CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/091,246, filed December 12, 2014, the entire content of which is incorporated by reference herein.

FIELD OF THE INVENTION

[0002] This invention relates to an epoxy-based insulation material for subsea oil and gas production equipment.

BACKGROUND OF THE INVENTION

[0003] The oil and gas industry utilizes deep water production well pipelines and associated processing equipment in subsea environments. These pipelines and equipment can be operated at depths greater than 5,000 ft below sea level, and potentially as deep as 12,000 feet below sea level. At these depths the process fluids coming out of the well head can exceed 300 °F, while the surrounding sea water is generally only a few degrees above freezing, i.e., around 34 °F. This temperature differential can cause the internal process fluid temperature to dip below 70 °F. If the temperature of the process fluids are not maintained above 70 °F, these fluids can condense and form thick hydrates, reducing the flow rate of the well head or possibly plugging the equipment completely. This can result in very expensive shutdowns and clean-outs, or possibly necessitate the re-drilling of the well. Moreover, ambient pressure at these depths can be greater than 5,000 psi. A protective insulation used to maintain the process fluid temperature above 70 °F also needs to have high compressive strength to withstand this pressure without cracking or disbonding from the substrate.

[0004] Because of the temperature differentials and pressure demands in subsea environments, insulation materials used on deep water production well pipelines and associated processing equipment need to withstand high pressure and protect against the extreme temperature differential. Additionally, insulating materials need to have good hydrolytic stability and not decompose under these high temperature and high pressure immersion conditions.

SUMMARY

[0005] The present application discloses exemplary embodiments of an amine-cured epoxy elastomer for use as thermal insulation for wells, pipelines, and associated processing equipment in subsea environments. By way of example to illustrate various aspects of the general inventive concepts, several exemplary embodiments of compositions and methods are disclosed herein.

[0006] In an exemplary embodiment, the present disclosure is directed to an epoxy-based insulation material for insulating a subsea production apparatus. The epoxy-based insulation material has an amine-cured epoxy elastomer matrix and a plurality of non-metallic beads suspended in the matrix. The epoxy matrix also comprises a relatively small amount of polysiloxane. The epoxy matrix comprises not greater than 10% polysiloxane in the matrix, including without limitation l%-5%, 1%-10%, 5%-10%. In certain embodiments, the epoxy matrix comprises 1%-15%, l%-20%, l%-30%, 5%-30%, etc. The epoxy-based insulation material is located on the subsea production apparatus to thermally insulate a hydrocarbon fluid from sea water.

[0007] In an exemplary embodiment, the present disclosure is directed to an epoxy-based insulation material for insulating a subsea production apparatus. The epoxy-based insulation material is an amine cured epoxy elastomer matrix with a suspended uniform distribution of hollow glass spheres. This epoxy elastomer matrix contains no more than 10% polysiloxane, including without limitation l%-5%, 1%-10%, 5%-10%. In certain embodiments, the epoxy matrix comprises 1%-15%, l%-20%, l%-30%, 5%-30%, etc.

[0008] In an exemplary embodiment, the present disclosure is directed to a method of thermally insulating a subsea production apparatus. The method comprises the steps of: providing a two- component epoxy; mixing component A and component B; installing component A and component B on at least a portion of the subsea production apparatus; and allowing the mixture to cure to form an amine-cured epoxy elastomer insulating material. [0009] In an exemplary embodiment, the two-component epoxy comprises component A and component B. Component A comprises an epoxy resin diluent, an epoxy resin, a silane, a dispersive additive, a polyether siloxane, and an acrylic polymer. Component B comprises an aminopolysiloxane, at least one curing agent, an alkoxysilane, polyoxypropylenediamine, and at least one thickening agent. In an exemplary embodiment, Component B further comprises an accelerator. Both component A and component B further contain a plurality of non-metallic beads.

[0010] In an exemplary embodiment, the present disclosure is directed to a method of thermally insulating a subsea production apparatus comprising the steps of: providing an epoxy comprising component A and component B; mixing component A and component B; injecting components A and B into a molded form; and encapsulating at least a portion of the subsea production apparatus in the mold. The mixture of components A and B acts to insulate the subsea production apparatus. Component A is comprised of an epoxy resin diluent, an epoxy resin, a silane, a dispersive additive, a polyether siloxane, and an acrylic polymer. Component B is comprised of an aminopolysiloxane, at least one curing agent, an alkoxysilane,

polyoxypropylenediamine, and at least one thickening agent. Both component A and component B further contain a plurality of non-metallic beads.

