US20130299191A1 - Long thin structures for generating an entangled flow restricting structure - Google Patents

Abstract

A wire includes a plurality of units. Each unit has a relatively stiff region joined to an intermediate region. The intermediate region has a varying stiffness along its length. The intermediate region is joined to a relatively pliable region.

Description

RELATED APPLICATIONS
• This application claims priority to U.S. Pat. App. 61/646,328, filed May 13, 2012, the entirety of which is incorporated by reference herein.
• The present disclosure relates to wire and leading end structures for injecting into a flow stream to controllably create a flow resistance. The technology disclosed can be used, among other ways, with the techniques described in U.S. Pat. App. 61/646,319, filed May 13, 2012, and co-pending patent application Ser. No. 13/893,152, filed May 13, 2013 by the inventors of the current application. The entireties of both of these applications are hereby incorporated by reference herein.
TECHNICAL FIELD
• The present disclosure relates to shapes, structures, and configurations of continuous media (including but not limited to wire) to promote entanglement in a flowing medium (i.e. liquid, gas, and combination thereof) to create in a controlled manner a flow resistance.
BACKGROUND
• Currently, blowout preventers (BOPs), are the primary safety device for controlling an oil well in the case of an unwanted influx of formation fluids entering the well. When a BOP fails, currently the main recourses are to either inject a “junk shot” below the BOP to plug the flow through the BOP, or drill a relief well to pump in concrete into the well to seal the high pressure region. The junk shot injects (pumps) large quantities of discrete pieces of material (e.g. pieces of rope, balls, etc.) with the intent that some of the materials will hang up on features inside the wellbore and then further bits of junk will build up behind; this approach is difficult because it can suddenly stop the flow and generate a pressure wave that can break the casing rupture disks and fracture the formation thus damaging the well and the reservoir. This can result in the entire reservoir being lost through the casing and fractured formation which then could catastrophically leak to the surface over a wide area. Drilling a relief well can take months to complete, during which time the well continues to produce out of control. Therefore, an alternative solution is needed to controllably close off uncontrolled flow through a damaged BOP.
OBJECTS
• Among other things, an object of the present disclosure is to provide a long thin structure, such as (but not limited to) a wire, for incrementally reducing uncontrolled flow in a device by feeding a wire into a flow device, by entangling to form a structure that grows as more is fed into the flow until the desired flow resistance is achieved.
• Another object is to provide continuous structural connectivity through the resultant plug, as opposed to a plug created from discrete elements, to provide strength to the plug and resist breakup and failure of the plug due to high pressure fluid acting the plug.
• Another object is to provide deforming features that can interact (e.g. creep (i.e., flow together to close gaps), fuse, melt, etc.) to make the entanglement a cohesive plug to block the flow of fluid and gas.
SUMMARY
• In general, in one aspect, a wire includes a plurality of units. Each unit has a relatively stiff region joined to an intermediate region. The intermediate region has a varying stiffness along its length. The intermediate region is joined to a relatively pliable region.
• In general, in another aspect, a wire having a distal end and a body includes a stinger coupled to the distal end. The body has a varying stiffness.
• Implementations may have one or more of the following features: the stinger includes a flexible body. The stinger includes a pair of flexure legs. The flexure legs comprise a shape memory alloy. The stinger includes a trigger switch that, when activated, causes the stinger to deploy. The stinger includes a torsion spring and a shell, in which activating the trigger switch causes the torsion spring to rotate the shell. The wire also includes a plurality of entanglement-promoting features disposed along a body of the wire. The entanglement-promoting features include a hook, a deformable bead, a region of varying surface roughness, a coating, and a barb. The wire includes a creep-capable material. The creep-capable material coats the wire. The creep-capable material is contained in a hollow portion of the wire. The creep-capable material is a thermoplastic, a thermoresin, a heat activated polymer, or a pressure and/or temperature sensitive adhesive, or a polymer that flows at temperatures above 50 degrees C.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1ashows a wire with integral features in the cross section;
