HIGH-PERFORMANCE, REGULAR EXPANSION ELEMENTS FOR OIL AND GAS APPLICATIONS

Abstract

HIGH-PERFORMANCE, REGULAR EXPANSION ELEMENTS FOR OIL AND GAS APPLICATIONS. The invention relates to a downhole sealing device, a well system employing a downhole sealing device, and a method of sealing within a borehole. The downhole sealing device, in one aspect, comprises one or more downhole sealing features and an elastomeric element comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features. In at least one aspect, the elastomeric element can be used to be compressed in a downhole application against tubing as a seal.

Description

Title of the invention: HIGH-PERFORMANCE, REGULAR EXPANSION ELEMENTS FOR OIL AND GAS APPLICATIONS CONTEXT

[0001] Significant challenges exist in the design of high-expansion, high-performance elements (e.g., sealing elements, such as packing elements, plugs, etc.) for oil and gas applications. Such element designs are often complex, involving, for example, numerous sealing element components, such as those incorporated into temporary plugs placed below the production column. One way to simplify the design is to create a single element (e.g., with internal features that control its own deployment). Currently, however, there are no robust, single-element materials for downhole sealing applications. Available rubbers, such as 3D-printed polymers, are generally brittle, exhibit low tensile strength, and low elongation at break. BRIEF DESCRIPTION

[0002] Reference is now made to the following description, taken together with the attached drawings, in which:

[0003] Figures 1 and 2 are perspective views of a well system comprising an example of an operating environment in which the devices, systems and processes described herein can be used;

[0004] Figure 3 illustrates a flowchart of an example of a process for preparing a VAT resin for a thiomethane polymer according to the principles of this description;

[0005] Figure 4 illustrates a flowchart of an example of a three-dimensional stereolithography printing process for a thiourethane polymer part according to the principles of this description;

[0006] Fig. 5 illustrates a cross-sectional diagram representing a wellhead sealing device having an elastomeric element designed, manufactured and used according to the description;

[0007] Figure [Fig. 6] illustrates a cross-sectional diagram representing another bottom well sealing device having an elastomeric element designed, manufactured and used according to the description;

[0008] Figure 7 illustrates a cross-sectional diagram representing a downhole sealing device in an uncompressed state positioned inside a tubular casing according to certain aspects of the present description;

[0009] Figure [8] illustrates a cross-sectional diagram representing the bottom well sealing device of Figure [7] in a compressed state (for example, a defined state) according to certain aspects of this description;

[0010] Figure 9 illustrates an end view of an anti-extrusion device in a deployed state according to certain aspects of this description;

[0011] Fig. 10 illustrates an isometric view of the anti-extrusion device of Fig. 9 in a retracted state according to certain aspects of this description;

[0012] Figure 11 illustrates an isometric view of the anti-extrusion device of Figure 9 in a deployed state according to certain aspects of this description; and

[0013] Figure 12 illustrates a flowchart representing a process for forming a bottom well sealing device according to certain aspects of the present description. DETAILED DESCRIPTION

[0014] In the following drawings and descriptions, similar parts are generally marked in the specification and drawings with the same numerical references, respectively. The figures drawn are not necessarily to scale. Certain features of the invention may be shown enlarged to scale or in a somewhat schematic form, and certain details of elements may not be shown for the sake of clarity and conciseness.

[0015] The present invention can be implemented in various embodiments. Specific embodiments are described in detail and are shown in the drawings, it being understood that the present invention is to be considered an example of the principles of the invention and is not intended to limit the invention to that illustrated and described herein. It should be clearly understood that the various teachings of the embodiments discussed herein can be used separately or in any suitable combination to produce the desired results. Furthermore, all statements made herein referring to the principles and aspects of the invention, as well as specific examples thereof, are intended to encompass their equivalents. In addition, the term "or," as used herein, refers to a non-exclusive "or," unless otherwise indicated.

[0016] Unless otherwise indicated, the use of the terms "connect", "engage", "couple", "fix" or any other term describing an interaction between elements is not intended to limit the interaction to a direct interaction between the elements and may also include an indirect interaction between the described elements.

[0017] Unless otherwise specified, the use of the terms "up," "upper," "upward," "top of hole," "upstream," or similar terms shall be interpreted as generally toward the surface of the well; likewise, the use of the terms "down," "lower," "downward," "bottom of hole," or similar terms shall be interpreted as generally toward the lower terminal end of a well, regardless of the wellbore's orientation. The use of one or more of the preceding terms shall not be interpreted as designating positions along a perfectly vertical or horizontal axis. Unless otherwise specified, the use of the term "subsurface formation" shall be interpreted as encompassing both exposed underground areas and underground areas covered by water, such as ocean or fresh water.

[0018] Figure 1 shows a perspective view of a well system 100 including an example of an operating environment in which the apparatus, systems, and processes described herein can be used. For example, the well system 100 could use a downhole sealing device 170 designed, manufactured, and / or used according to any of the embodiments, aspects, applications, variations, designs, etc., described in the following paragraphs. The well system 100 shown in Figure 1 includes a maintenance platform 110 (for example, a drilling rig, completion rig, work platform, or other mast structure, or a combination thereof) extending over and around a borehole 120 formed in an underground formation 130. As those skilled in the art will understand, the borehole 120 may be fully cased, partially cased, or an uncased borehole.In the illustrated embodiment of [Fig.1], the borehole 120 is partially cased and thus comprises a cased region 140 and an uncased region 145. The cased region 140, as illustrated, can use a casing 150 which is held in place by cement 160.

[0019] The well system 100 illustrated in [Fig. 1], according to at least one embodiment, includes the downhole sealing device 170 located inside the borehole 120. The downhole sealing device 170 can be supported by a means of transport 190, which may be a cable line, a slick cable, a cable, a tubular (for example, a drill string, a casing train, a completion train, a coiled tube, or the like), or another structure suitable for supporting the downhole sealing device 170. In some aspects, the maintenance platform 110 may include a derrick with a drilling floor through which the means of transport 190 extends downward from the maintenance platform 110 into the borehole 120. In an offshore situation, the The maintenance platform 110 may be supported by risers or piers extending downward to the seabed in some implementations. Alternatively, the maintenance platform 110 may be supported by columns resting on hulls or pontoons (or both) that are ballasted below the water surface; this may be referred to as a semi-submersible drilling platform or rig. In an offshore location, tubing may extend from the maintenance platform to exclude seawater and contain drilling fluid returns. Other mechanical features not shown may control the insertion and removal of the transport means 190 into the wellbore 120.Examples of these other mechanical features include a drilling winch coupled to a lifting device, a smooth cable unit or a cable line unit including a winching device, another service vehicle, or other such mechanisms. The downhole sealing device 170 may be a temporary plug, a sealing pack, or another type of sealing device that can be used down the well. Furthermore, the downhole sealing device 170 may be located in the uncased region 145 of the borehole 120, or alternatively as a sealant between two downhole tools.

[0020] The downhole sealing device 170, in at least one embodiment, may include an elastomeric element 172. In one or more embodiments, the elastomeric element 172 comprises a thiourethane / acrylate polymer that can be used to be compressed inside the borehole 120, for example against tubing (for example, borehole casing 150 in the illustrated embodiment), as a seal. The term thiourethane / acrylate polymer, as used herein, is intended to encompass thiourethane polymers, thiolacrylate polymers, and mixed combinations of thiourethane and thiolacrylate polymers. Accordingly, in some embodiments, the elastomer element 172 may comprise a thiourethane polymer, and in other embodiments, the elastomer element 172 may comprise a thiolacrylate polymer.However, in some other embodiments, the elastomer element 172 may comprise a mixture of a thiourethane polymer and a thiolacrylate polymer, for example using various different proportions.

[0021] In at least one embodiment, depending on the specific manufacturing process and the composition of the elastomer element 172, the elastomer element 172 can be used to be compressed inside the borehole 120, for example against a casing (for example, the borehole casing 150 in the illustrated embodiment), and used to seal at least 6,900 kPa (for example, about 1,000 psi) of pressure difference at a temperature of at least 80 °C. In another In this embodiment, the elastomer element 172 can be used to be compressed inside the borehole 120, for example against a tubular (for example, the borehole casing 150 in the illustrated embodiment), and used to seal at least 20,700 kPa (for example, about 3,000 psi) of pressure difference at a temperature of at least 80 °C. In yet another embodiment, depending on the specific manufacturing process and the composition of the elastomer element 172, the elastomer element 172 can be used to be compressed inside the borehole 120, for example against a tubular (for example, the borehole casing 150 in the illustrated embodiment), and used to seal at least 20,700 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C.In other embodiments, the elastomeric element 172 can be used to be compressed inside the borehole 120, for example against the tubing (for example, the borehole casing 150 in the illustrated embodiment), and used to seal at least 27,575 kPa (for example, about 4,000 psi) of pressure difference at a temperature of at least 80 °C. In at least one or more other embodiments, the elastomeric element 172 can be used to be compressed inside the borehole 120, for example against the tubing (for example, the borehole casing 150 in the illustrated embodiment), and used to seal at least 27,575 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C. In addition, in at least one or more embodiments, the elastomeric element 172 has a breaking toughness of at least 40 MJ / m3 and a tensile strength of at least 25 MPa.In at least one embodiment, the elastomer element 172 is sensitive to a high degree of elongation (for example, up to and at least about 200%).

[0022] In at least one embodiment, the downhole sealing device 170 is a first downhole sealing device, and the well system 100 further includes a second downhole sealing device 180. In at least this embodiment, the second downhole sealing device 180 can be placed near the downhole sealing device 170, for example to complement the downhole sealing device 170. For example, the second downhole sealing device 180 could comprise a material (for example, a polymer material) different from the thiourethane / acrylate polymer, and thus be suitable for applications in which the downhole sealing device 170 might be lacking.For example, the second 180 downhole sealing device could have higher pressure ratings at extremely high temperatures, whereas it has lower pressure ratings at lower temperatures.

[0023] The elastomeric element 172, according to one embodiment, is coupled to one or more downhole sealing features. For example, in the embodiment of [Fig. 1], the one or more downhole sealing features are first and second end plates coupled to opposite ends of the elastomeric element 172, the first and second end plates 174 being configured to move relative to each other to axially compress the elastomeric element 172 to engage with the borehole casing 150. If the downhole sealing device 170 were positioned in the uncased region 145 of the well system 100, the first and second end plates 174 would axially compress the elastomeric element 172 to engage with the borehole 120 itself.In some cases, the elastomer element 172 and the first and second end plates 174 are positioned between two anti-extrusion devices 176. As shown in [Fig.1], the downhole sealing device 170 is in an uncompressed state and can be moved inside the borehole 120. Once positioned at a desired location, axial compression forces can be applied to the first and second end plates 174 to axially compress the elastomer element 172 into a compressed state, as shown in [Fig.2].

