WO2014108692A2 - Ensemble joint expansible pour outil de fond de trou - Google Patents

Ensemble joint expansible pour outil de fond de trou Download PDF

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Publication number
WO2014108692A2
WO2014108692A2 PCT/GB2014/050063 GB2014050063W WO2014108692A2 WO 2014108692 A2 WO2014108692 A2 WO 2014108692A2 GB 2014050063 W GB2014050063 W GB 2014050063W WO 2014108692 A2 WO2014108692 A2 WO 2014108692A2
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WO
WIPO (PCT)
Prior art keywords
seal assembly
component
seal
primary component
expandable
Prior art date
Application number
PCT/GB2014/050063
Other languages
English (en)
Other versions
WO2014108692A3 (fr
Inventor
Mark Buyers
David Glen Martin
Stephen Philip ANDERSON
Original Assignee
Omega Completion Technology Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Omega Completion Technology Limited filed Critical Omega Completion Technology Limited
Publication of WO2014108692A2 publication Critical patent/WO2014108692A2/fr
Publication of WO2014108692A3 publication Critical patent/WO2014108692A3/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/10—Sealing or packing boreholes or wells in the borehole
    • E21B33/12—Packers; Plugs
    • E21B33/1208—Packers; Plugs characterised by the construction of the sealing or packing means
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/10—Sealing or packing boreholes or wells in the borehole
    • E21B33/12—Packers; Plugs
    • E21B33/128—Packers; Plugs with a member expanded radially by axial pressure

