Reinforced polymeric pipe with light-permeable reinforcing casing and pipe inspection method

Abstract

The invention relates to the oil and gas industry, and more particularly to multi-layered reinforced polymeric pipes which can be used for collecting and transporting oil, water, gas and chemical reagents. The present reinforced polymeric pipe comprises the following, applied successively to the outer surface of an inner polymeric thermoplastic shell: a reinforcing layer, and an outer polymeric thermoplastic shell, wherein the reinforcing layer is comprised of unidirectional tapes consisting of materials sintered together by a polymer matrix. The technical result is that of providing a pipeline structure that can be inspected, which in turn leads to increased operating reliability.

Description

POLYMER REINFORCED PIPE WITH A LIGHT-TRANSMITTING REINFORCING FRAME AND A METHOD FOR ITS DIAGNOSING

[0001] The initial patent application for the invention was filed in the Russian Federation, No. 2024120643, dated July 12, 2024. Patent No. RU 2 838 883, dated April 23, 2025, was issued for the application.

[0002] Composite thermoplastic pipes are described in API Specification 15S, "Spoolable Reinforced Plastic Line Pipe," 2nd edition, March 2016, and GOST R 59834-2021 "Field pipelines. Flexible polymer-reinforced pipes and fittings thereto. General specifications." Pipes manufactured in accordance with these requirements are an inner pipe consisting of a thermoplastic polymer, onto which a composite reinforcing layer is applied, having a cohesive connection with the inner layer and the outer layer.

[0003] A thermoplastic polymer layer. In some cases, a polymer tape reinforced with unidirectional fibers is wound onto the inner tube without forming a bond.

[0004] According to standards, the service life of a pipe is determined on the basis of long-term hydrostatic tests, the conditions of which do not cover all possible operating conditions of pipelines and, accordingly, cannot provide reliable information on the actual service life of such pipes.

[0005] The most likely cause of failure of these pipelines is a decrease in the strength of the reinforcing layer during operation, caused by the destruction of reinforcing fibers due to the diffusion of the transport flow medium, which can manifest itself as a general decrease in the strength of the fiberglass, or in the form of destruction of individual fibers.

[0006] Due to the fact that the main stresses arising during operation are absorbed by the reinforcing frame of the pipe, the task of diagnosing the technical condition of the reinforcing frame is the most significant for assessing the condition of polymer-reinforced pipes as a whole.

[0007] A design of a reinforced polymer oil field pipe is known according to patent WO1995007428, which consists of a thermoplastic-based core to which a composite material consisting of reinforcing fibers and thermoplastic is seamlessly attached.

[0008] A design of a reinforced polymer oil field pipe is known according to patent RU 204558 U1, which consists of an inner pipe made of a thermoplastic polymer, a composite material surrounding it, consisting of a thermoplastic polymer composite material and unidirectional continuous reinforcing fibers, and an outer polymer shell, in which the inner pipe, the composite material and the outer shell are smoothly fused together by heating, characterized in that the composite material of the composite pipe contains at least one elastic interlayer made of a thermoplastic polymer material, the modulus of elasticity of which is 20...3600 MPa less than the modulus of elasticity of the thermoplastic polymer composite material, wherein the elastic interlayer is fused with the composite material by heating.

[0009] A flexible pipeline for transporting various media and a pipe for its manufacture, RU 7245550, is known. It is intended for transporting various media overland, with installation on the land surface, in a trench, in an embankment, on an overpass, or in a sleeve. The flexible polymer-reinforced pipe comprises an inner liner, a reinforcing layer, a separating layer, and a reinforcing shell. The reinforcing layer may contain elements such as metal strips, metal wires, polymer strips, and polymer threads in any combination, or consist of only one element. Additionally, a multilayer auxiliary shell may be positioned over the reinforcing shell, comprising at least one separating layer and a protective shell. The auxiliary shell may comprise a conductor layer and a thermal insulation layer.The conductor layer may contain electrical signal, power, heating, optical conductors and a communication channel, as well as a long-length sensor for monitoring the presence of pipe damage.

[0010] A design for a reinforced polymer oilfield pipe (OIP) according to patent RU 7245550 is known, providing high-temperature fiber-reinforced polymer OIPs and a method for producing such pipes. The OIPs are formed from a composite material containing a high-strength fiber material and a high-temperature thermosetting resin. The method comprises the steps of combining the high-strength fiber material and the high-temperature thermosetting resin to create a high-performance composite material and winding the composite material around a core while applying sufficient heat to the material at the winding point to maintain the temperature of the thermosetting resin above its melting point. Additionally, the design may utilize coating materials applied to the composite material in a manner that prevents external and internal environmental exposure.