[0024] The [Fig.2] is a schematic diagram of the well system 100 of the [Fig.1] comprising the wellhead sealing device 170 in a compressed state according to certain aspects of this description. The axial compression force 205 is applied through the first and second end plates 174 to the elastomer element 172 to deform the elastomer element 172 so that the elastomer element 172 creates a seal in the borehole 120. In cases where the anti-extrusion devices 176 are used, the axial compression force 205 can cause the anti-extrusion devices 176 to expand in diameter and provide a surface against which the deformable elastomer element 172 cannot easily protrude (for example, to prevent the elastomer element 172 from deforming too far beyond the end plates 174).In some cases, the axial compression forces 205 can be removed from the —or axial extension forces can be applied (for example, in a direction opposite to the axial compression forces 205) — wellhead sealing device 170 in order to return the wellhead sealing device 170 to an uncompressed state, such as that shown in [Fig. 1].

[0025] The elastomeric elements designed, manufactured, and used according to the description, without limitation, can be applied to: 1) O-ring applications (e.g., from -65 °C to 270 °C) manufactured using 3D printing or other conventional processes; 2) T-seals, stack seals, quad seals, 3) bonded gaskets or any other gasket application (e.g., -65°C to 270°C) manufactured using 3D printing or other conventional processes; 4) ExtremGrip ELH elastomer components (e.g., -40°C to 250°C) manufactured using 3D printing or other conventional processes; 5) gasket elements with complex or simple external geometric features (e.g., -65°C to 270°C) manufactured using 3D printing or other conventional processes; 6) gasket elements with internal geometric features and with or without external features (e.g., -65°C to 270°C) manufactured using 3D printing processes; 7) gaskets for on-demand or one-off applications (e.g., -65°C to 270°C) manufactured using 3D printing processes;7) old seals that are no longer in commercial production (from -65 °C to 270 °C) manufactured using 3D printing processes; 8) sealing elements directly bonded to a rigid substrate (for example, from -65 °C to 270 °C) manufactured using 3D printing processes;and 9) multi-component sealing elements and bonded sealing systems with crystalline or high Tg regions to serve as integrated replacement systems (e.g., -65 °C to 270 °C) manufactured using 3D printing or other conventional processes. The seals mentioned above can be any type of sealing element for reclaimable, production, permanent, temporary plugs, take-and-abandon applications, fracking, onshore or offshore applications, conventional and HPHT applications, and geothermal applications up to a certain temperature (e.g., up to 270 °C). Furthermore, the seals can be used statically or dynamically.

[0026] All the seals mentioned above and their variants may or may not have alternative systems, for example depending on the nominal pressure and / or the application temperature. Generally, for high pressures and / or high temperatures, properly designed alternative systems are used, which significantly improves the performance of the components made from this material.

[0027] The use of elastomeric elements manufactured according to this description offers the following additional advantages: a reduced number of parts in the high-expansion seal / plug; expansion of the design space to include elements with internal geometric characteristics, as well as compositional changes within the part that modify the glass transition and / or crystallinity to affect mechanical behavior; and the production of 3D-printed elements with internal characteristics having a very high expansion rate. high (e.g., 150% or 200%, instead of about 25%); the considerable expansion of the temperature range of seal applications from -65°C to 270°C; the improvement of operational efficiency through on-demand field manufacturing of high-expansion elements for manufacturers, operators, and their customers; the potential replacement of conventional oil and gas elastomers when acidic conditions are a concern. Thiourethane polymers

[0028] Within the scope of this description, VAT resin additives suitable for use in the manufacture of thiourethane polymer parts are used.One embodiment of the description includes a photopolymerizable thiourethane resin for additive manufacturing in an oxygen environment, the resin comprising: a first type of monomer comprising two or more thiol functional groups; a second type of monomer comprising two or more isocyanate functional groups; a photolatent base, in which the photolatent base is decomposable upon exposure to light to form a non-nucleophilic base catalyst having a pKa greater than 7; an inhibitor of anionic step-polymerization reaction, the inhibitor having an acid group configured to form an acid-base pair with the non-nucleophilic base; and a light absorber having an absorbance in the liquid mixture that is greater than an absorbance of the photolatent base at a wavelength of light used for exposure.

[0029] In at least one embodiment, because thiourethane polymers are cured using a non-nucleophilic Lewis base, free radical initiator and radical or oxygen inhibitor type additives developed for use with acrylate-based resins may not be suitable for use with thiourethane polymer manufacturing processes and systems.

[0030] As described in more detail here, embodiments of the VAT resin may include a combination of resin additives comprising an anionic step-polymerization reaction inhibitor (e.g., a cationic inhibitor) and a light absorber. These resin additives may be provided in quantities to reduce or prevent the propagation of photopolymerization of the thiourethane polymer in regions of the VAT resin that are outside the photo-defined development areas, thereby improving the photo-definition of the thiourethane polymer part.

[0031] Therefore, one aspect of the description is a VAT resin for three-dimensional (3D) SLA printing of a part made of thiourethane polymer (for example, an elastomer element). Some embodiments of the resin may include A liquid mixture comprising a first type of monomer, a second type of monomer, and a photolatent base. The first type of monomer may comprise two or more thiol functional groups, and the second type of monomer may comprise two or more isocyanate functional groups. The photolatent base decomposes upon exposure to light to form a non-nucleophilic base catalyst having a pKa greater than 7. The VAT resin may further comprise an anionic step-polymerization reaction inhibitor having an acid group configured to form an acid-base pair with the non-nucleophilic base. The VAT resin may also comprise a light absorber whose absorbance in the liquid mixture is greater than the absorbance of the photolatent base in the liquid mixture at a wavelength of light used for exposure.

[0032] In some embodiments, the VAT resin is substantially free of water (for example, less than 0.1% by weight or less than 0.01% by weight or less than 0.001% by weight in some embodiments). For example, anhydride or non-hydrated forms of monomers, photolatent base, inhibitor, and light absorber are used in the liquid mixture of the resin.

[0033] Without limiting the scope of the description by theoretical considerations, it is believed that the shelf life of the resin may be reduced by the presence of water, probably due to the reaction between water and the isocyanate functional groups of the second type of monomer. This reaction reduces the total number of isocyanate-functionalized monomers available to participate in the stepwise polymerization reaction to form the thiourethane polymer part and may form a cyanuric acid byproduct that can degrade the structure of the thiourethane polymer part after curing. Furthermore, it is believed that one of the reaction products between water and the isocyanate functional groups may be carbonic acid, which in turn can form cyanuric anhydride.It is further believed that, although cyanuric anhydride can extend the polymer chain, upon chain breakage it will release CO2 which in turn can degrade the structure of the printed polymer part after curing.

[0034] In some embodiments of the VAT resin, the molar ratio of the photolatent base to the anionic step-polymerization reaction inhibitor is in the range of approximately 5:1 to 15:1, and in some embodiments of approximately 10:1. Such ratios are conducive to allowing the polymerization reaction to proceed in the target region of light illumination where the light causes relatively high concentrations of activated non-nucleophilic base catalyst molecules (e.g., photodecomposed photolatent base molecules) and at the same time still provide sufficient inhibitor molecules in the non-target regions to form acid-base pairs with activated non-nucleophilic basic catalyst molecules that have diffused out of the target region.

[0035] In some embodiments, the anionic step-polymerization reaction inhibitor is a strong organic acid and is non-oxidizing. That is, the inhibitor is substantially completely ionized (for example, more than 90% ionized and in some embodiments, more than 99% ionized) in the liquid resin mixture, and the inhibitor does not substantially oxidize the thiol functional groups of the first type of monomer in the liquid mixture. The use of an anionic step-polymerization reaction inhibitor that is a strong acid facilitates the availability of acid groups that can form acid-base pairs with activated non-nucleophilic base catalyst molecules, for example, those diffused into non-target regions of the resin.The use of a non-oxidizing, anionic step-polymerization reaction inhibitor facilitates the shelf life of the resin by maintaining the availability of thiol functional groups that can participate in the polymerization reaction.

[0036] Non-limiting examples of embodiments of the anionic step-polymerization reaction inhibitor include: octanoic acid, methanesulfonic acid, trifluoromethanesulfonic acid, or carboxylic acid. For example, in some embodiments, the p-toluenesulfonic acid type anionic step-polymerization reaction inhibitor has a concentration in the liquid mixture in the range of approximately 0.001 to 0.2 wt%, and in some embodiments, in the range of approximately 0.05 to 0.2 wt%.

[0037] In some embodiments, the light absorber in the liquid mixture has an absorbance that is at least about 1 percent higher than the absorbance of the photolatent base at the wavelength of light to which the resin is exposed. In some other embodiments, it is 5% higher, 10% higher, or even 20% higher.

[0038] Such embodiments are conducive to the photolatent base molecules absorbing sufficient light and thus being activated non-nucleophilic basic catalyst molecules in the target area to catalyze the polymerization reaction and at the same time still allowing the light absorber to absorb the light scattered in the non-target areas of the resin and thus reduce the amount of light available to activate the photolatent base molecules in the non-target areas.

[0039] In some embodiments, the light absorber has a high molar extinction coefficient at the wavelength used to activate the photoplating base (for example, at least about 10,000 M⁻¹cm⁻¹). Having a high molar extinction coefficient is advantageous for the use of low concentrations (per for example, millimolar or lower concentrations of the light absorber in the fluid mixture of the resin, which in turn is conducive to the complete dissolution of the light absorber in the mixture, for example to mitigate the light scattering effects of partially precipitated light absorbers.

[0040] An example can be taken where the light absorber is or comprises 2,2'-(2,5-thiophenediyl)bis(5-tert-butylbenzoxazole (molar extinction coefficient of approximately 47,000 M⁻¹cm⁻¹ at approximately 373 nm) with a concentration in the fluid mixture that is in the range of approximately 0.001 to 1 wt%. At a concentration of approximately 1 wt% (for example, approximately 23 mM), the absorbance in the fluid mixture would be approximately 1080. At a fluid concentration of approximately 0.01 wt% (for example, approximately 0.23 mM), the absorbance in the fluid mixture would be approximately 10.8, and at a fluid concentration of approximately 0.001 wt% (for example, approximately 0.023 mM), the absorbance in the fluid mixture would be approximately 1.08.

[0041] Based on the present description, a person skilled in the art would appreciate that the light absorber could be selected molecules having a sufficiently high molar extinction coefficient in the UV or in the visible light spectrum to be soluble in the fluid mixture and to have an absorbance greater than the absorbance of the photolatent base and the wavelength of light which is used to activate the photolatent base.

[0042] In some embodiments of the resin, the photoplating base is or comprises 5-(2'-(methyl)thioxanthone)-1,5-diazabicyclo[4.3.0]non-5-ene tetraphenylborate. Other, non-limiting examples of other photoplating bases could also be used.

