Patent Grant
10787864
Embodiments usable within the scope of the present disclosure relate, generally, to apparatus, systems, and methods for protecting one or more components of a downhole tool during activation of the downhole tool. And more particularly, the embodiments relate to systems and methods for using a liner or a web protector to minimize, block, or prevent erosion of a pillar that is adjacent to an opening of the downhole tool.
Many wellbore operations necessitate deploying a downhole tool within a wellbore. Some operations may be accomplished through the use of tools employing brute-force methods such as explosive charges, drill bits, fluid pressurized at the surface of the wellbore, or other high-energy and high-impact methods. Other less-destructive operations may require downhole tools capable of performing precise or delicate jobs. For an increasing number of these operations, a non-explosive downhole tool is preferred. Non-explosive downhole tools include, for example, torches, perforators, setting tools, fracturing equipment, and the like (collectively referred to herein as downhole tools) that can be powered through the use of thermite fuel or fuel derived from a chemical reaction.
A need exists, in the oil and gas industry, for the ability to activate non-explosive downhole tools with a controlled expulsion of the molten fuel or chemical fuel, and to maintain accuracy of the sprayed (i.e., projected) molten fuel over multiple uses of the downhole tool. Non-explosive tools are powered by a reaction that is slower and more controlled than explosive-type downhole tools. This can allow for directed blasts of molten fuel forced through nozzles or openings. Over repeated uses, the openings can be worn out and can change shape, causing inaccurate flow during firing. In some embodiments, when the downhole tool wears out, the structural integrity of the downhole tool can be compromised. In such embodiments, the downhole tool may break apart during firing, causing more trouble and potentially additional time taking the remains of the downhole tool out of the wellbore.
Additionally or alternatively, a need exists to create a forceful blast or projection of the molten fuel or chemical fuel. Past examples of downhole tools utilizing thermite fuel or chemical fuel have been limited in the size and shape of the nozzles that may be used. The previous tools have used broader nozzles due to the lack of protection to the areas around the nozzles. The nozzles wear out causing a change in the flow of the molten fuel or chemical fuel, and in some instances could cause breakage or premature destruction of the downhole tool.
The present embodiments meet these needs.
The disclosed embodiments include a downhole tool that is configured to be inserted into a wellbore, wherein the downhole tool comprises: a tool body comprising an external surface and an internal volume that can be configured to store a thermite fuel, wherein the thermite fuel is configured to ignite into a molten thermite fuel. The thermite fuel comprises a metal and an oxidizer that can oxidize the metal. The downhole tool further comprises an opening extending from the internal volume and through the external surface, wherein the opening can be configured to project (i.e., spray) the molten thermite fuel, and a pillar defining one side of the opening. The pillar can comprise an internal side that faces the internal volume, and an opening side that faces the opening. The downhole tool includes a web protector that can abut at least the internal side of the pillar to block the molten thermite fuel from impinging the internal side of the pillar.
In an embodiment, the web protector further abuts the opening side of the pillar to also block the molten thermite fuel from impinging the opening side of the pillar.
In an embodiment the downhole tool can comprise an additional opening, wherein the pillar further defines a side of the additional opening. The opening and the additional opening can be configured to project (i.e., spray) the molten thermite fuel in a pattern that severs a production tubing. In an embodiment, the opening and the additional opening together can extend around eighty percent (80%) to ninety-nine percent (99%) of a circumference of the downhole tool.
Embodiments of the downhole tool include a web protector that comprises polyether ether ketone, another polymer, a ceramic material, a graphite material, or combinations thereof. In an embodiment, the web protector can be attached to the pillar with a securing connector, wherein the securing connector can comprise a chemical adhesive, a magnet, a mechanical fastener, or combinations thereof.
In an embodiment, the downhole tool can comprise a liner that can be configured to line the internal volume. The liner can comprise a first material, and the web protector can comprise a second material that is different from the first material. In an embodiment, the web protector is the liner.
An embodiment of the downhole tool can include: an opening for projecting (i.e., spraying) molten thermite fuel, a pillar that defines one side of the opening, and a web protector that comprises a body that is made from a material that is heat resistant and erosion resistant to the molten thermite fuel. The body of the web protector can further include at least one side that is configured to abut a side of the pillar of the downhole tool to block the molten thermite fuel from impinging the side of the pillar. In an embodiment, two sides of the body of the web protector can abut two sides of the pillar.
