RU178047U1 - HIGH-PRESSURE POLYMERIC REINFORCED PIPE - Google Patents

Abstract

The utility model relates to the oil and gas industry, in particular to multilayer polymer reinforced pipes that can be used to collect and transport oil, water, gas, chemicals. The technical result of the claimed utility model is to reduce the specific gravity of the pipe while maintaining the strength characteristics, reducing the time for installation and maintenance of the pipeline, increasing the life of the pipeline. The reinforced polymer pipe comprises a reinforced layer and an outer polymer shell successively applied to the outer surface of the polymer pipe, the reinforcing layer being made of four sequentially spirally wound coils of reinforcing polymer tapes.

Description

The utility model relates to the oil and gas industry, in particular to multilayer polymer reinforced pipes that can be used to collect and transport oil, water, gas, chemicals.

BACKGROUND

Known pipes with a non-metallic core covered with a multilayer sheath of wound metal tape (SU 185161 A1, publ. 30.07.1966). The metal strip has a stepped shape in cross section.

The disadvantage of this design can be considered the greater rigidity of the pipe, since the metal tape has a stepped shape and is attached to the core along the plane with glue. The consequence of the large stiffness of the pipe will be a large bending radius and the inability to wind on a drum. Creating a step shape is possible only for plastic tape, which reduces the mechanical strength of the structure as a whole.

Known non-metallic pipe, consisting of a reinforcing metal tape frame with overlaps with a width of at least half the width of the tape and filler, characterized in that, in order to increase strength and heat resistance, the frame has the shape of a screw conoid with a gap between the turns, and its tape is transversely profiled (SU 1200066 A1, publ. 12/23/1985).

The disadvantage of this design can be considered the large dimensions of such a frame and, as a consequence, the inability to perform a multilayer structure. The strength of the single-layer frame will not be enough to provide resistance to high pressure inside the pipe. It is impossible to provide multilayer winding of a frame of such a shape and combining it into one compact and reliable pipe design.

A known design of a flexible reinforced pipe, which has an outer layer and one inner layer made of polymer material, between which is located at least one reinforcing layer made of a steel tape coated on at least one side with an adhesive (RU 151014 U1, published March 20, 2015).

The disadvantages of the design of this pipe can be considered the use of only steel tape as the reinforcing layer and a very small ratio of the thickness of the steel tape to the inner diameter of the pipe, which is 0.0006-0.002.

Known multilayer pipe disclosed in RU 120183 U1, publ. 09/10/2012 (prototype). The multilayer pipe contains an inner polymer pipe reinforcing a system of high-strength filaments, which can be combined into groups forming ribbons.

A multilayer pipe has the following disadvantages:

- due to the reinforcement of the base pipe with polymer threads, there is the possibility of an uneven distribution of the threads and the appearance of local places with a low density of their winding, which accordingly will lead to a decrease in the strength characteristics in these places.

- to overcome this drawback, it is necessary to increase the number of reinforcing threads by a multiple, or to combine reinforcing threads into ribbons by weaving them, to introduce longitudinal threads into the structure, which are also intertwined with the main wound layers of reinforcing threads.

- the formation of tapes from elementary threads and their mutual interweaving extremely complicate the very design of the reinforced pipe and the technological process of its manufacture.

Known flexible polymer reinforced pipe disclosed in RU 165000 U1, publ. 09/27/2016, (prototype). The pipe contains an inner and outer layer made of a polymeric material, between which there is a reinforcing layer of metal tapes spirally wound with 4 coils, the first two coils of metal bands having the same direction, and the subsequent coils having the opposite direction, with the angle of the coils of metal tapes relative to the axis of the pipe, it has a value of 55 ° ± 5%, and there is a gap between the metal tapes of one winding, comprising 5 to 15% of the width of the tape, the thickness of which is 0.3-1.5 mm.

