Reinforced polymeric pipe with insulated rovings and method of inspecting same

Abstract

The invention relates to the oil and gas industry, and more particularly to multi-layered reinforced polymeric pipes and methods for inspecting same, which can be used for collecting and transporting oil, water, gas and chemical reagents. The technical result of the claimed invention is a pipe structure and a method for inspecting same which provide improved operational reliability and an increased working life and make it possible to inspect the technical condition of the pipe during use. A reinforced polymeric pipe comprises a reinforcing layer and an external polymeric casing, which are applied consecutively to the outer surface of a polymeric pipe, wherein the reinforcing layer is formed of consecutively helically wound multi-layered rovings.

Description

POLYMER REINFORCED PIPE WITH INSULATED ROVINGS AND A METHOD FOR ITS DIAGNOSING

[0001] POLYMER REINFORCED PIPE WITH INSULATED ROVINGS AND A METHOD FOR ITS DIAGNOSING

[0002] The initial application for the invention was filed in the Russian Federation, No. 2024103264 dated 08.02.2024. The application was granted a patent for invention No. RU 2 836 307 dated 12.03.2025.

[0003] The closest in design are polymer-reinforced pipes with a polymer inner liner, reinforced with wound rovings from metal tapes and an outer polymer layer presented by the authors in the standards (RU177704U1, published 06.03.2018, RU165000U1, published 27.09.2016, WO / 2013 / 071449 published 23.05.2013).

[0004] The patents use various variations in the angles of the tape windings, the dimensional characteristics of the tapes and the size of the gap between them, but the main unifying factor of all the cited patents is the use of a metal tape as the main element of the reinforcing layer.

[0005] The disadvantage of using the tape is the uncontrolled impact of gases and liquids transported through the outer polymer shell, which increases due to the destruction of the inner liner during the service life. The possibility of confirming the service life and assessing the technical condition of the reinforcing elements is not provided by the authors of the patents. Patent RU178047U1 published 21.03.2018 considers the possibility of using polymer tapes as a reinforcing layer.

[0006] Due to the temperature-time dependence of polymer strength, these materials are poorly suited for use as reinforcing elements, given the decrease in their strength depending on the time of operation. The problem of monitoring the technical condition of reinforcing tapes during pipeline operation remains unresolved.

[0007] In patent RU136519U1, published on 10.01.2014, reinforcing threads made of polymer or mineral material are used as a reinforcing layer.

[0008] Due to the incomplete coverage of the reinforcing layer by the threads, the stress of the material in the inner casing is distributed unevenly, as a result of which the destruction of the material of the inner casing is increased relative to pipeline structures where the reinforcing layer completely covers the inner liner.

[0009] The authors also did not propose options for monitoring the technical condition of reinforcing tapes during pipeline operation.

[0010] In patents RU203164U1 published on 24.03.2021 and RU204558U1 published on 31.05.2021, the authors propose a pipeline design with connected layers reinforced with a tape consisting of a polymer and unidirectional continuous fibers (glass fibers, carbon fibers, aramid fibers, boron fibers, ceramic fibers, basalt fibers, silicon carbide fibers, polyamide fibers, polyester fibers, liquid crystal polyester fibers, polyacrylonitrile fibers, polyimide fibers, polyetherimide fibers, polyphenylene sulfide fibers, polyether ketone fibers, polyether ether ketone fibers, polyketone fibers, ultra-molecular polyethylene fibers.), linked together.

[0011] This structure has interconnected layers, which negatively affects the stresses on the structure, arising due to the creation of additional stresses caused by different gas permeability coefficients of the structure layers.

[0012] The authors also did not propose options for monitoring the technical condition of reinforcing tapes during pipeline operation.

[0013] Due to the particular danger arising from the transportation of hydrocarbons and gas under high pressure, including during the construction of offshore facilities, the presence of a polymer-reinforced pipe design that allows for its diagnostics during operation is most in demand.

