A light-cured prepreg sheet for pipeline directional drilling crossing protection

Abstract

The application discloses a photocured prepreg sheet for pipeline directional drilling crossing protection, which is a reinforced substrate of impregnated resin glue. The reinforced substrate comprises a laminated long glass fiber axial cloth and a glass fiber chopped felt. The long glass fiber axial cloth comprises a first unidirectional layer and a second unidirectional layer, which are obtained by laying fiber untwisted roving. The axial angles of the fiber untwisted roving in the first unidirectional layer and the second unidirectional layer are 90 degrees. The photocured prepreg sheet for pipeline directional drilling crossing protection adopts the laminated long glass fiber axial cloth and the glass fiber chopped felt as the reinforced substrate. The long glass fiber axial cloth has 0 / 90 bi-axial layers composed of untwisted roving. The two layers are laminated. The tensile strength of the sheet is high. After curing, the interaction force between the untwisted rovings in the layers is small under the local compression condition of the protective layer. The protective layer has higher wear resistance and scratch resistance. The application further discloses a surface coating structure of a crossing pipeline.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline surface corrosion protection, in particular to a pipeline directional drilling crossing protection light-cured prepreg sheet and a crossing pipeline surface coating structure. BACKGROUND

[0002] Pipeline crossing refers to a means of laying a pipeline underwater or underground to form a pipeline road crossing a river, a lake, and a railway or a highway. In a long-distance pipeline directional drilling crossing project, the continuous friction between the pipeline surface and the bottom layer easily damages the pipeline anticorrosion layer, affecting the service life of the pipeline. The pipeline anticorrosion layer within a range of 20 m before back dragging is most severely damaged. In the improved technical solution, the pipeline is first coated with a pipeline directional drilling crossing protection light-cured prepreg sheet, and a protection layer mainly composed of fiber reinforced materials and cured unsaturated resin is obtained after curing.

[0003] The known pipeline directional drilling crossing protection light-cured prepreg sheet, as disclosed in CN102305334A Petroleum and Natural Gas Engineering Directional Drilling Crossing Pipeline Anticorrosion Layer Protection Method, uses glass fiber cloth as a reinforcing base material to coat the crossing pipeline, and is sequentially wound and laid from one end of the pipeline to the other end in a sequential lap joint manner (as shown in FIG. 1). Figure 1 The structure of a general protection layer is a laminated structure of epoxy adhesive-glass fiber cloth-epoxy adhesive-glass fiber cloth-epoxy adhesive, and the structure of a reinforced protection layer is a laminated structure of epoxy adhesive-glass fiber cloth-epoxy adhesive-glass fiber cloth-epoxy adhesive-glass fiber cloth-epoxy adhesive.

[0004] The grid fiber cloth used for pipeline coating in the prior art is usually glass fiber interwoven as warp and weft. The above grid fiber cloth is prone to deformation during coating, and the internal stress of the interwoven part of the warp and weft increases after the pipeline is extruded by external force, resulting in low pressure-bearing capacity of the pipeline body. The untwisted roving of the glass fiber square cloth is also not conducive to the adhesion of the resin glue, so a multiple spaced coating structure of epoxy adhesive-glass fiber cloth is required. In addition, the sequential lap joint coating method has the following defects: first, the axial surface of the pipeline is concave-convex, and the concave and convex parts are easily scratched by rocks in the borehole, eventually forming deep scratches along the axial surface of the crossing pipeline; second, the inner layer of the wrapping tape at the bottom of the crossing pipeline is less exposed to light, and cannot be fully cured, forming a defect area of the pipeline protection layer. SUMMARY

[0005] One of the purposes of the present application is to overcome the defects in the prior art and provide a pipeline directional drilling crossing protection light-cured prepreg sheet with high strength, good scratch and wear resistance after curing.

[0006] In order to achieve the above technical effects, the technical scheme of the present application is: a photocured prepreg sheet for pipeline directional drilling crossing protection, characterized in that the photocured prepreg sheet is a reinforced substrate impregnated with resin glue, the reinforced substrate comprises a laminated composite long glass fiber axial cloth and a glass fiber chopped mat, the long glass fiber axial cloth comprises a first unidirectional layer and a second unidirectional layer obtained by laying glass fiber untwisted roving, and the axial angle of the fiber untwisted roving in the first unidirectional layer and the second unidirectional layer is 90°.

[0007] Preferably, the surface layer of the reinforced substrate is a glass fiber chopped mat.

[0008] Preferably, the long glass fiber axial cloth and the glass fiber chopped mat are interlayer stitched by stitching threads.

