Core-containing sealing assembly

Information

  • Patent Grant
  • 6446717
  • Patent Number
    6,446,717
  • Date Filed
    Thursday, June 1, 2000
    24 years ago
  • Date Issued
    Tuesday, September 10, 2002
    22 years ago
Abstract
The invention generally provides a sealing assembly with a deformable portion and a core at least partially disposed within the deformable portion that can be radially expanded to engage an adjacent surface and effect a seal. In one embodiment, the core is a fluid-containing core that preferably comprises a compressible fluid and the deformable portion comprises a deformable metal. The core can retain an amount of stored energy and adjust to changing conditions that otherwise might affect the seal integrity. The core can be sealed within the deformable portion and can be compressed by a force applied to the deformable portion to cause radial expansion. The core can also be coupled to a piston which can apply a force to fluid within the core to cause the radial expansion necessary to effect sealing. An elastomeric member can be attached to the deformable portion to assist in sealing.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to an apparatus and method for sealing between two or more surfaces. Specifically, the present invention relates to an expandable packer for sealing oil field wellbores.




2. Background of the Related Art





FIG. 1

is a schematic view of a typical oil field well


10


. A wellbore


12


is drilled through the strata


16


and a casing


14


is inserted therein to maintain the integrity of the wellbore for subsequent production of hydrocarbons from beneath the surface of the well. Typically, a replaceable tubing string


18


, comprising a plurality of tubes that are longitudinally connected together, is inserted into the casing


14


to a certain depth in the well, such that the lower end of the tubing string is proximate a production zone


20


containing hydrocarbons. Perforations


22


are formed in the casing at the depth of the formation to be produced to allow the hydrocarbons to enter the wellbore


12


through the casing


14


. In many cases, it is desirable that the hydrocarbons flow to the surface through the tubing string


18


to avoid corrosion and flow damage to the casing


14


. In those cases, a sealing assembly, such as a packer


23


, may be run on the lower end of the tubing string


18


. The packer


23


seals an annulus between the tubing outside diameter and the casing inside diameter, thereby diverting the hydrocarbons to flow through the tubing to the surface. In other examples, a packer seal is effected inside the tubing string


18


and can be referred to as a plug. Alternatively, the packer may seal an annulus between a smaller tubing string (not shown) outer diameter and the tubing string


18


inner diameter.





FIG. 2

is a schematic cross sectional view of one commercially available permanent type packer


23


. The packer is shown in a disengaged state, i.e., “running position”, on the left side of the schematic view and in an engaged state, i.e., “set position”, on the right side of the view. The packer


23


includes a packer body


24


having a ridge portion


25


. A lock ring housing


26


is disposed in an upper portion of the packer


23


. A lock ring


43


is disposed between the lock ring housing


26


and the ridge portion


25


. The lock ring


43


includes mating ridges


27


adjacent the ridges on the ridge portion


25


. At least one upper slip


28


and typically a plurality of slips are disposed below the lock ring housing


26


and include a serrated outer surface where the serrations are typically referred to as wickers


29


. The upper slip


28


is disposed about the circumference of the packer


23


and are used to hold the packer in position when the wickers


29


grip the casing


14


. An upper cone


30


is disposed below the upper slip


28


. The upper cone


30


includes a tapered surface


41


that mates with a corresponding tapered surface on the upper slip


28


. The upper cone


30


is used to displace the upper slip


28


radially outward as an axial force is applied to the slip


28


in a direction toward the upper cone. A pair of backup rings


31


,


32


is disposed below the upper cone


30


and includes tapered surfaces that allow the backup rings to be displaced toward the casing


14


during “setting” of the packer into a sealing position. A seal ring


33


is disposed below the backup ring


32


. A deformable packing element


34


is disposed below the seal ring


33


and is typically an elastomeric material that can be axially compressed and radially expanded toward the casing


14


to effect a seal. A corresponding arrangement of elements is disposed below the packing element


34


as is disposed above the packing element. The arrangement of members below the packing element includes a seal ring


35


, a pair of backup rings


36


,


37


, a lower cone


38


having a tapered surface


42


, and a lower slip


39


having wickers


40


.