• FIG. 1bshows a wire with features to promote entanglement cohesion;
• FIG. 1cshows a wire bundle with discrete features intertwined along the length;
• FIG. 1dshows a chain structure that can feed into the flow stream;
• FIG. 2ashows a flat ribbon wire;
• FIG. 2bshows a flat ribbon in a collapsed configuration;
• FIG. 2cshows a helical ribbon wire;
• FIG. 3ashows a ribbon wire whose thickness varies along its length;
• FIG. 3bshows a cylindrical wire with varying features along its length;
• FIG. 3cshows a pipe where a stiff wire provides structural support and a flexible wire fills in the open regions to provide a seal;
• FIG. 3dshows a series of stiff and flexible sections used to create a fused entanglement plug;
• FIG. 4ashows wires with spherical elements along its length;
• FIG. 4bshows wires with cylindrical elements along its length;
• FIG. 4cshows wires with barbed elements along its length;
• FIG. 4dshows barbed wire strand as part of a pair of coated wire bundles;
• FIG. 5 shows feeding rollers for wires with inclusions along its length;
• FIG. 6showsa parallel wire bundle that can be fed simultaneously into the wellbore;
• FIG. 7 shows feeding mechanism pulling a parallel wire bundle from a wire spool;
• FIG. 8ashows a stinger at the tip of the wire to guide the wire into a wellbore;
• FIG. 8bshows a stinger that guides wire into wellbore and with a flexible body and features along length of body used for entangling;
• FIG. 8cshows a stinger with a rigid body and features along the body for generating entangling;
• FIG. 9 shows a flexural stinger at the tip of the wire;
• FIG. 10ashows an isometric view of a deployable stinger;
• FIG. 10bshows a cross sectional image of the unit mention inFIG. 10a;
• FIG. 10cshows a deployable singer in the deployed configuration;
• In the drawings, embodiments are illustrated by way of example, it being expressly understood that the description and drawings are only for the purpose of illustration, and are not intended as a definition of the limits of the invention.
DETAILED DESCRIPTION
• As described in the co-pending utility application described above, one approach to limiting fluid flow through a pipe, conduit, or other flow device involves continuously feeding a long, thin structure into the flowing medium. The long, thin structure is taken up by the fluid flow, and may interact with itself or other features in the environment to become tangled, thereby forming a plug that reduces fluid (i.e., liquid or gas) flow. As more of the long, thin structure (wire or various types and configurations as set forth herein) is fed in, the size of the plug increases, and thus further reduces the fluid flow in the environment. The techniques and structures described below, among other things, describe various designs of long, thin structures that promote self-interaction, thereby increasing the efficacy of plug formation in a flowing environment.
• In what follows, the term “wire” is used for a long, thin structure. It should be understood, however, that the term “wire” cover any structure capable of being fed continuously into a flowing environment. This includes structures that may not ordinarily be considered “wires,” such as chains, and hollow tubing.
• A wire1 according to the techniques below can be constructed from any combination of suitably stiff and suitably flexible material to allow the formation of nest-like structures by entanglement. In some implementations, the wire1 is constructed from a material sufficient to withstand the environment of a typical oil wellbore, which is typically hot (e.g., temperatures exceeding 60 degrees C.), hydro-carbon rich, varying fluid mixtures, and in high-pressure conditions (e.g., pressure exceeding 5000 psi). In some implementations, a wire1 can be made from any of many types of metal including but not limited to steel, aluminum, brass, magnesium or other alloys such as Nitinol (Nickel Titanium) and or polymers including but not limited to polypropylene, nylon, Kevlar, PVC, silicone rubber, or blends thereof. Natural fiber, such as hemp, can also be employed as a rope that is fed into the wellbore. In some implementations, the wire can be made of a combination of materials, for example a brass wire with a silicone sheath that softens once deployed into the flow stream to create a binding material in the entanglement structure. The binding material further aids in the restriction of gaseous medium flow as well as liquid flow.
