Flexible ultra-high molecular weight polyethylene composite tube as well as preparation method and production system thereof

Abstract

The invention discloses a flexible ultra-high molecular weight polyethylene composite tube as well as a preparation method and a production system thereof. The composite tube comprises an ultra-high molecular weight polyethylene inner pipe, a middle layer of a bidirectional wound glass fiber composite belt, and an outer polyethylene cladding layer, wherein the ultra-high molecular weight polyethylene inner tube, the glass fiber composite belt and the polyethylene outer layer are respectively compounded in a surface softening or melting state, so that all composite layers are compact in structure and totally fused into a whole. The preparation method of the composite tube mainly comprises the steps of extrusion molding of the ultra-high molecular weight polyethylene inner tube, winding of the glass fiber composite belt, heating and compounding and cladding of the fused polyethylene on the outer wall. The ultra-high molecular weight polyethylene composite tube has the advantages of no cracking of the inner tube, no stripping of the composite layers, capacity of coiling, low production cost, high compression strength and uniform and stable pressure resistant values in all places, and is suitable for oil pumping tubes and gathering and transportation tubes of land oil fields and underwater oil gas conveying tubes for offshore oil production.

Description

technical field [0001] The invention relates to a composite pipe, its preparation method and production system, in particular to a flexible ultra-high molecular weight polyethylene composite pipe, its preparation method and production system. Background technique [0002] In the process of oil extraction, a large number of various oil and gas pipes, such as oil well pipes, are used. Generally, after the oil well is drilled into the oil layer, the oil well casing is lowered, and oil well cement is injected into the annular space between the casing pipe and the well wall to maintain the well. According to the requirements of oilfield development, perforating guns are used to open the oil layer to form a channel, which is lowered into the oil pipe, and the oil is raised from the bottom of the oil well to the head of the well with a suitable induction method. [0003] In the prior art, oil well pipes are mainly produced by continuous rolling, or by double-sided submerged arc wel...

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Problems solved by technology

[0009] Chinese patent application 201210584568.3 discloses a method for preparing fiber-wound reinforced pipes. Although the obtained composite pipes have the advantages of wear resistance, corrosion resistance, and high compressive strength, the glass fibers are directly wound on the inner pipe, and the glass fiber reinforced layer is uniform. Insufficient resistance, it will peel off when it is subjected to radial stress and lateral stress fatigue, and there will be instability, which will affect the performance of the composite pipe

However, this type of ultra-high molecular weight polyethylene composite pipe cannot be coiled, so its length is limited, and the number of joints is greatly increased during use, which affects the performance of the composite pipe and increases the workload.

[0011] Moreover, for the above two types of ultra-high molecular weight polyethylene composite pipes that use fiber materials as reinforcement layers, since the individual fibers in the fiber bundles of traditional fiber materials cannot maintain the same tension, the composite pipes made of this material , the compressive strength of the outer wall cannot maintain strict uniformity and consistency

Practice has proved that when the composite pipe is under pressure, the fiber in the fiber layer often breaks first at the weakest point of its pressure resistance, so that the fibers in the progressive fiber layer continue to break until the entire composite pipe is damaged.

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