To set the packer


23


, mechanical or hydraulic methods can be used and are well known in the art. Regardless of the method used to set the packer, generally the objective is to lower the packer attached to a tubing string to a setting depth and axially compress the assembly of external components relative to the packer body. The axial compression causes at least a portion of the external components, such as the slips


28


,


39


and the packing element


34


, to expand radially outward into engagement with the casing


14


. The lock ring housing


26


and the lock ring


43


are forced along the ridge portion


25


of the packer body


24


as the slips and the packing element are radially expanded. When the desired amount of longitudinal compression is reached, the ridges on the ridge portion


25


in cooperation with the ridges


27


on the lock ring


43


maintain the lock ring and the lock ring housing


26


in the set position. The wickers


29


,


40


of the slips


28


,


39


“bite” into the casing surface to hold the packer


23


in position.




Elastomeric materials are frequently used for the packing element


34


and other sealing elements because of the resiliency of the elastomeric materials. However, under certain adverse conditions, elastomeric elements may be insufficient for the duty. Adverse conditions such as high temperatures, high pressures, and chemically hostile environments are common in downhole oil field wells that produce hydrocarbons. For example, the temperatures and/or pressures can cause extrusion of elastomeric elements and can result in leakage past the packer after installation. Another problem associated with elastomeric elements is “swab off”, where a pressure differential between two surfaces of the elastomeric element, such as the inner and outer surfaces, can deform the element and cause the element to become dislodged from the tool during run-in.




Providing a ductile metal as the packing element has been suggested as one solution to the failure of elastomeric elements. Thus, a “metal to metal” contact is theoretically made between, for example, the packing element and the casing inside diameter that is less prone to extrusion under such adverse circumstances. However, typical manufacturing tolerances of the casing leading to nonconformities, such as the casing ovality, typically reduce the sealing capabilities of the metal to metal contact and leakage can result. Further, even if an initial seal occurs, the seal may leak under changing conditions of temperature and/or pressure, because the metal is not sufficiently resilient.




Prior efforts, such as shown in U.S. Pat. No. 2,519,116, incorporated herein by reference, to effect metal to metal contact have employed detonating explosive charges disposed on a rod within a packer cavity to expand an outer ductile metal wall of the packer. The expanded metal wall engages the casing and forms a metal to metal contact. However, once deformed from the explosion, the cavity is no longer able to expand to meet changing conditions.




Further, U.S. Pat. No. 2,306,160, also incorporated herein by reference, teaches a fluid injected into a cavity to inflate the cavity and effect a seal. The reference discloses that suitable liquid materials injected into the cavity are those liquids which harden after expansion and, thus, are unable to meet changing conditions.




Therefore, there remains a need for a metal sealing assembly with increased sealing capabilities and sufficient resiliency, particularly under adverse conditions in an oil field well.




SUMMARY OF THE INVENTION




The invention generally provides a sealing assembly with a deformable portion and a core at least partially disposed within the deformable portion that can be radially expanded to engage an adjacent surface and effect a seal. In one embodiment, the core is a fluid-containing core that preferably comprises a compressible fluid and the deformable portion comprises a deformable metal. The core can retain an amount of stored energy and adjust to changing conditions that otherwise might affect the seal integrity. The core can be sealed within the deformable portion and can be compressed by a force applied to the deformable portion to cause radial expansion. The core can also be coupled to a piston which can apply a force to fluid within the core to cause the radial expansion necessary to effect sealing. An elastomeric member can be attached to the deformable portion to assist in sealing.




In one aspect, the invention provides a sealing assembly comprising a deformable portion and a fluid-containing core that deforms the deformable portion toward a surface and retains a quantity of stored energy for further deformation. In another aspect, the invention provides a method of sealing between two surfaces comprising positioning a sealing assembly adjacent a surface, increasing a pressure of a fluid in a fluid-containing core in the sealing assembly, deforming a deformable portion of the sealing assembly toward the surface, engaging the surface, and retaining an amount of stored energy in the core after engaging the surface. In another aspect, the invention provides a packer for use in a wellbore comprising a deformable portion and a fluid-containing core within the deformable portion that radially expands the deformable portion in the wellbore. The core can retain stored energy after the radial expansion occurs. In another aspect, the invention provides a sealing assembly comprising a deformable portion and a core that expands the deformable portion toward a surface and retains a quantity of stored energy for further deformation. In another aspect, the invention provides a sealing assembly comprising a deformable portion, a fluid-containing core disposed at least partially within the deformable portion, and a piston in communication with the fluid-containing core.