[0043] In some embodiments, the first type of monomer in the resin is or comprises one or more of the following: 2,2'-(ethylenedioxy)diethanethiol, decanedithiol, hexanedithiol, glycol dimercaptoacetate, glycol dimercaptopropionate, thiobisbenzenethiol, xylene dithiol, pentaerythritol tetramercaptoacetate, pentaerythritol tetramercatopropionate, dipentaerythritol hexamercaptopropionate, trimethylolpropane trimercaptoacetate, trimethylolpropane trimercaptoacetate or tris[2-(3-mercaptopropionyloxy)ethyl] isocyanurate.

[0044] In some embodiments, the second type of monomer in the resin is or comprises one or more of the following: hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanatooctane, isophorone diisocyanate, xylene diisocyanate, toluene diisocyanate, phenylene diisocyanate, bis(isocyanatexomethyl)cyclohexane, 4,4'-methylenebis(phenyl isocyanate), 4,4'-methylenebis(cyclohexyl isocyanate) or tris(6-isocyanatohexyl isocyanurate).

[0045] Based on the present description, a person skilled in the art would appreciate that the amounts of inhibitor and light absorber present in the resin depend on the amount of photolatent base initiator present in the resin as well as on the absorbance of the photolatent base at the wavelength of the light beam used to activate the exposure of the photolatent base to form the non-nucleophilic base catalyst.

[0046] Fig. 3 illustrates, by way of a flowchart, selected aspects of an example of a process 300 for preparing a VAT resin for a thiourethane polymer according to the principles of this description.

[0047] With continuous reference to [Fig. 3] hereafter, certain embodiments of process 300 may include the formation of a liquid mixture (step 310). The formation of the liquid mixture (step 310) comprises the combination of a first type of monomer and a second type of monomer to form a mixture of monomers (step 320). Any combination of the first and second types of monomer described herein could be mixed together to form a homogeneous mixture of monomers. For example, the first type of monomer may comprise two or more thiol functional groups and the second type of monomer may comprise two or more isocyanate functional groups.

[0048] The formation of the liquid mixture (step 310) also includes the addition of an anionic step-polymerization reaction inhibitor to the monomer mixture (step 330), for example, any anionic step-polymerization reaction inhibitor that has an acid group configured to form an acid-base pair with the non-nucleophilic base.

[0049] The formation of the liquid mixture (step 310) also includes the addition of a photolatent base to the monomer mixture (step 340), for example, any described photolatent base which decomposes upon exposure to light to form a non-nucleophilic base catalyst having a pKa greater than 7.

[0050] The formation of the liquid mixture (step 310) also includes the addition of a light absorber to the mixture of monomers (step 350), for example, any light absorber which, in the liquid mixture, will have an absorbance which is greater than an absorbance of the photolatent base at a wavelength of light used for exposure.

[0051] Embodiments of the process 300 may include any combination of sequential additions of the anionic step-polymerization reaction inhibitor, the photolatent base and the light absorber to the monomer mixture, or, the addition of two or of them or of all three to the monomer mixture simultaneously to form a homogeneous liquid mixture.

[0052] Fig. 4 illustrates, by way of a flowchart, selected aspects of an example of a 400 three-dimensional stereolithography process printing a thiourethane polymer part in accordance with the principles of this description.

[0053] With continuous reference to [Fig. 4] hereafter, certain embodiments of the process 400 may include the addition of a resin to a vat of a three-dimensional stereolithography printer (step 410). The resin may comprise any one of the embodiments of the liquid mixture comprising the first type of monomer, the second type of monomer, the photolatent base, the anionic step-polymerization reaction inhibitor, and the light absorber described herein.

[0054] Embodiments of process 400 may also include positioning (step 420) the resin or a platform of a manufacturing table located in the tank so that a thin layer of the resin is located on the platform.

[0055] In some embodiments, during the positioning step (420), the build table can be moved to pour a thin layer of resin (for example, a layer 100 to 500 microns thick) over a previously cured layer of the part. In other embodiments, during the positioning step (420), the amount of liquid platform in the tank can be increased by adding liquid platform to the tank via a pump (for example, a syringe or a peristaltic pump) to raise the resin level in the tank and thus pour a thin layer of resin over the previously cured layer. In some embodiments, part of the liquid platform can be removed from the tank via the pump to lower the resin level in the tank but leave the thin layer of resin above the previously cured layer.

[0056] In yet other embodiments, the light source can be moved and / or the focal plane of the projected light beam can be adjusted so that only the thin layer of the resin is exposed to the light beam (step 430).

[0057] Embodiments of the process 400 may also include exposing (step 440) a target area of ​​the thin film to a beam of light, the light having a pattern corresponding to a cross-section of the thiourethane polymer part so that the photolatent base in the light-exposed target area of ​​the resin decomposes to form the non-nucleophilic basic catalyst and thus catalyzes the polymerization of the first and second types of monomer together to form a patterned layer of the thiourethane polymer part.

[0058] In embodiments of process 400, inhibitor and light-absorbing additives in the resin can substantially prevent polymerization of the first and second types of monomer in the areas of the resin located outside the target area.

[0059] Based on this description, a person skilled in the art will understand how the process of selectively exposing target areas of successive thin layers of resin to a light beam can be repeated until the final three-dimensional part is formed. The part is then removed from the tank, cleaned, and post-cured.

[0060] Liquid thiourethane resins and additives could, now or possibly in the future, be purchased from the manufacturer Adaptive3D in Piano, TX. Thiolacrylate polymers

[0061] Within the scope of this description, VAT resin additives suitable for use in the manufacture of thiolacrylate polymer parts are used. One embodiment of the description includes a light-cured thiolacrylate resin for additive manufacturing in an oxygenated environment, the resin comprising: a crosslinking component; at least one monomer and / or oligomer; and a chain transfer agent comprising at least one of a thiol, a secondary alcohol, and / or a tertiary amine, wherein the resin can be configured to react upon exposure to light to form a cured material.

[0062] The crosslinking component may include any compound that reacts by forming chemical or physical bonds (e.g., ionic, covalent, or physical entanglement) between the resin components to form a connected polymer network. The crosslinking component may include two or more reactive groups capable of binding to other resin components. For example, the two or more reactive groups of the crosslinking component may be capable of chemically bonding to other resin components. The crosslinking component may include terminal reactive groups and / or side-chain reactive groups. The number and position of the reactive groups may affect, for example, the crosslinking density and the structure of the polymer network.

[0063] The two or more reactive groups may include an acrylic functional group. For example, a methacylate, acrylate, or acrylamide function. In some cases, the crosslinking component includes a difunctional acrylic oligomer. For example, the crosslinking component may include an aromatic urethane acrylate oligomer or an aliphatic urethane acrylate oligomer. The crosslinking component may include at least one of CN9167, CN9782, CN9004, polyethylene glycol diacrylate, bisacrylamide, decanedimethanol tricycle diacrylate, and / or trimethylolpropane triacrylate. The size of the crosslinking component may affect, for example, the length of the polymer network crosslinks.

[0064] The number of crosslinks or the crosslink density can be chosen to control the properties of the resulting polymer network. For example, polymer networks with fewer crosslinks may exhibit higher elongation, while polymer networks with more crosslinks may exhibit higher stiffness. This may be because the polymer chains between the crosslinks can stretch under elongation. Chains with low crosslink density can coil upon themselves to pack more tightly and satisfy entropic forces. When stretched, these chains can uncoil and elongate before pulling on the crosslinks, which may break before they can elongate further. In highly crosslinked materials, the high number of crosslinked chains can lead to a chain length that is poorly or not at all coilable and to almost immediate bond failure upon deformation..

[0065] The amount of the crosslinking component can be chosen to control the crosslinking density and the resulting properties of the polymer network. In some cases, the crosslinking component represents 1 to 95% by weight of the resin. In other cases, the crosslinking component is >1%, 1.0–4.99%, 5–10%, or approximately 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% by weight of the resin.

[46] In some cases, the resin comprises at least one monomer and / or oligomer. In some embodiments, at least one monomer and / or oligomer represents 1 to 95% by weight of the resin. In other cases, at least one monomer and / or oligomer is >1%, 1.0–4.99%, 5–10%, or approximately 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% by weight of the resin. The monomer may consist of small molecules that combine with each other to form an oligomer or a polymer.A monomer can include bifunctional monomers with two functional groups per molecule and / or polyfunctional monomers with more than one functional group per molecule. An oligomer can include molecules composed of a few monomer units. For example, in some cases, an oligomer may be composed of two, three, or four monomers (e.g., a dimer, trimer, or tetramer). An oligomer can include bifunctional oligomers with two functional groups per molecule and / or polyfunctional oligomers with more than one functional group per molecule.

[0066] At least one monomer and / or oligomer may be capable of reacting with the other resin components to form a connected polymer network. For example, at least one monomer and / or oligomer may comprise one or more functional groups capable of reacting with two or more reactive groups of the crosslinking component. At least one monomer and / or oligomer may comprise an acrylic functional group. For example, a methacylate, acrylate, or acrylamide functional group.

[0067] In some cases, at least one monomer and / or oligomer comprises one or more monomers. For example, the one or more monomers may represent approximately 1 to 95% by weight of the resin. Alternatively, the resin may comprise at least approximately 50% or at least approximately 60% of the one or more monomers. In other cases, at least one monomer and / or oligomer comprises an acrylic monomer. The acrylic monomer may have a molecular weight of less than 200 Da, less than 500 Da, or less than 1000 Da. The acrylic monomer may comprise at least one of 2-ethylhexyl acrylate, hydroxypropyl acrylate, cyclic trimethylolpropane formalacrylate, isobornyl acrylate, butyl acrylate, and / or N,N'-dimethylacrylamide.

[0068] Chain transfer agents can include any compound that possesses at least one weak chemical bond that potentially reacts with a free radical site on a growing polymer chain and interrupts chain growth. In the free radical chain transfer process, a radical can be temporarily transferred to the chain transfer agent, which re-initiates growth by transferring the radical to another component of the resin, such as the growing polymer chain or a monomer. The chain transfer agent can affect the kinetics and structure of the polymer network. For example, the chain transfer agent can delay network formation. This delayed network formation can reduce stress in the polymer network, leading to favorable mechanical properties.

[0069] In some cases, the chain transfer agent can be configured to react with an oxygen radical to initiate the growth of at least one new polymer chain and / or to re-initiate the growth of an oxygen-terminated polymer chain. For example, the chain transfer agent may include a weak chemical bond so that the radical can be displaced from the oxygen radical and transferred to another polymer, oligomer, or monomer.

[0070] Additive manufacturing processes, such as 3D printing, can produce three-dimensional objects by sequentially curing layers of a photopolymerizable resin. Thus, articles produced by additive manufacturing may comprise a majority or a plurality of photocured layers. Additive manufacturing can be carried out in an oxygenated environment, in which oxygen can diffuse into a deposited resin layer.

[0071] In some cases, an oxygen radical can be formed by a reaction of diffused oxygen with a growing polymer chain. For example, on the oxygen-rich surface of a resin layer, oxygen can react with initiator radicals or polymer radicals to form an oxygen radical. The oxygen radical can be attached to a polymer side chain. Oxygen radicals, for example, peroxy radicals, can slow down the curing of the resin. This slowed curing can lead, for example, to the formation of a thin, sticky layer of uncured monomers and / or oligomers on the oxygen-rich surface of a previously cured resin layer, which would otherwise reduce adhesion to a subsequently cured adjacent resin layer.