The disadvantages of a flexible polymer reinforced pipe are:

- the use as a reinforcing layer of only metal tapes reduces the operational characteristics of the pipe in terms of weight characteristics and thermal conductivity;

- in the design of the pipe in question there are two coils of metal tapes in one direction, then two coils of metal tapes in the other direction, which limits the ability to use a different reinforcement order;

- despite the fact that the thermal conductivity of the pipe under consideration due to the polymer layers is lower than that of metal pipes, however, the pipes under consideration will be inferior in this indicator to metal pipes with a heat-insulating coating.

DISCLOSURE OF A USEFUL MODEL

The objective of the claimed utility model is the development of a flexible high-pressure polymer reinforced pipe with high performance properties.

The technical result of the claimed utility model is to increase the reliability of the pipe while maintaining weight and size characteristics, reduce the complexity in the manufacture of the pipe, reduce the time for installation and maintenance of the pipeline, increase the life of the pipeline.

The specified technical result is achieved due to the fact that the high-pressure polymer reinforced pipe contains a reinforced layer and an external polymer shell successively applied to the outer surface of the polymer pipe, while the reinforcing layer is made of four sequentially wound coils of reinforcing polymer tapes.

A gap is made between the reinforcing tapes of each midwife.

At least one coil of reinforcing tapes has an opposite winding direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clear from the description, which is not restrictive and given with reference to the accompanying drawings, which depict:

FIG. 1 - high-pressure flexible polymer reinforced pipe with a two-layer coating.

1 - polymer pipe; 2 - the first winding of reinforcing tapes; 3 - the second winding of reinforcing tapes; 4 - the third winding of reinforcing tapes; 5 - the fourth winding of reinforcing tapes; 6 - gaps; 7 - the outer polymer shell.

IMPLEMENTATION OF A USEFUL MODEL

The high-pressure polymer reinforced pipe (1) contains a reinforced layer and an external polymer shell (7) sequentially applied to the outer surface of the polymer pipe (1), while the reinforcing layer is made of four sequentially wound coils (2-5) of reinforcing polymer tapes.

Between the reinforcing tapes of each winding (2-5), a gap (6) is made.

At least one winding (3-5) of reinforcing tapes has an opposite winding direction compared to a lower winding winding.

Polymer pipe (1) - the inner layer that forms the basis of the pipe, and the outer polymer shell (7) are made of a corrosion-resistant polymer material selected from the group: polyethylene, polyamide, ultra high molecular weight polyethylene, polyvinyl chloride.

As reinforcing polymer tapes, a polymer material selected from the group: polyester, polyolefins, ultra-high molecular weight polyethylene is used.

Apply tapes with a thickness of 0.5-2.0 mm, a width of 20-95 mm. Justification of the thickness and width of the applied tapes is given below.

The claimed high-pressure polymer reinforced pipe is made as follows.