• Referring toFIG. 1a, a wire5 has an irregular cross section withintegral features6a,6b,6c,6dthat help to give the wire5 buckling resistance during insertion. Inside an environment such as a wellbore, these features help to increase turbulence and hence resistance to the flow which in turn helps to increase tangling of the wire1 to create a blockage. In some embodiments, these features can be designed to interact with other features along the wire1 to promote entanglement strength. For example,FIG. 1bshows awire7 with integral features8a-8rto promote entanglement cohesion. As thewire7 buckles and bends the integral features8a-8rcan interact with each other, thereby surrounding and interconnectingstructure9bto promote a plug strength. For some embodiments, thecore9aof thewire7 is hollow or filled with a medium (e.g. thermo resin, plastic, etc.) that is released into the flow to promote entanglement cohesion. Thehollow body9bof thewire7 can collapse in the wellbore. In some embodiments, the medium may heat up in the wellbore environment to the extent where it can creep to help fill gaps in the entanglement structure or to help intra-wire cohesion, thereby strengthening the entanglement structure.
• In another embodiment, shown inFIG. 1c, awire bundle10 has discrete strands intertwined11a,11b,11c,11d,11eto form a cable. Each strand of can vary in material, yield criteria, surface friction, etc. The surface roughness of the wires can also vary amongst each strand and along theirlength12b,12c. For example, having small hooks oriented in one direction, such that the friction between individual strands ofwire10 increases thus further promotes generating a tangled nest-like structure.
• Referring toFIG. 1d, achain13 having a series of interlockedregions14a-14othat are connected to form a continuous structure. The shape, stiffness, of each interlockedregion14a-14ocan vary in each section. In some embodiments, the interlockingregions14a-14ocan also have features to promote entanglement.
• Referring toFIG. 2a, awire15 whose crosssectional area16 is non-circular and whose stiffness along its length can vary along its length to encourage bending and twisting atspecified sites17a,17b. As thewire15 bends along the specifiedsites17a,17bthe straight cross sections18a-18ccollapse on each other to reduce the flow across the entanglement, as shown inFIG. 2b.
• FIG. 2cillustrates awire20 that is helically twisted along its length to promote flow reduction. In some embodiments, thecross section21 of thehelical wire10 can be irregular.
• Properties of the wire can be modified in a number of ways including but not limited: 1) heat treatment, 2) coating, 3) roughing purpose, 4) shielding, among other ways.
• Wires25 and28 with variable stiffness along their lengths are shown inFIGS. 3a, and3b. For example, stiffness in aribbon wire25 can be modified by changing the crosssectional surface26a,27a,26b,27b, material, dimensions, coating, etc. The physical structure of the wire1 can be altered by heat treatment for different areas, which creates ductile and rigid sections. The wire1 will then be more likely to buckle in regions of low yield stress. The wire1 could be asymmetric25 or symmetric28 with varying cross sectional area.
• A wire1 can be coated, or constructed at least in part from with any suitable material to promote entanglement. For example, as discussed below, when an insulated wire (metal wire with plastic coating) is deployed in an environment containing relatively hot hydrocarbons, the plastic insulation may completely or partially melt, thereby becoming sticky and promoting intra-wire cohesion, which in turn promotes maintaining an entangled structure. More generally, any coating in the nature of a heat- or hydrocarbon-activated adhesive can be used at various sites along the wire1 to promote cohesion and/or entanglement. For example, a plain round wire1 (solid, braided or stranded) can be coated with a polymer, such as one would find in electrical wire. Another option is to coat any of the wire1 variations disclosed herein, and still another option is coat any wire1 (e.g. commercial barbed wire) with a plastic such as polyurethane or PVC. In general, appropriate coatings can also include (but are not limited to) a pressure sensitive adhesive, a temperature sensitive adhesive, a thermoplastic, a thermoresin, a heat-activated polymer, or a polymer that can flow at the ambient temperature of the wellbore. Typically, such temperatures are at least 50 degrees C.
• Moreover, such coatings can also be beneficial insofar as they may have a tendency to partially or totally melt, or otherwise become fluid like, in the relatively hot wellbore environment. Thus, such coatings may have a tendency to creep into gaps in the entanglement, thus further limiting the flow in the wellbore.
