The disclosure relates to systems and methods for self-healing composite wraps. The self-healing composite wraps can be used to repair a defective section in a pipe, structure, and/or process equipment.
Composite wraps can be used to repair defect sections in metal pipes. The matrix of the composite wraps can be brittle, resulting in microscopic crack development due to stresses. The cracks can propagate and induce additional stresses causing debonding at the matrix-fiber interface and/or damage to the matrix of the composite wrap.
The disclosure relates to systems and methods for self-healing composite wraps. The self-healing composite wraps can be used to repair a defect section in a pipe (e.g., a metal pipe), such as corrosion, dents, pits and cracks.
The composite wraps include fibers. Each of the fibers has an open space. Some of the open spaces are filled with a matrix material, and some of the open spaces are filled with a hardening agent. When contacted together, the matrix material and the hardening agent can fill and cure microscopic cracks in the matrix. The fibers can be arranged in two dimensions, multilayered in three dimensions, and/or randomly oriented to address axial, transverse, hoop and/or shear stress that can result in tension, compression, shear and/or localized stress on the composite wrap.
The systems and methods can be used to repair a defect section in a pipe in an oil and gas system, such as an oil and gas production system (e.g., a pipe in an oil and gas production system, a surface casing,), an oil and gas transportation system (e.g., a transportation pipeline), an oil and gas processing system (e.g., a pipe in oil and gas processing system) and/or a chemical or process industry. The systems and methods can be applied to a straight and/or bent segment of a pipe, such as an elbow joint, a reducer, or a branch. The systems and methods can also be used on process equipment and structures.
The systems and methods can be relatively inexpensive to manufacture and implement. The systems and methods can increase the lifetime of a composite wrap repair, thereby resulting in reduced costs and time associated with repairs and shutdowns.
In a first aspect, the disclosure provides an article that includes a first composite wrap. The first composite wrap includes a fabric that supports a matrix. The matrix includes a plurality of first fibers and a plurality of second fibers. The plurality of first fibers and the plurality of second fibers are arranged parallel to one another and in an alternating fashion. The first fibers include an inner space including a matrix former. The second fibers include an inner space including a hardening agent. The matrix former and hardening agent are configured to form a solid matrix upon contact.
In some embodiments, the article further includes a second composite wrap atop the first composite wrap. The second composite wrap includes a fabric that supports a matrix which includes a plurality of third fibers and a plurality of fourth fibers. The plurality of third fibers and the plurality of the fourth fibers are arranged parallel to one another and in an alternating fashion. The third fibers include an inner space including the matrix former. The fourth fibers include an inner space including the hardening agent.
In some embodiments, the third and fourth fibers are oriented at an angle of from 2° to 178° relative to the first and second fibers.
In some embodiments, a thickness of the matrix of the first composite wrap is from 1 μm to 10 μm.
In some embodiments, the first and second fibers have a maximum cross-sectional dimension of 5 μm to 1000 μm. In some embodiments, the first and second fibers have a wall thickness of from 1 μm to 5 μm.
In some embodiments, the first and second fibers include polyester, polyester, polyurethane, polyvinylacetate, polysulphone (PSF), polyethersulphone (PES), polyacrylonitrile (PAN), polyvinyl, and/or polyvinylidene fluoride (PVDF).
In some embodiments, the matrix former includes epoxy, vinylester, and/or polyurethane.
In some embodiments, the hardening agent includes a polymercaptan, a polyamide, an amidoamine, an aliphatic amine, a cycloaliphatic amine, an aromatic amine, and/or a phenalkamine.
In a second aspect, the disclosure provides a system, including a pipe and an article according to the disclosure wrapped around a portion of the pipe.
In some embodiments, the article is wrapped at an angle of 1° to 89° relative a longitudinal direction of the pipe.
In some embodiments, the pipe is a component of an oil and gas production system, an oil and gas processing system, an oil and gas storage system, and/or a power plant.