[0014] The invention relates to the oil and gas industry, in particular to multilayer polymer reinforced pipes and methods for diagnosing them, which can be used to collect and transport oil, water, gas, and chemical reagents. The technical result of the claimed invention is a pipeline design and a method for diagnosing it, which increases the reliability of operation, increases the service life, and makes it possible to diagnose the technical condition during operation. The polymer reinforced pipe contains a reinforced layer and an external polymer shell sequentially applied to the outer surface of the polymer pipe, wherein the reinforcing layer is made of sequentially spirally wound multilayer rovings.

[0015] The objective of the invention is to develop a design for a polymer reinforced pipe that makes it possible to reduce the impact of aggressive environments penetrating through the internal polymer shell on the reinforcing layer and to ensure the possibility of conducting diagnostics during operation.

[0016] The technical result of the claimed invention is a polymer-reinforced pipeline consisting of internal and external polymer shells and a reinforcing layer and a method for diagnosing it. The reinforcing layer is formed by a strand of rovings consisting of a conductive core (usually a metal tape, a metal thread, but not limited to) and covered with a protective polymer shell made of polymer, composite materials, enamels and paints and varnishes (but not limited to them, other options for protecting the core that meet the operating conditions of the pipeline can be used). The internal, external shells and the reinforcing layer are not connected to each other.

[0017] The use of isolated (with a protective coating) rovings allows eliminating the influence of transport products penetrating through the internal polymer shell, due to which, when calculating the strength of the reinforcing roving, allowances for corrosion and destruction of the reinforcing layer during operation can be reduced.

[0018] The reinforcing roving may contain a material that improves the adhesion of the protective layer to the core.

[0019] The specified technical result is achieved due to the fact that the polymer reinforced pipe contains:

[0020] - reinforcing rovings (at least one winding of the reinforcing rovings has a winding direction opposite to the pipe axis) and an outer polymer shell, sequentially applied to the outer surface of the inner polymer shell, twisted at angles from 0 to 180 degrees to the pipe axis.

[0021] The number of layers of reinforcing rovings and the direction of the windings are selected based on the required characteristics of the pipe. The gap between the reinforcing rovings can vary from 1 to 50 mm, and the width of the reinforcing rovings can be from 20 to 500 mm, depending on the requirements for rigidity and strength of the structure.

[0022] The inner, outer and covering polymer (if thermal insulation is required) shells can be made of polymers (polyethylene (PE, HDPE, LDPE), polyethylene of high (increased) heat resistance PE-RT (Polyethylene of Raised Temperature resistance), cross-linked polyethylene (PE-X or XLPE, PE-S), copolymer of polyethylene with octene, copolymer of polyethylene with octene-1, copolymer of polyethylene with hexene, copolymer of polyethylene with hexene-1, metallocene high-density polyethylene, polypropylene (PP, PP-R), polypropylene copolymers, polybutene (PB, PB-1), polybutene copolymers, polyvinyl chloride (PVC, HPVC), acrylonitrile butadiene styrene (ABS), polyamide (PA), polyphthalamide (PPA), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene naphthalate (PBT), fluoropolymer (PFA), fluoroethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), polyether sulfone (PES), polyphenyl sulfone (PPSU), polyimide (PI), polyether imide (PEI), polyoxymethylene (POM),polyarylene ether ketone (PAEK), polyether ether ketone (PEEK, PEK), polyketone (PK, Polyketon), as well as mixtures and compositions of the above polymers, but not limited to them), the chemical composition of which is selected based on the required temperature, mechanical and gas barrier properties, while the layers, the number of which can be from 1 to 7 and the thickness of each layer from 0.5 mm or more, must be connected to each other (sintered). The total thickness of the inner and outer liners must be at least 2 mm.,

[0023] If necessary, the pipe may include heat-insulating layers applied over the outer polymer shell of the pipeline. The heat-insulating layer may consist of a heat-insulating layer made of polymineral foam, polyurethane foam (but not limited to). A covering polymer shell must be applied over the heat-insulating layer.