[0011] Examples of the subsea production apparatuses that can be insulated with the inventive epoxy matrix to prevent unacceptable cooling of hot crude oil include without limitation, wells, pipelines, Christmas trees and wellheads. This equipment is used in the transportation and flow control of hot crude oil from beneath the ocean floor to the surface where it is transferred to holding tanks for transportation to onshore processing facilities.

DETAILED DESCRIPTION

[0012] Several illustrative embodiments will be described in detail with the understanding that the present disclosure merely exemplifies the general inventive concepts. While embodiments encompassing the general inventive concepts may take various forms, the general inventive concepts are not intended to be limited to the specific embodiments described herein. [0013] Deep water, subsea insulation composite materials are used on processing equipment during deep water oil and gas production to maintain the temperature of the internal process fluids, including gases. The term subsea as used herein refers essentially to technology, methods, processes or equipment used in the oil and gas industry which are primarily used or situated beneath the surface of the sea, including without limitation, offshore oil and gas developments and underwater mining.

[0014] The present invention is an epoxy-based insulation material that exhibits tough, resilient and flexible properties specifically developed to provide thermal insulation to subsea oil wells, pipelines, and associated equipment in subsea environments. Its extreme mechanical properties make it suitable to use on hot pipe having temperatures as high as 300 °F (149 °C) and under extreme pressures of over 5,000 psi, including without limitation 4,500 psi, in depths up to 12,000 feet where the seawater temperatures are as low as 34 °F (1.1 °C). In certain

embodiments, the epoxy-based insulation material is suitable for use on hot pipe having temperatures as high as 350 °F (177 °C). The epoxy-based insulation material is ideal for jumpers and short pipe runs where a flexible, non-cracking thermal insulation is preferred for providing flow assurance to prevent reduced flow rates or equipment plugging.

[0015] As detailed herein, the epoxy-based insulation material features low thermal conductivity, flexibility, and flowability for castable applications. The epoxy-based insulation material has a long working time for ease of application and is tough and resilient to handle shipping and installation. The epoxy-based insulation material tolerates extreme pressures of over 5,000 psi, including without limitation 4,500 psi, at extreme depths of over 12,000 feet or over 3,600 meters. It is dimensionally stable under extreme subsea exposures.

[0016] In certain embodiments, the epoxy-based insulation material of the present invention may have a yellow or white color. It may have a solids content of 100% +/- 2% by volume.

[0017] The epoxy-based insulation material for insulating a subsea production apparatus has an amine-cured epoxy elastomer matrix and a plurality of non-metallic beads suspended in the matrix. The epoxy matrix also comprises a relatively small amount of polysiloxane. In an exemplary embodiment, at least a portion of the polysiloxane is reacted in the backbone of one of the amine curing agents. Specifically, the polysiloxane is present as an aminopolysiloxane. The epoxy matrix comprises not greater than 10% polysiloxane, including without limitation l%-5%, 1%-10%, 5%-10%. In certain embodiments, the epoxy matrix comprises 1%-15%, 1%- 20%, l%-30%, 5%-30%, etc. The epoxy-based insulation material is located on the subsea production apparatus to thermally insulate a hydrocarbon fluid from sea water.

[0018] In an exemplary embodiment, the present disclosure is directed to an epoxy-based insulation material for insulating a subsea production apparatus. The epoxy-based insulation material is an amine cured epoxy elastomer matrix with a suspended uniform distribution of hollow glass spheres. This epoxy elastomer matrix contains no more than 10% polysiloxane, including without limitation l%-5%, 1%-10%, 5%-10%. In certain embodiments, the epoxy matrix comprises 1%-15%, l%-20%, l%-30%, 5%-30%, etc.

[0019] In an exemplary embodiment, the amine-cured epoxy elastomer matrix is formed by a reaction of a two-component epoxy having component A and component B. Component A comprises an epoxy resin diluent, an epoxy resin, a silane, a dispersive additive, a polyether siloxane, and an acrylic polymer. Component B comprises an aminopolysiloxane, at least one curing agent, an alkoxysilane, polyoxypropylenediamine, and at least one thickening agent. Both component A and component B further contain a plurality of non-metallic beads.