BRIEF DESCRIPTION OF THE DRAWINGS




So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.




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.





FIG. 1

is a schematic view of a typical downhole well having at least one packer.





FIG. 2

is a schematic cross sectional view of a typical packer.





FIG. 3

is a schematic cross sectional view of a sealing assembly.





FIG. 4

is a detail schematic view of a deformable portion shown in FIG.


3


.





FIG. 5

is a schematic cross sectional view of an alternative embodiment of a sealing assembly.





FIG. 6

is a schematic cross sectional view of an alternative embodiment of a sealing assembly.





FIG. 7

is a schematic cross sectional view of an alternative embodiment of a sealing assembly.





FIG. 8

is a schematic cross sectional view of an alternative embodiment of a sealing assembly.





FIG. 9

is a schematic cross sectional view of an alternative embodiment of a sealing assembly.





FIG. 10

is a detail schematic view of an alternative embodiment of a core.











DESCRIPTION OF THE PREFERRED EMBODIMENT




The present invention provides a sealing assembly that can seal against an adjacent surface using deformable materials, such as deformable metal, with a core disposed within the sealing assembly. The invention can be used as a packer downhole in an oil field well and the embodiments described herein relate to such use, although it should be understood that the invention can be used in other applications and is not limited to the exemplary embodiments shown and described.





FIG. 3

is a schematic cross sectional view of a sealing assembly


50


of the invention, such as a packer. The sealing assembly


50


is shown in a running position on the left side of the schematic view and in a set position on the right side of the view. Generally, in this embodiment, the sealing assembly


50


can include various components surrounding a sealing assembly body


51


, such as described in reference to the components shown in

FIG. 2

with the components being similarly numbered. The embodiment shown in

FIG. 3

shows a deformable portion


60


that is disposed generally between the slips


28


,


39


and is described in reference to FIG.


4


.





FIG. 4

is a detail schematic view of the deformable portion


60


. The deformable portion


60


is dimensioned to expand outward toward the casing or other adjacent structure upon axial compression of the core


62


so that the portion


60


engages the casing


14


. The deformable portion


60


can be a metal including metallic substances, such as ductile iron, stainless steel, or a composite, such as a polymer matrix composite or metal matrix composite. Other materials could be high strength polymers, such as polyether-etherketone (PEEK), polyether-ketone and polyamide-imide. In other embodiments, the deformable portion could be disposed radially inward of the packer and effect an inwardly directed seal. For instance, a pipe disposed through an internal portion of the packer can be sealed about the outside diameter of the pipe with a inwardly directed deformable portion.




The core


62


contains a fluid in at least one embodiment. The fluid may be liquid or gaseous, or a combination thereof. The fluids can include a variety of gases, such as nitrogen, argon, carbon dioxide, and other gases, and/or can be a variety of liquids, such as relatively compressible liquids, where silicone oil is one example. Liquids as used herein include gels. The fluid can also include a solid that becomes a fluid at the operating conditions surrounding the sealing assembly


50


, including, for example, a solid having a low melting temperature. The fluid can also be formed from gases created from a chemically activated reaction between two or more substances. The fluid in the core


62


can also be expanded by a timed or temperature activation with or without a controller, described more fully in reference to FIG.


6


.




Preferably, the fluid, or combination of fluids, is compressible to create a potential or stored energy in a compressed state. While liquids are typically considered incompressible, liquids exhibit compressible characteristics depending on the pressure or force exerted on the fluid. Further, some liquids are more compressible than other liquids. For example, silicone oil, used in the oil field industry, is known to be several times more compressible than water and, thus, would have a greater stored energy at a given compressive force. In a compressed condition, the liquid retains an amount of stored potential energy that can be released to further expand the deformable portion after the initial expansion of the metal, should conditions change that affect the seal integrity between the sealing assembly and adjacent surface. Furthermore, when the core contains a compressible gaseous portion, the compressed gases can also store a quantity of energy that can likewise be used to further expand the deformable portion. The deformable portion can also contract if necessary, thereby compressing the fluid in the core, due to changing conditions in the wellbore


12


, tubing string


18


(shown in

FIG. 1

) and/or other components that can affect the seal.