Definitions

  • the present invention relates to an expandable seal assembly for a downhole tool.
  • the present invention relates to an expandable seal assembly for a downhole packer.
  • the present invention also relates to a downhole tool, such as a packer, incorporating the expandable seal assembly.
  • wellbore fluids comprising oil and/or gas are recovered to surface through a wellbore which is drilled from surface.
  • the wellbore is lined with metal wellbore-lining tubing, which is known in the industry as 'casing'.
  • the casing serves numerous purposes, including: supporting the drilled rock formations; preventing undesired ingress/egress of fluid; and providing a pathway through which further tubing and downhole tools can pass.
  • the second is the completion phase, in which the well is prepared for production by cleaning the wellbore and installing production tubing extending to surface, through which well fluids are recovered.
  • the third is the production phase, in which well fluids are recovered to surface through the production tubing; this typically involves perforating the wellbore-lining tubing to allow the well fluids to enter the wellbore and flow into the production tubing.
  • intervention activities include stimulating production by injecting water or chemicals into the producing rock formation; operating a downhole valve to close or open flow from a particular zone; and inserting a straddle to bridge across a deteriorated or corroded section of the wellbore-lining tubing.
  • the packer includes an expandable seal element of a material having a relatively low modulus of elasticity, and which is typically of a suitable elastomeric material.
  • the seal element is mounted on a tubular mandrel of the packer, and is compressed by applying an axially directed force on the seal element. This expands the seal element radially outwardly, to bridge the radial gap between the packer mandrel and an internal surface of the tubing in which the packer is located, or conceivably against the wall of the drilled wellbore.
  • Conventional packer seal elements have a main or central portion which is of a relatively low modulus of elasticity, the central portion performing the primary seal function when the seal element is radially expanded.
  • the material adjacent the axial ends of the seal elements is of a higher modulus of elasticity than that of the central portion, to resist axial extrusion of the seal element under load.
  • So-called 'garter springs' are moulded into the axial ends of the seal element. These consist of an outer helical spring wound in a first direction, and an inner helical spring wound in a second direction and located within the outer spring. The garter springs perform two main functions.
  • the first is to provide additional stiffness, in an effort to resist axial extrusion of the relatively soft central portion of the seal element along the wellbore, which can lead to seal failure.
  • the second is to provide an elastic restoring force, to facilitate return movement of the seal element to an unexpanded configuration when the packer is to be removed from the wellbore.
  • Packer seal elements of this type suffer from a number of disadvantages. Chief amongst these is that, when the seal element is expanded, the garter springs are expanded, opening up the spring coils. The elastomeric material forming the seal element has a tendency to extrude into the spring coils, and can hamper retraction of the seal element. In addition, the inner and outer springs, although wound in opposite directions, can still become entangled and so again hamper retraction. Another significant disadvantage is that the relatively soft material forming the bulk of the seal element, which bridges the radial gap, still has a tendency to extrude axially along the wellbore under the high fluid pressure forces which the packers experience during use. This can lead to packer failure, and so fluid migration past the packer seal element, and can also further hamper retraction.
  • the packer can become lodged in the wellbore, requiring the packer to be drilled or milled out, for example using an overshot tool which passes around the packer and mills away the seal element.
  • an expandable seal assembly for a downhole tool comprising:
  • seal component of a second material having a modulus of elasticity which is less than that of the first material, the primary component being at least partially encased within the seal component;
  • an expandable seal assembly for a downhole tool comprising:
  • an elastically deformable primary load bearing component of a first material and a seal component of a second material having a modulus of elasticity which is less than that of the first material, the primary load bearing component being at least partially encased within the seal component;
  • the seal assembly in which, in use, the seal assembly is radially expandable between an unexpanded configuration where the seal component is out of contact with a downhole surface, and an expanded configuration where the seal component sealingly abuts the downhole surface;
  • the seal assembly of the present invention provides numerous advantages over prior seal assemblies. These may include that the primary component can be arranged to bear a majority of the loading on the seal assembly during use. As the primary component is of a first material having a modulus of elasticity which is greater than that of the second material forming the seal component, the primary component may provide a primary resistance to axial extrusion of the seal assembly. In simple terms, this is because the primary component is of a material which is harder than that of the seal component. This is achieved without compromising sealing performance, as the seal which is formed with the downhole surface is between the softer, second material of the seal component and the downhole surface.