[0024] Pipeline diagnostics are carried out by sequential diagnostics of the internal (1), external polymer shells (2) and the reinforcing layer (but not limited to).

[0025] Due to the unconnected design of the pipeline, gas can freely pass into the area between the inner and outer polymer shells, due to which the diagnostics of the inner shell can be performed both by direct measurement by passing an in-pipe (usually ultrasonic) diagnostic tool along the inner polymer shell to assess the continuity and residual wall thickness, and by evaluation by means of the absence of the transported medium in the area between the inner and outer polymer shells. To ensure control of the technical condition, metal fittings pressed onto the ends of the pipeline to connect it together are equipped with nozzles that remove gas accumulating between the shells by diffusion through the inner polymer shell during operation.

[0026] The technical condition of the outer shell is assessed by applying pressure of at least 1 atm to the area of ​​the reinforcing rovings (between the inner and outer shells) and monitoring the tightness of this area.

[0027] Roving diagnostics is performed by measuring the resistance of the conductive core and comparing it with the data at the time of pipe release. To ensure resistance measurement, conductive cables are mounted to the conductive cores at the ends of the reinforcing rovings, the ends of the rovings are insulated and the cables are brought to the control cabinet through a sealed joint in the wall of the fitting. The permissible resistance reduction is determined empirically during acceptance tests of the structure. By ensuring the insulation of each conductive core inside the multilayer reinforcing roving, each individual roving in the structure is diagnosed. In case of maintaining the integrity of the insulating coating, it is necessary to consider the results of the resistance reduction of the conductive cores as a general (throughout the entire diagnosed tape), and not a local reduction in the cross-section or a change in the structure of the steel.The integrity of the protective shell must be assessed by the absence of contact between the conductive cores, or by assessing the presence of contact between the electrolyte, which can be passed through the gas ventilation system and each individual core during diagnostics.

[0028] Additionally, conductive cables can be added to the pipeline structure after the reinforcing layer, which are necessary to create an electrically conductive circuit between the initial and final sections of the roving. IMPLEMENTATION OF THE INVENTION

[0029] The polymer reinforced pipe (Fig. 1) contains a reinforcing layer (2) and an outer shell (3) sequentially applied to the outer surface of the inner shell (1), wherein the reinforcing layer is made of spirally wound layers of reinforcing rovings.

[0030] There is a gap between the reinforcing tapes of each layer.

[0031] At least one layer of reinforcing rovings has the opposite winding direction compared to the layer wound below.

[0032] The reinforcing roving (Fig. 2, Fig. 3) is a conductive core (4) (usually made of metal tape, metal thread, but not limited to) and covered with a protective (dielectric) shell (5) made of polymer, composite materials, enamels and paints and varnishes (but not limited to them, other options for protecting the reinforcing tape that meet the operating conditions of the pipeline and the method of its manufacture can also be used).

[0033] The coating of the reinforcing roving makes it possible to measure the resistance of the reinforcing cores of each roving separately.

[0034] The diagnostics of reinforcing rovings is achieved by measuring their resistance, for which purpose (Fig. 4) the end parts of the reinforcing rovings inside the steel fittings (6) are connected to the conductive cable (7), the connections are insulated to ensure the absence of contact between them. The conductive cables (8) are led out to the control cabinets (9) to ensure the convenience of reading the information. Diagnostics is performed by measuring the resistances of the conductive cores of the reinforcing rovings by supplying electric current from one cabinet located at the beginning of the pipeline section and measuring the resistance on another cabinet located at the end of the pipeline section.

[0035] If it is necessary to reduce the number of control cabinets, an alternative scheme for supplying current to the initial section can be used (Fig. 5). Current can be supplied to the initial section of the pipeline by means of a conductive cable (10), which can be located behind the reinforcing layer (Fig. 6), or in the heat-insulating layer (11) (Fig. 7) to ensure remote transmission of information. In this case, it is possible to place the control cabinet away from the section being directly diagnosed, for laying the pipeline in extended casings, for example, when arranging underwater crossings.

