BOP elastomeric seal with improved self-repair

Abstract

A self-repairing elastomeric compound for a blowout preventer packer includes one or more elastomers, carbon black, silica, and a self-repairing agent uniformly distributed throughout the compound.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Ser. No. 63 / 352,506, filed on June 15, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to extending the reliability of blowout preventers, and more particularly to self-repairing seals and packers. Background Art

[0004] Oil and gas field operations typically involve drilling and operating wells to locate and recover hydrocarbons. Drilling rigs are located at well sites in relatively deep water. Tools (such as drilling tools), pipes and pipelines are deployed in these wells to explore underwater reservoirs. It is important to prevent well liquids from spilling and leaking into the environment. Excessive pressure kicks may cause drilling pipes, casing, drilling mud and hydrocarbons to "blow out" from the wellbore, resulting in well failure.

[0005] Blowout preventers ("BOPs") are commonly used in the drilling and completion of oil and gas wells to protect drilling and operating personnel, as well as the well site and its equipment from the effects of a blowout. Generally speaking, a blowout preventer is a remotely controlled valve or group of valves that can close the wellbore in the event of an unexpected increase in well pressure. Modern blowout preventers typically include multiple valves that are arranged in a "stack" around the drill string. The valves within a given stack typically differ from each other in their mode of operation and pressure rating, thereby providing different degrees of well control. The life and reliability of the BOP are critical to the safe operation of an oil well.

[0006] A typical BOP stack consists of multiple ram BOPs with an annular BOP on top. If a blowout is detected, the annular BOP is usually closed first, and then the ram is used as a backup if the annular BOP fails. Multiple BOPs of the same type are usually provided for redundancy, ensuring the effectiveness of a fail-safe device.

[0007] Typically, BOP packers include elastomeric polymers that are subjected to high pressures and temperatures in the field. Exposure of elastomeric seals to extremely high temperatures can lead to physical and / or chemical degradation, where the seal initially softens and then swells, resulting in increased friction in dynamic applications. High pressure applications are also susceptible to failure, as room temperature testing may provide inaccurate results. Over time, irreversible chemical changes occur at high pressure / temperature, increasing seal hardness and causing compression set and volume changes.

[0008] Due to the reduction in the number of sites available on land, certain industrial activities, such as oil and gas production, have been increasingly extended to subsea locations. Subsea wells require the BOP to remain submerged in extreme conditions for up to a year. As a result, the BOP components of subsea wells have become larger and heavier, but the space allocated to the BOP stack on existing offshore drilling rigs has not increased accordingly. Therefore, during oil and gas production, the site needs to improve the ability to operate safely and extend the life of the BOP. Summary of the invention

[0009] A key failure mode of conventional BOP packers / seals is rupture under high pressure or high temperature (HP / HT) loading and repeated cycling. In order to improve the service life and operating range of existing packers, a BOP sealer / packer is provided herein, wherein the elastomeric matrix in the packer is modified with self-healing properties, thereby allowing in-situ repair of cracks and preventing degradation of the matrix to the point of failure.

[0010] A first embodiment of the present technology provides a self-healing elastomeric compound that is specifically designed to form a packer or other high pressure, high temperature (HP / HT) seal that exhibits improved performance. This self-healing elastomeric compound may include at least one or more elastomers, carbon black, silica, and a self-healing agent. In some embodiments, the elastomer may be a nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), carboxylated nitrile rubber (XNBR), fluoroelastomer (FKM), perfluoroelastomer (FFKM) or natural rubber (NR), or a combination of elastomers. In other embodiments, the carbon black may be N326 carbon black, N550 carbon black, or a combination of the two. In some embodiments, the carbon black may have a concentration between 5phr and 40phr in the elastomeric compound.

[0011] In another embodiment, the silica can be fumed silica, and its concentration in the elastomeric compound is between 5 phr and 60 phr. In other embodiments, the self-healing agent can be polyethyleneimine, and its concentration in the elastomeric compound is between 0.05 phr and 30 phr. In some embodiments, the self-healing agent is uniformly distributed throughout the elastomeric compound.