An additional seal can be established by compressing an elastomeric member


65


, such as a rubber-containing compound, with the deformable portion


60


against the casing


14


. The elastomeric member


65


can be bonded or otherwise attached to the deformable portion


60


. The term “elastomeric” is broadly defined and can include other deformable materials that exhibit some resiliency after compression. If an elastomeric member is used, preferably the elastomeric material is at least partially disposed between various deformable portions which engage the casing, thus, “trapping” the elastomeric member therebetween. For instance, the elastomeric member


65


can be disposed longitudinally between ridges


63


and


64


. When the ridges are expanded toward the casing


14


, at least a portion of the elastomeric member


65


is disposed radially between the casing and the deformed metal, and longitudinally between the ridges. The longitudinal extrusion of the elastomeric member is thus minimized.




The size of the core


62


varies depending on the needed expansion of the deformable portion


60


. For example, the sealing assembly


50


with the core can be a production packer that typically is a substantially permanent packer disposed adjacent or between production zones in a production well and engages a tubing string and the casing. The sealing assembly can be also be a liner top packer that is used to “pack off” an annulus between a casing and a liner. A liner top packer typically has a greater expansion need compared to the production packer, due to greater distances between a liner and a casing. The sealing assembly can also be a service packer that is used to temporarily isolate zones of a production well to perform maintenance on the well and thus is designed to be removable. Plugs and other seals can also use the expandable sealing assembly.




Further, the interface between the body


51


, shown in

FIG. 3

, and the deformable portion


60


can be sealed with seals


46


,


48


, such as O-rings. Corresponding grooves in either the body or the deformable portion can be formed to support the seals.




In some embodiments, the slips


28


,


39


with associated gripping surfaces can be included with the deformable portion


60


, in

FIGS. 3 and 4

.

FIG. 5

is a schematic cross sectional view of such an alternative embodiment of a sealing assembly


66


. The sealing assembly


66


includes a sealing assembly body


51


disposed along a tubing string or liner (shown in

FIG. 1

) or near the end of the tubing string. A lock ring housing


67


is disposed at an upper end of the sealing assembly body


51


and is coupled to a lock ring


79


. The lock ring


79


has ridges, similar to ridges


27


shown in

FIG. 3

, and engages ridges on a ridge portion of the sealing assembly body


51


. In this embodiment, an upper retainer ring


70


is disposed below the lock ring housing


67


and above a deformable portion


71


. The deformable portion


71


includes a core


72


, similar to the core


62


, shown in FIG.


3


. Gripping surfaces


73


,


74


are disposed on the deformable portion


71


and face the inside surface of the casing


14


. Alternatively, the gripping surfaces


73


,


74


could be separate members disposed adjacent the deformable portion


71


. A lower retainer ring


75


is disposed below the deformable portion


71


and a lower support


78


is disposed below the ring


75


to support the ring longitudinally along the sealing assembly


66


. An elastomeric member


81


, disposed longitudinally between ridges


80


and


82


is coupled to the exterior surface of the deformable portion


71


.




When the sealing assembly body


51


is held in place and the lock ring housing


67


is pushed down, the lock ring


79


is moved down toward the lower support


78


, which compresses the various parts disposed therebetween. The movement also axially compresses the deformable portion


71


and the core


72


, so that the deformable portion expands radially toward the casing


14


or other adjacent surfaces. The gripping surfaces


73


,


74


also expand radially and engage the casing


14


as the deformable portion


71


expands radially, thereby fixing the sealing assembly in position.





FIG. 6

is a schematic cross sectional view of an alternative embodiment of the sealing assembly. Similar elements as shown in

FIGS. 3-5

are similarly numbered and have been described above. In the embodiment shown in

FIG. 6

, the upper cone


30


and the lower cone


38


may extend to the seal rings


33


,


35


respectively. The sealing assembly


50


includes a controller


85


, shown schematically, that can be coupled to the core


62


, such as through a connection


86


, such as a pneumatic, electrical or hydraulic connection. The controller


85


can be located on the inside of the sealing assembly body


51


, at remote locations such as the well surface or downhole near other equipment or other locations as appropriate. The controller