[0072] Due at least in part to the presence of a chain transfer agent, at least some bonding between a previously cured resin layer and an adjacent, subsequently cured resin layer can occur despite an oxygen-rich surface present on the previously cured resin layer at an interface between the previously cured resin layer and the subsequently cured resin layer. In some cases, the bonding may be covalent. In some embodiments, the bonding may be ionic. In some cases, the bonding may be a physical entanglement of polymer chains. Furthermore, in some cases, the chain transfer agent represents from U2 to 50% by weight of the resin. In some cases, the chain transfer agent represents approximately 0.5 to 4.0%, 4.0 to 4.7%, 4.7 to 4.99%, 4.99 to 5%, or 5 to 50% by weight of the resin.

[0073] Thiolacrylate polymer resin materials can exhibit excellent interlayer strength when 3D printed in outdoor environments. Because three-dimensional prints are built layer by layer, during outdoor printing each resin layer has the opportunity (for example, during pattern creation) to become oxygen-enriched at its air-exposed surface. With previous resins, this oxygen enrichment resulted in poor interlayer adhesion because the oxygen available at the oxygen-rich interfaces between the layers inhibited free radical polymerization, thus limiting chain growth and delaying the reaction.Thiolacrylate polymer resins, however, include a chain transfer agent (e.g., a secondary thiol) that can overcome this problem and promote chemical and physical crosslinking between 3D printed layers even in the presence of high or ambient oxygen levels at the layer interfaces.

[0074] Furthermore, thiolacrylate polymer resin materials may exhibit lower sensitivity to oxygen. In free-radical polymerization systems, oxygen reacts with primary initiator or propagating radicals to form peroxy radicals. In previous resins, these peroxy radicals would tend to terminate the polymerization. In thiolacrylate polymer resins, however, thiols can act as a chain transfer agent, allowing further propagation of the polymerization reaction. Lower oxygen sensitivity may enable open-air manufacturing processes without the costs of reduced-oxygen manufacturing (e.g., nitrogen or argon blanketing).

[0075] Thiolacrylate polymer resin can undergo a chain transfer reaction during photocuring. Chain transfer is a reaction by which the free radical of a growing polymer chain can be transferred to a chain transfer agent. The newly formed radical then re-initiates chain growth. It is believed that the chain transfer reaction can reduce stress in materials formed from thiolacrylate polymer resins, among other advantages.

[0076] In some cases, the chain transfer agent can be configured to transfer a radical from a first polymer chain or chain branch within the pre-cured resin layer to a second polymer chain or chain branch within the bulk of the photocurable resin. This can, for example, enable the formation of chemical or physical crosslinks between adjacent photocured layers in an additively manufactured article. In other cases, the chain transfer agent can be configured to promote the growth of at least one new polymer chain near the oxygen-rich surface present on the pre-cured resin layer. This can also, for example, enable the formation of chemical or physical crosslinks between adjacent photocured layers in an additively manufactured article.In addition, the thiolacrylate polymer resin may comprise a monomer or oligomer with a side chain capable of cooperating with the chain transfer agent to affect the chain transfer mechanism.

[0077] The chain transfer agent may comprise at least one of a thiol, a secondary alcohol, and / or a tertiary amine. The secondary alcohol may comprise at least one of isopropyl alcohol and / or hydroxypropyl acrylate. In some cases, the thiol represents approximately 0.5% to 4.0%, 4.0% to 4.7%, 4.7% to 4.99%, 4.99-5%, or 5% to 50% by weight of the resin. The thiol may comprise a secondary thiol. The secondary thiol may comprise at least one of pentaerythritol tetrakis(3-mercaptobutylate); 1,4-bis(3-mercaptobutylyloxy)butane; and / or 1,3,5-tris(3-melcaptobutyloxethyl)-1,3,5-triazine. The tertiary amine may include at least one of the following: aliphatic amines, aromatic amines, and / or reactive amines. The tertiary amine may include at least one of the following: triethylamine, N,N'-dimethylaniline, and / or N,N'-dimethylacrylamide.

[0078] Any suitable additive compound may optionally be added to the resin. For example, the resin may further comprise polyethylene glycol. The resin may further comprise polybutadiene. The resin may further comprise poly(dimethylsiloxane acrylate). The resin may further comprise a poly(styrene-maleic coanhydride) copolymer.

[0079] The resin may further comprise a photoinitiator, an inhibitor, a dye, and / or a filler. The photoinitiator may be any compound that undergoes a photoreaction upon absorption of light, producing a reactive free radical. Therefore, photoinitiators may be capable of initiating or catalyzing chemical reactions, such as free radical polymerization. The photoinitiator may comprise at least one of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, bis-acylphosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and / or 2,2'-dimethoxy-2-phenylacetophenone. In some cases, the photoinitiator represents 0.01–3% by weight of the resin.

[0080] The inhibitor may be any compound that reacts with free radicals to give products that may not be capable of inducing further polymerization. The inhibitor may include at least one of hydroquinone, 2-methoxyhydroquinone, butylated hydroxytoluene, diallylthiourea, and / or diallyl-bisphenol A.

[0081] The colorant can be any compound that changes the color or appearance of a resulting polymer. The colorant can also serve to attenuate stray light in the printing area, reducing the generation of unwanted radicals and overhardening of the sample. The colorant can comprise at least one of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, carbon black, and / or Disperse Red 1.

[0082] The filler can be any compound added to a polymer formulation that can occupy space and / or replace other resin components. The filler can include at least one of titanium dioxide, silica, calcium carbonate, clay, aluminosilicates, crystalline molecules, crystalline oligomers, semi-crystalline oligomers and / or polymers, wherein said polymers have a molecular mass between about 1,000 Da and about 20,000 Da.

[0083] The viscosity of the resin can be any value that facilitates its use in the additive manufacturing (e.g., 3D printing) of an article. Resins with higher viscosity are more resistant to flow, while resins with lower viscosity are less resistant to flow. The viscosity of the resin can affect, for example, printability, printing speed, or print quality. For example, the 3D printer may only be compatible with resins of a certain viscosity. Or, increasing the viscosity of the resin may increase the time required to smooth the surface of the deposited resin between printing layers because the resin may not deposit as quickly.

[0084] The thiolacrylate polymer resin of the described materials can also have a high curing rate and low viscosity. Additive-based fabricated objects are created by building materials layer by layer. Each layer is built up by depositing liquid resin and applying light to photocure it. The viscosity and curing rate of the resin therefore affect the printing speed. A low-viscosity resin will spread rapidly (e.g., 1 to 30 seconds) into a flat layer without the need to apply heat or mechanically manipulate the layer. Spreading can be faster (e.g., 1 to 10 seconds) with mechanical manipulation. In addition, lower viscosity can allow for faster movement of the overlay blade. The faster the curing rate, the faster a subsequent layer can be created.

[0085] The viscosity of the resin can be adjusted, for example, by changing the ratio of monomers to oligomers. For example, a resin with a higher monomer content may have a lower viscosity. This may be because lower molecular weight monomers are able to solvate oligomers, reducing oligomer-oligomer interactions and thus decreasing the overall viscosity of the resin. The resin may have a viscosity at or above room temperature of less than approximately 250 centipoise, less than approximately 500 centipoise, less than approximately 750 centipoise, or less than approximately 1,000 centipoise. In some cases, the resin has a viscosity at a temperature between 0 °C and 80 °C of less than approximately 1,000 centipoise, less than approximately 500 centipoise, or less than approximately 100 centipoise.

[0086] An article can be manufactured from the resin as described in any embodiment. The article can be manufactured by casting polymerization or by additive manufacturing processes, such as 3D printing. The article can include a shoe midsole, memory foam, an implantable medical device, a wearable item, an automobile seat, a gasket, a seal, a shock absorber, a hose, and / or a fitting. An article can be manufactured with a majority of layers comprising the resin as described in any embodiment.

[0087] In some embodiments, an article may be manufactured from the resin as described in any embodiment further comprising a surface coating. The surface coating may be applied to an article to potentially obtain the desired appearance or physical properties of said article. The surface coating may comprise a thiol. The surface coating may comprise a secondary thiol. The surface coating may comprise an alkane. The surface coating may comprise a siloxane polymer. The surface coating may include at least one semi-fluorinated polyether and / or one perfluorinated polyether.

[0088] In some embodiments, the photoinitiator can be configured to generate a free radical after exposure to light. In some embodiments, the crosslinking component and at least one monomer and / or oligomer are configured to react with the free radical to provide the growth of at least one polymer chain radical in a volume of the photopolymerizable resin. In some embodiments, the at least one polymer chain radical reacts with diffused oxygen to provide an oxygen radical. In some embodiments, the chain transfer agent can be configured to transfer the oxygen radical to initiate the growth of at least one new polymer chain radical.

[0089] In some embodiments, the crosslinking component and at least one monomer and / or oligomer are configured to react to provide one or more polymer chains after exposure to light. In some embodiments, the chain transfer agent can be configured to transfer a free radical associated with one of the polymer chains to another of the polymer chains.

[0090] In some embodiments, the photoinitiator can be configured to generate a free radical after exposure to light, wherein the free radical initiates a chain reaction between the crosslinking component and at least one monomer and / or oligomer to provide one or more polymer chains in a volume of the photopolymerizable resin. In some embodiments, the chain transfer agent can be configured to re-initiate the chain reaction to provide one or more new polymer chains in a volume of the photopolymerizable resin.

[0091] The curing rate of the resin layers may depend on the tendency of the resin components to polymerize by free radical reactions during curing by a light source (e.g., ultraviolet light). The resin may optionally include a photoinitiator or an inhibitor that can be used to accelerate or delay the curing process. A resin layer of the description, when supplied in a thickness suitable for 3D printing or other additive manufacturing, may be capable of photocuring in the times required for efficient article production. For example, in some cases, a resin layer approximately 100 mm thick may be configured to form a cured material in no more than 30 seconds, 20 seconds, 10 seconds, 3 seconds, 1 second, or 1 / 10 of a second.In other cases, a resin layer approximately 400 mm thick can be configured to form a hardened material in no more than one second. In other cases, a resin layer approximately 300 mm thick can be configured. to form a hardened material in no more than one second. In other cases, a resin layer approximately 200 mm thick can be configured to form a hardened material in no more than one second. In other cases, a resin layer approximately 1000 mm thick can be configured to form a hardened material in no more than 30 seconds. In other cases, a resin layer approximately 10 mm thick can be configured to form a hardened material in no more than 2 seconds, no more than 1 second, no more than half a second, or no more than a quarter of a second.

[0092] Another embodiment of the description includes a photopolymerizable resin for additive manufacturing, the resin comprising: at least one monomer and / or oligomer; and less than about 5% of a thiol, wherein the resin can be configured to react upon exposure to light to form a cured material. In some cases, the resin can be configured to form a cured material in an aerobic environment.