In a third aspect, the disclosure provides a method that includes applying a first composite wrap on a restored section of a pipe. The first composite wrap includes a fabric that supports a matrix. The matrix includes a plurality of first fibers and a plurality of second fibers. The plurality of first fibers and the plurality of second fibers are arranged parallel to one another and in an alternating fashion. The first fibers include an inner space including a matrix former. The second fibers include an inner space including a hardening agent. The matrix former and hardening agent are configured to form a solid matrix upon contact.
In certain embodiments, the method further includes applying a second composite wrap atop the first composite wrap. The second composite wrap includes a fabric that supports a matrix including a plurality of third fibers and a plurality of fourth fibers. The plurality of third fibers and the plurality of the fourth fibers are arranged parallel to one another and in an alternating fashion. The third fibers include an inner space including the matrix former. The fourth fibers include an inner space including the hardening agent.
In certain embodiments, the third and fourth fibers are oriented at an angle of from 2° to 178° relative to the first and second fibers.
In certain embodiments, the first composite wrap is applied at an angle of from 1° to 89° relative to a longitudinal direction of the pipe.
In certain embodiments, the method further includes rupturing at least a portion of the plurality of first and second fibers, releasing at least a portion of the matrix former and hardening agent within the ruptured first and second fibers, and reacting the matrix former and the hardening agent to form a solid matrix within a crack in the matrix.
In certain embodiments, the method further includes, prior to applying the first composite wrap on the restored section of a metal pipe, cleaning a defect section of the metal pipe, disposing a filler material into the defect section to convert the defect section to a restored section, and disposing an adhesive primer onto the restored section.
In certain embodiments, the method further includes, after applying the first composite wrap on the restored section of a metal pipe, applying a shrink wrap to the restored section, perforating the shrink wrap, allowing the matrix to cure, and removing the shrink wrap.
In certain embodiments, the method further includes, prior to applying the first composite wrap, forming the first composite wrap, including applying a first portion of the matrix on the fabric, disposing the first and second fibers on the fabric, and applying a second portion of the matrix on the fabric and the first and second fibers.
In a fourth aspect, the disclosure provides a method that includes forming a composite wrap. Forming the composite wrap includes applying a first portion of a matrix on a fabric, disposing a plurality of first and second fibers on the fabric, and applying a second portion of the matrix on the fabric and plurality of first and second fibers. The plurality of first fibers and second fibers are arranged parallel to one another and in an alternating fashion. The first fibers include an inner space including a matrix former. The second fibers include an inner space including a hardening agent. The matrix former and hardening agent form a solid matrix upon contact.
The composite wrap 1000 can be used in a composite wrap repair of a defect section of a pipe, such as a pipe in an oil and gas system (see discussion below).
In general, each of the fabric 1100, the matrix 1200, the fibers 1300 and the fibers 1400 can be formed of any appropriate material(s). In some embodiments, the fabric 1100 can include carbon, glass or aramid fibers. In certain embodiments, the matrix 1200 is a polymer matrix that can include epoxy, polyurethane and/or vinylester. In some embodiments, the fibers 1300 and fibers 1400 can include fibers composed of polyester, polyurethane, polyvinylacetate, polysulphone (PSF), polyethersulphone (PES), polyacrylonitrile (PAN), polyvinyl alcohol (e.g., PVC), and/or polyvinylidene fluoride (PVDF). In certain embodiments, the fibers 1300 are formed of the same material as the fibers 1400. In some embodiments, the fibers 1300 are formed of a different material from the fibers 1300.
In general, the fibers 1300 and 1400 can have any desired cross-sectional shape, such as a circular, oval, triangular, rectangular, square or trapezoid. In some embodiments, the maximum cross-sectional dimension of the fibers 1300 and/or fibers 1400 is at least 5 (e.g., at least 10, at least 20, at least 50, at least 100, at least 200, at least 500) μm and/or at most 1000 (e.g., at most 500, at most 200, at most 100, at most 50, at most 20, at most 10, at most 5) μm.