[0020] In accordance with one embodiment, the epoxy resin diluent may be Epotuf® 37051, which is available from Reichhold Inc. The epoxy resin may be Epalloy 5000, which is available from CVC Emerald Performance Materials. The silane may be Silquest A-187, which is available from Momentive. The dispersive additive may be Anti-Terra-U 100, available from Byk Additives and Instruments. The polyether siloxane may be Tego Wet 270, which is available from Evonik Industries. The acrylic polymer may be Modaflow available from Allnex USA Inc.

[0021] In accordance with one embodiment, the aminopolysiloxane may be CI 008, which is available from Milliken Chemical. In accordance with one embodiment, the aminopolysiloxane may be an aminoalkyl-terminated polydimethylsiloxane. In accordance with one embodiment, the aminoalkyl-terminated polydimethylsiloxane is WACKER® FLUID H 15 D, which is available from Wacker Chemie AG. In accordance with one embodiment, the

aminopolysiloxane may be a linear aminated polydimethylsiloxane or a di-methyl-3 - aminopropyl terminated polysiloxane. In accordance with one embodiment, the linear aminated polydimethylsiloxane is Silmer H Di-8, which is available from Siltech Corp. In certain embodiments the aminopolysiloxane may be di-methyl-3 -aminopropyl terminated polysiloxane of the formula shown in Equation 1.

[0022] In accordance with one embodiment, the alkoxysilane may be Xiameter OFS 6020 silane, which is available from Dow Corning Corporation. The polyoxypropylenediamine may be Jeffamine D-2000/Poly-A 27-2000, which is available from Huntsman Corporation. At least one of the thickening agents may be Aerosil R202, which is a fumed silica after treated with a polydimethylsiloxane available from Evonik Industries AG.

[0023] In an exemplary embodiment, component A further contains a rheological additive. In an exemplary embodiment, component B further contains a rheological additive. In an exemplary embodiment, component B further contains an accelerator. The rheological additive may be modified urea. In certain embodimets, the rheological additive may be Byk 410 (Mod Urea Soln Thixotrope), which is available from BYK USA Inc.

[0024] In an exemplary embodiment, the accelerator is 2,4,6-tri(dimethylaminom ethyl) phenol. In an exemplary embodiment, the curing agent may be a polyamine. In an exemplary

embodiment, the curing agent may be a cycloaliphatic amine. At least one of the curing agents may be Amicure Cycloaliphatic Amine (PACM) available from Air Products and Chemicals, Inc. An additional curing agent may be IPD Adduct 7181 available from Air Products and Chemicals, Inc. At least one of the curing agents may be Ancamine K54, available from Air Products and Chemicals, Inc. Additionally a curing agent may be polyamine, specifically Epikure 3378, available from Momentive Specialty Chemicals, Inc. [0025] In an exemplary embodiment, component A, component B, or both component A and component B further contain a pigment. In an exemplary embodiment, the pigment may be a benzimidazolone pigment. The benzimidazolone pigment may be Hostaperm Yellow H4G (PY 151 Benzimidazolone), which is available from Clariant International Ltd.

[0026] In an exemplary embodiment, the non-metallic beads may be made of glass, ceramic, plastic or any other non-metallic substance. In an exemplary embodiment, the non-metallic beads may be bubbles, spheres, microspheres, or any other bead-like filler material. In an exemplary embodiment, the non-metallic beads may be glass bubbles, hollow ceramic microspheres, hollow glass spheres, or any non-metallic filler. In an exemplary embodiment, the non-metallic beads S42XHS glass bubbles types K and S, which are available from 3M.

