   .3249   9.00       142149   142       149   61       65   48 Bi, 25.7 Pb, 12.7 Sn,    .3429   9.50                                   9.6 Cd, 4 In         143   143   E   143   61.5   E   61.5   61.72 In, 30.78 Bi, 7.5 Cd   .2895   9.01       156158   156       158   68       69   52 Bi, 26 Pb, 22 In   .3450         158   158   E   158   70   E   70   49.5 Bi, 27.3 Pb, 13.1 Sn, 10.1 Cd   .3458   9.58           158165A   158       165   70       73   50.5 Bi, 27.8 Pb, 12.4 Sn, 9.3 Cd   .3491   9.67       158173   158       173   70       78   50 Bi, 34.5 Pb, 9.3 Sn, 6.2 Cd   .3579   9.89       158194   158       194   70       90   42.5 Bi, 37.7 Pb, 11.3 Sn, 8.5 Cd   .3541   9.81       160190   160       190   71       88   42 Bi, 37 Pb, 12 Sn, 9 Cd   .3541   9.81         162   162   E   162   72   E   72   66.3 In, 33.7 Bi   .2886   7.99       165200   165       200   73       93   50 Bi, 39 Pb, 7 Cd, 4 Sn   .3650   10.11       170180   170       180   77       82   50 Bi, 39 Pb, 8 Cd, 3 Sn   .6570   10.13         171   171   E   171   77.5   E   77.5   48.5 Bi, 41.5 In, 10 Cd   .3066   8.49         178   178   E   178   81   E   81   54.1 Bi, 29.6 In, 16.3 Sn   .3058   8.47       178185   178       185   81       85   50.4 Bi, 39.2 Pb, 8 Cd, 1.4 In, 1 Sn   .3664   9.80       190200   190       200   87       93   51.45 Bi, 31.35 Pb, 15.2 Sn, 1 In   .3480   9.64         197   197   E   197   92   E   92   51.6 Bi, 40.2 Pb, 8.2 Cd   .3700   10.25         200   200   E   200   93   E   93   44 In, 42 Sn, 14 Cd   .2693   7.46       200210   200       210   93       99   50 Bi, 31 Pb, 19 Sn   .3458   9.58         202   202   E   202   95   E   95   52 Bi, 30 Pb, 18 Sn   .3465   9.60       203204   203       204   95       95.5   52 Bi, 32 Pb, 16 Sn   .3500   9.69           203219A   203       219   95       104   56 Bi, 22 Pb, 22 Sn   .3382   9.37           203219B   203       219   95       104   50 Bi, 30 Pb, 20 Sn   .3440   9.53           203219C   203       219   95       104   46.1 Bi, 19.7 Pb, 34.2 Sn   .3270   9.06       203239   203       239   95       115   50 Bi, 25 Pb, 25 Sn   .3364   9.32       203264   203       264   95       129   51.6 Bi, 37.4 Sn, 6 In, 5 Pb   .3097   8.58       203277   203       277   95       136   36 Bi, 32 Pb, 31 Sn, 1 Ag   .3328   9.22       205225   205       225   96       107   45 Bi, 35 Pb, 20 Sn   .3465   9.60       205271   205       271   96       133   34 Pb, 34 Sn, 32 Bi   .3303   9.15       208221   208       221   98       105   52.2 Bi, 37.8 Pb, 10 Sn   .3599   9.97       208234   208       234   98       112   51.6 Bi, 41.4 Pb, 7 Sn   .3657   10.13         212   212   E   212   100   E   100   35.7 Sn, 35.7 Bi, 28.6 Pb   .3370   9.34       215226   215       226   102       108   54.5 Bi, 39.5 Pb, 6 Sn   .3660   10.14         219   219   E   219   104   E   104   53.9 Bi, 25.9 Sn, 20.2 Cd   .3111   8.67         229   229   E   229   109   E   109   67 Bi, 33 In   .3180   8.81       242248   242       248   117       120   55 Bi, 44 Pb, 1 Sn   .3751   10.39         244   244   E   244   118   E   118   52 In, 48 Sn   .2635   7.30       244257   244       257   118       125   50 In, 50 Sn   .2635   7.30       244268   244       268   118       131   52 Sn, 48 In   .2635   7.30       244293   244       293   118       145   58 Sn, 42 In   .2635   7.30       248250   248       250   120       121   55 Bi, 44 Pb, 1 In   .3751   10.38       248266   