  • movement of the seal assembly to the expanded configuration causes the inner diameter of the seal assembly to increase (as the inner diameter of the seal assembly in the expanded configuration is greater than that in the unexpanded configuration).
  • This is further facilitated by providing the primary component as an elastically deformable component; the primary component acts to return the seal assembly to the unexpanded configuration in the absence of an applied expansion force.
  • the primary component may therefore be deformable between the unexpanded and expanded configurations in an elastic fashion, so that the component recovers to the unexpanded configuration in the absence of an applied expansion force or load.
  • the seal component of the seal assembly of the present invention can seal by contact with any downhole surface of a suitable shape.
  • the primary component may be a primary load bearing component.
  • the seal assembly may describe an outer diameter, the outer diameter of the seal assembly in the expanded configuration being greater than the outer diameter of the seal assembly in the unexpanded configuration.
  • the seal assembly in particular the primary component, may be arranged so that it deforms uniformly.
  • the assembly in particular the primary component, may describe a main inner diameter which is uniform along a length of the assembly when it is in the expanded configuration, and optionally also in the unexpanded configuration.
  • the primary component may be generally annular in shape.
  • the primary component may be configured so that it circumferentially expands when the seal assembly is moved to the expanded configuration.
  • the primary component may comprise a plurality of slots, channels or the like, each extending between an inner surface of the component and an outer surface of the component, and so which may extend through a wall of the component.
  • Said slots may extend in an axial direction along the component, and may be positioned so that their main axes are disposed generally parallel to a main longitudinal axis of the component.
  • Said slots may open when a force is exerted on the seal assembly to move it to the expanded configuration.
  • Said slots may have a width in a direction around a perimeter of the component, which may be a circumferential width, and the width may increase when the seal assembly is moved to the expanded configuration. The component may therefore circumferentially expand when the seal assembly is moved to the expanded configuration.
  • At least part of said slot which may be a main part, may have a width which is
  • Said slots may be arranged so that, on expansion of the seal assembly, the width increases and may then be non-constant in a direction along at least said main part of the slot.
  • Said slots may extend inwardly from an axial end of the primary component partway along a length of the component, and may terminate in an axially inner end, which may define an expansion node.
  • Each said slot may have opposed sidewalls which extend from the axial end to the respective node, and expansion may occur by at least part of each of said sidewalls pivoting or deflecting about the node. The sidewall may pivot or deflect in a scissors-fashion about the node.
  • the node may effectively form a root of the slot, and expansion may occur by pivoting/deflecting of said part of the sidewalls from the root so that the sidewalls diverge in a direction away from the root.
  • Each node may have a wall which is curved, and which may have a substantially constant radius of curvature, the node wall communicating with the slot or channel sidewall. Providing a node wall which has such a substantially constant radius of curvature results in the node being generally circular, which may reduce stress concentrations under load.
  • the primary component may comprise first and second sets of slots or channels, each set comprising a plurality of slots or channels, said slots of the first set extending inwardly from a first axial end of the component, and said slots of the second set extending inwardly from a second axial end of the component opposite to the first end. Said slots of the first set may axially overlap said slots of the second set.
  • the slots or channels of the first and second sets may be circumferentially spaced around the component.
  • the slots or channels of the first set may be spaced alternately between slots or channels of the second set around the circumference of the component.
  • the seal assembly may comprise at least one load surface which is shaped to cooperate with a corresponding load surface on an actuation member of the downhole tool, for moving the seal assembly to the expanded configuration.
  • the at least one load surface may be inclined relative to a longitudinal axis of the component. This provides the advantage that axial movement of the actuation member acts to urge the seal assembly radially outwardly to bring the seal component into contact with the downhole surface. This can be achieved whilst maintaining sliding contact between the load surfaces on the seal assembly and on the actuation member.
  • the at least one load surface may be a tapered or chamfered surface, and may extend in an axial direction from an axial end of the component.
  • the seal assembly may comprise a first load surface extending from a first axial end thereof, and a second load surface extending from a second axial end thereof which is opposite to the first end.
  • the load surface may incline/taper from the end of the seal assembly in such a way that the inner diameter described by the load surface decreases in a direction along the component from the end.
  • the at least one load surface may be defined by the primary component, and the seal component may extend over or cover said load surface. This may serve for sealing between the seal assembly and the downhole tool, the seal being formed between the seal component on said load surface and the
  • the primary component may have an axial length, and the component may be configured such that the length remains substantially constant during movement of the seal assembly from the unexpanded configuration to the expanded configuration.