[0027] In an exemplary embodiment, the epoxy-based insulation material as a whole has an ASTM D630 elongation of between 5% to 50%, including without limitation at least 15%. The epoxy-based insulation material has a Shore D hardness of between 20 to 85 before being exposed to water, including without limitation a Shore D hardness of 55 before being exposed to water. The epoxy-based insulation material has a Shore D hardness of between 20 to 85 after being exposed to water at 250 °F for 5 weeks, including without limitation a Shore D hardness of 30 after being exposed to water at 250 °F for 5 weeks. The epoxy-based insulation material has an ASTM D630 tensile strength of between 500 to 5,000 psi, including without limitation 1,500 psi (10.34 Mpa). The epoxy-based insulation material has an ASTM C518 thermal conductivity of between 0.0835 W/m°K to 0.334 W/m°K, including without limitation 0.167 W/m°K at between 86 °F and 140 °F.

[0028] In an exemplary embodiment, the present disclosure is directed to a method of thermally insulating a subsea production apparatus. The method comprises the steps of: providing a two- component epoxy; mixing greater than 1 part by volume of component A with 1 part by volume of component B; installing the insulating material on at least a portion of the subsea production apparatus; and allowing the mixture to cure to form an amine-cured epoxy elastomer insulating material. The two-component epoxy comprises component A and component B. The volumetric ratio of component A to component B may be greater than 1 part component A to 1 part component B, including without limitation, 1.1A : IB , 1.2A : IB , 1.3A : IB , 1.4A : IB , 1.5A IB , 1.6A : IB , 1.7A : IB , 1.8A : IB , 1.9A : IB , 2A : IB , 3A : IB , 4A : IB , etc.

[0029] Component A comprises an epoxy resin diluent, an epoxy resin, a silane, a dispersive additive, a polyether siloxane, and an acrylic polymer. Component B comprises an

aminopolysiloxane, at least one curing agent, an alkoxysilane, polyoxypropylenediamine, and at least one thickening agent. Both component A and component B further contain a plurality of non-metallic beads.

[0030] In an exemplary embodiment, the present disclosure is directed to a method of thermally insulating a subsea production apparatus comprising the steps of: providing an epoxy; mixing component A and component B; injecting components A and B into a molded form; and encapsulating at least a portion of the subsea production apparatus in the mold. The mixture of components A and B acts to insulate the subsea production apparatus. The epoxy comprises component A and component B. Component A comprises an epoxy resin diluent, an epoxy resin, a silane, a dispersive additive, a polyether siloxane, and an acrylic polymer. Component B comprises an aminopolysiloxane, at least one curing agent, an alkoxysilane,

polyoxypropylenediamine, and at least one thickening agent. Both component A and component B further contain a plurality of non-metallic beads.

[0031] In an exemplary embodiment, the method further comprises the step of: heating components A and B. The mixture may be heated to between 70 °F and 350 °F, including without limitation between 120 °F and 150 °F. The method may further comprise the step of: allowing components A and B to cure for between 30 minutes to 24 hours, including without limitation between 4 to 6 hours.

[0032] In certain embodiments of the method, the mixing may occur by hand. A power mixer may be used to provide the mixing. Components A and B may be pumped through a heated plural component spray pump. The mixture may be pumped through a manifold. The manifold may have static mixers. [0033] In an exemplary embodiment, the method may employ circulating air at a temperature greater than 75 °F through at least the portion of the subsea production apparatus being insulated.

Substrates & Surface Preparation

[0034] Examples of the subsea production apparatuses that can be insulated with the inventive epoxy matrix to prevent unacceptable cooling of hot crude oil include without limitation, wells, pipelines, Christmas trees and wellheads. For applications using steel, decontaminate surfaces as needed. Additionally, the surfaces may be abrasive cleaned to a specified SSPC (Steel Structures Painting Council) standard. In an exemplary embodiment, the cleaning may be per SSPC SP-10 (Near White Metal Condition) and may produce a specified anchor pattern or surface profile, including without limitation a 3½ mil (0.09 mm) surface profile. The surfaces may be sweep- blasted to remove flash rust, if any, before coating. If possible, the steel should be dry and dust- free before coating. In one exemplary embodiment, application to wet steel is not recommended. The epoxy-based insulation material may be applied over recommended primers.