248       266   120       130   40 In, 40 Sn, 20 Pb   .2837   7.86       248306   248       306   120       152   42 Pb, 37 Sn, 21 Bi   .3307   9.16       ∘ 250277      250       277   121       136   55.1 Bi, 39.9 Sn, 5 Pb   .3130   8.67         253   253   E   253   123   E   123   74 In, 26 Cd   .2751   7.62            255   255   E   255   124   E   124   55.5 Bi, 44.5 Pb   .3769   10.44        255259       255       259   124       126   58 Bi, 42 Pb   .3754   10.40         257       MP   257       MP   125   70 In, 15 Sn, 9.6 Pb, 5.4 Cd   .2754   7.63       257302   257       302   125       150   95 In, 5 Bi   .2673   7.40       262269   262       269   128       132   75 In, 25 Sn   .2720   7.30       ∘ 262271      262       271   128       133   56.84 Bi, 41.16 Sn, 2 Pb   .3105   8.60       266343   266       343   130       173   50 Pb, 30 Sn, 20 Bi   .3419   9.47       268338   268       338   131       170   51.5 Pb, 27 Sn, 21.5 Bi   .3458   9.58       268375   268       375   131       190   80 In, 20 Sn   .2710   7.30       270282   270       282   132       139   45 Sn, 32 Pb, 18 Cd, 5 Bi   .3115   8.63           ∘ 275       MP   275       MP   135   57.4 Br, 41.6 Sn, 1 Pb   .3097   8.58        *281   281   E   281   138   E   138   58 Bi, 42 Sn   .3090   8.56       *281299   281       299   138       148   50 Bi, 50 Sn   .2970   8.23       *281333   281       333   138       167   43 Bi, 57 Sn   .2960   8.16       *281338   281       338   138       170   60 Sn, 40 Bi   .2931   8.12       *284324   284       324   140       162   48 Sn, 36 Pb, 16 Bi   .3170   8.78         291   291   E   291   144   E   144   60 Bi, 40 Cd   .3361   9.31       291295   291       295   144       163   90 In, 10 Sn   .2710   7.51        291325       291       325   144       163   43 Pb, 43 Sn, 14 Bi   .3245   8.99         293   293   E   293   145   E   145   51.2 Sn, 30.6 Pb, 18.2 Cd   .3050   8.45       293325   293       325   145       162   75 In, 25 Pb   .2830   7.84         296   296   E   296   146   E   146   97 In, 3 Ag   .2664   7.38       298300   298       300   148       149   80 In, 15 Pb, 5 Ag   .2834   7.85           307A       MP   307       MP   153   99.5 In, .5 Ga   .2639   7.31       307322   307       322   153       161   70 Sn, 18 Pb, 12 In   .2812   7.79         313       MP   313       MP   156.7   100 In   .2639   7.31       320345   320       345   160       174   70 In, 30 Pb   .2956   8.19         *338   338   E   338   170   E   170   65.5 Sn, 31.5 Bi, 3.0 In   .2901   8.03       345365   345       365   174       185   60 In, 40 Pb   .3077   8.52         348   348   E   348   176   E   176   67.8 Sn, 32.2 Cd   .2772   7.68         355   355   E   355   179   E   179   62 Sn, 36 Pb, 2 Ag   .3036   8.41       355410   355       410   179       210   55 Pb, 44 Sn, 1 Ag   .3289   9.10       355450   355       450   179       232   60 Pb, 37 Sn, 3 Ag   .3390   9.39       355500   355       500   179       260   50 Sn, 47 Pb, 3 Ag   .3198   8.86       356408   356       408   180       209   50 In, 50 Pb   .3198   8.86         361   361   E   361   183   E   183   63 Sn, 37 Pb   .3032   8.40       361367   361       367   183       186   70 Sn, 30 Pb   .2946   8.16       361370   361       370   183       188   60 Sn, 40 Pb   .3068   8.50       361378   361       378   183       192   75 Sn, 25 Pb   .2888   8.00       361390   361       390   183       199   80 Sn, 20 