[0009] Preferably, the reinforced substrate is formed by laminating a biaxial long glass fiber axial cloth and a glass fiber chopped mat, and the edges of the long glass fiber axial cloth and the glass fiber chopped mat are flush.

[0010] Preferably, the reinforced substrate comprises an inner composite mat and an outer composite mat with consistent shapes, the inner composite mat and the outer composite mat respectively comprise a glass fiber chopped mat and a biaxial long glass fiber axial cloth which are laminated and have flush edges, and the side edges of the inner composite mat and the outer composite mat are parallel and laminated in a staggered manner.

[0011] Preferably, the inner composite mat and the outer composite mat are rectangular.

[0012] Preferably, the number of layers of the long glass fiber axial cloth and the glass fiber chopped mat in the inner composite mat and the outer composite mat is one.

[0013] The second object of the present application is to provide a wrapping structure of a photocured prepreg sheet for pipeline directional drilling crossing protection, characterized in that, based on the photocured prepreg sheet for pipeline directional drilling crossing protection described above, the inner composite mat and the outer composite mat are laminated in a staggered manner to form inner and outer staggered edges, a first photocured prepreg sheet and a second photocured prepreg sheet are wrapped around a pipeline in a circumferential direction, the outer staggered edge of the first photocured prepreg sheet is laminated and adhered to the inner staggered edge of the second photocured prepreg sheet, and the inner composite mat and the outer composite mat of the first photocured prepreg sheet and the second photocured prepreg sheet are butt-jointed.

[0014] Preferably, the circumferential butt-joint line of the first photocured prepreg sheet and the second photocured prepreg sheet is laminated and adhered with a glass silk cloth.

[0015] Preferably, the two ends of the light-cured prepreg sheet covering the pipeline in the circumferential direction are overlapped to form an overlapping part, and the inner layer composite felt and the outer layer composite felt in the overlapping part are staggered and overlapped.

[0016] The advantages and beneficial effects of the present application are that:

[0017] The light-cured prepreg sheet for pipeline directional drilling crossing protection adopts long glass fiber axial cloth and glass fiber chopped felt as reinforcing base material, the long glass fiber axial cloth has 0° / 90° biaxial layer composed of untwisted roving, and the two layers are stacked, and the tensile strength of the sheet is high; due to the fixing effect of the resin material, the interaction force of the untwisted roving between the layers is small under the condition of local pressure of the cured protection layer, so that the cured protection layer has higher wear resistance and scratch resistance;

[0018] The surface covering structure of the crossing pipeline is flat without concave and convex, compared with the sequential overlapping method in the prior art, the force point for scratching the rock in the drilling is reduced, the scratch resistance of the protection layer is improved, the pipeline protection layer is fully and uniformly cured under natural light conditions. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the sequential overlapping covering structure of the light-cured prepreg sheet for pipeline directional drilling crossing protection in the prior art;

[0020] Figure 2 is a structural schematic diagram of the reinforcing base material in the light-cured prepreg sheet for pipeline directional drilling crossing protection of example 1;

[0021] Figure 3 is a sectional structural schematic diagram of the reinforcing base material in the light-cured prepreg sheet for pipeline directional drilling crossing protection of example 2;

[0022] Figure 4 is a top view structural schematic diagram of the reinforcing base material in the light-cured prepreg sheet for pipeline directional drilling crossing protection of example 2;

[0023] Figure 5 is a top view structural schematic diagram of the reinforcing base material in the light-cured prepreg sheet for pipeline directional drilling crossing protection of example 3;

[0024] Figure 6 is a sectional structural schematic diagram of the crossing pipeline and the surface covering structure of example 4;

[0025] Figure 7 is a three-dimensional structural schematic diagram of the surface covering structure of example 4;

[0026] Figure 8 is a sectional structural schematic diagram of the crossing pipeline and the surface covering structure of example 5;

[0027] Figure 9 is a schematic diagram of the cross-sectional structure of the pipe and the surface coating structure of Example 6;

[0028] Figure 10 is a schematic diagram of the cross-sectional structure of the pipe and the surface coating structure of Example 6;

[0029] In the figure: 1, glass fiber biaxial cloth; 11, first unidirectional layer; 12, second unidirectional layer; 2, glass fiber chopped mat; 3, stitching thread; 4, first photocured prepreg sheet; 5, first photocured prepreg sheet; a, pipe; b, inner layer composite mat; b1, inner layer misaligned edge; c, outer layer composite mat; c1, outer layer misaligned edge; 6, glass cloth. DETAILED DESCRIPTION

[0030] The specific embodiments of the present application are further described below in conjunction with the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0031] Long glass fiber axial cloth

[0032] The fiber uniaxial cloth generally includes uniaxial cloth and multi-axial cloth, and the multi-axial cloth is divided into biaxial cloth, triaxial cloth and quadaxial cloth. In the uniaxial cloth, the untwisted roving is arranged in parallel in the plane to form a layer, and in the biaxial cloth, two layers are included. The axial direction of the untwisted roving in the two or more layers is a combination of 0°, 90°, +45°, -45°, +60° and -60°. The preferred long glass fiber axial cloth is a 0° / 90° biaxial cloth.

