LONG THIN STRUCTURES FOR GENERATING AN ENTANGLED FLOW RESTRICTING STRUCTURE
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.
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 FIELDThe 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.
BACKGROUNDCurrently, 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.
OBJECTSAmong 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.
SUMMARYIn 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.
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 DESCRIPTIONAs 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 wire 1 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 wire 1 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 wire 1 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 to
In another embodiment, shown in
Referring to
Referring to
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.
Wires 25 and 28 with variable stiffness along their lengths are shown in
A wire 1 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 wire 1 to promote cohesion and/or entanglement. For example, a plain round wire 1 (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 wire 1 variations disclosed herein, and still another option is coat any wire 1 (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 wire 1 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.
Referring to
Wires 1 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 wire 1 that potentially may interlock or stick, even temporarily; with another such feature at another location along the wire 1 or with the wire 1 itself. For example as shown in
Referring to
As shown in
As shown in
Stingers at the tip of the wire 1 can be used to assist the wire 1 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 wire 1 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 wire 1 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.
The examples of
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 wire 1 with non insulated and insulated sections, or two or more different wires such as shown in
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
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 of claim 1, further comprising a stinger coupled to a distal end of the wire.
3. The wire of claim 2, wherein the stinger further comprises a flexible body.
4. The wire of claim 2, wherein the stinger further comprises a pair of flexure legs.
5. The wire of claim 4, wherein the flexure legs comprise a shape memory alloy.
6. The wire of claim 2, wherein the stinger includes a trigger switch that, when activated, causes the stinger to deploy.
7. The wire of claim 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 of claim 1, further comprising a plurality of entanglement-promoting features disposed along a body of the wire.
9. The wire of claim 8, in which the plurality of entanglement-promoting features includes a hook disposed along the body of the wire.
10. The wire of claim 8, in which the plurality of entanglement-promoting features includes a deformable beads disposed along the body of the wire.
11. The wire of claim 8, in which the plurality of entanglement-promoting features includes regions of varying surface roughness along the body of the wire.
12. The wire of claim 8, in which the plurality of entanglement-promoting features includes an entanglement-promoting coating.
13. The wire of claim 12, in which the entanglement-promoting coating is creep-capable.
14. The wire of claim 12, in which the entanglement-promoting coating is swellable.
15. The wire of claim 8, in which the plurality of entanglement-promoting features includes a barb.
16. The wire of claim 1, in which the wire is included as a discrete strand of a cable.
17. The wire of claim 1, further comprising a creep-capable material contained in a hollow portion of the wire.
18. The wire of claim 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 of claim 19, in which the body includes at least two different materials.
21. The wire of claim 19, in which the body includes a plurality of entanglement-promoting features.
22. The wire of claim 21, in which the plurality of entanglement-promoting features includes a hook disposed along the body of the wire.
23. The wire of claim 21, in which the plurality of entanglement-promoting features includes a bead disposed along the body of the wire.
24. The wire of claim 21, in which the plurality of entanglement-promoting features includes regions of varying surface roughness along the body of the wire.
25. The wire of claim 21, in which the plurality of entanglement-promoting features includes an entanglement-promoting coating.
26. The wire of claim 21, in which the plurality of entanglement-promoting features includes a barb.
27. The wire of claim 19, wherein the stinger further comprises a flexible body.
28. The wire of claim 19, wherein the stinger further comprises a pair of flexure legs.
29. The wire of claim 28, wherein the flexure legs comprise a shape memory alloy.
30. The wire of claim 19, wherein the stinger includes a trigger switch that, when activated, causes the stinger to deploy.
31. The wire of claim 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 of claim 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.
Type: Application
Filed: May 13, 2013
Publication Date: Nov 14, 2013
Inventors: Folkers Eduardo Rojas (Boston, MA), Alexander H. Slocum (Bow, NH)
Application Number: 13/893,227
International Classification: E21B 21/08 (20060101); E21B 34/06 (20060101);