For the manufacture of polymer pipe (1) - the inner layer that forms the basis of the pipe, an extruder is used, in which polymer material is loaded, for example, polyethylene and heated to a viscous-flowing state and extruded through a forming head in the form of a continuous polymer pipe (1), which forms the inner layer that forms the base of the pipe. The resulting pipe is wound on a process drum. The external diameter of the pipe is from 40 to 219 mm, the wall thickness is from 3 to 20 mm. The specific wall thickness is selected by the SDR parameter (the ratio of the external diameter of the pipe to the wall thickness), which is usually 6 to 17 in the technique. Next, the polymer pipe (1) is fed to the winding unit of the polymer tape wound, in which the outer surface of the polymer pipe (1 ) is covered with four coils (2-5) of polymer tapes, for example, of polyethylene terephthalate by winding using a twisting machine, with a tape winding angle of 55 ° ± 5%. When winding polymer tapes, at least one winding (3-5) has the opposite winding direction, for example, the second winding (3) has the opposite winding direction with respect to the first winding (2), the third and fourth windings (4, 5) have a direction winding, which coincides with the first winding (2), or, for example, in accordance with another variant of winding: the first and second windings (2,3) are wound in one direction, and the third and fourth windings (4,5) have the opposite direction of winding . The winding of the coils (2-5) of polymer tapes is carried out in such a way that a gap is made between the polymeric tapes of each cove (2), amounting to 5-10% of the width of the tape, and the gap below the wound coils is closed above the wound coils. After the unit for winding the coils of polymer tapes, a steel pipe (1) with four coiled coils (2-5) is fed into the extruder for applying the outer polymer sheath (6), in which a continuous polymer layer is applied by extrusion onto the fourth coil (5) of the polymer tape, for example, polyethylene forming the outer polymer shell (6) of the polymer pipe (1). The thickness of the polymer shell is also selected based on the SDR parameter, the indicators of which in this case are from 5 to 15. Since the ribbons of the reinforcing layer have a thickness of up to 2 mm, and in this case there are gaps between the ribbons in the outer coil, and irregularities caused by these gaps may appear on the outer polymer shell during extrusion. For leveling the surface of the outer layer of reinforcing elements, twisting of thin tapes, for example, polyethylene, polypropylene or polyethylene terephthalate, can be used. The thickness of these tapes is between 0.2 and 0.6 mm. In the final operation, a flexible polymer reinforced pipe containing 4 coils of polymer tapes and an outer polymer shell is wound into a bay or onto transport drums. The continuous length wound around the transport drum of the claimed flexible polymer reinforced pipe with a diameter of 40 mm can be 2500 m, and with a diameter of 170 mm, 200 m.

The main strength characteristics for a pressure polymer pipe are the characteristics of the maximum pressure that the pipe and tensile strength can withstand. In the proposed utility model, these characteristics are achieved as follows. Under conditions when a high-strength material is used as a reinforcing system - a continuous polymer tape, the reinforcing system takes on all the load arising from the action of internal pressure, and the polymer layers, due to the large coefficients of relative elongation and small deformation of the reinforcing system, are slightly loaded. In this regard, the strength properties of such pipes are primarily determined by the corresponding characteristics of a continuous polymer tape, and the choice of reinforcing system parameters: tape thickness, number of tape layers, tensile strength of the material from which the tape is made can be carried out without taking into account the strength and deformation characteristics of polymer layers. To calculate the reinforcing system for internal hydrostatic pressure, we use the formula:

,

,

where P is the internal pressure in the pipe;

D _H is the outer diameter of the pipe;

e is the minimum wall thickness of the pipe;

σ is the tensile strength of a continuous polymer tape.

For example, take two designs of a flexible polymer reinforced pipe:

The constructions are made in accordance with the proposed utility model, where solid polymer (polyethylene terephthalate) tape with a tensile strength of 400 MPa and a thickness of 0.5 to 2.0 mm is used as reinforcing elements. The calculation results are shown in table 1. The width of the tape is selected so that when winding coils of tape on the pipe between the tapes of one coils there is a gap of 5-15% of the width of the tape. For example, with a winding diameter of 110 mm and six tapes, the width of the tape should be 28 mm, and with 4 tapes 44 mm. The angle of winding tapes can be from 50 to 60 degrees. This winding angle is selected to ensure equal strength of the reinforcing elements in the radial and axial directions. It is known that the condition of equal strength is determined by the expression: tg ² (c) = 2, where c ≈ 55 ° is the angle of winding of polymer tapes to the axis of the pipe. The layers of polymer tape laid in mutually opposite directions at an angle of ≈ 55 ° provide equal strength of the reinforcement system to the action of internal pressure in the axial and radial directions. In practice, it is difficult to ensure the exact angle of the meanings of metal tapes, so it is chosen by a certain error, for example, at 10%.

As the calculations confirmed by experiments showed, the claimed flexible reinforced polymer pipe allows to reduce the specific gravity of the pipe (see table. 1) while maintaining the strength characteristics (see table. 2), compared with the prototype, in which metal tapes are used as reinforced tapes .