[0033] Glass fiber chopped mat

[0034] The gaps between the randomly distributed fibers in the glass fiber chopped mat help to increase the resin content of the reinforced substrate. Further, the glass fiber chopped mat is used as the surface layer of the reinforced substrate, and the cured sheet has a relatively thick photocured resin layer, which helps to enhance the protection performance.

[0035] Stitching thread interlayer stitching

[0036] The function of the stitching thread interlayer stitching is to ensure that there is no relative displacement between the layers during the impregnation production process, so that the sheet has neat edges, and the end splicing joint is small and easy to control during the subsequent pipe coating process.

[0037] Misaligned lamination of composite mat

[0038] The commonly used misaligned lamination of the composite mat is rectangular. The rectangular composite mat has a pair of long edges and a pair of wide edges. Two composite mats are misaligned and laminated, including two cases: one, the wide edges of the two laminated composite mats are flush, and the long edges are parallel and misaligned; two, the wide edges and the long edges of the two composite mats are parallel and misaligned.

[0039] Based on the first structure described above: during construction, the wide edge of the composite felt is consistent with the generatrix of the pipeline, and the long edge of the composite felt is wrapped around the circumference of the pipeline. The wide edge is flush with the surface of the pipeline, forming a smooth and seamless joint line consistent with the generatrix of the pipeline. The misaligned long edge forms an inner misaligned edge and an outer misaligned edge on the outer circumference of the pipeline. The inner misaligned edge and the outer misaligned edge are overlapped with the adjacent photocured prepreg sheet, and finally form a smooth protection structure in which the inner composite felt and the outer composite felt of adjacent photocured prepreg sheets are seamlessly jointed.

[0040] Based on the second structure described above: during the construction of the composite felt overlapping at both ends of the prepreg sheet, not only does it form an inner misaligned edge and an outer misaligned edge on the outer circumference of the pipeline, but it also forms an inner misaligned edge and an outer misaligned edge along the axial direction of the pipeline at the wide edges of both ends of the same photocured prepreg sheet. The inner misaligned edge and the outer misaligned edge on the outer circumference of the pipeline are overlapped with the adjacent photocured prepreg sheet, and the inner misaligned edge at one end and the outer misaligned edge at the other end of the photocured prepreg sheet are overlapped and laid in sequence along the extension direction of the pipeline. Finally, a smooth protection structure is formed in which the inner composite felt and the outer composite felt of adjacent photocured prepreg sheets are seamlessly jointed.

[0041] The overlapping of the composite felt serves to increase the stability of the overlapping of the prepreg sheet. The structure of the overlapping of the composite felt is as follows: the two ends of the prepreg sheet are the A end and the B end. The inner composite felt of the A end of the prepreg sheet is attached to the pipeline, the inner composite felt of the B end of the prepreg sheet is attached to the surface of the inner composite felt of the A end of the prepreg sheet, the outer composite felt of the A end of the prepreg sheet is attached to the surface of the inner composite felt of the B end of the prepreg sheet, and the outer composite felt of the B end of the prepreg sheet is attached to the surface of the outer composite felt of the A end of the prepreg sheet.

[0042] The overlapping allows the inner overlapping edge in the overlapping part to be free of air gaps between the surface of the pipeline and the pipeline, allowing the protective layer to be closely attached to the pipeline and optimizing the protection effect.

[0043] Further, in order to fully cure the overlapping part, the overlapping part is located at the top end of the protective cylinder segment.

[0044] Example 1

[0045] As shown in Figure 2 Example 1, the photocured prepreg sheet for directional drilling of the pipeline is a reinforced substrate impregnated with resin glue. The reinforced substrate includes 0° / 90° biaxial glass fiber cloth 1 and glass fiber chopped felt 2 stacked in order from the inside to the surface, i.e., the biaxial glass fiber cloth is composed of a first unidirectional layer 11 and a second unidirectional layer 12 obtained by laying glass fiber untwisted roving. The axial angle of the untwisted roving in the first unidirectional layer 11 and the second unidirectional layer 12 is 90°.