  • the unexpanded configuration which is referred to is one in which the seal component of the seal assembly is out of contact with the downhole surface in question, and in which the seal assembly describes the smaller inner diameter.
  • the unexpanded configuration may or may not be a rest configuration of the seal assembly, that is a configuration which the seal assembly takes in the absence of an applied external force, such as may be imparted on the seal assembly when it is mounted on the downhole tool.
  • the primary component may experience an insignificant change in axial length on movement of the seal assembly to the expanded configuration. It will be understood that the change in axial length may depend on factors including the extent of the radial expansion of the component when the seal assembly is moved to the expanded
  • the seal assembly may have an axial length, and the primary component may extend along substantially the entire length of the seal assembly. This may provide the advantage that the primary component can provide primary resistance to axial extrusion of the seal assembly under applied load.
  • the seal component In the unexpanded configuration of the seal assembly, the seal component may extend into said slots in the primary component. The seal component may extend through said slots so that said slots are entirely filled by the material of the seal component. The presence of seal component material in said slots in the unexpanded configuration may avoid difficulties in returning the seal assembly to the unexpanded configuration.
  • the second material may be selected to have a modulus of elasticity which results in the seal component exerting a restorative force which tends to urge the seal assembly towards the unexpanded configuration when an expansion force is removed.
  • the primary component being at least partially encased within the seal component.
  • the primary component may be entirely encased within the seal component, such that an entire external surface (or surfaces) of the primary component is/are covered by the seal component.
  • the seal assembly may be arranged so that at least part of a surface (or surfaces) of the primary component remains uncovered by the seal component. At least part of a radially inner surface of the primary component may be uncovered. This may facilitate movement of the seal assembly between the unexpanded and expanded configurations, in that it may facilitate relative movement between the seal component and the primary component.
  • the material forming the seal component may move along or within the slots in a radial direction during expansion/contraction.
  • the seal assembly may have first and second axial ends each describing respective piston faces having corresponding piston areas.
  • a proportion of the piston area defined by the first and second axial ends may be described by portions of the seal component which are not axially supported under load by the primary component. Said proportion will typically be less than for an equivalent conventional (rubber/elastomeric) packer seal, which has a piston area dictated by the tubing inner diameter (ID) and mandrel outer diameter (OD), that is the seal assembly has a smaller piston area as it does not require to seal on or against an outer surface of a sealing mandrel.
  • the primary component may be of a material selected from the group comprising metals, metal alloys and plastics materials.
  • the seal component may be of an elastomeric or rubber material.
  • the modulus of elasticity of the primary component may be in the range of around 180 GPa to around 200 GPa.
  • the modulus of elasticity of the seal component may be in the range of around 0.01 GPa to around 0.1 GPa.
  • a downhole tool comprising at least one expandable seal assembly according to the first or the second aspect of the invention.
  • the downhole tool may be a packer or a straddle or similar products.
  • the downhole tool may comprise a plurality of said seal assemblies, which may be spaced axially along a length of the tool.
  • the at least one seal assembly may be mounted on a main body of the downhole tool, and the downhole tool may comprise at least one actuation member which is moveable relative to the main body to urge the seal assembly to the expanded configuration.
  • the downhole tool may comprise a further actuation member, which may be fixedly or moveably mounted relative to the main body of the tool, and the actuation members may cooperate to urge the seal assembly to the expanded configuration.
  • Said actuation member may comprise the load surface described above in relation to the first/second aspect of the invention.
  • the load surface of the seal assembly may sealingly abut the load surface of the actuation member.
  • each may sealingly abut a respective load surface of first and second actuation members.
  • the seal assembly may seal between the load surface on said actuation member and the downhole surface in question, when the seal assembly is moved to the expanded configuration.
  • the seal assembly may be arranged on the main body of the downhole tool so that, in both the unexpanded and expanded configurations, the primary component axially overlaps the, or each actuation member.
  • the load surface of the seal assembly may sealingly abut the load surface of the actuation member in both the unexpanded and expanded configurations.
  • Fig. 1 is a schematic side view of a downhole tool, comprising at least one expandable seal assembly, according to an embodiment of the invention
  • Fig. 2 is an enlarged view of the seal assembly of Fig. 1 , in which the downhole tool has been longitudinally sectioned;
  • Fig. 3 is a view similar to Fig. 2, but showing the downhole tool following actuation, in which the seal assembly has been radially expanded;
  • Fig. 4 is a perspective view of the seal assembly of Fig. 1, sectioned and shown prior to expansion, as in Fig. 2;