[0093] Although thiols have an unpleasant odor, thiolacrylate resin may have little or no discernible odor. This low odor characteristic is thought to result, at least in part, from the use of high molecular weight thiols in substoichiometric amounts to reduce or eliminate the thiol odor. Furthermore, the thiol may become almost completely incorporated into the polymer network.

[0094] Volatile thiol compounds can result from cured materials or during manufacturing processes that use thiols. The volatile thiol compounds can be adjusted to be below the thresholds detectable by the human sense of smell. This can be achieved, for example, by using a resin containing less than approximately 5% of a thiol. Volatile thiol compounds can be measured in a sample using gas chromatography-mass spectrometry (GC-MS). In some cases, the cured material contains less than 1 part per 100 million of volatile thiol compounds at ambient temperature and pressure for 50 seconds in an oxygen environment. In other cases, the cured material contains less than 1 part per 10 billion of volatile thiol compounds at ambient temperature and pressure for 50 seconds in an oxygen environment.In some cases, the cured material contains less than 1 part per billion of volatile thiol compounds at ambient temperature and pressure for 50 seconds in an oxygen environment. In some embodiments, the cured material contains less than 1 part per 10 billion of volatile thiol compounds at ambient temperature and pressure for 50 seconds in an oxygen environment.

[0095] The at least one monomer and / or oligomer and the thiol used for additive manufacturing may be any monomer and / or oligomer or thiol compound as described for the resin in the description. For example, the at least one monomer and / or oligomer includes an alkene, an alkyne, an acrylate or an acrylamide, a methacrylate, an epoxide, a maleimide and / or an isocyanate.

[0096] In some cases, the thiol has a molecular weight greater than about 200 or greater than about 500. In some embodiments, the thiol has a molecular weight greater than about 100 and contains groups comprising hydrogen bond acceptors and / or hydrogen bond donors, in which said groups undergo hydrogen bonding.

[0097] In some cases, the resin comprises the thiol and at least one monomer and / or oligomer in an approximately stoichiometric ratio. In other embodiments, the thiol represents less than approximately 20% by weight of the resin, less than approximately 10% by weight of the resin, or less than approximately 5% by weight of the resin.

[0098] In other cases, the thiol comprises an ester-free thiol. In some embodiments, the thiol comprises a hydrolytically stable thiol. In some embodiments, the thiol comprises a tertiary thiol.

[0099] The curing speed can be such that a layer of the light-curing resin approximately 100 mm thick is configured to cure in no more than 30 seconds. The materials can have a strain at break greater than 100%, up to 1000%. The materials have a toughness between approximately 30 MJ / m³ and approximately 100 MJ / m³.

[0100] In some embodiments, the resin comprises at least about 50% of one or more acrylic monomers and about 0 to 45% of one or more oligomers with acrylic functionality. The thiolacrylate resin can be stored as a single-pot system at room temperature.

[0101] In some cases, the resin components can be combined and stored in a single container (e.g., a suitable chemical storage container) for at least 6 months at room temperature without an increase in resin viscosity exceeding 10 to 20%. In some cases, the resin mixture components can be combined and stored in a single container for at least 6 months at room temperature with no more than a 2%, 5%, 10%, 25%, 50%, or 100% increase in resin viscosity.

[0102] Stabilized thiols can be any thiol that exhibits fewer ambient thermal reactions (e.g., nucleophilic substitution with monomers or oligomers) compared to other thiols. In some cases, the stabilized thiol comprises a bulky side chain. Such bulky side chains may comprise at least one chemical group, such as a C1-C18 cyclic alkyl, aryl, or heteroaryl group, branched or linear. In some cases, the stabilized thiol comprises a secondary thiol. In other cases, the stabilized thiol comprises a multifunctional thiol. In some cases, the stabilized thiol comprises at least one of a difunctional, trifunctional and / or tetrafunctional thiol. In some embodiments, the stabilized thiol comprises at least one of pentaerythritol tetrakis(3-mercaptobutylate); and / or 1,4-bis(3-mercaptobutylyloxy)butane.

[0103] Thiolacrylate polymer resin may exhibit improved storage stability. Resin compositions containing thiols and non-thiol reactive species such as -enes and acrylates may undergo a reaction in the dark (e.g., room-temperature thermal free-radical polymerization or Michael addition), which reduces the shelf life of these compositions. To account for the shorter shelf life of these resins, they may be stored cold or as a two-pot system. In contrast, thiolacrylate resins such as those in the materials described may include a stabilized thiol (e.g., a secondary thiol). The stabilized thiol may have reduced reactivity, which may potentially increase the shelf life of 3D-printable resin compositions and allow storage as a single-pot resin system at room temperature.Furthermore, the resin remaining at the end of a 3D printing cycle can be reused in a subsequent cycle.

[0104] In some embodiments, the components of the resin mixture can be combined and stored in a single container for at least 6 months at room temperature without an increase of more than 10% in the resin viscosity. The increase in shelf life, pot life, and / or print time may be due, at least in part, to the presence of a stabilized thiol in the resin mixture. Resin compositions containing thiols and reactive non-thiol species, for example, acrylates, may undergo reactions in the dark (e.g., ambient thermal free radical polymerizations or Michael nucleophilic additions). However, the stabilized thiol may have reduced reactivity in the dark reaction.

[0105] In some cases, the resin can be configured for continuous use in a 3D printing operation in an outdoor environment for a period of 2 weeks without an increase in viscosity exceeding 2%, 5%, 10%, 25%, 50%, or 100%. In some cases, the resin can be configured for continuous use in a 3D printing operation in an outdoor environment for a period of 4 weeks without an increase in viscosity exceeding 2%, 5%, 10%, 25%, 50%, or 100%. In some cases, the resin can be configured for continuous use in a 3D printing operation in an outdoor environment for a period of 10 weeks without an increase in viscosity exceeding 2%, 5%, 10%, 25%, 50%, or 100%. In some cases, the resin can be configured for a Continuous use in a 3D printing operation in an outdoor environment for a period of 26 weeks without a viscosity increase exceeding 2%, 5%, 10%, 25%, 50%, or 100%. In some cases, the resin can be configured for continuous use in a 3D printing operation in an outdoor environment for a period of 1 year without a viscosity increase exceeding 2%, 5%, 10%, 25%, 50%, or 100%.

[0106] In other cases, at least one monomer and / or oligomer comprises one or more acrylic monomers. In some embodiments, the one or more acrylic monomers represent at least about 50% by weight of the resin. In other cases, the resin comprises less than about 5% of a stabilized thiol comprising one or more thiol functional groups, wherein the stabilized thiol can be configured to inhibit a nucleophilic substitution reaction between the one or more thiol functional groups and the one or more monomers or oligomers.

[0107] Other embodiments of the description may include a photopolymerizable resin for additive manufacturing, the resin comprising: less than about 5% of a thiol, at least about 50% of one or more monomers; wherein the resin can be configured to react by exposure to light to form a cured material, wherein the cured material has a toughness in the range of about 3 to 100 MJ / m3 and a strain at break in the range of about 30 to 1000%.

[0108] The cured thiolacrylate resin can also exhibit a time-temperature superposition, such that its properties change with temperature and frequency. At temperatures below the onset of the glass transition, the material is glassy and brittle. However, at temperatures above the onset, the material can become viscoelastic and strong until the glass transition is shifted. The thiolacrylate resin can have a glass transition temperature close to the service temperature. For example, the resin can have an onset Tg close to 20 °C.

[0109] At temperatures above the beginning of the Tg, thiolacrylate resin can be a robust, high-deformation material. Specifically, cured thiolacrylate resin exhibits a toughness between 3 and 100 MJ / m³ and a strain at break between 30 and 800%.

[0110] The hardened materials in this description can provide mechanical properties that are strong and flexible (measured, for example, as a percentage of strain at break) that may be suitable for use in manufactured articles in which these properties are desired (for example, (Shoe midsoles, insoles, outsoles). Articles incorporating these hardened materials can thus be produced at a reduced cost with maximum efficiency and customization of product designs and mechanical properties in an additive manufacturing process. For example, customization of toughness and flexibility is possible with the hardened resin materials described above.

[0111] Due to the material properties of thiolacrylate resin, articles 3D printed from the resin can be used in a variety of applications. Specific applications may include mattresses, game pieces, and other household items, as well as articles worn on the body or used in the body or ear. The resin may also be suitable for form and fit prototypes. For example, the resin can be used to produce low-cost shoe soles (midsoles, insoles, outsoles) for trial manufacturing. In another embodiment, the resin, over a wide temperature range (e.g., 0 °C to 80 °C), has a toughness of between 3 and 100 MJ / m³ and a strain at break of between 200 and 1000%. Articles 3D printed from the resin can be used in a variety of applications.Specific applications may include gaskets, seals, hoses, shock absorbers, midsoles, automotive parts, and aerospace components. It can also be suitable for form, fit, and function prototypes. For example, it can be used to produce low-density technical shoe soles (midsoles, insoles, outsoles) for large-scale manufacturing.

[0112] Specifically, toughness can be customized by controlling the percentage and type of monomers with an optional combination of oligomers, fillers, and additional additives. Controlling these parameters allows for a specific design of the material's elongation capacity (strain) and the force at which this elongation occurs (stress). Taken together, the stress / strain behavior of a material can impact its fracture toughness. In some cases, the hardened material has a toughness of approximately 3 MJ / m³. In some cases, the hardened material has a toughness of approximately 5 MJ / m³. In some cases, the hardened material has a toughness of approximately 10 MJ / m³. In some cases, the hardened material has a toughness of approximately 15–25 MJ / m³. In some cases, the hardened material has a toughness of approximately 30 to 100 MJ / m3.

[0113] Furthermore, the deformation at break can be customized by controlling the percentage and type of monomers with an optional combination of oligomers, fillers, and additional additives. Control of the network morphology The underlying density between the crosslinks and the material's tear resistance (enabled by filler and matrix-filler interactions) can control the material's elongation (deformation). In some cases, the cured material has a break strain of approximately 100%. In other cases, the cured material has a deformation at break of approximately 200%. In some cases, the hardened material has a deformation at break of approximately 300%. In some cases, the hardened material has a deformation at break of approximately 400%. In some cases, the hardened material has a deformation at break of approximately 500%. In some cases, the hardened material has a deformation at break of approximately 600%. In some cases, the hardened material has a break deformation of approximately 700%. In some cases, the hardened material has a deformation at break of approximately 800%.