Mixing & Thinning

[0035] In an exemplary embodiment, the epoxy-based insulation material is hand mixed at room temperature of 75 °F (24 °C) and the gel time may be approximately 4 hours or more. However, a variety of mixing temperatures may be used, which may result in varying gel times. The mixture may be heated to between 70 °F and 350 °F, including without limitation between 120 °F and 150 °F. In an exemplary embodiment, the gel time at 120 °F (49 °C) may be approximately 30 minutes or less. In an exemplary embodiment, the gel time at 150 °F (66 °C) may be less than 30 minutes. Both components A and B may be power mixed separately with an agitator or mixer until homogenous prior to use. In certain embodiments, mixing can take up to 20-30 minutes in a drum container. Materials are normally combined through the use of a plural component mixing equipment. However, hand mixing may be used for small area applications or repairs. In certain embodiments, reaction injection molding (RTM) may be employed to allow the curing reaction to take place. In an exemplary embodiment, the mixing ratio by volume for the epoxy-based insulation material is 2 parts component A to 1 part component B (2A: IB).

However, other volumetric mixing ratios may be used and are contemplated within the scope of the invention. In certain embodiments, the volumetric ratio of component A to component B may be 1 part component A to 1 part component B or greater than 1 part component A to 1 part component B, including without limitation, 1.1 A : IB , 1.2A : 1 , 1.3 A : IB , 1.4A : IB , 1.5A : IB , 1.6A : IB, 1.7A : IB , 1.8A : IB , 1.9A : IB , 2A : IB , 3A : IB , 4A : IB , etc.

Application Equipment Guidelines

[0036] Listed below are general equipment guidelines for the application of epoxy-based insulation material of the instant invention. However, job site conditions may require modifications to these guidelines to achieve the desired results. Modifications to the equipment guidelines are contemplated within the scope of the invention. In general, the epoxy-based insulation material may be cast into a cavity created by a mold that has been configured around a pipe or piece of equipment, including without limitation wells, pipelines, Christmas trees and wellheads. In certain embodiments, the epoxy-based insulation material maybe be applied through plural-component equipment designed for molded applications. Plural component spray equipment with a high pressure airless proportioned pump with any of the A to B volumetric ratios listed herein can be used. In certain embodiments, other volumetric ratios may be used. However, care should be taken to reduce the possibility of introducing air into the epoxy-based insulation material.

[0037] The components A and B of the epoxy-based insulation material may be pumped through a heated plural component spray pump and pumped through a manifold fitted with static mixers. The materials may be heated and then injected or pumped into a mold formed around the pipe or piece of equipment, including without limitation wells, pipelines, Christmas trees and wellheads. In an exemplary embodiment, the material will flow and encapsulate all surfaces including bolts, edges and welds and is cast at thicknesses needed to meet thermal conductivity requirements as determined by the user.

[0038] In certain exemplary embodiments, a pump set at a fixed-volume ratio of 2A : IB may be utilized for applying the epoxy-based insulation material. However, other volumetric ratios may be utilized as described herein including without limitation, 1 part component A to 1 part component B, 1.1A : IB , 1.2A : IB , 1.3A : IB , 1.4A : IB , 1.5A : IB , 1.6A : IB, 1.7A : IB , 1.8A : IB , 1.9A : IB , 2A : IB , 3 A : IB , 4A : IB , etc. Standard equipment typically includes heated hoses, drum heaters, pressure feed from 50 gallon steel drums or heated hoppers, recirculation system, automatic high-pressure shut-off system. Generally, gel times are temperature dependent. Although optimum working temperatures are between 120 °F and 150 °F (49 °C and 66 °C), other temperatures are contemplated within the scope of the invention. The mixture may be heated to between 70 °F and 350 °F, including without limitation between 120 °F and 150 °F

[0039] In certain embodiments using hand tools to mix the epoxy-based insulation material, the material may be preheated to approximately 120 °F - 150 °F (49 °C - 66 °C) and then may be mixed to uniformity taking care not to whip air into the mixture. Other preheating temperatures may be used and are contemplated within the scope of the invention, including without limitation between 70 °F and 350 °F, including without limitation between 120 °F and 150 °F. In an exemplary embodiment, the epoxy-based insulation material may be poured into a mold. If the material is not preheated, external or supplemental heat may be necessary to initiate and drive the reaction to fully cure the material.