[0012] A second embodiment of the present technology provides a self-repairing blowout preventer (BOP) comprising at least one elastomeric packer and at least one self-repairing agent uniformly distributed throughout the elastomeric packer. In some embodiments, the BOP may include a variable aperture gate packer. In other embodiments, the BOP may include an annular packer. And in another embodiment, the BOP may include a fixed bore ream packer.

[0013] In some embodiments, the self-healing agent can be made of polyethyleneimine. In some embodiments, the self-healing agent can be a multifunctional, cationic, branched polyethyleneimine having Compositions commercially available under the name of (such as Lupasol PR). In other embodiments, the self-healing agent may have a concentration between 0.05 phr and 30 phr in the BOP.

[0014] A third embodiment of the present technology provides a method for extending the life of a BOP by uniformly dispersing at least one self-repairing agent throughout a BOP packer, wherein the self-repairing agent is polyethyleneimine. In other embodiments, fumed silica may also be dispersed throughout the BOP packer. In another embodiment, the self-repairing agent may be activated under crack propagation conditions. In some embodiments, the activated self-repairing agent may repair microcracks in the BOP packer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present technology will be better understood by reading the following detailed description of non-limiting embodiments and reviewing the accompanying drawings, in which:

[0016] Figure 1 is a cross-sectional view of the BOP stack.

[0017] Figure 2 is a perspective view of a variable gate pair.

[0018] Figure 3 is a schematic diagram of a typical gate packer assembly.

[0019] Figure 4A and 4B is a schematic view of a typical annular packer assembly. DETAILED DESCRIPTION

[0020] The foregoing aspects, features, and advantages of the present technology will be further understood when considered with reference to the following description of preferred embodiments and the accompanying drawings, in which like reference numerals represent like elements. In describing preferred embodiments of the technology illustrated in the accompanying drawings, specific terminology will be used for clarity. However, the present technology should not be limited to the specific terminology used, and it should be understood that each specific term includes equivalent terms that operate in a similar manner to achieve similar purposes.

[0021] When introducing the elements of various embodiments of the present invention, the articles "a / an", "an / an", "the" and "said" are intended to mean that there are one or more elements. The terms "comprise", "include" and "have" are intended to be inclusive and mean that there may be additional elements in addition to the listed elements. The examples of any operating parameters and / or environmental conditions do not exclude other parameters / conditions of the disclosed embodiments. Additionally, it should be understood that references to "one embodiment", "embodiment", "certain embodiments" or "other embodiments" of the present invention should not be interpreted as excluding the existence of additional embodiments that also introduce the features. In addition, references to terms such as "above", "below", "above", "below", "side", "front", "rear" or other direction-related terms are made with reference to the illustrated embodiments and are not intended to be restrictive or exclude other directions.

[0022] Elastomeric packers / sealing elements in blowout preventers (BOPs) can be used to seal around pipes of various sizes. Variable gate packers can consist of a metal insert and an elastomer that act as a coherent unit to form a seal. Currently available elastomers in the field experience large deformations during operation at the bore face, surface recesses, and other critical areas. These deformations can lead to material breakdown and ultimately failure. In addition to BOP packers, other high pressure, high temperature (HP / HT) seals also have a variety of failure modes associated with rupture, such as rapid gas decompression and fatigue, resulting in a lack of reliable sealing under HP / HT conditions.

[0023] Provided herein is a method for improving the reliability of packers and sealers, including HP / HT sealers and BOP sealers / packers. The method involves utilizing elastomeric materials with self-healing properties in BOP packers that are susceptible to stress and cracking. The compositions described herein allow cracks to be repaired immediately after formation, thereby improving the reliability and application space of packers and sealers, including BOP packers and HP / HT seals.