[0114] In specific cases, the cured material has a toughness in the range of approximately 3 to 30 MJ / m³ and a strain at break in the range of approximately 30 to 300%. In other cases, the cured material has a toughness in the range of approximately 8 to 15 MJ / m³. In some cases, the cured material has a toughness of less than approximately 1 MJ / m³. In some cases, the cured material has a strain at break in the range of approximately 50 to 250%. In some cases, the cured material has a glass transition temperature in the range of approximately 10 to 30 °C. In other cases, the resin has a toughness in the range of approximately 3 to 100 MJ / m³ and a strain at break in the range of approximately 200 to 1000%. In some cases, the hardened material has a toughness in the range of approximately 3 to 8 MJ / m³. In some cases, the hardened material has a strain at break in the range of approximately 350 to 500%.In some cases, the hardened material has a toughness in the range of approximately 3 to 30 MJ / m³ at approximately 20 °C. In other cases, the hardened material has a toughness of approximately 10 MJ / m³ at approximately 20 °C. In some embodiments, the hardened material has a strain at break in the range of approximately 30 to 100% at approximately 20 °C.

[0115] In some cases, the hardened material has a glass transition temperature in the range of approximately 10 to 30 °C. In some cases, the hardened material has a Shore A hardness of approximately 95 at approximately 20 °C. In some cases, the hardened material has a toughness in the range of approximately 1 to 5 MJ / m³ at approximately 20 °C. In specific cases, the hardened material has a toughness of approximately 3 MJ / m³ at approximately 20 °C.

[0116] In specific cases, the hardened material has a toughness in the range of approximately 20 to 40 MJ / m³ at approximately 20 °C. In other cases, the hardened material has a toughness of approximately 40 MJ / m³ at approximately 0 °C. In other cases, the hardened material has a toughness of approximately 30 MJ / m³ at approximately 20 °C. In other embodiments, the hardened material has a toughness of approximately 20 MJ / m³ at approximately 40 °C. In other embodiments, the hardened material has a toughness of approximately 1 MJ / m³ at approximately 80 °C.

[0117] In some cases, the hardened material has a strain at break in the range of approximately 250 to 300% at approximately 0°C. In some embodiments, the hardened material has a strain at break in the range of approximately 400 to 500% at approximately 20°C. In some cases, the hardened material has a strain at break in the range of approximately 400 to 500% at approximately 40°C. In some embodiments, the hardened material has a strain at break in the range of approximately 275 to 375% at approximately 80°C. In some embodiments, the hardened material has a glass transition temperature in the range of approximately 35 to 55°C.

[0118] The curing rate of the resin layers may depend on the tendency of the resin components to polymerize by free radical reactions during curing by a light source (e.g., ultraviolet light). The resin may optionally include a photoinitiator or an inhibitor that can be used to accelerate or delay the curing process. A resin layer of the description, when supplied in a thickness suitable for 3D printing or other additive manufacturing, may be capable of photocuring within the timeframes required for efficient article production. The curing rate may be such that a layer of the photopolymerizable resin approximately 100 mm thick is configured to cure in no more than 30 seconds.For example, in some cases, a resin layer approximately 100 mm thick can be configured to form a cured material in no more than 30 seconds, 20 seconds, 10 seconds, 3 seconds, 1 second, or 1 / 10 of a second. In other cases, a resin layer approximately 400 mm thick can be configured to form a cured material in no more than one second. In other cases, a resin layer approximately 300 mm thick can be configured to form a cured material in no more than one second. In other cases, a resin layer approximately 200 mm thick can be configured to form a cured material in no more than one second. In other cases, a resin layer approximately 1000 mm thick can be configured to form a cured material in no more than 30 seconds.In other cases, a resin layer approximately 10 mm thick can be configured to form a hardened material in no more than 2 seconds, no more than 1 second, no more than half a second, or no more than a quarter of a second.

[0119] The hardened material may also have a desired hardness suitable for manufactured articles. In some cases, the hardened material has a Shore A hardness of approximately 30 at approximately 20 °C. In some cases, the hardened material has a Shore A hardness of approximately 90 at approximately 20 °C.

[0120] The glass transition temperature (Tg) of the cured material is the temperature at which a polymer transitions from a rigid amorphous state to a more flexible state. The glass transition temperature of the cured material can be customized by controlling the percentage and type of monomer, the percentage and type of oligomer, filler, plasticizer, and curing additives (e.g., colorant, initiator, or inhibitor). In some cases, the cured material has a glass transition temperature in the range of approximately 10 °C to approximately -30 °C. In some embodiments, the cured material has a glass transition temperature at half full width (HFU) of more than 20 °C, more than 30 °C, more than 40 °C, or more than 50 °C. In specific cases, the cured material has a glass transition temperature at HFU of more than 50 °C.

[0121] Furthermore, the cured material is in a glassy state below the glass transition temperature, and the cured material is in a robust state above the glass transition temperature. In some cases, a robust state occurs in the range of approximately 5 to 50 °C. In some cases, the robust state occurs in the range of approximately 20 to 40 °C. In some cases, the resin has a glass transition temperature between approximately 20 and 25 °C.

[0122] The materials may have a strain at break greater than 100%, up to 1000%. The materials may have a toughness ranging from approximately 30 MJ / m³ to approximately 100 MJ / m³. In specific cases, the hardened material has a strain at break in the range of approximately 400 to 500% at approximately 20°C. In some cases, the hardened material has a glass transition temperature in the range of approximately 10 to 30°C. In some cases, the hardened material has a Shore A hardness of approximately 30 at approximately 20°C. In some cases, the hardened material has a Shore A hardness of approximately 19 at approximately 20°C. In some cases, the hardened material in the robust state has a toughness in the range of approximately 3 to 30 MJ / m³. In some embodiments, the robustly cured material has a toughness in the range of approximately 30 to 100 MJ / m3. In some cases, the glassy-cured material has a modulus of elasticity less than 5 GPa, greater than 2 GPa or greater than 1 GPa.In some cases, the glass-hardened material has a modulus of elasticity between 2 and 5 GPa.

[0123] Other embodiments of the description may include a photopolymerizable resin for additive manufacturing, the resin comprising: less than about 5% of a thiol, at least about 50% of one or more monomers; and a photoinitiator, wherein the photoinitiator can be configured to form a free radical upon exposure to light, such that the free radical initiates the growth of one or more polymer chains comprising at least the difunctional and monofunctional monomers; wherein the resin can be configured to react upon exposure to light to form a cured material, in which the hardened material has a glass transition temperature in the range of approximately 5 to 30 °C.

[0124] In specific cases, the resin further comprises a difunctional oligomer. In some cases, the difunctional oligomer represents less than approximately 45% by weight of the resin. In some cases, the thiol represents approximately 0.5% to 5% by weight of the resin. In some cases, one or more monomers represent approximately 1% to 95% by weight of the resin. In some cases, the photoinitiator represents 0.01–3% by weight of the resin.

[0125] The resin may further comprise a trifunctional monomer. In some cases, the trifunctional monomer comprises trimethylolpropane triacrylate.

[0126] Another embodiment of the description proposes a photopolymerizable resin for additive manufacturing, the resin comprising: about 5 to 15 percent parts rubber (“phr”) of a thiol; about 20 to 60 percent of a difunctional acrylic oligomer; and about 40 to 80 percent of one or more monofunctional acrylic monomers; wherein the resin can be configured to react by exposure to light to form a cured material.

[0127] Another embodiment of the description proposes a photopolymerizable resin for additive manufacturing, the resin comprising: about 4 to 6 phr of pentaerythritol tetrakis(3-mercaptobutylate); about 40% to 50% of CN9167; and about 50% to 60% of hydroxypropyl acrylate; wherein the resin can be configured to react by exposure to light to form a cured material.

[0128] Another embodiment of the description proposes a photopolymerizable resin for three-dimensional printing, the resin comprising: approximately 5 to 20 parts per hectare of a thiol; approximately 0 to 5 parts per hectare of poly(dimethylsiloxane acrylate) copolymer; approximately 20 to 100% of a difunctional acrylic oligomer; and approximately 0 to 80% of at least one of a monofunctional acrylic monomer; wherein the resin can be configured to react upon exposure to light to form a cured material.

[108] Another embodiment of the description proposes a photopolymerizable resin for three-dimensional printing, the resin comprising: approximately 4 to 6 parts per hectare of pentaerythritol tetrakis(3-mercaptobutylate); approximately 20% to 40% of CN9004; and approximately 60% to 80% of hydroxypropyl acrylate; in which the resin can be configured to react by exposure to light to form a hardened material.

[0129] Another aspect of the description proposes a photopolymerizable resin for three-dimensional printing, the resin comprising: approximately 5 to 10 parts per million of a thiol; approximately 0 to 20% of trimethylolpropane triacrylate; approximately 30 to 50% of at least one of a difunctional acrylic oligomer; approximately 50 to 86% of acrylate of isobornyl; and about 0 to 21% of hydroxypropyl acrylate; in which the resin can be configured to react by exposure to light to form a cured material.

[0130] Another aspect of the description proposes a photopolymerizable resin for three-dimensional printing, the resin comprising: about 4 to 6 phr of pentaerythritol tetrakis(3-mercaptobutylate); about 0% to 5% of trimethylolpropane triacrylate; about 25% to 35% of CN9004; and about 65% to 75% of isobornyl acrylate; wherein the resin can be configured to react by exposure to light to form a cured material.

[0131] Another embodiment of the description proposes a photopolymerizable resin for three-dimensional printing, the resin comprising: about 5 to 10 phr of a thiol; about 0 to 20% of trimethylolpropane triacrylate; about 30 to 50% of at least one of a difunctional acrylic oligomer; about 5 to 75% of isobornyl acrylate; and about 0 to 80% of hydroxypropyl acrylate; wherein the resin can be configured to react by exposure to light to form a hardened material.

[0132] A photopolymerizable resin for additive manufacturing can be prepared according to the following procedure.

[0133] The resins can be printed in a top-down DLP printer (such as the Octave Light RI), in an open atmosphere and under ambient conditions. The printing tank can be filled with Z fluid (typically 70 to 95% of the total volume), and then the printing resin is placed on top of the Z fluid (at proportional levels; for example, 5 to 30%). The printing parameters are entered into the control software: exposure time (which typically ranges from 0.1 to 20 seconds), layer height (which typically ranges from 10 to 300 micrometers), and the surface is covered between each layer in 0.25 to 10 seconds. A computer-aided design (“CAD”) file is loaded into the software, oriented and supported if necessary, and the printing process is initiated.The printing cycle is as follows: the build table lowers to allow the resin to coat the surface, rises to a layer height (also called Z-axis resolution) below the resin surface, the coating blade smooths the resin surface, and the optical engine exposes a mask (a cross-sectional image of the printed part at the current height), causing the liquid resin to gel. The process is repeated, layer by layer, until the item is fully printed. In some embodiments, the 3D-printed resin parts are post-cured at a temperature between 0 and 100 °C for 0 to 5 hours under UV irradiation of 350 to 400 nm.

[0134] Liquid thiolacrylate resins and additives can be purchased from the manufacturer Adaptive3D, under the trade name Elastic Tough Rubber (“ETR90”) in Piano, TX.