  • Fig. 5 is a perspective view of the complete seal assembly of Fig. 1, showing hidden detail;
  • Fig. 6 is a perspective view of a primary component of the seal assembly shown in Fig. 1 ;
  • Fig. 7 is a view of the seal assembly of Fig. 1, and of actuation members forming part of the downhole tool.
  • Fig. 1 there is shown a side view of a downhole tool comprising at least one expandable seal assembly, according to an embodiment of the invention, the downhole tool indicated generally by reference numeral 10 and the seal assembly by reference numeral 12.
  • the downhole tool 10 takes the form of a packer.
  • the packer 10 is shown coupled to a string of tubing 14, which has been located in a wellbore 16 that has been drilled from surface and lined with wellbore-lining tubing in the form of a metal casing 18.
  • the casing 18 typically comprises a number of sections of tubing coupled together end-to-end, and has been installed and cemented in the wellbore 16 using cement 20, in a fashion which is well known in the field of the invention.
  • the tubing 14 carrying the packer 10 defines a tool string 15, which has been run-in to the wellbore 16 to carry out a desired downhole function or functions, optionally involving the activation of a tool or tools (not shown) carried by the string.
  • the packer 10 is employed to seal the tubing 14 relative to an inner wall 22 of the casing 18. This is desirable to enable the particular downhole function(s) to be carried out, which may involve supplying a fluid from surface down through the tubing 14, and/or recovering fluid to surface through the tubing.
  • the tool string 15 may be run-in to the wellbore 16 in a number of different ways.
  • the tubing 14 may be coiled tubing extending to surface, on which the packer 10 is mounted.
  • the tubing 14 may be suspended from a slickline at surface which deploys the tool string 15 into and along the wellbore 16.
  • the packer 10 is shown in Fig. 1 with the seal assembly 12 in an unexpanded
  • the tubing 14 is positioned within the casing 18 using a dedicated tubing hanger (not shown).
  • the packer 10 is set by applying 'weight' to the packer after the tubing 14 has been set in (or 'hung' from) the casing 18. This is achieved by exerting an axially directed load on the seal assembly 12, to radially expand it outwardly into contact with the casing inner wall 22. The application of weight to set the packer 10 will be described in more detail below.
  • the seal assembly 12 is better shown in the enlarged view of Fig. 2, in which the packer 10 has been longitudinally sectioned. Fig.
  • FIG. 3 is a view similar to Fig, 2, but showing the packer 10 following actuation, in which the seal assembly 12 has been radially expanded.
  • Fig. 4 is a perspective view of the seal assembly 12, sectioned and shown prior to expansion, as in Fig. 2.
  • Fig. 5 is a perspective view of the complete seal assembly 12, showing hidden detail.
  • the seal assembly 12 generally comprises an elastically deformable primary component 28, which is of a first material, and a seal component 30.
  • the primary component 28 may be a primary load bearing component.
  • the seal component 30 is of a second material having a modulus of elasticity which is less than that of the first material.
  • the primary component 28 is at least partially encased within the seal component 30.
  • the seal assembly 12 is radially expandable between an unexpanded configuration (Fig. 2), where the seal component 30 is out of contact with a downhole surface in the form of the casing inner wall 22, and an expanded configuration (Fig. 3), where the seal component 30 sealingly abuts the casing inner wall 22.
  • the seal assembly 12 describes an inner diameter, and the inner diameter of the seal assembly in the expanded configuration (D E - Fig. 3) is greater than the inner diameter of the seal assembly in the unexpanded configuration (Du - Fig. 2).
  • the seal assembly 12 is mounted on a main body 32 of the packer 10, which is a base pipe or mandrel.
  • the packer 10 comprises a pair of opposed actuation members 34 and 36 which cooperate to urge the seal assembly 12 to the expanded configuration.
  • the actuation member 34 forms an upper (or uphole) actuation member of the pair, and is moveable relative to the packer mandrel 32, to urge the seal assembly 12 to the expanded
  • the actuation member 36 which forms a lower (or downhole) actuation member, may be movable relative to the mandrel 32 to urge the seal assembly 12 to the expanded configuration.
  • both actuation members 34 and 36 may be movable relative to the mandrel 32.
  • the seal assembly 12 is expanded by translating the upper actuation member 34 axially towards the lower actuation member 36. This imparts an axially directed expansion force F (Fig. 3) on the seal assembly 12, to urge it radially outwardly to seal against the casing inner wall 22.
  • the seal assembly 12 comprises at least one load surface and, in the illustrated
  • the embodiment comprises two such load surfaces 38 and 40 at respective first and second axial ends 42 and 44 of the assembly.
  • the load surfaces 38 and 40 are shaped to cooperate with corresponding load surfaces 46 and 48 on the respective actuation members 34 and 36, for moving the seal assembly 12 to the expanded configuration.
  • the load surfaces 38 and 40 of the seal assembly 12 are inclined relative to a longitudinal axis 50 (Fig. 2) of the assembly.
  • the load surfaces 46 and 48 on the packer actuation members 34 and 36 are oppositely inclined, so that axial movement of the upper actuation member 34 acts to urge the seal assembly 12 radially outwardly, to bring the seal component 30 into contact with the casing inner wall 22.
  • the load surfaces 38 and 40 of the seal assembly 12 are effectively tapered, and extend in axially inward directions from the respective ends 42 and 44.