[0024] As used herein, in one embodiment, the term "elastomer" or "elastomeric" encompasses thermosetting plastics (e.g., polymers that require vulcanization). In other embodiments, the term "elastomer" or "elastomeric" encompasses thermoplastics. In yet another embodiment, the term "elastomer" or "elastomeric" encompasses a mixture of one or more thermosetting plastics and one or more thermoplastics. In one set of embodiments, any elastomer-based packer described herein is composed of one or more of nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), carboxylated nitrile rubber (XNBR), fluoroelastomer (FKM), perfluoroelastomer (FFKM), natural rubber (NR), etc., or a combination thereof. In another set of embodiments, examples of elastomeric materials may include rubber, chloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, carboxylated nitrile rubber, natural rubber, butyl rubber, ethylene propylene rubber, epichlorohydrin, chlorosulfonated polyethylene, fluoroelastomers, etc., or a combination thereof.

[0025] As used herein, "processing conditions encountered during compounding of the packer and during normal operation of the packer" relate to typical temperatures and pressures during compression molding of the packer. Typical temperatures during compression molding of the packer may vary from about 100 degrees Celsius to about 210 degrees Celsius, although other temperature ranges are possible and are expressly contemplated herein as being within the scope of the embodiments described herein. Typical pressures during compression molding of the packer may vary from about 90 psi to about 110 psi, although other pressure ranges are possible and are expressly contemplated herein as being within the scope of the embodiments described herein.

[0026] As used herein, "crack propagation conditions in an elastomer" refers to conditions in which higher than normal stress / strain is applied in a BOP packer. During normal operation, a BOP packer is typically subjected to a temperature range of about 0 degrees Celsius to about 177 degrees Celsius at a pressure of about 15 to 20 psi. However, the combination of high temperature (HT) and high pressure (HP) and cyclic loading may trigger the appearance of cracks in an elastomeric packer. For example, failure of a BOP may originate from microcracks, which are reorientations caused by slippage between polymer chains in which the chains acquire a state of tension. Subsequently, a local scission may occur, which may then propagate to adjacent chains, which may result in irreversibly propagating cracks. Under such crack propagation conditions, the self-healing agent will initiate repair of the elastomer. Under crack propagation conditions, activation of the self-healing agent in a self-healing elastomeric compound according to an embodiment of the present disclosure includes initiating the creation of chemical bonds within the compound. Thus, when crack propagation conditions (eg, HT and HP conditions) activate the self-healing agent in the self-healing elastomeric compound, the self-healing agent is triggered to initiate chemical bond creation within the compound, thereby repairing microcracks formed by the crack propagation conditions.

[0027] In a typical blowout preventer, an elastomeric sheet may be placed between metal inserts and then subjected to a transfer or compression molding process. According to the methods described herein, the elastomeric sheet may be replaced with the self-healing elastomeric sheet described herein.

[0028] In addition to maintaining integrity during normal well operations and / or "bumping", the BOPs currently described, including modified elastomers in the packers, can also be used to seal the drilled pipe during "stripping" operations. During stripping operations, the drilled pipe can be pulled out of the wellbore using a blowout preventer that is close to the drilled pipe. This can cause wear of the gate packer (especially the elastomeric sealing element). Therefore, it is also contemplated within the scope of the embodiments presented herein to use the currently described BOP during the stripping operation. It is further contemplated within the scope of the embodiments presented herein to use a BOP including a modified (self-repairing) elastomer in the packer to regulate and monitor wellbore pressure; shut down the well (e.g., seal the gap, annulus, between the drilled pipe and the casing); "kill the well" (prevent formation fluids from flowing into the wellbore from the reservoir); seal the wellhead (close the wellbore); or cut the casing or drilled pipe in an emergency. U.S. Application Ser. No. 14 / 964,639 describes certain blowout preventers with modified designs, the disclosure of which is incorporated herein by reference, and also contemplates the use of the methods and compositions provided herein to improve the elastomers in such blowout preventers. According to embodiments of the present disclosure, one or more packers in a BOP may be made in whole or in part of the self-healing elastomers described herein.

[0029] Figure 1 A cross-sectional view of a blowout preventer stack 10 is illustrated, which may include one or more packers made of a self-healing elastomer according to an embodiment of the present disclosure. The stack may include a first blowout preventer 14, which may contain a pair of variable rams 16; a second blowout preventer 18, which may include a pair of blind shear rams; and one or more annular blowout preventers 23. The blowout preventer stack may be mounted on a wellhead casing 12. The wellhead casing 12 may be disposed around a wellbore 22, which is formed by a tubular member (such as a drilling pipe 26) passing through a surface 24. In one example, a drill bit may be coupled to a lower end of the drilling pipe 26, which may extend through the wellhead casing 12 and the wellbore 22 to extract hydrocarbons from the reservoir.