• Similarly, the wire1 can be coated with, or be constructed at least in part from, a swellable material. Such materials include, but are not limited to, certain elastomeric matrix materials to which super absorbent polymer molecules have been added. Such particles can include starch systems, cellulose systems, and synthetic resin systems. Further description of other swellable materials can be found in U.S. patent application Ser. No. 12/665,160, the entirety of which is incorporated by reference herein.
• FIG. 3billustrates awire28 whose cross sectional area varies along its length. The relativelythin regions29b,29e,29h, provide a preferential regions to flex and buckle while the relativelythick regions29a,29d,29gdeform but not as significantly. Intermediate regions of continuously-varyingthickness29c,29f,29ican be used to provide a gradual transition to the flex region. Similarly, in some implementations a wire can have relatively stiff and relatively pliable regions, connected by intermediate regions of continuously-decreasing pliability. Thus, a wire1 can be comprised of several “units,” with each unit having a relatively thick (or stiff) region, followed by an intermediate region of continuously-decreasing thickness (or stiffness), followed by a relatively thin (or pliable) region. Here, the term “relatively” connotes the fact that, when compared to each other, the various sections are thicker/stiffer or thinner/more pliable than other sections. In particular, the term does not imply the exercise of any judgment to decide what qualifies as thick, thin, stiff, or pliable.
• Referring toFIG. 3c, feedingwires68 and69 of different stiffness into the flow4 inside a flow device (e.g., a pipe)2 leads to an anchoring feature that provides support for a relativelypliable wire69 to pack and seal the gaps left by thestiffer wire68. Variability along the length of the wire1 can also be used to create an entanglement that is periodic in nature going from stiffer wire68ato lessstiff wire69a,69b, back tostiffer wire regions68b,68c, and so forth, as shown inFIG. 3d. The stiffness between the different sections ofstiff wire68a,68b,68cand lessstiff wire69a,69bcan also differ. In some implementations, a wire includes a relatively thick and/or stiff region at a distal end (i.e., the end of the wire that first enters the wellbore), and a relatively thin and/or pliable region thereafter (i.e., in the middle of the wire or at a proximal end of the wire). In some implementations, the thickness and/or stiffness of a wire1 decreases monotonically along the longitude of the wire1 from one end to another (e.g., from the distal end to the proximal end).
• Wires1 with periodic or aperiodic entanglement-promoting features along their length could also be used to promote entanglement. An “entanglement-promoting feature” is any structure or element along the wire1 that potentially may interlock or stick, even temporarily; with another such feature at another location along the wire1 or with the wire1 itself. For example as shown inFIG. 4a, awire30 with beads of varyingdiameter31a,31b,31ycould be used to promote entanglement. In some implementations, thebeads31a,31b,31y, can deform and theintermediate sections32a,32ballow for the beads to compress into an entangled nest. Other alternative embodiments, referring toFIG. 4b, arewires35 withbeads36a,36b,36ywhich can be partially composed of a binding compound that is gradually melted to fill in gaps and solidify to form a solid entangled plug. Other alternative embodiments, referring toFIG. 4c, is a continuous structure similar to abarbed wire32ewithbarbs41a,41b,41ythat can interact with each other, the surroundings, and any other structure. Other types of features such as hooks can also be used.
• Referring toFIG. 4d, awire42 that consists of two bundles withintegrated barbs41c,41d,41e,41f. Theindividual strands44a,44b,44c,44d,44e,44fthat make up the bundles havecoatings43a,43b,43c,43d,43e,43fthat can deform or partially melt. Although only two bundles are shown inFIG. 4d, in general any number can be used.
• As shown inFIG. 5, feeding awire45 withperiodic features46 could be done usingdrive wheels48 that have recesses (pockets)47 to accommodate the periodic features46. In some embodiments, the feeding system can feed wires with non-periodic features. For example, the drive wheel can include a compliant channel that deforms around such features during the feeding process.
• As shown inFIGS. 6 an7,multiple wire group70 withindividual wires71a,71b,71c,71d,71ethat are not bonded together can be fed withrollers49 simultaneously from aspool71 into a wellbore. In some embodiments, the grippingsurfaces72 of the drive system are modified to maintain thewire group70 from traversing off therollers49. The feeding mechanism for the wires1 is not limited to drive wheels but can also include the use of drive belts, gripping pads, etc. In some embodiments, features on the wire1 can include pocket like structures to push the wire1 into the wellbore hydrodynamically.