  • the load surfaces 38 and 40 incline in such a way that the inner diameter described by the load surfaces decrease in a direction along the assembly 12 from the respective end 42, 44.
  • the seal component 30 extends over the entire load surfaces 38, 40 and serves for sealing between the seal assembly 12 and the corresponding load surfaces 46 and 48 on the packer actuation members 34 and 36. In use, and following expansion of the seal assembly 12, the assembly seals between the load surfaces 46 and 48 on the packer actuation members 34 and 36, and the casing inner wall 22.
  • the seal assembly 12 is arranged on the packer mandrel 32 so that, in both the unexpanded and expanded configurations, the primary component 28 axially overlaps each actuation member 34, 36.
  • the primary component 28 bears a majority of the loading on the seal assembly 12 during use.
  • the primary component 28 is of a first material having a modulus of elasticity which is greater than that of the second material forming the seal component 30, the primary component 28 resists axial extrusion of the seal assembly 12. In simple terms, this is because the primary component 28 is of a material which is harder than that of the seal component 30. This is achieved without compromising sealing performance, as the seal which is formed with the casing inner wall 22 is between the softer, second material of the seal component 30 and the wall 22. As can be seen from Figs. 2 and 3, movement of the seal assembly 12 to the expanded configuration causes the inner diameter of the seal assembly to increase, from Du to D E , the inner diameter of the seal assembly 12 in the expanded configuration being greater than that in the unexpanded configuration.
  • Fig. 6 is a perspective view of the primary component 28
  • Fig. 7 is a view of the seal assembly 12 and the packer actuation members 34 and 36, shown separately from a remainder of the packer 10.
  • the seal assembly 12 in particular the primary component 28, is arranged so that it deforms uniformly.
  • the assembly 12 describes an inner diameter which is uniform along a main length of the assembly when it is in the expanded configuration (D E ), and also in the unexpanded configuration (Du).
  • the primary component 28 is generally annular in shape, and configured so that it circumferentially expands when the seal assembly is moved to the expanded configuration.
  • the primary component 28 comprises a plurality of slots, channels or the like, designated by numerals 56 and 58.
  • Each slot 56, 58 extends between inner and outer surfaces 60, 62 of the component 28, and so extends entirely through a wall 64 of the component.
  • the slots 56 and 58 also extend in an axial direction along the component 28, and are positioned so that their respective main axes 66 and 68 are disposed generally parallel to a main longitudinal axis 70 of the component, in the unexpanded configuration.
  • the primary component 28 actually comprises a first set of the slots 56, each of which extends inwardly from a first axial end 72 of the component, and a second set of the slots 58, each of which extends inwardly from a second axial end 74 of the component.
  • the slots 56 of the first set axially overlap the slots 58 of the second set, and the slots 56 and 58 are alternately circumferentially spaced around the circumference of the component 28.
  • the slots 56, 58 open when a force is exerted on the seal assembly 12 to move it to the expanded configuration, and each have a circumferential width W which increases when the seal assembly is moved to the expanded configuration.
  • the component 28 therefore circumferentially expands when the seal assembly 12 is moved to the expanded
  • Main parts 76 and 78 of the slots 56 and 58 have a width (W) which is substantially constant when the component is in the unexpanded configuration, and the slots are arranged so that, on expansion of the seal assembly 12, the width increases and is then non-constant in a direction along at least said main parts.
  • the slots 56 and 58 extend inwardly from the axial ends 72, 74 of the component 28 partway along a length of the component, and terminate in axially inner ends 80 and 82, which define expansion nodes.
  • the slots 56 each have opposed sidewalls 84 which extend from the axial end 72 to the respective node 80, and the slots 58 similarly each have opposed sidewalls 86 which extend from the axial end 74 to the respective node 82. Expansion occurs by at least part of each of said slot sidewalls 84, 86 pivoting or deflecting about the respective nodes 80, 82.
  • the sidewalls 84, 86 pivot or deflect in a scissors-fashion about the nodes 80 and 82, the nodes effectively forming roots of the slots 56, 58 with expansion occurring by pivoting/deflecting of said part of the sidewalls 84, 86 from the root so that the sidewalls diverge in a direction away from the root.
  • Each node 80, 82 has a respective wall 88, 90 which is curved, and which optionally has a substantially constant radius of curvature, the node walls communicating with the slot or channel sidewalls 84, 86.
  • Providing a node wall which has such a substantially constant radius of curvature results in the node being generally circular, which can reduce stress concentrations in the primary component 28 under load.
  • the primary component 28 has an axial length L l5 and is configured such that the length remains substantially constant during movement of the seal assembly 12 from the unexpanded configuration to the expanded configuration. The primary component 28 thus experiences a relatively small change in axial length on movement of the seal assembly to the expanded configuration. It will be understood that the change in axial length may depend on factors including the extent of the radial expansion of the component 28 when the seal assembly 12 is moved to the expanded configuration.
  • the seal assembly 12 has an axial length L 2 , and the primary component 28 extends along substantially the entire length L 2 of the seal assembly. This provides the advantage that the primary component 28 resists axial extrusion of the seal assembly 12 under applied load.