[0036] Pipeline diagnostics are performed by sequentially diagnosing the internal (1), external liners (2) and reinforcing layer. The scope of diagnostics can be adjusted depending on the materials and design used.

[0037] Diagnostics of the inner shell is carried out by in-pipe (usually ultrasonic) diagnostic devices to assess the continuity and residual wall thickness. Additionally, the tightness of the inner shell can be assessed by the absence of the transported medium in the area between the inner and outer shells.

[0038] The technical condition of the outer shell is assessed by applying pressure of at least 1 atm to the reinforcing roving area (between the inner and outer shells) and monitoring the tightness of the area between the inner and outer shells. The areas between the inner and outer shells of adjacent sections of pipelines are hermetically connected to each other by means of additional channels in the fittings or between them. Valves are periodically installed in the area between the inner and outer shells to ensure gas discharge. Positive effects of the invention

[0039] The effects of the invention include an increase in the reliability of the structure of the polymer reinforced pipe, due to the application of insulation to the elements of the reinforcing frame and the emergence of the ability to diagnose the reinforcing frame, due to the measurement of the resistance of the reinforcing elements.

[0040] Fig. 1 shows the design of a polymer reinforced pipe containing a reinforcing layer (2) and an outer polymer shell (3) sequentially applied to the outer surface of the inner polymer shell (1).

[0041] Fig. 2 shows the design of a reinforcing layer containing reinforcing rovings (2), inside which are conductive cores (4).

[0042] Fig. 3 shows a cross-section of reinforcing roving consisting of a conductive core (4) covered with a protective (dielectric) shell (5).

[0043] Fig. 4 shows a diagram of the organization of pipeline diagnostics, where a section of polymer reinforced pipe (6) connected by fittings (7) is connected by conductive cables (8) to control cabinets (9).

[0044] Fig. 5 shows a diagram of the organization of pipeline diagnostics, where a section of a polymer reinforced pipe (6) connected by fittings (7) is connected by conductive cables (8) to control cabinets (9) and is additionally equipped with conductive cables (10) located inside the pipeline structure. Current is supplied to the initial section using a control cabinet (9) and a conductive cable (10), thus the presence of a conductive cable (10) inside the pipeline allows for a reduction in the number of control cabinets.

[0045] Fig. 6 shows a cross-section of a polymer reinforced pipe containing a reinforcing layer (2), an outer polymer liner (3) and a conductive cable (10) sequentially applied to the outer surface of the inner polymer shell (1).

[0046] Fig. 7 shows a cross-section of a polymer-reinforced pipe containing a reinforcing layer (2), an outer polymer shell (3), a conductive cable (10), a heat-insulating layer (11) and a covering shell (12) sequentially applied to the outer surface of the inner polymer shell (1). Figure 1

[0047] Figure 2

[0048] Figure 3

[0049] Figure 4

[0050] Figure 5

[0051] Figure 6

[0052]