[0135] Figure 5 is a cross-sectional diagram representing a downhole sealing device 500 having an elastomeric element 510 designed, manufactured, and used as described. For example, the elastomeric element 510 could comprise a thiourethane / acrylate polymer manufactured using any or a combination of the manufacturing processes described above. In the illustrated embodiment, the elastomeric element 510 is positioned between the first and second end plates 530. In one or more embodiments, the first and second end plates 530 include a hook feature 535 that secures the elastomeric element 510 sufficiently so that the first and second end plates 530 apply expansion forces (for example, so that the first and second end plates 530 pull on the elastomeric element 510).The elastomer element 510 may comprise an internal surface 520 having an internal diameter and an external surface 525 having an external diameter.

[0136] Figure 6 is a cross-sectional diagram representing another downhole sealing device 600 having an elastomeric element 610 designed, manufactured, and used as described. For example, the elastomeric element 610 could comprise a thiourethane / acrylate polymer manufactured using any or a combination of the manufacturing processes described above. In the illustrated embodiment, the elastomeric element 610 is positioned in a groove 635 in a sealing feature 630 (for example, a single sealing feature). Thus, according to at least this embodiment, the elastomeric element 610 is an O-ring or other sealing element with a thin cross-sectional geometry positioned inside the groove 635.Unlike the downhole sealing device 500, the downhole sealing device 600 can use fluid pressure to axially compress the elastomer element 610 to engage with the tubing, borehole, etc. In addition to the embodiment shown in [Fig. 6], the elastomer element 610 is a single-element elastomer.

[0137] Figure 7 is a cross-sectional diagram representing a downhole sealing device 700 in an uncompressed state positioned inside a tubular structure 705 according to certain aspects of this description. The tubular structure 705 can be any suitable tubular structure, such as a drill well, casing string, or downhole tool. The downhole sealing device 700, according to the description, comprises an elastomeric element 710 designed, manufactured, and used according to the description. For example, the elastomeric element 710 could comprise a thiourethane / acrylate polymer manufactured using any one or a combination of the manufacturing processes described above. In the embodiment illustrated in [Fig. 7], the elastomer element 710 is positioned between the first and second end plates 730, and comprises an inner diameter 720 and an outer diameter 725. The first and second anti-extrusion devices 740, shown schematically, can be located next to the first and second end plates 730, opposite the elastomer element 710. The anti-extrusion devices 740 can be in a closed state, but upon application of an axial compressive force, can be actuated to an open state.

[0138] A mandrel 750 may, in some embodiments, be located inside the inner diameter 720 of the elastomer element 710 so that the elastomer element 710 fits around the mandrel 750. The mandrel 750 may provide support to the elastomer element 710 during axial compression to prevent the elastomer element 710 from deforming radially inward (for example, toward a central longitudinal axis 760). The mandrel 750 may have an inner diameter, but not in other examples. The ring that can be sealed by the bottom-well sealing device 700 may be the ring between the outer diameter of the mandrel 750 and an inner diameter of the surrounding tubing 705.

[0139] When in an uncompressed state, the downhole sealing device 700 can move freely inside the tubing 705. To move the downhole sealing device 700 into a compressed state, and to seal the tubing 705, an axial force (for example, a force applied toward the elastomeric element 710 parallel to the longitudinal axis 760 of the elastomeric element 710) can be applied. An axial force can be applied through the first and second end plates 730. In some cases, an axial force can be applied via an axial compression tool 770. The axial compression tool 770 can be any tool capable of inducing axial compression forces in the downhole sealing device 700.The axial compression tool 770 may include a linear actuator positioned either in the wellbore (e.g., adjacent to the downhole seal 700 or not adjacent to the downhole seal) or external to the wellbore. When not positioned next to the downhole seal 700, the axial compression tool 770 may include a tubular component to transmit axial compression forces to the downhole seal 700. When an axial compression force is applied, the elastomeric element 710 can be compressed, as shown in [Fig. 8].

[0140] Figure 8 is a cross-sectional diagram representing the downhole sealing device 700 of Figure 7 in a compressed state (for example, a defined state) according to certain aspects of this description. An axial compressive force 810 is applied to the bottom well sealing device 700, for example from the axial compression tool 770 and through the first and second end plates 730. The axial compression force 810 causes deformation of the elastomer element 710. As shown in [Fig.8], the anti-extrusion devices 740 are extended in response to the axial compression forces 810, and thus in the open state. The anti-extrusion devices 740 can help reduce the gap between the first and second end plates 730 and the tubular 705, preventing over-extrusion or deformation of the elastomer element 710 beyond the first and second end plates 730. When in a compressed state, the elastomer element 710 can expand sufficiently in an outside diameter to seal the tubular 720, for example by filling the ring between the mandrel 750 and the tubular 705.

[0141] Figure 9 is an end view of an anti-extrusion device 900 in a deployed state according to certain aspects of this description. The anti-extrusion device 900 may include a central opening 910 through which a mandrel or other tubular component can pass. When in a deployed state (e.g., under axial compression), the blocking faces 920 can be rotated to be perpendicular to a longitudinal axis of the anti-extrusion device 900. The blocking faces 920 prevent the extrusion element from extending excessively beyond the end plates, as described herein.

[0142] Rollers 930 may be present on the ends of the blocking faces 920 adjacent to where the blocking face 920 would be in contact or nearly in contact with the inner diameter of the tube in which it has been placed. These rollers 930 may facilitate the deployment of the anti-extrusion device 900. These rollers 930 may also facilitate the positioning of the anti-extrusion device 900 inside the tube.

[0143] Figure 10 is an isometric view of the anti-extrusion device 900 of Figure 9 in a retracted state according to certain aspects of this description. The anti-extrusion device 900 can be forced into a retracted state such that the elimination of axial compressive forces causes the anti-extrusion device 900 to move into the retracted state. In some cases, the anti-extrusion device 900 can be moved into the retracted state by axial tensile forces (e.g., opposing axial compressive forces) applied to it.

[0144] When retracted, the blocking faces 920 are moved to a position parallel or substantially parallel to the longitudinal axis of the anti-extrusion device 900. The rollers 930, being positioned at the ends of the blocking faces 920, are thus retracted by the inner diameter of the tube in which the anti-extrusion device 900 is placed. Longitudinal supports 940 are shown in a retracted state, parallel or generally parallel to the longitudinal axis of the anti-extrusion device 900.

[0145] When axial compressive forces are applied to the anti-extrusion device 900, a rear body 950 is pushed towards a front body 960. As the rear body 950 moves towards the front body 960, the blocking faces 920 rotate outwards, with the distal ends of the longitudinal supports 940 forming a triangular support where the angle between a blocking face 920 and its longitudinal support 940 is less than 90°. Under axial compressive forces, the anti-extrusion device 900 moves from the retracted state of [Fig. 10] to the deployed state of [Fig. 11].

[0146] Fig. 11 is an isometric view of the anti-extrusion device 900 of Fig. 9 in a deployed state according to certain aspects of this description. The blocking faces 920 are shown deployed and available to block the extrusion of an elastomer element. The rollers 930 are visible at the ends of the blocking faces 920. The longitudinal supports 940 are shown supporting the blocking face 920.

[0147] In some cases, one or more rollers 930 may be positioned on each blocking face 920 or on the distal end of each longitudinal support 940 so that the roller 930 is positioned adjacent to the inner diameter of a tube when the anti-extrusion device 900 is positioned in a tube in the deployed state. These rollers 930 may be single-axial rollers (e.g., flat rollers) or may be multi-axial rollers (e.g., partially captured ball bearings).

[0148] Fig. 12 is a flowchart representing a process 1200 for forming A downhole sealing device according to certain aspects of this description. As described herein, any suitable technique may be used. In at least one embodiment, any suitable additive manufacturing technique may be used, allowing the application of individual layers (e.g., complete layers or portions of layers) to be applied sequentially to form the complete elastomeric element. The elastomeric element may be formed independently of other parts of the downhole sealing device, or it may be formed with one or more parts of the downhole sealing device. For example, the elastomeric element may be formed around the first and second end plates, a mandrel, or any combination thereof.

[0149] Optional block 1210 may be supplied with a base portion. The base portion may be the mandrel, one or more end plates, or any combination thereof. In some cases, when the elastomer element is formed independently of the other parts of the downhole sealing device, block 1210 may be omitted.

[0150] In block 1220, a pattern for the elastomeric material is determined. The pattern may be the first layer or any subsequent layer of the elastomeric material, including the final layer. The pattern may include the shape of the layer.

[0151] In optional block 1230, the material for the layer can be selected. The material can be any suitable elastomeric material conforming to the description. In at least one embodiment, the material can be any of the materials described above to form an elastomeric element comprising a thiourethane / acrylate polymer. Furthermore, additives can be included with the material, thereby making the elastomeric element not only more thermally stable but also having a greater modulus range.

[0152] At block 1240, the elastomeric material layer can be applied. The layer can be applied directly to the base portion, to a temporary portion (for example, a portion that will be removed from the elastomeric element before the elastomeric element is incorporated into the wellbore sealing device), to a fabrication platform (for example, a surface that can be used to temporarily construct the elastomeric element before the elastomeric element is removed for incorporation into the wellbore sealing device), or to a previously applied layer of elastomeric material. A layer can be applied using any suitable process appropriate for the additive manufacturing style used.

[0153] The method for applying the layer in block 1240 can be any 3D printing process known or subsequently discovered, without limitation including SLA and / or DLP printing. For example, a commercially available desktop polymer 3D printer (e.g., an Octave Light printer) could be used to apply the layer to block 1240. Therefore, the layers, and thus the elastomer element, can be produced on demand, for example, in the on-site service workshop.

[0154] Blocks 1220, 1230 and 1240 can constitute an iteration of 1270 layers. Multiple iterations of 1270 layers can be used to produce an elastomeric element.

[0155] At block 1250, process 1200 can determine whether an additional layer should be applied. If an additional layer is to be applied, process 1200 can perform another iteration of layers 1270, continuing to block 1220, to determine the pattern for the additional layer.

[0156] When several materials are used, two or more layers applied sequentially may be applied in the same plane as each other, but made of different materials. For example, to produce a single layer having the appearance of a circle filled with a first material in a square field For a second material, a first iteration of 1270 layers can be performed to apply the first material in a circular shape, and a second iteration of 1270 layers can be performed to apply the second material in a square shape. Thus, at block 1240, if the current layer is applied over a previously applied layer of elastomeric material, the current layer does not necessarily need to be applied over the layer that was applied in the immediately preceding iteration, but can be applied over a layer that was previously applied two or more iterations ago.

[0157] In block 1250, if process 1200 determines that no additional coating is required, the part may be supplied to block 1260. The supply of the part may include supplying the elastomer element or any other part or combination of parts formed using process 1200. The supply of the part may include performing an additional assembly of the part with one or more other parts. The supply of the part may include supplying the part to another process or additional steps not illustrated in process 1200. In some cases, the supply of the part may include performing an additional finish, such as an additional finish of the elastomer element. For example, an additional finish may include polishing or surface texturing, or even further machining.The supply of the part may be the supply of the part to be used, such as for use in a borehole or tubular structure.

