A method for reconstructing and regenerating an old pipeline in service

Abstract

The application relates to a pipeline reconstruction technology field, and relates to a reconstruction structure and a reconstruction method of an old pipeline in service, which comprises the following steps: S1, cutting the old pipeline in service into sections, welding steel blind plates at two ports of each section, and sealing the end of the old pipeline in service by the steel blind plates; S2, welding a steel reducing pipe on the steel blind plate; the steel reducing pipe is communicated with the inside of the old pipeline in service; S3, slowly inserting a hose into the steel reducing pipe and the inside of the old pipeline in service, with the hose being pasted to the inner wall of the steel reducing pipe, and the two ends of the hose being fixed by turning up; S4, injecting water into the hose and maintaining pressure, so that the hose is maintained in a cylindrical shape; S5, respectively arranging a grouting port and a venting port at the two ends of the old pipeline in service, slowly injecting cement slurry from the grouting port, and discharging air from the venting port, until the space between the old pipeline in service and the hose is completely filled with the cement slurry; and S6, discharging water in the hose after the cement slurry is solidified.

Description

Technical Field

[0001] This invention belongs to the field of pipeline renovation technology, and in particular relates to a structure and method for regenerating and renovating old pipelines in service. Background Technology

[0002] As oilfield development enters its mid-to-late stages, especially during periods of reduced and stabilized production, crude oil output continues to decline. In some older oilfields, actual production is only 30%-50% of designed capacity, and the overall water cut has generally risen above 80%, fundamentally altering the properties of the produced fluid. The surface gathering and transportation pipelines in these oilfields were mostly designed in the early or mid-stages of development based on high production capacity demands, with sufficient capacity expansion margins in the pipe diameter selection to accommodate the then-current production scale and future expansion expectations. However, under the current low-flow-rate, high-water-cut production conditions, the original gathering and transportation pipelines have become a typical "large-diameter, low-flow-rate" operating condition, leading to a sharp decline in system adaptability and becoming a key bottleneck restricting cost reduction, efficiency improvement, and safe operation of the oilfield.

[0003] How to regenerate existing large-diameter, aging oil, gas, and water pipelines through technological upgrades to meet the low-volume demand during periods of reduced and stable production has become an urgent need in the field of oil and gas surface transportation engineering. Summary of the Invention

[0004] To achieve the regeneration and renovation of aging oil, gas, and water pipelines, this invention provides a structure and method for regenerating and renovating in-service aging pipelines. This invention involves installing a flexible hose inside the aging pipeline and filling the space between the hose and the aging pipeline with cement slurry as a rigid support, thereby improving the hose's internal pressure resistance and thus obtaining a regenerated transportation pipeline that meets the current output requirements at a low cost.

[0005] The technical solution provided by this invention is: a structure for the renovation and regeneration of in-service aging pipelines, comprising an aging pipeline, a steel blind flange, a steel reducer, and a flexible hose. The steel blind flange is sealed and welded to the end of the aging pipeline, sealing the end of the aging pipeline. The steel reducer is sealed and welded to the steel blind flange, and the interior of the steel reducer is connected to the interior of the aging pipeline. The flexible hose is folded over and built into the interior of the steel reducer and the aging pipeline. The flexible hose is adhered and bonded to the inner wall of the steel reducer and has a flanged end on the steel reducer. The space between the aging pipeline and the flexible hose is filled with cement grout. After the cement grout solidifies, it provides rigid support to the flexible hose, thereby improving the hose's internal pressure resistance.

[0006] A further technical solution is: one end of the old pipeline has a grouting port for filling with cement slurry, and the other end of the old pipeline has an exhaust port.

[0007] A further technical solution is to have a bevel at the end of the steel reducing pipe to facilitate hose flanging.

[0008] A further technical solution is to place the steel reduced-diameter pipe parallel to the axis of the old pipeline and at the bottom of the old pipeline.

[0009] A method for regenerating and upgrading aging pipelines in service includes the following steps:

[0010] S1 involves cutting the old pipeline into sections and welding steel blind flanges at both ends of each section. The steel blind flanges will then seal the ends of the old pipeline.

[0011] S2, Weld a steel reducer to the steel blind flange; The steel reducer is connected to the interior of the old pipeline in service, and the axis of the steel reducer is parallel to the axis of the old pipeline in service.

[0012] S3. Apply adhesive to the uncoated layer of the hose and slowly insert it into the steel reducer and old pipelines, ensuring that the hose fits against the inner wall of the steel reducer. Fix the ends of the hose by flipping them over.

[0013] S4, inject water into the hose and maintain pressure to keep the hose in a cylindrical shape;

[0014] S5. Grouting ports and venting ports are opened at both ends of the old pipeline in service. Cement grout is slowly injected from the grouting port and air is discharged from the venting port until the space between the old pipeline in service and the hose is completely filled with cement grout.

[0015] S6. After the cement slurry has solidified, drain the water from the hose.

[0016] A further technical solution is that, in S4, the temperature of the water injected into the hose is 40-50℃.

[0017] A further technical solution is to first wet the inside of the old pipeline in service before injecting cement grout in S5, and then inject cement grout after the wet treatment is completed.