The material of the web protector can comprise polyether ether ketone, another polymer, a ceramic material, a graphite material, or combinations thereof. In an embodiment, the web protector can further include a securing connector for attaching the web protector to the pillar, wherein the securing connector can comprise a chemical adhesive, a magnet, a mechanical fastener, or combinations thereof. In an embodiment, the non-explosive fuel comprises: a thermite, a thermite mixture, or a chemical. In an embodiment, the chemical is an acid, nitrogen fluoride, a nitrogen fluoride mixture, a nitrogen trifluoride, a bromine trifluoride, or a solid gas.
Embodiments of the present invention include a method of using a downhole tool within a wellbore, wherein the downhole tool includes a thermite fuel that can comprise a metal and an oxidizer that can oxidize the metal. The thermite fuel can be contained within an internal volume of the downhole tool. The downhole tool can further comprise an opening for projecting (i.e., spraying) molten thermite fuel and a pillar defining one side of the opening. The steps of the method comprise: attaching a web protector to the pillar of the downhole tool so that at least one side of the web protector abuts a side of the pillar, wherein the web protector comprises a material that is heat resistant and erosion resistant to the molten thermite fuel, and inserting the downhole tool into the wellbore. The steps of the method continue by activating the thermite fuel in the internal volume of the downhole tool to generate the molten thermite fuel, and projecting (i.e., spraying) the molten thermite fuel through the opening of the downhole tool, wherein the web protector blocks the molten thermite fuel from impinging the side of the pillar.
The steps of the method can further comprise retrieving the downhole tool from the wellbore, replacing the thermite fuel with a second thermite fuel, inserting the downhole tool into the wellbore a second time, activating the second thermite fuel to generate a second molten thermite fuel, and projecting (i.e., spraying) the second molten thermite fuel through the opening of the downhole tool. In an embodiment, the projecting (i.e., spraying) of the molten thermite fuel can sever a production tubing within the wellbore.
In an embodiment, the web protector can be attached to the pillar with at least one of a chemical, a magnetic, and a mechanical connection.
In the detailed description of various embodiments usable within the scope of the present disclosure, presented below, reference is made to the accompanying drawings, in which:
One or more embodiments are described below with reference to the listed FIGS.
Before describing selected embodiments of the present disclosure in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. The disclosure and description herein is illustrative and explanatory of one or more presently preferred embodiments and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, means of operation, structures and location, methodology, and use of mechanical equivalents may be made without departing from the spirit of the invention.
As well, it should be understood that the drawings are intended to illustrate and plainly disclose presently preferred embodiments to one of skill in the art, but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views to facilitate understanding or explanation. As well, the relative size and arrangement of the components may differ from that shown and still operate within the spirit of the invention.
Moreover, it will be understood that various directions such as “upper”, “lower”, “bottom”, “top”, “left”, “right”, “uphole”, “downhole”, and so forth are made only with respect to explanation in conjunction with the drawings, and that components may be oriented differently, for instance, during transportation and manufacturing as well as operation. Because many varying and different embodiments may be made within the scope of the concept(s) herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and non-limiting.
To complete such operations, the downhole tool 14 may hold a non-explosive fuel, such as a thermite fuel 22, during descent down the wellbore 20. As shown, an external surface 24 can protect the thermite fuel 22 as the downhole tool 14 descends to a target area 26. The target area 26 is the location where the downhole tool 14 is meant to perform the operation. The thermite fuel 22 is non-explosive fuel, but once activated, the thermite fuel can burn at a temperature that may exceed 3000 degrees Celsius. The reaction occurs over a long enough period of time that the resultant molten fuel may be directed through a nozzle without causing the external surface 24 to deform due to internal pressure.
The thermite fuel includes a combination or a mixture of a metal and an oxidizer. Examples of such metals can include: aluminum, magnesium, chromium, nickel, silver and/or other metals.
When the metal is combined or mixed with the oxidizer, a metal oxide is created that can form, or at least partially form, a combustion product(s). Oxidizers that can be used to oxidize the metal can include, for example: cupric oxide, iron oxide, aluminum oxide, ammonium perchlorate, and/or other oxidizers. Applicant incorporates U.S. Pat. No. 8,196,515, having the title of “Non-Explosive Power Source For Actuating A Subsurface Tool” by reference, in its entirety, herein. The ignition point of thermite can vary, depending on the specific composition of the thermite. For example, the metal and the oxidizer may or may not be combined prior to ignition, which can affect the ignition point. As another example and in regard to thermite mixtures, the ignition point of a thermite mixture of aluminum and cupric oxide is approximately 1200 degrees Fahrenheit, while other thermite mixtures or combinations can have an ignition point as low as 900 degrees Fahrenheit.