Application Procedures

[0040] In certain embodiments of the epoxy-based insulation material of the present invention, heat may be necessary to initiate and drive the reaction for optimum gel and cure times. Heating the material to 120 °F - 150 °F (49 °C - 66 °C) may be sufficient for this purpose. Other temperatures may be used and are contemplated within the scope of the invention, including without limitation between 70 °F and 350 °F. The material may be poured or injected into a mold that has been fitted around the pipe or equipment at a spacing to achieve the desired material thickness. In certain embodiments, reaction injection molding (R M) may be employed to allow the curing reaction to take place. Because the material has a low viscosity, it can penetrate the mold cavity and surround the piece of equipment being insulated. To prevent leakage of material, the mold-equipment interface may be sealed. To retain heat, the mold may be wrapped in standard insulation during application to help shorten the gel times and de-mold times. Warm air may be circulated through the inside of the pipe or equipment to aid the cure process.

Curing Schedule

[0041] In an exemplary embodiment, the curing schedule for the epoxy-based insulation material is described in Table 1 below. The firm set times are exemplary only and are not intended to limit the scope of the invention described herein, but are solely for the purpose of describing the gel times sufficient to allow de-molding in certain exemplary embodiments of the present invention. Different firm set times are contemplated within the scope of the invention, as many variations thereof are possible and also encompassed by the general inventive concepts. The firm set times are approximations provided that the heat is maintained through insulation at the temperature indicated. Applying external heat may shorten the times listed for a faster de-mold. The curing reaction is exothermic, releasing enough heat to leave the material approximately 50 °F - 100 °F or more above its initial temperature. For example, if the material starts at 120 °F, the material could reach about 180 °F, 190 °F, 200 °F, 210 °F, 220 °F or more during cure.

Table 1

EXAMPLES

[0042] The following examples illustrate exemplary embodiments and features of various epoxy- based insulation materials encompassed by the general inventive concepts. The examples are given solely for the purpose of illustration and are not to be construed as limiting the present disclosure, as many variations thereof are possible and also encompassed by the general inventive concepts. [0043] Examples 1-2 illustrate certain embodiments of the amine-cured epoxy elastomer matrix. The components of Examples 1 and 2 are listed in Table 2.

Table 2

All resins are amine or epoxy reactive even those containing polysiloxane.

[0044] Performance data for Examples 1 and 2 are summarized in Tables 3-7 below. The performance data is exemplary only and is not intended to limit the scope of the invention described herein, but is provided solely for the purpose of describing how the material performs in the exemplary embodiments described in Examples 1 and 2.

Table 3

Table 4

Exposure Simulated Subsea Exposure

Substrate Temperature: 300°F (149°C)

Water Temperature: 32°F (0°C)

Pressure: 4,000-4,500 psi (27.6-31 MPa)

Duration 90 days (2160 hours)

Results @86°F/30°C 0.166 W/m°K

@122°F/50°C 0.166 W/m°K

@140°F/60°C 0.166 W/m°K

Table 5

Table 6

Simulated Subsea Exposure - Dimensional Changes

Method Reference: ISO/CD 12736

System Substrate: 2 foot steel pipe

Surface Prep: SSPC-SP10 with a 3-4 mils profile

Primer: 2 coats of Thermaline 450 at 7-8 mils/coat

Examples 1 and 2 (Carboline L8900-1) at 2" thick (approx.)

Exposure Simulated Subsea Exposure

Substrate Temperature: 300°F (149°C)

Water Temperature: 32°F (0°C)

Pressure: 4,000-4,500 psi (27.6-31 MPa)

Results General: Negligib e dimensional changes or weight gain

Circumference

Weight Gain Length Increase

Duration Increase

(Loss) (Decrease)

(Decrease) Pretest 0 0 0

30 days 0.31% 1.38% 2.57%

24 hrs recovery (0.31%) 1.10% 2.57%

48 hrs recovery (0.31%) 1.10% 2.57%

90 days (0.15%) 1.10% (0.24%)

24 hrs recovery (0.15%) 1.10% (0.24%)

168 hrs recovery 0 1.10% (0.24%)

Table 7

[0045] The foregoing description of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications or variations are possible in light of the above teachings. Epoxy-based insulation in accordance with the present invention may include any combination or sub-combination of the features or concepts disclosed by the present application.

[0046] The embodiments were chosen and described to illustrate the principles of the invention and its practical application. It is clear that modifications and variations are within the scope of the invention as determined by the appended claims. The preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.