[0046] Example 2

[0047] As shown in Figure 3 and 4 , the photocured prepreg sheet for pipeline directional drilling protection in Example 2 is a reinforced substrate impregnated with resin glue, the 0° / 90° long glass fiber axial cloth 1 and the glass fiber chopped strand mat 2 in Example 1 are stitched into a composite mat by stitching thread 3, the reinforced substrate in Example 2 includes inner layer composite mat b and outer layer composite mat c of uniform size, the long glass fiber axial cloth 1 of the inner layer composite mat b and the outer layer composite mat c are in close contact, and the two surface layers of the photocured prepreg sheet for pipeline directional drilling protection are glass fiber chopped strand mat 2. The wide edges of the inner layer composite mat b and the outer layer composite mat c are flush, and the long edges are parallel and staggered.

[0048] Example 3

[0049] As shown in Figure 5 , Example 3 is based on Example 2, the difference is that the long edges and wide edges of the inner layer composite mat b and the outer layer composite mat c in the photocured prepreg sheet for pipeline directional drilling protection in Example 3 are parallel and staggered.

[0050] Example 4

[0051] As shown in Figure 6-7 , based on the photocured prepreg sheet for pipeline directional drilling protection described in Example 2, the length of the long edge in Example 2 is greater than the outer circumference of the pipeline. The inner layer composite mat b and the outer layer composite mat c are staggered and stacked to form inner layer staggered edges b1 and outer layer staggered edges c1, the long edges of the first photocured prepreg sheet 4 and the second photocured prepreg sheet 5 are circumferentially wrapped around the pipeline a and arranged adjacent to each other, the outer layer staggered edges c1 of the first photocured prepreg sheet 4 are stacked and adhered to the inner layer staggered edges b1 of the second photocured prepreg sheet 5, the flush wide edges at both ends of the first photocured prepreg sheet 4 are overlapped, and the flush wide edges at both ends of the first photocured prepreg sheet 5 are also overlapped.

[0052] Example 5

[0053] As shown in Figure 8-9 , based on Example 4, glass silk cloth 6 is stacked and adhered outside the circumferential joint line of the first photocured prepreg sheet 4 and the second photocured prepreg sheet 5.

[0054] Example 6

[0055] As shown in Figure 10 , based on Example 3, by stacking and adhering the outer layer staggered edges c1 at the long edges and wide edges to the inner layer staggered edges b1, the inner layer composite mat b and the outer layer composite mat c of the first photocured prepreg sheet 4 and the second photocured prepreg sheet 5 are in close contact.

[0056] Example 6

[0057] As shown in Figure 10As shown, based on Example 4, the difference is that the first photocured prepreg sheet material 4 is overlapped at both ends to form an overlapping portion, and the inner layer composite felt b and the outer layer composite felt c are alternately overlapped in the overlapping portion.

[0058] The comparative example shows the lapping method of the comparative example as shown in FIG. 2. Figure 1 As shown, the glass filament cloth (warp and weft weaving) in the comparative example is used as the reinforcing substrate.

[0059] 1. Resin content comparison

[0060] The glass filament cloth layer with warp and weft weaving is cut to make a comparative sheet material covering the axial direction of the pipeline, and the sheet material in Example 6 is respectively immersed in a resin glue with a temperature of 25°C and a viscosity of 1500cps. After taking out and standing for 5 minutes, the resin glue in the sheet material is free to seep out, and the resin content in the comparative sheet material and the sheet material in Example 6 is 22% and 35% respectively after 5 minutes.

[0061] [Resin content = (sheet material mass after standing - sheet material mass before dipping) / sheet material mass before dipping × 100%]

[0062] The greater the resin content, the greater the thickness of the protective layer of the pipeline, and the further optimization of the protective performance.

[0063] 2. Structure comparison of the cured protective layer

[0064] The glass filament cloth with warp and weft weaving with a resin content of 35% and the sheet material in Example 6 are used to cover the pipeline and are cured, wherein the glass filament cloth uses the sequential lapping method in the background technology, and the prepreg sheet material uses the lapping method in Example 6. The measured values of the grammage, edge pressing protrusion and protective performance of the surface protective layer of the pipeline obtained by curing are shown in the following table:

[0065] Serial number Comparative project Unit Comparative example 6 Detection method Appearance 1 With sequential lap convex ring, there is annular hollow drum under the convex ring, the inner layer of the bottom lap joint has un-solidified defect Smooth and flat, no hollow drum, complete solidification Visual inspection Gram weight 2 Actual measurement g / m 2 ]] ≤3.5 5.6 Edge pressing protrusion 3 mm Actual measurement of slice ≤2 ≤0.5 Lap protrusion 4 mm Actual measurement of cutting edge ≤2 ≤0.4 Thickness 5 mm GB / T 6672 ≥1.5 ≥2.5 ​