When ignited, the thermite produces a non-explosive, exothermic reaction. The rate of the thermite reaction occurs on the order of milliseconds, while an explosive reaction has a rate occurring on the order of nanoseconds. While explosive reactions can create detrimental explosive shockwaves within a wellbore, use of a thermite-based power charge (non-explosive or deflagration reaction) avoids such shockwaves.
The thermite combination can include a polymer, which can be disposed in association with, or as a part of, the thermite combination. The polymer can be of a type that produces a gas responsive to the thermite reaction, which slows the reaction time of the thermite. Usable polymers can include, without limitation, polyethylene, polypropylene, polystyrene, polyester, polyurethane, acetal, nylon, polycarbonate, vinyl, acrylin, acrylonitrile butadiene styrene, polyimide, cylic olefin copolymer, polyphenylene sulfide, polytetrafluroethylene, polyketone, polyetheretherketone, polytherlmide, polyethersulfone, polyamide imide, styrene acrylonitrile, cellulose propionate, diallyl phthalate, melamine formaldehyde, other similar polymers, or combinations thereof.
As the molten fuel 30 continues to expand, the downhole tool 14 projects a molten fuel projection (i.e., spray) 32 at the target area 26. The molten fuel projection 32 may be shaped by an opening in the downhole tool 14 as described below. A sufficiently focused molten fuel projection 32 may contact the target area 26 with enough force to destroy some or all of the target area 26. Thus, a hole 34 may be cut or torched through the target area 26 or the production tubing 16, casing 18, or further into the formation. Additionally, the hole may include a complete circle of the production tubing 16, severing the bottom of the production tubing 16 from the top and allowing retrieval of the top production tubing 16.
In certain embodiments, the system 10 may be used to completely sever the production tubing 16, or other downhole component. In these embodiments, the openings 40 produce molten fuel projection 32 around a significant portion of the circumference of the downhole tool 14. A significant portion of the circumference means that the molten fuel projection 32 produces a hole 34 in the production tubing 16 such that the target area 26 will be severed substantially completely or completely by pulling on the production tubing 16 from the surface. For such an operation of severing, the downhole tool 14 may include several openings 40 that cover a significant portion of the circumference of the downhole tool 14. For example, the openings 40 may cover eighty to ninety-nine percent (80%-99%) of the circumference, eighty-five to ninety-five percent (85%-95%) of the circumference, about ninety percent (90%) of the circumference, or some other percentage of the circumference. In the illustrated embodiment, the downhole tool 14 includes four openings 40.
Between the openings 40, a web protector and/or a pillar 42 can hold the downhole tool 14 together, and can define the shape of the openings 40 by bordering the opening 40 on one side. Additional pillars 42 may border the openings 40 on other sides. As the molten fuel projection 32 projects (i.e., sprays) through the openings 40, it can weaken the pillars 42 due to heat or contact erosion. For example, heating up pillars 42 made from certain types of steel can make the pillars 42 elastic, and the weight of the downhole tool 14 (i.e., a lower portion 43) can stretch the pillars 42. This can affect the flow of the molten fuel projection 32 by changing the shape of the openings 40. Additionally, the pillars 42 may, sometimes, be stretched beyond the pillar's 42 ability to hold the downhole tool 14, causing the downhole tool 14 to split (i.e., at the openings 40). That is, if the pillars 42 are compromised, the lower portion 43 of the downhole tool 14 can break apart from the remainder of the downhole tool 14. This can cause problems of many types for operation of the system 10. The lower portion 43 may fall and get stuck within the wellbore 20, requiring an additional operation for retrieval. Additionally, the breaking of the lower portion 43 may severely hinder the operation of the downhole tool 14 in cutting, destroying, or annihilating the target area 26. Specifically, if the lower portion 43 splits from the downhole tool 14, the molten fuel 30 possibly could be poured down the wellbore 20 without contacting, or with minimal contact of, the target area 26.