[0030] The BOP 14 may be installed below one or more annular blowout preventers at the upper end of the wellhead casing 12. The BOP 14 may include a housing 28, a pair of variable gates 16, and a pair of biasing devices 32. The housing 28 may have an opening 30, which may be configured to receive a drilling pipe 26. The variable gates 16 pairs may be arranged facing each other in the housing 28. Each biasing device 32 may be coupled to a corresponding variable gate in the variable gate 16 pairs. In certain embodiments, each biasing device 32 may include a piston configured to reciprocate in a cylinder and a connecting rod coupled to the piston. Each biasing device 32 may be configured to selectively move the variable gates 16 pairs into and out of the housing 28 relative to the opening 30. Various other types of biasing devices 32 may be envisioned without limiting the scope of the present technology.

[0031] In certain embodiments, each variable ram 16 may include a ram block and a ram packer assembly at least partially disposed within the ram block. In such an embodiment, the ram packer assembly may include a plurality of inserts and a packer member made of a self-healing elastomer as described herein. The variable ram 16 will be discussed in more detail below. In some embodiments, a second blowout preventer 18 may be disposed below the BOP 14 and mounted on the wellhead casing 12.

[0032] It should be noted that, in the cylindrical coordinate system, reference numeral 34 denotes the axial direction of the variable gate 16 , reference numeral 36 denotes the radial direction of the variable gate 16 , and reference numeral 38 denotes the circumferential direction of the variable gate 16 .

[0033] During operation, the drilling pipe 26 can be configured to rotate in the circumferential direction 38 to dig the wellbore 22 and extract hydrocarbons (fluids) from the reservoir along the wellhead casing 12. In such an embodiment, the fluid extracted from the reservoir can be transported to a remote fluid storage facility via a pipeline connected to the wellhead casing 12. In some embodiments, during certain transient operating conditions, each biasing device 32 is configured to move the corresponding variable gate 16 out of the housing 28 and toward the opening 30. In such an embodiment, the aperture face 60 ( Figure 2) can seal the drilling pipe 26 to inhibit the flow of fluid along the wellhead casing 12. In other words, the variable gate 16 pair can close the bore face 60 against the drilling pipe 26 to inhibit the flow of fluid along the wellhead casing 12. In some other embodiments, during certain transient operating conditions, the second blowout preventer 18 can be configured to cut off the drilling pipe 26 when the blind shear gate pair closes the wellhead casing 12 to seal the wellbore 22 from the external environment. In one or more embodiments, the transient operating conditions may include extremely high pressure in the wellbore 22 and / or uncontrolled flow of fluid along the wellhead casing 12. In one or more embodiments, the variable gate 16 pair can be configured to provide a uniform and high contact pressure between the packer member and the drilling pipe 26, thereby preventing leakage of the fluid.

[0034] Figure 2 An embodiment of the present technology is shown in FIG. Figure 1 16. Each variable gate 16 may include a gate block 40 and a gate packer assembly 42. Although, in the illustrated embodiment, only one gate block 40 and a portion of a gate packer assembly 42 are shown to simplify the illustration of the variable gate 16 pair. However, the illustrated embodiment should not be considered as limiting the present technology. In one embodiment, each biasing device 32 (such as Figure 1 4) can be connected to the corresponding gate block 40 for selectively moving the variable gate 16 into and out of the housing 28 (as shown in FIG. Figure 1 shown).