[0066] As can be seen from the above table, the photocured prepreg sheet material is immersed in resin glue, and the protective performance of the pipeline obtained is as follows: tensile strength ≥ 300 MPa (GB / T 1447), bending strength ≥ 300 MPa (GB / T 1449), compression strength ≥ 200 MPa (GB / T 1448), Barus hardness ≥ 60 (GB / T 2411), Shore-D hardness ≥ 90 (GB / T 2411), scratch resistance (50Kg) ≤ 350μm (SY / T 4113), wear resistance ≥ 7 L / μm, bending resistance: 3° without cracks (SY / T 0315), adhesion to FBE ≥ 7 MPa (ASTM D4541), impact resistance ≥ 350.

[0067] Due to the existence of the above table, the edge protrusion, the lap protrusion and the lap inner layer unhardened defect area and the hollow, the pipe after crossing the hollow and the lap edge scratch are obvious, due to the existence of the pipe bottom inner layer unhardened defect, the pipe bottom after crossing is more prone to scratch through the protective layer. The pipe protective layer surface obtained by the embodiment 6 is smooth, no hollow, smooth and complete, the pipe surface scratch after crossing is significantly less than the comparative example 1, no serious scratch through the protective layer.

[0068] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A light-curing prepreg sheet for protection during directional drilling of pipelines, characterized in that, The photocurable prepreg sheet is a reinforcing substrate for impregnated resin adhesive. The reinforcing substrate includes a laminated composite long glass fiber axial cloth and glass fiber chopped strand mat. The long glass fiber axial cloth includes a first unidirectional layup and a second unidirectional layup obtained by laying untwisted glass fiber rovings. The axial angle between the untwisted fiber rovings in the first unidirectional layup and the second unidirectional layup is 90°. The surface layer of the reinforcing substrate is chopped glass fiber mat; the reinforcing substrate comprises an inner composite mat and an outer composite mat with consistent shapes, the inner composite mat and the outer composite mat respectively comprising stacked and flush-edge chopped glass fiber mat and bidirectional long glass fiber axial fabric, the sides of the inner composite mat and the outer composite mat are parallel and staggered; both the inner composite mat and the outer composite mat are rectangular. The long glass fiber axial fabric is a biaxial fabric with a 0° / 90° angle. The two ends of the photocurable prepreg sheet covering the circumferential pipe are used to overlap to form an overlap portion, in which the inner composite felt and the outer composite felt are alternately overlapped.

2. The light-cured prepreg sheet for protection during directional drilling of pipelines according to claim 1, characterized in that, The layers of the long glass fiber axial fabric are stitched together with braided thread, or the long glass fiber axial fabric and the glass fiber chopped strand mat are stitched together with braided thread.

3. The light-cured prepreg sheet for protection during directional drilling of pipelines according to claim 1, characterized in that, The reinforcing substrate is composed of a layer of bidirectional long glass fiber axial cloth and a layer of glass fiber chopped strand mat, with the edges of the long glass fiber axial cloth and the glass fiber chopped strand mat flush.

4. The light-cured prepreg sheet for protection during directional drilling of pipelines according to claim 1, characterized in that, The inner and outer composite felts each have one layer of long glass fiber axial cloth and one layer of glass fiber chopped strand mat. Both surface layers of the light-cured prepreg sheet for pipeline directional drilling protection are glass fiber chopped strand mat.

5. A coating structure for a light-cured prepreg sheet used for protection during directional drilling of pipelines, characterized in that, Based on the light-cured prepreg sheet for pipeline directional drilling protection according to any one of claims 1 to 4, the inner composite felt and the outer composite felt are staggered to form an inner staggered edge and an outer staggered edge. The first light-cured prepreg sheet and the second light-cured prepreg sheet are adjacent to each other in the circumferential direction and cover the outside of the pipeline. The outer staggered edge of the first light-cured prepreg sheet is stacked and bonded to the inner staggered edge of the second light-cured prepreg sheet. The inner composite felt and the outer composite felt of the first light-cured prepreg sheet and the second light-cured prepreg sheet are all matched and connected. The two ends of the photocurable prepreg sheet covering the circumferential pipe overlap to form an overlap portion, in which the inner composite felt and the outer composite felt overlap alternately.

6. The covering structure of the photocurable prepreg sheet for pipeline directional drilling protection according to claim 5, characterized in that, Glass fiber cloth is laminated on the outer layer of the circumferentially connected seams of the first and second photocurable prepreg sheets.

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