[0018] A further technical solution is to use ordinary silicate cement in S5, prepare cement slurry with a fluidity of 400mm, or directly purchase cement slurry that meets the requirements.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] This invention achieves technical transformation without abandoning existing large-diameter pipelines by incorporating a built-in reduced-diameter flexible hose. This matches the effective flow cross-section within the pipe to the current production rate, increasing the fluid velocity to a reasonable range and fundamentally solving the problems of fluid accumulation and high energy consumption caused by low flow rates. Furthermore, the smooth inner wall of the hose provides excellent corrosion resistance, solving the pipeline corrosion problem. Supported by solidified cement slurry, the hose has strong pressure-bearing capacity, fully meeting usage requirements. This technology eliminates the need for large-scale demolition and reconstruction, saving significant investment. The hose has low purchase and transportation costs, is easy to install by flipping it over, has a short construction period, and minimal disruption to production. It aligns with the development trend of green transformation and cost reduction and efficiency improvement in old oilfields, possessing significant technical feasibility and economic value, and providing a new path for the optimization and upgrading of oilfield gathering and transportation systems during periods of reduced and stable production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 yes Figure 1 Cross-sectional view at point AA.

[0023] In the diagram: 1. Steel reducing pipe; 2. Steel blind flange; 3. Grouting port; 4. Old pipeline; 5. Flexible hose; 6. Cement grout. Detailed Implementation

[0024] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0025] like Figure 1 and Figure 2 As shown, this invention includes an old pipeline 4, a steel blind flange 2, a steel reducer 1, and a flexible hose 5. During on-site renovation, the old pipeline 4 is cut off at a certain point. The steel blind flange 2 is sealed and welded to the end of the old pipeline 4, sealing the end of the old pipeline 4. The steel reducer 1 is sealed and welded to the steel blind flange 2, and after sealing and welding, the interior of the steel reducer 1 is connected to the interior of the old pipeline 4. The flexible hose 5 is inverted and built into the interior of the steel reducer 1 and the old pipeline 4. The flexible hose 5 is attached and bonded to the steel reducer 1, and the end of the steel reducer 1 is beveled to facilitate the beveling of the flexible hose 5. The space between the old pipeline 4 and the flexible hose 5 is filled with cement grout 6. After the cement grout 6 solidifies, it provides rigid support to the flexible hose 5, thereby improving the internal pressure resistance of the flexible hose 5.

[0026] The old pipeline 4 has a cement grouting port 3 at one end for filling cement slurry 6, and an air vent at the other end of the old pipeline 4 (the air vent is not shown in the attached drawing).

[0027] The steel reducer 1 is axially parallel to the old pipeline 4 and located at the bottom of the old pipeline 4, thereby improving the coaxiality between the hose 5 and the steel reducer 1. Higher coaxiality results in lower oil transport resistance.

[0028] The hose 5 in this invention can be a TPU film hose, but it is not limited to one material. The pressure-bearing capacity of the hose 5 can be selected as needed.

[0029] In this application, the old pipeline 4 does not simply refer to old oil, gas, or water pipelines, but can also be oil-gas mixed pipelines, oil-water mixed pipelines, gas-water mixed pipelines, oil-gas-water mixed pipelines, etc. This invention is applicable to the regeneration and renovation of any of the old pipelines 4 mentioned above. Of course, this invention is also applicable to the diameter reduction renovation of old pipelines 4 in other industries.

[0030] A process for on-site diameter reduction retrofitting of aging pipelines in oilfields includes the following steps:

[0031] S1, the old pipeline 4 in service is cut into sections, and steel blind flanges 2 are welded at the two ends of each section. The steel blind flanges 2 will seal the ends of the old pipeline 4 in service.

[0032] S2, the steel blind flange 2 has a hole for the steel reducer pipe 1 to pass through. The steel reducer pipe 1 is welded to the steel blind flange 2. After welding, the steel reducer pipe 1 is connected to the interior of the old pipeline 4 in service. The axis of the steel reducer pipe 1 is parallel to the axis of the old pipeline 4 in service.

[0033] S3, apply adhesive to the uncoated layer of the hose 5 and slowly insert it into the steel reducer 1 and the old pipeline 4, ensuring that the hose 5 fits against the inner wall of the steel reducer 1, and fix the ends of the hose 5 by flipping them over.

[0034] S4, fill water into hose 5 and maintain pressure (specifically: install the sealing joints at both ends of hose 5 to ensure a tight seal, then connect one end of the sealing joint to the outlet pipe of the pressure pump, and close the other end of the sealing joint or install a valve to close it, and check whether the entire pipeline connection is secure and there is no looseness or leakage risk). The purpose is to keep hose 5 in a cylindrical shape.

[0035] S5, grouting port 3 and venting port are opened at both ends of the old pipeline 4. Cement grout 6 is slowly injected from the grouting port 3 and air is discharged from the venting port until the space between the old pipeline 4 and the hose 5 is completely filled with cement grout 6.