  • the seal assembly 12 has a radial thickness or width T, and the primary component 28 extends across part of the radial thickness T (Fig. 7), the seal component 30 being provided over the component 28, for sealing with the casing inner wall 22.
  • the seal component 30 In the unexpanded configuration of the seal assembly 12, the seal component 30 extends into the slots 56 and 58 in the primary component 28, as best shown in Fig. 4.
  • the seal component 30 can extend completely through the slots 56 and 58, so that the slots are entirely filled by the material of the seal component.
  • the presence of seal component 30 material in the slots 56 and 58 may avoid (or at least restrict) difficulties in returning the seal assembly 12 to the unexpanded configuration.
  • the primary component 28 is typically of a metal, metal alloy or plastics materials.
  • the seal component 30 is typically of an elastomeric or rubber material, the material selected having a modulus of elasticity which results in the seal component 30 exerting a restorative force which tends to urge the seal assembly 12 towards the unexpanded configuration, when an expansion force is removed.
  • Typical moduli of elasticity for the material of the primary component are in the range of around 180 GPa to around 200 GPa.
  • Typical moduli of elasticity for the material of the seal component are in the range of around 0.01 GPa to around 0.1 GPa.
  • the primary component is typically formed by machining a tubular body to form the required slots 56, 58 and inclined surfaces 92 and 94 at the axial ends 72 and 74.
  • the seal component 30 is typically moulded on to the primary component 28 in an 'over-moulding' procedure.
  • the inclined surfaces 92 and 94 of the component 28 form the load surfaces 38 and 40 of the seal assembly 12, when the seal component 30 has been moulded over the component 28.
  • the primary component 28 is partially encased within the seal component 30 so that at least part of the inner surface 60 of the primary component is uncovered. This may facilitate movement of the seal assembly 12 between the unexpanded and expanded configurations, in that it may facilitate relative movement between the seal component 30 and the primary component 28.
  • the material forming the seal component 30 may be capable of movement along or within the slots 56, 58 in the primary component 28, in a radial direction, during expansion/ contraction.
  • the axial ends 72 and 76 of the primary component 28 may be exposed. This may provide hard-stops for contact with, for example, a part of the packer 10 during the expansion process.
  • the first and second axial ends 42 and 44 of the seal assembly each describe respective piston faces 96 and 98, having corresponding piston areas.
  • Fig. 4 shows an external radius Ri and internal radius R 2 of the piston faces 96 and 98, when the seal assembly 12 is in the unexpanded position.
  • the area of each piston face 96 and 98 can be determined by subtracting the area 7t(R 2 ) 2 of a circle having the inner radius R 2 from the area 7t(Ri) 2 of a circle having the outer radius Rj. It will be understood that this is determined according to the point of sealing contact between the load surfaces 38 and 40 of the seal assembly 12 and the load surfaces 46 and 48 of the packer actuation members 34 and 36.
  • a proportion of the piston areas defined by the first and second axial ends 42 and 44 is described by portions of the seal component 30 which are not axially supported under load by the primary component 28.
  • At least part of the piston faces 96 and 98 are defined by the primary component 28. This may provide the advantage that the primary component 28 supports at least part of the load which is exerted on the piston faces 96 and 98 in use, when the seal assembly 12 is in the expanded configuration, due to fluid pressure acting on one or both of said faces. This helps to resist extrusion of the softer seal component 30 in an axial direction along the wellbore 16.
  • the activation member 34 When it is desired to deactivate the packer 10, for example following completion of the desired downhole function(s), the activation member 34 is axially translated back along the packer mandrel 32 towards the start position (Fig. 2). The inherent elasticity of the primary component 28 tends to return the seal assembly 12 to the unexpanded
  • a downhole tool may be provided comprising a plurality of seal assemblies according to the invention, the seal assemblies typically spaced axially along a length of the tool.
  • a straddle in particular may comprise two such axially spaced assemblies which are arranged, when actuated, to isolate a portion of a wellbore-lining tubing (or conceivably an open hole portion of a wellbore) located between the seal assemblies.
  • the primary component being at least partially encased within the seal component.
  • the primary component may be entirely encased within the seal component, such that an entire external surface (or surfaces) of the primary component is/are covered by the seal component.
  • the seal component of the seal assembly of the present invention can seal by contact with any downhole surface of a suitable shape.
  • any desired number or arrangement of slots may be provided in the primary component.
  • the lengths of the slots may be varied.
  • the proportion of the length of the component that the slots extend may be varied.
  • At least one slot may have a different axial length from at least one other slot.
  • the slots extending from the axial ends of the component may be arranged in different patterns and so not spaced alternately around the circumference of the component.
  • the load surface(s) of the component may extend along a different proportion of a length of the component. An angle of incline of the load surface(s) may be varied.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Gasket Seals (AREA)
  • Earth Drilling (AREA)