[0011] Sensors, including wireless sensors, wires, fiber optics, and other devices, can be embedded between the coating material and the composite material.

[0012] Current designs do not allow for reliable diagnosis of the pipe's condition along its entire length. Optical fibers used in the pipeline's construction are positioned above the reinforcing cord and serve to transmit information between the sensors.

[0013] The objective of this utility model is to develop a pipe design that will enable diagnostics of the reinforcing frame.

[0014] The invention relates to the oil and gas industry, specifically to multilayer polymer-reinforced pipes that can be used for collecting and transporting oil, water, gas, and chemical reagents. The polymer-reinforced pipe comprises a reinforced layer and an outer polymer thermoplastic shell, sequentially applied to the outer surface of an inner polymer thermoplastic shell. The reinforcing layer is made of unidirectional tapes consisting of materials sintered together in a polymer matrix. The technical result is a pipeline design that enables diagnostics, thereby increasing operational reliability.

[0015] The objective of the invention is to develop a design for a polymer-reinforced pipe that allows for diagnostics during operation.

[0016] The technical result of the claimed invention is a polymer-reinforced pipe consisting of an inner and outer polymer thermoplastic shell and a reinforcing frame located between the shells, consisting of reinforcing tapes fused together. The reinforcing frame is formed by wrapping the reinforcing tapes around the inner shell. The reinforcing tapes are composed of unidirectional fiber materials (fiberglass, carbon fiber, carbon, Kevlar, aramid, but not limited to) located in a thermoplastic matrix similar in composition to the inner and outer shells, to ensure sintering. To enable diagnostics, the reinforcing tape includes optical translucent fibers (quartz, plastic, but not limited to), which ensure light transmission throughout the entire pipe section. The result is a reinforcing frame in which the optical fibers are uniformly integrated.

[0017] The inclusion of optical fibers in reinforcing tapes occurs during the manufacturing process by alternating reinforcing and optical fibers.

[0018] The strength and diameter of the reinforcing and optical fibers must be selected to match each other as closely as possible to ensure equivalent stresses experienced by the reinforcing and optical fibers during pipe operation.

[0019] Depending on the required level of reinforcing cord control, the number of integrated optical fibers in the prepreg can vary.

[0020] The angle of the winding of the reinforcing prepregs from 1 to 89⁰ to the axis of the pipe (at least one winding of the reinforcing prepreg has a winding direction opposite to the axis of the pipe).

[0021] The number of layers of reinforcing tapes and the direction of the layers are selected based on the required characteristics of the pipe.

[0022] The inner and outer shells may be 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), as well as mixtures and composites of the above polymers, but not limited to), the chemical composition of which is selected based on the required temperature, mechanical and gas barrier properties. If it is necessary to combine mechanical, temperature and erosion properties, the shells may consist of non-split layers sintered together, the number of which may be from 1 to 7 and the thickness of each layer from 0.2 mm or more. The total thickness of both the inner and outer shells must be at least 1 mm.

[0023] Since the main element that ensures the strength of the pipeline is the reinforcing frame, its diagnostics will provide a high degree of assessment of the residual strength (durability) of the pipe.

[0024] During operation, it is necessary to evaluate the decrease in light transmittance due to the destruction of fibers or their rupture to a value characteristic of the destructive pressure (if necessary, taking into account the safety factors), according to the obtained dependence. IMPLEMENTATION OF THE INVENTION

[0025] The polymer-reinforced pipe (Fig. 1) comprises a reinforcing frame (3) and an outer polymer thermoplastic shell (2) sequentially applied to the outer surface of the inner polymer thermoplastic shell (1), wherein the reinforcing frame is made of spirally wound reinforcing tapes into which optical light-transmitting fibers (4) are embedded. The shells and tapes of the reinforcing frame are sintered into a single structure.

[0026] The winding angle of the reinforcing tapes ranges from 1 to 89°, and at least one layer of the reinforcing tapes has a winding direction opposite to the layer wound below. The reinforcing tapes (Fig. 2) consist of unidirectional reinforcing threads (5) and unidirectional optical fibers (4) sintered with a polymer thermoplastic matrix (6). After application of the reinforcing tapes, a thermal sintering process is performed between the tapes and the inner and outer shells.