85


can also be located within the core


62


. The controller


85


can control the expansion of the core


62


and thus the expansion of the deformable portion


60


. The connection


86


can be an electrical wire, a conduit for transmission of liquids, chemicals, gases, or other activating elements through which the core


62


is activated to expand. Without limitation and as merely one example, the controller can include a timer that activates an electrical charge to the core


62


. The core


62


can contain an electrically sensitive material that changes upon electrical stimulation to produce a compressible fluid, such as a gas, in the core


62


as described herein, for example, electrically thixotropic materials. As another example, the controller can receive remote signals through acoustic, electrical or pressure transmission to actuate the core


62


. The controller


85


can also receive signals directly, for example, from a wireline instrument inserted downhole and coupled to the controller. The controller


85


can also provide pneumatic or hydraulic pressure into the core


62


to expand or contract the core through the connection


86


.





FIG. 7

is a schematic cross sectional view of another embodiment of a sealing assembly


52


. Similar elements, shown in

FIGS. 3-6

, are similarly numbered and have been described above. While the gripping surfaces


73


,


74


are shown coupled to the deformable portion


71


, it is understood that the gripping portions can be separate or can be similar to the slips shown in

FIGS. 3 and 6

. In some embodiments, the gripping portions may not be used at all. The embodiment shown in

FIG. 7

includes one or more flow members


83


, such as a check valve, disposed between the core


72


and internal bore


54


of the sealing assembly


52


. The check valve allows fluid in the internal bore of the sealing assembly to flow into the core


72


and restrict the flow of the fluid out of the core


72


. In some embodiments, the flow member


83


could be a solenoid actuated valve that opens and closes upon activation. In other embodiments, the flow member could simply be a port to allow fluid into and out of the core


72


.




As merely one example of an operation using the embodiment shown in

FIG. 7

, the sealing assembly


52


, such a packer, could be positioned downhole inside a casing of a wellbore. An internal sealing assembly


84


, such as a plug, could be inserted downhole with the use of a wireline instrument (shown schematically in dashed lines) and seal the inside bore


54


of the packer. Fluid could be pumped downhole through tubing


18


attached to the packer. The fluid could flow though the flow member


83


, into the core


72


, and expand the deformable portion


71


toward the casing


14


. The flow member


83


could restrict backflow of the fluid from the core


72


into the internal bore


54


to maintain a pressure in the core when the plug is removed. Alternatively, the fluid could be contained in a conduit, such as a hydraulic line, and delivered to the core


72


.





FIG. 8

is a schematic cross sectional view of a sealing assembly


87


. Similar elements are similarly numbered as those elements shown and described in

FIGS. 3-7

. In the embodiment shown in

FIG. 8

, a core


88


includes a material


89


that expands radially and still retains stored energy for further expansion and contraction. The material


89


can include, without limitation, expandable foam. The expansion of the foam can be activated downhole by a controller, such as the controller


85


, shown in FIG.


6


. The material


89


can include various elastomeric materials that likewise can be radially expanded toward an adjacent surface, such as a casing


14


, shown in FIG.


6


.




The material


89


can also include various shape memory alloys that can have an original shape under a first condition, be deformed to a second shape under a second condition, and then return to the original shape when the first condition is reestablished. Some shape memory alloys are temperature dependent and will return to a given shape based upon the reestablishment of a given temperature. Shape memory alloys include, for example, nickel/titanium alloys, such as “NITINOL™”, and certain two phase brass alloys. As one example, in the core


88


, the shape memory alloy material can be shaped to a compressed shape at a given condition, such as a first temperature, and an expanded shape at another condition, such as an elevated second temperature. The temperature of the memory material can kept temporarily lower than the second temperature as the sealing element


87


is inserted downhole to an appropriate location. Then, the temperature of the core can be raised to the second temperature, so that the core expands.





FIG. 9

is a schematic cross sectional view of an alternative embodiment of a sealing assembly


90


having a piston in communication with fluid in the core.