Table 1

table 2

Thus, given that the most popular pipes in the oil and gas sector are pipes with a pressure of up to 150 bar, a continuous polymer tape selected for the reinforcing system provides strength characteristics of the pipeline, which can be classified as high-pressure.

The claimed high-pressure polymer reinforced pipe is manufactured in large lengths and is delivered on drums, therefore, for the correct operation of the reinforcing layer of the pipe - coils of continuous polymer tapes when bending the pipeline, it is necessary to ensure the displacement of the coils relative to each other. When the pipe bends, sections of continuous polymer tapes located on the inner radius of the winding on the transport drum are compressed, and sections of continuous polymer tapes located on the outer radius of the winding on the transport drum are stretched. Because the reinforcing tapes have a high modulus of elasticity and cannot stretch / contract, the tapes move relative to each other and the gaps between them in the coils change without changing the geometric dimensions of the tapes themselves. Accordingly, when winding onto a transport drum, the gaps slightly increase on the outer radius, and decrease slightly on the inner one - due to this, stresses do not arise in a continuous polymer tape when the pipeline bends. Thus, the presence of gaps in the coils of tapes allows you to save the geometry of the pipe and to avoid the possible deformation of continuous polymer reinforcing tapes. In practice, the gaps between the tapes are calculated in such a way as to ensure winding or laying of the pipeline with a minimum bending radius without violating the strength characteristics of the reinforcing layer.

High-pressure polymer reinforced pipes have some characteristics that lead to higher productivity and lower cost compared to hard steel pipes. The main characteristic is the ease of installation and replacement, typical of bobbin flexible products. The large length of the pipes minimizes the number of welding points and joints, providing maximum reliability and service life of the pipeline. High-pressure polymer reinforced pipes have high internal and external corrosion resistance due to the absence of metal elements, ensuring durability and nullifying the need for corrosion protection and regular inspections required when using steel pipes.

High-pressure polymer reinforced pipes can be used for surface mounting or for trench laying, as well as using directional drilling or a pipeline restoration method in which the pipe is pulled through a normal damaged steel pipe. High-pressure polymer reinforced pipes are ideally suited for pipeline restoration due to the possibility of maintaining pressure and independence from the structural integrity of the pipeline through which it extends. The use of deepening methods allows minimizing the impact on the environment, reducing the degree of impact on the topsoil.

High-pressure polymer reinforced pipes can also be installed above the ground and are ideal for applications in harsh climatic conditions, such as the tundra, where an open pipeline can be installed with minimal use of infrastructure, such as supports, and in many cases can be installed in places not equipped with access for transport.

The claimed high-pressure polymer reinforced pipe in comparison with the prototype has a lower heat transfer coefficient, which provides lower heat loss of the transported fluid, for example, the thermal conductivity for various metals is from 35 to 400 W / (m⋅K), and the same coefficient for polymers on average has indicator 0.36 W / (m⋅K).

A utility model has been disclosed above with reference to a specific embodiment. For specialists, other embodiments of the utility model that do not change its essence, as disclosed in the present description, may be obvious. Accordingly, a utility model should be considered limited in scope only below by the following claims.

Claims (4)

1. A high-pressure polymer reinforced pipe containing a reinforced layer and an outer polymer shell successively applied to the outer surface of the polymer pipe, characterized in that the reinforcing layer is made of four sequentially spirally wound coils of reinforcing polymer tapes. 2. The pipe according to claim 1, characterized in that a gap is made between the reinforcing tapes of each winding. 3. The pipe according to claim 1, characterized in that at least one winding of the reinforcing tapes has the opposite direction of winding. 4. The pipe according to claim 1, characterized in that, according to the outer layer of the reinforcing layer, an additional layer of thin polymer tapes 0.2-0.6 mm thick is applied.

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