Generally, the walls 1305 and 1405 can have any appropriate thickness. In some embodiments, the thickness of the walls 1305 and/or the walls 1405 is at least 1 (e.g., at least 2, at least 3, at least 4) μm and/or at most 5 (e.g., at most 4, at most 3, at most 2) μm.
In general, the dimensions of the fabric 1100 are determined based on the size of the defect area to be repaired. In certain embodiments, the fabric 1100 has a length of at least 1 (e.g., at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9) meter(s) (m) and/or at most 10 (e.g., at most 9, at most 8, at most 7, at most 6, at most 5, at most 4, at most 3, at most 2) m. In certain embodiments, the fabric 1100 has a width of at least 5 (e.g., at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45) cm and/or at most 50 (e.g., at most 45, at most 40, at most 35, at most 30, at most 25, at most 20, at most 15, at most 10) cm. In certain embodiments, the fabric 1100 has a thickness of at least 200 (e.g., at least 300, at least 400) μm and/or at most 500 (e.g., at most 400, at most 300) μm. Typically, the length of the fibers 1300 and/or fibers 1400 is the same as the length of the fabric 1100.
Examples of the matrix former 1310 include a polymer such as epoxy, vinylester, and/or polyurethane. Examples of the hardening agent 1410 include a polymercaptan, a polyamide, an amidoamine, an aliphatic amine, a cycloaliphatic amine, an aromatic amine, and/or a phenalkamine.
Without wishing to be bound by theory, the hardening agent 1410 causes permanent networking among the polymer chains of the matrix former 1310 resulting in curing (see discussion below).
In certain embodiments, the thickness of the matrix 1200 is at least 1 (e.g., at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9) μm and/or at most 10 μm (e.g., at most 9, at most 8, at most 7, at most 6, at most 5, at most 4, at most 3, at most 2).
The steps 7400 and 7500 are repeated until a desired number of layers is reached. In certain embodiments, the desired number of layers is at least 2 (e.g., at least 3, at least 4, at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90) and/or at most 100 (e.g., at most 90, at most 80, at most 70, at most 60, at most 50, at most 40, at most 30, at most 20, at most 10).
While certain embodiments have been disclosed above, the disclosure is not limited to such embodiments.
As an example, while embodiments have been disclosed that include disposing the composite wrap 1000′ on the composite wrap 1000, such that the plurality of fibers 1300′ and 1400′ of the composite wrap 1000′ are approximately perpendicular to the plurality of fibers 1300 and 1400 of the composite wrap 1000, the disclosure is not limited to such embodiments. For example, the successive layers of the composite wrap 1000 and 1000′ can be disposed atop one another such that the plurality of fibers 1300′ and 1400′ of the composite wrap 1000′ are randomly oriented relative to the plurality of fibers 1300 and 1400 of the adjacent the composite wrap 1000.
As another example, while embodiments have been disclosed that include forming a matrix in a crack to seal the crack, the disclosure is not limited to such embodiments. The systems and methods can be used to repair any defect in a composite wrap. In certain embodiments, the systems and methods can repair delamination in a composite wrap.
As a further example, while embodiments, have been disclosed that include repairing a defect in a metal pipe, the disclosure is not limited to such embodiments. In some embodiments, the pipe is a composite or nonmetallic pipe, such as a FRP (fiber reinforced pipe), a TCP (thermoplastics composite pipe), a RTR (Reinforced Thermoset Resin) pipe, a RTP (Reinforced Thermoplastics Polymer) pipe, a ceramic pipe, or a plastic pipe (e.g., PVC).
As an additional example, while embodiments have been disclosed that include repairing a pipe in an oil and gas system, the disclosure is not limited to such embodiments. In certain embodiments, the pipe is a water line, a sewer line, a chemical line, a component in a pressure vessel. In certain embodiments, the pipe is a component in process equipment.