FIG. 9

shows the sealing assembly


90


disengaged with an adjacent surface on the left side of the figure and engaged on the right side. Elements similar to

FIGS. 3-8

are similarly numbered. The sealing assembly


90


includes a sealing assembly body


91


disposed between tubing joints, similar to the sealing assembly body


51


, shown in

FIGS. 3-7

. An actuator


98


is disposed adjacent the sealing assembly body


91


and is used to axially move the components of the sealing assembly


90


by mechanical, hydraulic, electrical, chemical or other modes well known in the art. The actuator


98


can be remotely controlled or directly controlled through, for example, a wireline inserted downhole. The actuator can be activated similar to the activation of controller


85


, shown in

FIG. 6. A

lock ring housing


97


that includes ridges


101


is disposed below the actuator


98


and is engaged to a lock ring


103


having ridges. The lock ring


103


is engaged with corresponding ridges on a ridge portion


105


of the sealing assembly body


91


and assists in locking the lock ring housing


97


in position when the sealing assembly


90


is “set”. The lock ring housing


97


is coupled to one or more pistons


92


that engage a deformable portion


71


. The deformable portion


71


is disposed about the sealing assembly body


91


and includes a fluid-containing core


96


formed therein. The piston


92


is disposed at least partially in a channel


93


of the sealing assembly


90


where the channel


93


is coupled to the core


96


. The channel


93


can include a constricted portion


95


to receive a tapered portion


99


of the piston


92


. One or more annular seals


94


are disposed around the piston


92


and assist in retaining fluid in the core


96


from leaking past the piston


92


. The piston


92


can have a variety of shapes, such as a concentric piston disposed in a circular channel


93


. An elastomeric member


81


can be attached to the outer surface of the deformable portion


71


and assists in resiliently engaging the casing


14


when the sealing assembly is “set.” A lower portion of the deformable portion


71


abuts a shoulder


102


in the sealing assembly body


91


. A slot


104


is formed between the deformable portion


71


and the sealing assembly body


91


. A seal


100


is disposed in the slot


104


and seals between the deformable portion


71


and the sealing assembly


91


. Gripping surfaces


73


,


74


are optionally included with the sealing assembly


90


and can engage an adjacent surface, such as the casing


14


, by expanding the core


71


, as described herein. Alternatively, separate slips with gripping surfaces can be used, such as shown in

FIGS. 3 and 6

.




In operation, the actuator


98


can use mechanical forces to “set” the sealing assembly


90


by forcing the lock ring housing


97


downward toward the piston


92


. The lock ring housing


97


moves axially and presses the piston


92


toward the core


96


, thereby increasing pressure in the core. The deformable portion


71


can be relatively thin adjacent the core


96


and relatively thick on either end from the core. The deformable material adjacent the core deforms from the increased core pressure and radially expands the deformable portion


71


toward the casing


14


. In this embodiment, the elastomeric member


81


is pressed against the casing


14


by the deformable portion


71


to assist in sealing against the casing. Similarly, the gripping surfaces


73


,


74


are engaged with the casing


14


to longitudinally secure the sealing assembly


90


in position. The piston


92


can be displaced along the channel


93


until the piston engages the constricted portion


95


in the channel, whereupon the piston lodges in position and seals the channel


93


. Further, the lock ring housing


97


and lock ring


103


engage the ridge portion


105


of the sealing assembly body


91


and longitudinally fix the piston in the channel


93


. Alternatively, the piston


92


can be spring-biased in the channel and “float” to compensate for changes in the pressure of the core


96


.




Other variations of the embodiments shown in FIG.


9


and other figures are possible. For example, the actuator


98


can be disposed below the lock ring housing


97


. The lock ring housing


97


can directly contact the ridge portion


105


of the sealing assembly body


91


without the lock ring


103


. Alternatively, the actuator can be a remote power source, such as a hydraulic cylinder, incorporating the piston


92


therein for pressurizing a fluid in communication with the fluid in the core


96


for expansion thereof. Slips, retainer rings, backup rings, and seal rings can also be used, such as described in reference to

FIGS. 3 and 6

. Further, the piston


92


can be an annular piston surrounding the sealing assembly body


91


and disposed in an annular channel.





FIG. 10

is a detail schematic view of an alternative embodiment of a core, such as the core


62


shown in

FIG. 3

, although the core can be used in various other embodiments described herein.