[0035] The gate packer assembly 42 may be at least partially disposed within the gate block 40. In one embodiment, the gate packer assembly 42 may include a plurality of inserts 44 and a packer member 46. According to embodiments disclosed herein, the packer member 46 may be made of a self-healing elastomer. In the illustrated embodiment, each of the plurality of inserts 44 may include a top plate 52, a bottom plate 54, and a central web 56 interconnecting the top plate 52 with the bottom plate 54. In certain embodiments, the plurality of inserts 44 may be made of metal. The plurality of inserts 44 may be disposed adjacent to each other to form an insert array 48. In one embodiment, the insert array 48 may include an outer peripheral surface 50 disposed facing an opening 30 configured to receive a drilling pipe 26 (e.g., Figure 1 shown).

[0036] In one embodiment, the packer member 46 may be coupled to at least a portion of the plurality of inserts 44 to provide a single or unitary structure for the gate packer assembly 42. In certain embodiments, the packer member 46 may protrude from the outer peripheral surface 50 of the insert array 48 into the opening 30 to define the bore face 60 of each variable gate 16. Specifically, the packer member 46 may protrude inwardly toward the opening 30 along the radial direction 36 of the variable gate 16. Further, the packer member 46 may extend along the circumferential direction 38 of the variable gate 16.

[0037] In one embodiment, the gate packer assembly 42 may also include a wing seal pair 62, a packer side seal 64, and a pin pair 66. The packer side seal 64 may be coupled to another peripheral surface 70 of the insert array 48, which is disposed opposite the peripheral surface 50. Each wing seal in the wing seal pair 62 may be coupled to a corresponding peripheral side of the gate packer assembly 42. Each pin in the pin pair 66 may be coupled to a corresponding wing seal of the wing seal pair 62. In such an embodiment, the gate packer assembly 42 may be at least partially disposed in the gate block 40 and may be secured to the gate block 40 via the pin pair 66 and a corresponding slot pair ( Figure 2 ) is coupled to the ram block 40.

[0038] Figure 3 A schematic diagram of a typical gate packer assembly 100 is illustrated. In the illustrated embodiment, the gate packer assembly 100 may include a plurality of inserts 102 and a packer member 104, wherein the packer member 104 may be formed of a self-healing elastomer as disclosed herein. The plurality of inserts 102 may be configured to form an insert array 106 having an outer peripheral surface 108 disposed facing an opening 110. Further, the outer peripheral surface 112 of the packer member 104 may be aligned with the outer peripheral surface 108 of the insert array 106 to define a bore face 114 of a variable gate. Specifically, the outer peripheral surface 112 of the packer member 104 may be aligned with the outer peripheral surface 108 of the insert array 106 along an axial direction 116 of the variable gate. In such an embodiment, during operation of the variable gate, the packer member 104 at the bore face 114 may be exposed to high pressure and high temperature conditions. Under high pressure (HP) and / or high temperature (HT) conditions, at the hole surface 114 (see Figure 3 ) at the packer member 104 (see Figure 3 ) may deform and wear. The directional self-repairing packer described herein advantageously reduces the wear / loss of the packer member 104.

[0039] Figure 4A and 4BA schematic view of a typical annular packer assembly 150 positioned circumferentially around a wellbore tubular 26 is illustrated. In the illustrated embodiment, the annular packer assembly 150 may include a wear plate 151 that eliminates metal-to-metal contact between the packer unit insert and the BOP latch head 152. A plurality of inserts 153 and packer members 154 may be configured to form a sealing element 160 disposed around the wellbore tubular 26. According to an embodiment of the present disclosure, the packer member 154 may be formed of a self-healing elastomer. Closure of the BOP may be hydraulically actuated, which pushes a closure chamber 169 to raise a piston 162 and squeeze the packer unit 160 radially inward to seal.

[0040] In order to improve the HP / HT performance of the annular isolation unit of the gate and annular BOP packers, a specific combination of physical properties must be met. For example, in order to maintain the operational performance of the packer, the modulus of the packer at 100% strain cannot be reduced. Therefore, it is problematic to incorporate self-healing agents into the packer material because self-healing agents typically reduce the modulus due to softening. Additionally, the strength properties of the packer, such as tear strength and tensile strength, must be maximized to obtain excellent performance of the packer under high pressure. By using the formulations described herein, compositions incorporating self-healing agents can be used to form packers without sacrificing the necessary properties for operational performance, such as modulus, tear strength, and tensile strength.