Pb   .2834   7.85       361403   361       403   183       205   85 Sn, 15 Pb   .2780   7.70       361413   361       413   183       212   50 Sn, 50 Pb   .3202   8.87       361415   361       415   183       213   90 Sn, 10 Pb   .2726   7.55       361432   361       432   183       222   95 Sn, 5 Pb   .2679   7.42       361460   361       460   183       238   60 Pb, 40 Sn   .3350   9.28       361496   361       496   183       257   70 Pb, 30 Sn   .3509   9.72       361514   361       514   183       268   75 Pb, 25 Sn   .3595   9.96       380450   380       450   193       232   65 Pb, 35 In   .3420   9.47       383437   383       437   195       225   60 Pb, 40 In   .3350   9.30         390   390   E   390   199   E   199   91 Sn, 9 In   .2626   7.27         422   422   E   422   217   E   217   90 Sn, 10 Au   .2730   7.30         430   430   E   430   221   E   221   96.5 Sn, 3.5 Ag   .2657   7.36       430448   430       448   221       238   96 Sn, 4 Ag   .2640   7.31       430465   430       465   221       240   95 Sn, 5 Ag   .2668   7.39       430563   430       563   221       295   90 Sn, 10 Ag   .2711   7.51         450       MP   450       MP   232   100 Sn   .2628   7.28       450456   450       456   232       235   98 Sn, 2 Sb   .2690   7.45       450464   450       464   232       240   95 Sn, 5 Sb   .2617   7.25         451       MP   451       MP   233   65 Sn, 25 Ag, 10 Sb   .2818   7.80       463470   463       470   239       243   85 Pb, 10 Sb, 5 Sn   .3820   10.58       463545   463       545   239       285   92 Pb, 5 Sn, 3 Sb   .3906   10.82       482508   482       508   250       264   75 Pb, 25 In   3599   9.97       486500   486       500   252       260   90 Pb, 10 Sb   .3826   10.60       514570   514       570   268       299   88 Pb, 10 Sn, 2 Ag   .3887   10.77       518536   518       536   270       280   81 Pb, 19 In   .3707   10.27         520       MP   520       MP   271   100 Bi   .3541   9.80       522603   522       603   273       316   96 Pb, 4 Sn   .3930   10.87       524564   524       564   274       296   95 Bi, 5 Sb   .3445   9.54       527576   527       576   275       302   90 Pb, 10 Sn   .3881   10.75       529553   529       553   277       290   85 Pb, 15 In   .3795   10.51         536   536   E   536   280   E   280   80 Au, 20 Sn   .5242   14.51       536558   536       558   280       292   90 Pb, 10 In   .3870   10.72       549565   549       565   287       296   92.5 Pb, 5 Sn, 2.5 Ag   .3978   11.02       554590   554       590   290       310   90 Pb, 5 In, 5 Ag   .3971   11.00         558       MP   558       MP   292   90 Pb, 5 Ag, 5 Sn   .3971   11.00       558598   558       598   292       314   95 Pb, 5 In   .3980   11.06       570580   570       580   299       304   95.5 Pb, 2.5 AG, 2 Sn   .4043   11.20         572       MP   572       MP   300   92.5 Pb, 5 In, 2.5 Ag   .3978   11.02         579   579   E   579   303   E   303   97.5 Pb, 2.5 Ag   .4090   11.33       581687   581       687   305       364   95 Pb, 5 Ag   .4079   11.30         583   588   E   588   309   E   309   97.5 Pb, 1.5 Ag, 1 Sn   .4072   11.28       590598   590       598   310       314   95 Pb, .5 Sn   .3980   11.06       590611   590       611   310       322   98.5 Pb, 1.5 Sb   .4054   11.23         597       MP   597       MP   313   91 Pb, 4 Sn, 4 Ag, 1 In   .4060   11.24         620       MP   620       MP   327   100 Pb   .4090   11.35+TZ, 1/55