[0036] S6. After the cement slurry 6 has cured, drain the water from the hose 5 (specifically: turn off the pressure pump, disassemble the sealing joint and connecting pipe, and drain the water from the hose 5).

[0037] In this invention, the adjacent steel reducer pipe 1 and hose 5 are connected by a "sealed connection joint" to form a continuous oil, water, and gas pipeline. The "sealed connection joint" can be found in Chinese Patent CN202321148889.9 or Chinese Patent CN202220064734.6.

[0038] In S4, the temperature of the water injected into the hose 5 is 40-50℃. At this temperature, the cement slurry 6 has better fluidity, better compaction, and shorter cement curing time.

[0039] In S5, before injecting cement grout 6, the interior of the existing old pipeline 4 is first moistened with water. After the moistening treatment is completed, cement grout 6 is injected. After the moistening treatment, the cement grout 6 has better fluidity, and it takes less time to fill cement grout 6.

[0040] In S5, ordinary silicate cement is used to prepare cement slurry 6 with a fluidity of 400 mm, or cement slurry 6 that meets the requirements is purchased directly.

[0041] In summary, this invention achieves technical transformation without abandoning the existing large-diameter, aging pipeline 4, by incorporating a built-in reduced-diameter flexible hose 5. This matches the effective flow cross-section within the pipe to the current production rate, increasing the fluid velocity to a reasonable range and fundamentally solving the problems of fluid accumulation and high energy consumption caused by low flow rates. Furthermore, the smooth inner wall of the hose 5 provides excellent corrosion resistance. Supported by the solidified cement slurry 6, the hose 5 has strong pressure-bearing capacity, fully meeting usage requirements. This technology eliminates the need for large-scale demolition and reconstruction, saving significant investment. The hose 5 has low purchase and transportation costs, is easy to install by flipping it over, has a short construction period, and minimal disruption to production. It aligns with the development trend of green transformation and cost reduction / efficiency improvement in old oilfields, possessing significant technical feasibility and economic value, and providing a new path for the optimization and upgrading of oilfield gathering and transportation systems during periods of reduced and stable production.

Claims

1. A structure for the renovation and regeneration of in-service aging pipelines, comprising aging pipelines (4), characterized in that: It also includes a steel blind flange (2), a steel reducer (1) and a hose (5). The steel blind flange (2) is sealed and welded to the end of the old pipeline (4). The steel reducer (1) is sealed and welded to the steel blind flange (2). The hose (5) is flipped over and built into the steel reducer (1) and the old pipeline (4). The hose (5) is attached and bonded to the inner wall of the steel reducer (1) and the end of the steel reducer (1) is turned upside down. The space between the old pipeline (4) and the hose (5) is filled with cement grout (6).

2. The in-service aging pipeline renovation and regeneration structure according to claim 1, characterized in that: The upper end of the old pipeline (4) has a grouting port (3) for filling cement slurry (6) and an vent.

3. The in-service aging pipeline renovation and regeneration structure according to claim 1, characterized in that: The end of the steel reduced diameter pipe (1) has a bevel that facilitates the flanging of the hose (5).

4. The in-service aging pipeline renovation and regeneration structure according to claim 1, characterized in that: The steel reduced-diameter pipe (1) is parallel to the axis of the old pipeline (4) and located at the bottom of the old pipeline (4).

5. A method for regenerating and renovating an in-service aging pipeline according to any one of claims 1-4, characterized in that, Includes the following steps: S1, the old pipeline (4) in service is cut into sections, and steel blind flanges (2) are welded at the two ends of each section. The steel blind flanges (2) seal the ends of the old pipeline (4) in service. S2, weld a steel reducer pipe (1) onto the steel blind flange (2); the steel reducer pipe (1) is connected to the interior of the old pipeline in service (4), and the axis of the steel reducer pipe (1) is parallel to the axis of the old pipeline in service (4); S3, apply adhesive to the uncoated layer of the hose (5) and slowly insert it into the steel reducer (1) and the old pipeline (4) in service, ensuring that the hose (5) fits against the inner wall of the steel reducer (1) and the two ends of the hose (5) are fixed. S4, inject water into the hose (5) and maintain pressure to keep the hose (5) cylindrical; S5, grouting port (3) and venting port are opened at both ends of the old pipeline (4). Cement grout (6) is slowly injected from the grouting port (3) and air is discharged from the venting port until the space between the old pipeline (4) and the hose (5) is completely filled with cement grout (6). S6. After the cement slurry (6) has solidified, drain the water from the hose (5).

6. The method for regenerating and upgrading aging pipelines in service according to claim 5, characterized in that: In S4, the temperature of the water injected into the hose (5) is 40-50℃.

7. The method for regenerating and upgrading aging pipelines in service according to claim 5, characterized in that: In S5, before injecting cement grout (6), the interior of the old pipeline (4) in service is first moistened with water, and then cement grout (6) is injected after the moistening treatment is completed.

8. The method for regenerating and upgrading aging pipelines in service according to claim 5, characterized in that: In S5, ordinary silicate cement is used to prepare cement slurry with a fluidity of 400 mm (6) or cement slurry that meets the requirements is purchased directly (6).

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