[0053] Patent literature

[0054] Patent RU 2665776 C1

[0055] Patent US 10001229 B2

[0056] EP 2895836 B1

[0057] RU 136519 U1

[0058] US 4554650 A1

Claims

A polymer reinforced pipe containing a reinforced layer and an outer polymer thermoplastic shell sequentially applied to the outer surface of an inner polymer shell, wherein the reinforced layer is made of sequentially spirally wound layers of reinforcing insulated rovings consisting of a conductive core and covered with a protective dielectric shell, wherein there is a gap between the reinforcing rovings. The polymer reinforced pipe according to item 1 is characterized in that the inner and outer polymer shells are made of thermoplastic polymers (polyethylene (PE, HDPE, LDPE), polyethylene of high (increased) heat resistance PE-RT (Polyethylene of Raised Temperature resistance), cross-linked polyethylene (PE-X or XLPE, PE-C), copolymer of polyethylene with octene, copolymer of polyethylene with octene-1, copolymer of polyethylene with hexene, copolymer of polyethylene with hexene-1, metallocene high-density polyethylene, polypropylene (PP, PP-R), polypropylene copolymers, polybutene (PB, PB-1), polybutene copolymers, polyvinyl chloride (PVC, HPVC), acrylonitrile butadiene styrene (ABS), polyamide (PA), polyphthalamide (PPA), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene naphthalate (PBT), fluoropolymer (PFA), fluoroethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), polyether sulfone (PES), polyphenyl sulfone (PPSU), polyimide (PI), polyether imide (PEI), polyoxymethylene (POM),polyarylene ether ketone (PAEK), polyether ether ketone (PEEK, PEK), polyketone (PK, Polyketon), as well as mixtures and compositions of the above polymers, but not limited to them), The polymer reinforced pipe according to item 1 is distinguished by the fact that the inner and outer polymer shells consist of layers, the number of which for each shell can be from 1 to 7 and the thickness of each layer can be from 0.5 mm or more. The polymer reinforced pipe according to paragraph 3 is distinguished by the fact that if the composition of the inner and outer polymer shells contains from 2 to 7 layers, they must be connected to each other (sintered). The polymer reinforced pipe according to paragraph 3 is distinguished in that the inner polymer shell, the reinforcing layer and the outer polymer shell are in a non-bonded state. The polymer reinforced pipe according to paragraph 3 is distinguished by the fact that the thickness of the inner and outer polymer shells must be at least 2 mm. The polymer reinforced pipe according to item 7 is distinguished by the fact that the dielectric shell of the reinforcing rovings consists of polymer, composite materials, enamels, resins and paints and varnishes. The polymer reinforced pipe according to item 7 is distinguished in that rolled products of various cross-sections can be used as the conductive core, for example, round wire, square rolled products, trapezoidal rolled products, oval rolled products, rolled products with variable cross-section radius, and flat rolled products in the form of a strip. The polymer reinforced pipe according to item 7 is distinguished in that the material of the conductive core is electrically conductive polymers, composite materials, steel or an alloy based on non-ferrous or ferrous metals, in particular an alloy based on iron or an alloy based on chromium, or an alloy based on nickel, or an alloy based on copper. The polymer reinforced pipe according to item 7 is distinguished in that the angle of the windings of the reinforcing rovings relative to the axis of the pipe has a value from 0° to 90° and from 90° to 180°. The polymer reinforced pipe according to item 7 is distinguished in that at least one winding of the reinforcing rovings has a winding direction opposite to the axis of the pipe. The polymer reinforced pipe according to item 7 is distinguished by the fact that between the rovings of one layer there is a gap of 1 to 50 mm. The polymer reinforced pipe according to item 7 is distinguished by the fact that the thickness of the reinforcing roving is 0.1 - 4 mm, and the width is from 20 to 500 mm. The polymer reinforced pipe according to item 1 is distinguished by the fact that a layer of thermal insulation made of foamed polyminerals or foamed polymer can be applied over the outer polymer shell. The polymer reinforced pipe according to item 1 is distinguished by the fact that a covering polymer shell made of a thermoplastic polymer can be applied over the heat-insulating layer. A method for diagnosing a polymer reinforced pipe containing a reinforced layer and an outer polymer thermoplastic shell sequentially applied to the outer surface of an inner polymer shell, wherein the reinforced layer of which is made of sequentially spirally wound layers of reinforcing insulated rovings consisting of a conductive core and covered with a protective dielectric shell, wherein having a gap between the reinforcing rovings, consists in sequentially 1) determining the thickness of the inner polymer shell by passing in-pipe diagnostic / ultrasonic projectiles, 2) assessing the insulation of the reinforcing rovings by measuring the presence of contact between the cores and measuring the presence of contact of the conductive medium passed into the space between the shells,with conductive cores of reinforcing rovings 3) measuring the resistance of insulated conductive cores of reinforcing rovings and 4) assessing the tightness of the outer polymer shell by monitoring the tightness of the area between the inner and outer polymer shells when excess pressure is applied to it.

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