FIG. 10

shows a core


62


disengaged from an adjacent surface on the left side of the figure and engaged on the right side. Elements similar to

FIG. 3

are similarly numbered. The core


62


includes two or more compartments


62




a


,


62




b


. Compartment


62




a


contains a first chemically reactive fluid and compartment


62




b


contains a second chemically reactive fluid. The compartments are fluidicly separated by a separable member


61


. The chemically reactive fluids react to form an expansive mixture when mixed together that is greater than the volume of the sum of the fluids in an unreacted state. The separable member


61


can be a flexible membrane stretched across the core, a brittle material or other materials. Regardless of the material, the separable member


61


generally seals the compartments from each other when the core is uncompressed.




In operation, the core is compressed generally axially and expands radially. As the distance between the walls of the core lengthens from the radially expansion, the separable member


61


is placed in tension and breaks or tears away or otherwise separates from the wall or walls or the member itself separates into two or more portions


61




a


,


61




b


. The displaced member


61


allows the chemically reactive fluids to mix which causes an increased volume and/or pressure. The core


62


expands generally radially and engages the casing


14


or other adjacent surface. The quantity of the chemically reactive fluids when mixed can be sufficient to provide an amount of stored energy within the core after the core has expanded against the casing.




Variations in the orientation of the sealing assembly, slip(s), seal(s), cone(s), packer, elastomeric member(s), core(s), and other components are also possible. Further, while the sealing assembly is preferably used as a packer, it is understood that the embodiment(s) of a packer is exemplary. The invention may be used in a variety of sealing applications. Further, actuation of the packer and/or sealing assembly can vary and can include mechanical, hydraulic, chemical, or other types of actuation. Additionally, all movements and positions, such as “inside”, “outside”, “radially”, “longitudinally” and “axially”, described herein are relative and accordingly, it is contemplated by the present invention to orient any or all of the components to achieve the desired movement of the deformable portion against surfaces whether in a direction inwardly or outwardly, radially, longitudinally or axially. For example, the expansion radially can be either outward to a larger circumference or inward toward a smaller inner circumference of an annular hole. Furthermore, while embodiments are shown that compress axially and expand radially, it is understood that other directions could be used and be within the scope of the invention, such as but not limited to, compression radially and expansion axially or compression at an angle and expansion radially and/or axially.




While foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.



Claims
  • 1. A sealing assembly for use in a wellbore, comprisinga) a deformable portion; and b) a fluid core comprising a relatively compressible fluid substantially enclosed within the deformable portion, the deformable portion to be initially deformed into contact with one or more adjacent surfaces within said wellbore, and the fluid core subsequently having sufficient stored energy to deform the deformable portion.
  • 2. The sealing assembly of claim 1, wherein the sealing assembly further comprises a packer.
  • 3. The sealing assembly of claim 1, wherein the deformable portion comprises a metal.
  • 4. The sealing assembly of claim 1, wherein the fluid comprises a liquid portion and a gaseous portion.
  • 5. The sealing assembly of claim 1, wherein the deformable portion expands in a radial direction under an axial force applied substantially perpendicular to the radial direction.
  • 6. The sealing assembly of claim 2, wherein the packer further comprises an elastomer member attached to the deformable portion.
  • 7. The sealing assembly of claim 1, wherein the sealing assembly further comprises an annular shape, and the deformable portion expands primarily radially inward from the sealing assembly.
  • 8. The sealing assembly of claim 1, wherein the sealing assembly further comprises an annular shape, and the deformable portion expands primarily radially outward from the sealing assembly.
  • 9. The sealing assembly of claim 1, wherein the core is sealed in the deformable portion.
  • 10. The sealing assembly of claim 1, further comprising a piston in communication with the core for pressurizing the fluid.
  • 11. The sealing assembly of claim 1, further comprising a piston at least partially disposed in the core.
  • 12. The sealing assembly of claim 11, wherein the piston is annularly shaped and axially aligned with the core.
  • 13. The sealing assembly of claim 11, further comprising an actuator that moves the piston toward the core to increase the pressure of the fluid.
  • 14. The sealing assembly of claim 13, further comprising a controller connected to the actuator.
  • 15. The sealing assembly of claim 11, further comprising a seal disposed about the piston.
  • 16. The sealing assembly of claim 1, wherein the core contains a quantity of stored energy.
  • 17. The sealing assembly of claim 1, wherein the core is sufficiently resilient for further reformation.
  • 18. The sealing assembly of claim 1, wherein the core comprises a shape memory material.
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