[0158] The process 1200 describes how an elastomeric element can be formed by sequential layer iterations 1270. The layer iterations 1270 can form the elastomeric element in any suitable orientation. For example, each layer of the elastomeric element can take a generally cylindrical shape, increasing in diameter for subsequent layers. In another example, each layer can take a generally annular or ring-like shape, each layer being perpendicular to the longitudinal axis of the elastomeric element (for example, the elastomeric element 310 of [Fig. 3] if it has been formed using consecutive layers from left to right). Other layer orientations can be used.

[0159] In some cases, a layer iteration 1270 may include the application of a layer of a temporary material. The temporary material may be any material that can be easily removed from the elastomer element without damaging the elastomer element. For example, the temporary material may be a material having a lower melting point than the elastomer element. In some cases, the temporary material may be a water-soluble material or a loosely bound material that can be removed by washing off the elastomer element. The temporary material may be applied in a 1270 layer iteration to provide temporary structural support for subsequent layers applied in later 1270 layer iterations. Once the elastomeric element has been formed, a finishing operation may include the removal of any temporary material, leaving voids or channels wherever the temporary material has been used.

[0160] In yet another embodiment, no layering process is required. For example, in at least one other embodiment, the pattern can be a mold. Accordingly, a selected material (for example, as described in the paragraphs above) can be placed inside a mold having a specific three-dimensional shape. The selected material can then be subjected to UV light through the UV-permeable mold, thereby forming the elastomeric element.

[0161] The aspects described here include:

[0162] A. A downhole sealing device, the downhole sealing device comprising: 1) one or more downhole sealing features, and 2) an elastomeric element comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features, the elastomeric element being able to be used to be compressed in a downhole application against a tubular.

[0163] B. A well system, the well system comprising: 1) a borehole situated in an underground formation, and 2) a downhole sealing device positioned inside the borehole, the downhole sealing device comprising: a) one or more downhole sealing features, and b) an elastomeric element comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features, the elastomeric element being able to be used to be compressed against a surface in the borehole.

[0164] C. A method for sealing inside a borehole, the method comprising: 1) positioning a downhole sealing device in a borehole located within an underground formation, the downhole sealing device comprising: a) one or more downhole sealing features; and b) an elastomeric element comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features; and 2) subjecting the elastomeric element to an axial compressive force, the axial compressive force compressing the elastomeric element against a surface in the borehole.

[0165] Aspects A, B, and C may have one or more of the following additional elements in combination: Element 1: wherein the thiourethane / acrylate polymer is a thiourethane polymer. Element 2: wherein the thiourethane / acrylate polymer is a thiolacrylate polymer. Element 3: wherein the polymer of Thiourethane / acrylate is a blended combination of a thiourethane polymer and a thiolacrylate polymer. Component 4: wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 6,900 kPa of pressure difference at a temperature of at least 80 °C. Component 5: wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 20,700 kPa of pressure difference at a temperature of at least 80 °C. Component 6: wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 20,700 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C.Component 5: wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 27,575 kPa of pressure difference at temperatures of at least 80 °C. Component 6: wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 27,575 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C. Component 9: wherein the elastomeric element has a tensile strength of at least 40 MJ / m³ and a tensile strength of at least 25 MPa.Element 10: wherein one or more downhole sealing features are first and second end plates coupled to opposite ends of the elastomeric element, the first and second end plates being configured to move relative to each other to axially compress the elastomeric element for engagement in the tubing. Element 11: wherein the elastomeric element and the first and second end plates are positioned between the first and second anti-extrusion devices, the first and second anti-extrusion devices being configured to expand in diameter when subjected to an axial compressive force such that the elastomeric element cannot deform axially beyond the first and second end plates.Element 12: wherein the one or more metallic sealing features are a single metallic sealing feature having a groove located inside, and further wherein the elastomeric element is an O-ring positioned inside the groove. Element 13: wherein the elastomeric element is a single element. Element 14: wherein the elastomeric element is a 3D-printed element manufactured using a VAT resin formed using a liquid mixture comprising: a first type of monomer comprising two or more thiol functional groups; a second type of monomer comprising two or more isocyanate functional groups; a photolatent base, wherein the photolatent base is decomposable upon exposure to light to form a non-nucleophilic base catalyst. having a pKa greater than 7; an anionic step-polymerization reaction inhibitor, the inhibitor having an acid group configured to form an acid-base pair with the non-nucleophilic base; and a light absorber having an absorbance in the liquid mixture that is greater than an absorbance of the photolatent base at a wavelength of light used for exposure. Element 15: wherein the elastomer element is a 3D-printed element made using a VAT resin formed using a liquid mixture comprising: a crosslinking component; at least one monomer and / or oligomer; and a chain transfer agent comprising at least one of a thiol, a secondary alcohol, and / or a tertiary amine, wherein the resin can be configured to react upon exposure to light to form a hardened solid material. Element 16: wherein the surface in the borehole is a borehole casing.Element 17: wherein one or more downhole sealing features are first and second end plates coupled to opposite ends of the elastomeric element, the first and second end plates being configured to move relative to each other to axially compress the elastomeric element to engage with the wellbore surface. Element 18: wherein the elastomeric element and the first and second end plates are positioned between the first and second anti-extrusion devices, the first and second anti-extrusion devices being configured to expand in diameter when subjected to an axial compressive force such that the elastomeric element cannot axially deform beyond the first and second end plates.Component 19: wherein the one or more metallic sealing features are a single metallic sealing feature having a groove located inside, and further wherein the elastomeric element is an O-ring positioned inside the groove. Component 20: wherein the downhole sealing device is a first downhole sealing device, and further comprising a second downhole sealing device positioned adjacent to the first downhole sealing device. Component 21: wherein the second downhole sealing device comprises a polymer material other than thiourethane / acrylate polymer.

[0166] Specialists in the field who are concerned by this application will understand that further additions, deletions, substitutions and modifications may be made to the embodiments described.

Claims

Demands

1. Downhole sealing device (600), comprising: one or more downhole sealing features (630); and an elastomeric element (610) comprising a thiourethane / acrylate polymer coupled to one or more downhole sealing features, the elastomeric element being able to be used to be compressed in a downhole application against a tubular (705), wherein the thiourethane / acrylate polymer is a thiourethane polymer, or alternatively a thiolacrylate polymer, or alternatively a mixed combination of a thiourethane polymer and a thiolacrylate polymer.

2. A downhole sealing device according to claim 1, wherein the elastomeric element can be used to be compressed in the downhole application against the tubing and used to seal at least 6,900 kPa of pressure difference at a temperature of at least 80 °C, or used alternatively to seal at least 20,700 kPa of pressure difference at a temperature of at least 80 °C, or alternatively to seal at least 20,700 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C, or alternatively used to seal at least 27,575 kPa of pressure difference at temperatures of at least 80 °C, or alternatively used to seal at least 27,575 kPa of pressure difference at temperatures as low as -65 °C and as high as 270 °C.

3. Bottom well sealing device according to claim 1, wherein the elastomeric element has a breaking toughness of at least 40 MJ / m3 and a tensile strength of at least 25 MPa.

4. A downhole sealing device according to claim 1, wherein one or more downhole sealing features are first and second end plates (730) coupled to opposite ends of the elastomer element, the first and second end plates being configured to move relative to each other to axially compress the elastomer element to engage in the tubing, or alternatively wherein the elastomer element and the first and second end plates are positioned between the first and second anti-extrusion devices (740).

5.

6.

7.

8. being configured to expand in diameter when subjected to an axial compressive force so that the elastomer element cannot deform axially beyond the first and second end plates. Downhole sealing device according to claim 1, wherein the one or more downhole sealing features are a single metallic sealing feature having a groove (635) located inside, and further wherein the elastomeric element is an O-ring positioned inside the groove. Well bottom sealing device according to claim 1, wherein the elastomer element is a single element. A wellhead sealing device according to claim 1, wherein the elastomeric element is a 3D-printed element manufactured using a VAT resin formed using a liquid mixture comprising: a first type of monomer comprising two or more thiol functional groups; a second type of monomer comprising two or more isocyanate functional groups; a photolatent base, wherein the photolatent base is decomposable upon exposure to light to form a non-nucleophilic base catalyst having a pKa greater than 7; an anionic step-polymerization reaction inhibitor, the inhibitor having an acid group configured to form an acid-base pair with the non-nucleophilic base; and a light absorber having an absorbance in the liquid mixture that is greater than an absorbance of the photolatent base at a wavelength of light used for exposure. A wellhead sealing device according to claim 1, wherein the elastomeric element is a 3D-printed element manufactured using a VAT resin formed using a liquid mixture comprising: a crosslinking component; at least one monomer and / or oligomer; and a chain transfer agent comprising at least one of a thiol, a secondary alcohol and / or a tertiary amine, in which the resin can be configured to react by exposure to light to form a hardened solid material.

9. Well system (100), comprising: a borehole (120) located in an underground formation; and a downhole sealing device (600) positioned inside the borehole, the downhole sealing device comprising: one or more downhole sealing features (630); and an elastomeric element (610) comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features, the elastomeric element being able to be used to be compressed against a surface in the borehole, wherein the thiourethane / acrylate polymer is a thiourethane polymer, or alternatively a thiolacrylate polymer, or alternatively a mixed combination of a thiourethane polymer and a thiolacrylate polymer.

10. Well system according to claim 10, wherein the surface in the borehole is a borehole casing (705).

11. A well system according to claim 10, wherein one or more downhole sealing features are first and second end plates (730) coupled to opposite ends of the elastomeric element, the first and second end plates being configured to move axially relative to each other to compress the elastomeric element to engage in the surface in the wellbore, or alternatively wherein the elastomeric element and the first and second end plates are positioned between the first and second anti-extrusion devices (740), the first and second anti-extrusion devices being configured to expand in diameter when subjected to an axial compressive force so that the elastomeric element cannot deform axially beyond the first and second end plates.

12. Well system according to claim 10, wherein the one or more bottom well sealing features are a single metallic sealing feature having a groove (635) located inside, and further wherein the elastomeric element is an O-ring positioned inside the groove.

13. Well system according to claim 10, wherein the downhole sealing device is a first sealing device of the well bottom, and further comprising a second well bottom sealing device positioned near the first well bottom sealing device, or alternatively, wherein the second well bottom sealing device comprises a polymer material other than the thiourethane / acrylate polymer.

14. A method for sealing inside a borehole, comprising: positioning a downhole sealing device (600) inside a borehole (120) located within an underground formation, the downhole sealing device comprising: one or more downhole sealing features (630); and an elastomeric element (610) comprising a thiourethane / acrylate polymer coupled to the one or more downhole sealing features; and subjecting the elastomeric element to an axial compressive force, the axial compressive force compressing the elastomeric element against a surface in the borehole, wherein the thiourethane / acrylate polymer is a thiourethane polymer, or alternatively a thiolacrylate polymer, or alternatively a mixed combination of a thiourethane polymer and a thiolacrylate polymer.

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