• Stingers at the tip of the wire1 can be used to assist the wire1 to initially go through valves and other channels prior to entering a wellbore into the flow stream. A “stinger” is a structure that helps a wire1 get taken up in the flow of the surrounding fluid and then later gets entangled in a discontinuity in the flow path and thus helps to promote formation of the wire1 tangle to control the flow. In some embodiments, the length and flexibility of the stinger varies and features as described above are included to further promote entanglement.
• FIG. 8ashows asimple stinger50 in the shape of a bullet, with aconical head51 and acylindrical body52. The rear of thestinger3 is connected to the wire1 that is being fed into the flow cavity. In some embodiments, thebody52 of thestinger50 can have entanglement promoting features as described above. For example thestinger55, illustrated inFIG. 8b, has features on the body56awhich can include a flexible or semi-flexible core that has hooks57 for entangling. In another embodiment, shown inFIG. 8c, astinger60 whosebody63 hasregion62 that includes barbs61a,61b. Thebody63 can either be rigid or allowed to flex to promote wire entanglement.
• FIG. 9 shows a passively activatedflexural stinger75 operable to expand once it is in the wellbore to create turbulence and act as a seed to make an entangled nest. In the undeployed configuration theflexural stinger75 can be fed through a small aperture. When theflexural stinger75 enters the wellbore the preload on theflexure legs76 is released thus changing shape to promote entanglement in the wellbore. This can be accomplished by theflexure legs76 being held closed before it is fed into the wellbore, or theflexure legs76 can be made of a shape memory alloy, that is activated by an environmental factor (e.g., heat, chemical composition) of a wellbore. One such alloy is Nitonol; when it is injected into the wellbore, the hot oil flow causes it to change shape. The body of thestinger77 is attached via astructure3, which could use a crimp or braze, to the wire1 being fed into the wellbore. Theanchor75 can serve to both guide the wire1 into the wellbore and to move in a chaotic motion when inside the wellbore; thus, bending, twisting, and deforming the wire1 to initiate and enhance entanglement.
• FIGS. 10a, and10bshow adeployable stinger80 that activates via atrigger switch76 to deploy. Thedeployable stinger80 includes twohalf shells82, and83 that can rotate about a givensection85 with the assist of atorsion spring86. The deployment of thestinger80 is initiated when thetrigger switch76 is pushed in when thetip81 bangs against something such as the opposite wall of the wellbore, which moves thetrigger switch76 from the lockedregion76binto theunlocked region76a. Once triggered, thetop shell83 is caused to rotate, e.g., by thetorsion spring86, around the common center held together via apin84. Aclearance channel83ballows the top half to move rotate. In some embodiments, the activation of the stinger can be performed with a chemical interaction, temperature change (e.g. via Nitinol components), mechanical (as illustrated), etc.
• FIG. 10cshows thedeployable stinger80 in a deployed state80a. The change in configuration can cause the stinger to spin, which twists the wire1 and promotes further entanglement.
• The examples ofFIGS. 9,10, and10b, illustrate particular implementations of a deployable stinger; i.e., a stinger which has both an undeployed state and a deployed state. The undeployed states, in general, are characterized by relatively high maneuverability and controllability, relatively low cross section, relatively low drag coefficients, etc. The deployed states, by contrast, are characterized by a relatively high propensity to undergo turbulent motion, a relatively high cross section, a relatively high drag coefficient, and more generally a relatively high tendency to promote entanglement of the wire1 it carries.
• In practice, 12-20 gauge wire can be used as the basis for the nominal wire size, and solid wire, as opposed to stranded, is less likely to buckle in the feeding mechanism before entering the wellbore. Plane wire has relatively high friction with itself and thus entangles easily. Insulated wire packs well because the plastic insulation yields under increasing pressure to form a more solid ball. Hence one embodiment involves a wire1 with non insulated and insulated sections, or two or more different wires such as shown inFIG. 3c, with one following the other.
• Further modifications will also occur to persons skilled in the art, and all such are deemed to fall within the spirit and scope of the invention as defined in the appended claims.