Abstract

La présente invention concerne un ensemble joint expansible pour un outil de fond de trou, tel qu'un packer de fond de trou, et un outil de fond de trou comprenant l'ensemble joint expansible. Un ensemble joint expansible (12) donné à titre d'exemple comprend un composant principal déformable élastiquement (28) d'un premier matériau, et un composant de joint (30) d'un second matériau présentant un module d'élasticité qui est inférieur à celui du premier matériau. Le composant principal est emboîté au moins partiellement à l'intérieur du composant de joint. Lors de l'utilisation, l'ensemble joint est expansible radialement entre une configuration non expansée dans laquelle le composant de joint n'est pas en contact avec une surface de fond de trou (22), et une configuration expansée dans laquelle le composant de joint bute de manière étanche contre la surface de fond de trou. L'ensemble joint décrit un diamètre interne, le diamètre interne (DE) de l'ensemble joint dans la configuration expansée étant supérieur au diamètre interne (Du) de l'ensemble joint dans la configuration non expansée.
PCT/GB2014/050063 2013-01-14 2014-01-10 Ensemble joint expansible pour outil de fond de trou WO2014108692A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1300621.8 2013-01-14
GB201300621A GB201300621D0 (en) 2013-01-14 2013-01-14 Expandable seal assembly for a downhole tool

Publications (2)

Publication Number Publication Date
WO2014108692A2 true WO2014108692A2 (fr) 2014-07-17
WO2014108692A3 WO2014108692A3 (fr) 2014-11-06

Family

ID=47757942

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2014/050063 WO2014108692A2 (fr) 2013-01-14 2014-01-10 Ensemble joint expansible pour outil de fond de trou

Country Status (2)

Country Link
GB (1) GB201300621D0 (fr)
WO (1) WO2014108692A2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110300835A (zh) * 2016-11-09 2019-10-01 匹克维尔系统私人有限公司 扩展和塌缩设备及其使用方法
US20240209714A1 (en) * 2022-12-22 2024-06-27 Halliburton Energy Services, Inc. Sealing element with sloped ends

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Publication number Priority date Publication date Assignee Title
NO335594B1 (no) * 2001-01-16 2015-01-12 Halliburton Energy Serv Inc Ekspanderbare anordninger og fremgangsmåte for disse
US7363970B2 (en) * 2005-10-25 2008-04-29 Schlumberger Technology Corporation Expandable packer
US20100072711A1 (en) * 2008-09-19 2010-03-25 Baker Hughes Incorporated Expandable metal-to-metal seal
US9429236B2 (en) * 2010-11-16 2016-08-30 Baker Hughes Incorporated Sealing devices having a non-elastomeric fibrous sealing material and methods of using same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110300835A (zh) * 2016-11-09 2019-10-01 匹克维尔系统私人有限公司 扩展和塌缩设备及其使用方法
US11078746B2 (en) 2016-11-09 2021-08-03 Schlumberger Technology Corporation Expanding and collapsing apparatus and methods of use
US20240209714A1 (en) * 2022-12-22 2024-06-27 Halliburton Energy Services, Inc. Sealing element with sloped ends

Also Published As

Publication number Publication date
GB201300621D0 (en) 2013-02-27
WO2014108692A3 (fr) 2014-11-06

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