[0041] Table 1 illustrates the interaction of the self-healing agent and silica in the self-healing elastomeric compounds according to embodiments of the present disclosure compared to the control compounds. The added components are measured in phr or parts per hundred rubber. Lupasol PR was selected as the self-healing agent. In the self-healing elastomeric compounds tested, HNBR was selected as the base elastomer.

[0042] Table 1

[0043]

[0044] Test results

[0045]

[0046] *Test stopped at 1000 cycles

[0047] In addition to the control experiment, each experiment used a polymer of 1,2-ethylenediamine and aziridine (as PR commercially available, average molar mass of 2,000) as a self-healing agent, used at 1.5 phr. Both precipitated silica and fumed silica were tested. Experiment B also included 20 phr of N550 carbon black. In general, polyethyleneimine (such as PR) can have the effect of improving the tensile strength, tear strength and fatigue at 250°F of the compound, but it will also reduce the modulus in an undesirable manner. Compound B exhibits a common way of recovering the modulus, but fatigue performance is found to be sacrificed. Compound C shows the benefit of using fumed silica instead of carbon black, and its concentration in compound D is further optimized. According to embodiments of the present disclosure, it is found that the blending of the N300 series and a larger amount of fumed silica with other components in compound D meets a unique set of physical properties, allowing the composition to be used to form a packer. In compounds containing self-healing agents according to embodiments of the present disclosure, both tear strength and tensile strength exceed these properties exhibited by the control composition, while also maintaining modulus and fatigue.

[0048] The carbon black used in the self-healing elastomer compound according to an embodiment of the present disclosure may include N110 series carbon black, N200 series carbon black, N300 series carbon black, N500 series carbon black, N700 series carbon black, or a combination thereof. The carbon black may be present in the compound at a concentration between 5 and 60 phr.

[0049] The silica used in the self-healing elastomeric compound according to embodiments of the present disclosure may include precipitated silica, fumed silica, or a combination thereof. The silica may be present in the compound at a concentration between 5 and 60 phr.

[0050] The self-healing agent used in the self-healing elastomeric compound according to an embodiment of the present disclosure may include a multifunctional cationic polyethyleneimine (PEI) having a branched polymer structure, such as PR, P. SK, WF, PR 8515, G 20, PS, G20water free, SC61B or a combination thereof are those commercially available. The self-healing agent may be present in the compound at a concentration between 0.05 and 30 phr.

[0051] The fatty acid used in the self-healing elastomeric compound according to embodiments of the present disclosure may include stearic acid. The fatty acid may be present in the compound at a concentration between 0.1 and 5 phr.

[0052] The metal oxide used in the self-healing elastomeric compound according to embodiments of the present disclosure may include zinc oxide. The oxide may be present in the compound at a concentration between 1 and 10 phr.

[0053] The sulfur used in the self-healing elastomeric compound according to an embodiment of the present disclosure may include ASD-75 sulfur. The sulfur may be present in the compound at a concentration between 0.1 and 5 phr. The sulfur may be soluble sulfur or insoluble sulfur.

[0054] The auxiliary agent used in the self-healing elastomer compound according to the embodiment of the present disclosure may include HVA-2 (N,N'-m-phenylene bismaleimide), TAIC (triallyl isocyanurate, C 12 H 15 N3O3), TAC (triallyl cyanurate), MPDM (N,N'-m-phenylene bismaleimide), TMPTA (trimethylolpropane triacrylate) or a combination thereof. The adjuvant may be present in the compound at a concentration between 0.1 and 10 phr.

[0055] The peroxide used in the self-healing elastomer compound according to the embodiment of the present disclosure can be used to initiate the free radical crosslinking process in the compound. Suitable peroxides can include, for example, VC 40KE, VC-60, diisopropyl peroxide (DCP), 1,3 1,4-bis(tert-butylperoxyisopropyl)benzene (DIPP), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3 (DYBP), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (DHBP), 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (TMCH), or a combination thereof. The peroxide can be present in the compound at a concentration between 0.1 and 10 phr.