Claims (33)

What is claimed is:

1. A wire comprising:

a plurality of units, each unit having:

a relatively stiff region joined to an intermediate region, the intermediate region having a varying stiffness along a length of the wire, and the intermediate region being joined to a relatively pliable region.

2. The wire ofclaim 1, further comprising a stinger coupled to a distal end of the wire.

3. The wire ofclaim 2, wherein the stinger further comprises a flexible body.

4. The wire ofclaim 2, wherein the stinger further comprises a pair of flexure legs.

5. The wire ofclaim 4, wherein the flexure legs comprise a shape memory alloy.

6. The wire ofclaim 2, wherein the stinger includes a trigger switch that, when activated, causes the stinger to deploy.

7. The wire ofclaim 6, wherein the stinger includes a torsion spring and a shell, in which activating the trigger switch causes the torsion spring to rotate the shell.

8. The wire ofclaim 1, further comprising a plurality of entanglement-promoting features disposed along a body of the wire.

9. The wire ofclaim 8, in which the plurality of entanglement-promoting features includes a hook disposed along the body of the wire.

10. The wire ofclaim 8, in which the plurality of entanglement-promoting features includes a deformable beads disposed along the body of the wire.

11. The wire ofclaim 8, in which the plurality of entanglement-promoting features includes regions of varying surface roughness along the body of the wire.

12. The wire ofclaim 8, in which the plurality of entanglement-promoting features includes an entanglement-promoting coating.

13. The wire ofclaim 12, in which the entanglement-promoting coating is creep-capable.

14. The wire ofclaim 12, in which the entanglement-promoting coating is swellable.

15. The wire ofclaim 8, in which the plurality of entanglement-promoting features includes a barb.

16. The wire ofclaim 1, in which the wire is included as a discrete strand of a cable.

17. The wire ofclaim 1, further comprising a creep-capable material contained in a hollow portion of the wire.

18. The wire ofclaim 13, in which the creep-capable material is selected from the group consisting of: a thermoplastic, a thermoresin, a heat-activated polymer, a pressure sensitive adhesive, a temperature sensitive adhesive, and a polymer that can flow at temperatures above 50 degrees C.

19. A wire having a distal end and a body comprising:

a stinger coupled to the distal end of the wire, wherein the body of the wire has varying stiffness along the body.

20. The wire ofclaim 19, in which the body includes at least two different materials.

21. The wire ofclaim 19, in which the body includes a plurality of entanglement-promoting features.

22. The wire ofclaim 21, in which the plurality of entanglement-promoting features includes a hook disposed along the body of the wire.

23. The wire ofclaim 21, in which the plurality of entanglement-promoting features includes a bead disposed along the body of the wire.

24. The wire ofclaim 21, in which the plurality of entanglement-promoting features includes regions of varying surface roughness along the body of the wire.

25. The wire ofclaim 21, in which the plurality of entanglement-promoting features includes an entanglement-promoting coating.

26. The wire ofclaim 21, in which the plurality of entanglement-promoting features includes a barb.

27. The wire ofclaim 19, wherein the stinger further comprises a flexible body.

28. The wire ofclaim 19, wherein the stinger further comprises a pair of flexure legs.

29. The wire ofclaim 28, wherein the flexure legs comprise a shape memory alloy.

30. The wire ofclaim 19, wherein the stinger includes a trigger switch that, when activated, causes the stinger to deploy.

31. The wire ofclaim 30, wherein the stinger includes a torsion spring and a shell, in which activating the trigger switch causes the torsion spring to rotate the shell.

32. A method of controlling fluid flow in a wellbore comprising:

coating a wire with a coating selected from the group consisting of a creep-capable material and a swellable material, thereby forming a coated wire; and

continuously feeding the coated wire into the structure.

33. The method ofclaim 32, in which the creep-capable material is selected from the group consisting of: a thermoplastic, a thermoresin, a heat-activated polymer, a pressure sensitive adhesive, a temperature sensitive adhesive, and a polymer that can flow at temperatures above 50 degrees C.

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