As mentioned above, the downhole tool 14 may include a liner 44 that protects the inside of the downhole tool 14 from the molten fuel 30. To ensure that the pillars 42 also remain structurally intact and do not break, the liner 44 may also protect the pillar 42 from the molten fuel 30, and the liner may have openings that coincide with the openings 40 in the downhole tool 14. The liner 44 may be constructed from a material that is temperature resistant, and does not react with the thermite fuel 22 or molten fuel 30. For example, the liner 44 may be constructed from carbon-based materials such as graphite or carbon-fiber. The liner 44 may also include polyetheretherketone (PEEK) a semi-crystalline organic polymer thermoplastic, exhibiting a highly stable chemical structure. The liner 44 may also include other members of the polyaryletherketone (PAEK) polymer group, or other polymers.
Eventually, the molten fuel 30 and the molten fuel projection 32 flowing past the pillar 42 could erode the internal volume face 48, and the pillar 42 could fail. The liner pillar 46 can be shaped to direct the molten fuel 30 and the molten fuel projection 32 away from an opening side 50 of the pillar 42. That is, the liner 44 and the liner pillar 46 may be shaped and/or configured to direct the molten fuel 30 away from all internal sides (i.e., internal volume face 48 and opening side(s) 50). For example, the liner pillar 46 may be wider than the pillar 42, or may have a flare 51, such that the liner pillar 46 broadens in width further from the internal volume 28. This broadening can focus the flow of the molten fuel projection 32 away from the opening side 50 of the pillar 42.
The web protectors 52 may be constructed of the same material as the liner 44, or may include different materials. For example, the liner 44 that is lining the internal volume face 48 of the internal volume 28 may include graphite, while the web protector 52 can be made from PEEK material. These types of materials are better suited to resist the heat and erosion of the molten fuel 30 as it passes through the opening 40. Embodiments tested with web protectors 52 have shown that the pillars 42 suffer much less stretching and weakening, and can therefore be constructed with smaller pillars 42 without breaking. As explained above, having a smaller pillar 42, and correspondingly larger opening 40 can provide a more thorough cutting of the target area 26, and thus more efficient and effective use of the downhole tool 14.
The web protector 52 may be customized and manufactured to be installed in specific downhole tools 14. For example, the web protector 52 may include a body 53 and a contacting side 54 that is shaped to completely contact the pillar 42 on all of the internal sides (e.g., internal volume face 48, and two opening sides 50). The web protectors 52 may be manufactured separately from any liner 44 within the internal volume 28. The liner 44 may thus be advantageously manufactured as a simple cylinder matching the dimensions of the internal volume 28. Separate manufacture of the liner 44 and the web protectors 52 may further enable the web protectors 52 to be replaced individually, based on need, and replaced more often or less often than the liner 44.
The web protectors 52 may be held in place around the pillar(s) 42 with a securing connector 56. The securing connector 56 may include a chemical, magnetic, or mechanical connection that keeps the web protector 52 from moving during descent of the downhole tool 14, and firing. For example, the connector 56 may include an epoxy that semi-permanently secures the web protector 52 in place. Additionally or alternatively, the connector 56 may include a magnet within the web protector 52 that enables an operator to remove the web protector 52 by hand, without requiring a tool. In certain embodiments, the connector 56 may include a snapping feature that locks or pinches into a corresponding feature on the pillar 42. Additionally or alternatively, the web protectors 52 may be held in place by inserting the liner 44 after the web protectors 52 have been placed around the pillars 42. The liner 44 can push the web protectors 52 tightly against the pillars 42 so that the web protectors 52 do not shift or dislodge.
The downhole tool 14 discussed above may be a tool that contains thermite fuel 22. In other embodiments, the downhole tool 14 may include other non-explosive fuels, such as chemicals that are activated by mixing the chemicals to form a resultant chemical fuel. The resultant chemical fuel may be directed through the nozzle without causing the external surface 24 to deform due to internal pressure. The liner 44 and the web protectors 52 may protect the inside of the downhole tool 14 and the pillars 42 from the chemical fuel in the same manner as discussed above. Some examples of the chemical used to form the resultant chemical fuel include: acids, nitrogen fluoride and mixtures (e.g., nitrogen fluoride and molecular fluoride), nitrogen trifluoride, bromine trifluoride, or solid gases (e.g., nitrogen).
While various embodiments usable within the scope of the present disclosure have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention can be practiced other than as specifically described herein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4889187 | Terrell | Dec 1989 | A |
| 20160186513 | Robertson | Jun 2016 | A1 |
| 20170298711 | Aitken | Oct 2017 | A1 |
| 20170335646 | Huang | Nov 2017 | A1 |
| 20190186243 | Huang | Jun 2019 | A1 |