[0056] The accelerator used in the self-healing elastomeric compound according to an embodiment of the present disclosure may include a thiuram compound, a dithiocarbamate compound, 2-2'-dithiobis(benzothiazole) (MBTS), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), or a combination thereof.

[0057] Self-healing elastomeric compounds according to embodiments of the present disclosure can be made by mixing ingredients, for example using a Banbury mixer or other high shear mixer (such as a roller mill). In one or more embodiments, all ingredients except the curing agent in the self-healing elastomeric compound can be mixed into a stock at a relatively high temperature (e.g., greater than 100°F to 300°F), wherein the stock ingredients are dispersed and distributed throughout the stock. After the stock is cooled, the curing agent can be added to the stock at a temperature not exceeding 210°F. The curing agent can include, for example, sulfur, accelerators, peroxides, and adjuvants. A sheet of this stock is cured in a mold at a temperature of up to 320°F to produce a packer according to an embodiment of the present disclosure.

[0058] The self-healing elastomeric compounds according to embodiments of the present disclosure can be formulated using sulfur or peroxide curing agents or both. In formulations including sulfur, the sulfur curing agent can include all sulfur (insoluble or soluble S8) or include sulfur plus an accelerator, as described above.

[0059] Although the present technology has been described herein with reference to embodiments, it should be understood that these embodiments are only used to illustrate the principles and applications of the present technology. It should therefore be understood that various modifications may be made to the exemplary embodiments and other arrangements may be designed without departing from the spirit and scope of the present technology as defined in the appended claims.

Claims

1. A self-healing elastomeric compound for a blowout preventer (BOP) packer, comprising: one or more elastomers; Carbon black; Silicon dioxide; as well as Self-healing agent.

2. The compound of claim 1, wherein the one or more elastomers are selected from the group consisting of nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), carboxylated nitrile rubber (XNBR), fluoroelastomer (FKM), perfluoroelastomer (FFKM) and natural rubber (NR).

3. The compound according to claim 1, wherein the carbon black is selected from the group consisting of N200 series carbon black, N300 series carbon black and N500 series carbon black.

4. The compound according to claim 3, wherein the carbon black has a concentration between 5 and 40 phr of the one or more elastomers.

5. The compound of claim 1, wherein the silica is precipitated silica, fumed silica, or a combination thereof.

6. The compound according to claim 5, wherein the silica has a concentration between 5 and 50 phr of the one or more elastomers.

7. The compound of claim 1, wherein the self-healing agent comprises polyethyleneimine.

8. The compound of claim 1, wherein the self-healing agent is uniformly distributed throughout the elastomeric compound.

9. The composition of claim 1, wherein the self-healing agent has a concentration between 0.05 and 20 phr of the one or more elastomers.

10. A blowout preventer (BOP), comprising: At least one elastomeric packer, wherein each of the at least one elastomeric packer is made of a self-healing elastomeric compound comprising: Elastomers; a self-healing agent uniformly distributed throughout said elastomeric compound; Carbon black; and Silicon dioxide.

11. The BOP of claim 10, wherein the at least one elastomeric packer comprises a variable aperture ram packer.

12. The BOP of claim 10, wherein the at least one elastomeric packer comprises an annular packer.

13. The BOP of claim 10, wherein the at least one elastomeric packer comprises a fixed bore enlargement packer.

14. The BOP of claim 10, wherein the self-healing agent comprises polyethyleneimine.

15. The BOP of claim 14, wherein the self-healing agent has a concentration between 0.05 and 20 phr of the elastomer.

16. A method for extending the life of a blowout preventer (BOP), comprising: Assembling a BOP packer in the BOP, wherein the BOP packer is made of an elastomeric compound comprising: Elastomers; Self-healing agent; Carbon black; and Silicon dioxide.

17. The method of claim 16, wherein the self-healing agent comprises polyethyleneimine.

18. The method of claim 16, wherein the silica is fumed silica dispersed throughout the BOP packer.

19. The method of claim 16, further comprising activating the self-healing agent during a crack propagation condition in the BOP packer.

20. The method of claim 19, further comprising repairing microcracks in the BOP packer using the self-healing agent.

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