[0027] The inclusion of optical fibers allows measuring changes in the luminous flux of the pipe reinforcing frame, thereby ensuring diagnostics. To ensure measurements of light transmittance during pipe operation (Fig. 3), a light source and luminous flux measurement sensors are built into the connecting fittings (7, 9), which are installed at the beginning and end of the pipe (8) (fittings are necessary for connecting the pipes to each other), respectively. The luminous flux passes from the fitting in which the light source (9) is located through the reinforcing frame of the pipe (8) and is received by luminous flux measurement sensors located in the fitting pressed onto the opposite end of the pipe (7). For convenient signal transmission to the light source and luminous flux measurement sensors, signal and power cables (10) are brought to the surface to control cabinets (11).

[0028] The luminous flux, entering the luminous flux measurement sensors (usually photocells are used, but not limited to) is converted into an electrical signal, which is proportional to the intensity of the luminous flux and is more convenient for further data transmission and interpretation.

[0029] To determine the rejection values ​​for the reduction in light transmittance of the reinforcing cage, after the pipe leaves the manufacturing plant, it is necessary to measure the light transmittance of the reinforcing cage to record it before use, and then determine the bursting pressure. To assess the potential reduction in light transmittance of the reinforcing cage, qualification tests must be conducted. This involves producing batches of pipelines with a reduced number of reinforcing cage layers (to reduce strength). These tests are used to determine the light transmittance and bursting pressures, and based on these data, a relationship between the reduction in pipeline strength and light transmittance is plotted. Positive effects of the invention

[0030] The effects of the invention include the possibility of diagnosing the reinforcing frame by measuring the light transmittance of the reinforcing frame.

[0031] The polymer-reinforced pipe Fig. 1 contains a reinforcing frame (3) and an internal polymer-thermoplastic shell (2) sequentially applied to the outer surface of the internal polymer-thermoplastic shell (1).

[0032] The reinforcing frame Fig. 2 consists of reinforcing tapes, which in turn consist of unidirectional reinforcing threads (5) with optical fibers (4) in a polymer thermoplastic matrix (6).

[0033] To ensure diagnostics during pipe operation (Fig. 3), a light source and luminous flux measurement sensors are built into the connecting fittings (7, 9), which are installed at the beginning and end of the pipe (8) (fittings are necessary for connecting the pipes together). The luminous flux passes from the fitting in which the light source (9) is located through the reinforcing frame of the pipe (8) and is received by the luminous flux measurement sensors located in the fitting pressed onto the opposite end of the pipe (7). For convenient signal transmission to the light source and luminous flux measurement sensors, the signal and power cables (10) are brought to the surface into control cabinets (11). Patent literature

[0034] Patent RU 204558

[0035] Patent RU 7245550

[0036] Patent RU 7245550

Claims

A polymer-reinforced pipe comprising a reinforced frame and an outer polymer thermoplastic shell sequentially applied to the outer surface of an inner polymer thermoplastic shell, which are sintered together, wherein the reinforcing frame is made of reinforcing tapes sequentially spirally wound and sintered together with each other and the inner and outer shells, which, in turn, consist of unidirectional reinforcing fibers and light-transmitting optical fibers that provide light transmission over a distance not less than the length of the pipe, wherein the reinforcing and optical fibers are included in the reinforcing frame by alternation and sintered with the polymer matrix. A polymer-reinforced pipe according to paragraph 1, characterized in that the inner and outer 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. A polymer-reinforced pipe according to paragraph 1, characterized in that the layers of the inner and outer polymer thermoplastic shells are connected to each other (sintered). A polymer-reinforced pipe according to paragraph 1, characterized in that the winding angle of the reinforcing tapes of the reinforcing frame relative to the axis of the pipe has a value from 1° to 89°. A polymer reinforced pipe according to paragraph 1, characterized in that at least one winding of the reinforcing tapes has a winding direction opposite to the axis of the pipe. A polymer-reinforced pipe according to paragraph 1, characterized in that fittings are used to connect pipelines, into which a light source is built on one side and sensors for measuring the luminous flux on the other side at opposite ends of the pipe. A polymer-reinforced pipe according to paragraph 1, characterized in that the thickness of the reinforcing tape is 0.1-4 mm, and the width is from 20 to 500 mm. A method for diagnosing the reinforcing frame of a polymer-reinforced pipe, characterized in that a light flux is passed through the reinforcing frame, made of successively spirally wound and sintered together and with the inner and outer shells of reinforcing tapes consisting of unidirectional reinforcing fibers and light-transmitting optical fibers, from the initial end of the pipe to the final end of the pipe, and the reduction in the light transmittance of the reinforcing frame is assessed, from the initial value determined for a new pipe during manufacture, to the actual light transmittance measured during operation, which corresponds to the degree of destruction of the fibers or the number of breaks in the reinforcing fibers.

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