Natural gas pipeline plug removal methanol injection temperature raising device
By using a diesel engine exhaust gas heating methanol device, the problem of severe blockage caused by low-temperature methanol was solved, effectively relieving hydrate freezing blockage and ensuring normal gas well production.
Patent Information
- Application Number
- CN202520056817.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2035-01-10
AI Technical Summary
When injecting low-temperature methanol in winter, it can easily accelerate or aggravate the blockage problem of natural gas wellbore or gas production pipeline. Existing technologies have poor dissolving effects of methanol on ice blockage and cannot effectively relieve hydrate freezing blockage.
The methanol is heated by the waste heat from the diesel engine exhaust, raising its temperature from -30℃ to above 15℃. The heat is transferred between the inner and outer walls of the double-walled hollow heat exchange cylinder to ensure that the methanol reaches an effective temperature before entering the wellhead or gas production pipeline, thus preventing ice blockage.
This effectively solves the problem of increased blockage caused by low-temperature methanol, ensuring that methanol can effectively relieve hydrate freezing blockage, preventing the formation of ice blockage, and improving the production efficiency of gas wells.
Smart Images
Figure CN223649117U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of natural gas pipeline unblocking technology, and in particular relates to a natural gas pipeline unblocking methanol injection and temperature raising device. Background Technology
[0002] Conditions for hydrate formation: presence of free water, high pressure, low temperature, and fluid disturbance. Once hydrates form in the wellbore or gas production pipeline, they can cause wellbore blockage, reduced gas well production, damage to internal pipeline components, and even well shutdown. Gas well dynamic data shows that when gas well production node parameters are in the high-risk zone for hydrate formation, wellbore or gas production pipeline hydrate freezing blockage is likely to occur, leading to the inability of the gas well to produce normally.
[0003] Conventional hydrate blockage treatment methods involve directly adding methanol to the blockage site. Methanol alters the chemical potential of the aqueous solution or hydrate, lowering the hydrate formation temperature. This prevents hydrate formation and dissolves existing hydrates, achieving the dual goals of prevention and relief from hydrate blockage. However, when gas well blockage occurs in winter, the ambient temperature is extremely low, reaching as low as -30°C. During the injection of low-temperature methanol, if the natural gas contains free water from the slug, it can easily and instantly turn into solid ice, causing ice blockage. Because the ice is relatively dense, methanol has poor dissolving effects, ultimately failing to relieve the blockage and instead accelerating and worsening the blockage in the wellbore or gas production pipeline. Utility Model Content
[0004] To address the problem that methanol injection into natural gas wells during winter can easily accelerate and worsen blockages, this invention provides a methanol injection and temperature-raising device for unblocking natural gas pipelines. This invention can raise the temperature of the injected methanol using the exhaust gas temperature of a diesel engine, and then add the heated methanol to the frozen blockage location, achieving the dual goals of preventing and relieving hydrate blockages.
[0005] The technical solution provided by this utility model is: a natural gas pipeline unblocking and methanol injection temperature raising device, including a natural gas pipeline, an methanol injection pump, a diesel engine, an outer shell, and a double-walled hollow heat exchange cylinder. The double-walled hollow heat exchange cylinder has a sealed space between its two walls. A methanol inflow pipe is provided at one end of the sealed space and is connected to the outlet end of the methanol injection pump. A methanol outflow pipe is provided at the other end of the sealed space and is connected to the natural gas pipeline. The outer shell is fitted onto the outside of the double-walled hollow heat exchange cylinder. An annular flow space is left between the outer shell and the outer wall of the double-walled hollow heat exchange cylinder. The double-walled hollow heat exchange cylinder has a central channel. The exhaust pipe of the diesel engine is connected to the central channel of the double-walled hollow heat exchange cylinder. An exhaust pipe is connected to the end of the outer shell near the diesel engine.
[0006] A further technical solution is as follows: one end of the double-walled hollow heat exchanger is located outside the outer shell, and the other end is located inside the outer shell. The double-walled hollow heat exchanger is composed of two double-walled hollow semi-circular cylinders. Each double-walled hollow semi-circular cylinder is provided with a methanol inflow pipe and a methanol outflow pipe at both ends. The methanol inflow pipe is located on the outer wall of the double-walled hollow semi-circular cylinder located outside the outer shell, and the methanol outflow pipe is located on the inner wall of the double-walled hollow semi-circular cylinder located inside the outer shell. This not only allows the two double-walled hollow semi-circular cylinders to be connected in parallel, but also allows the two double-walled hollow semi-circular cylinders to be pulled out of the outer shell without obstruction.
[0007] Optionally: One end of the double-walled hollow heat exchanger is located outside the outer shell, and the other end is located inside the outer shell. The double-walled hollow heat exchanger is composed of two double-walled hollow semi-circular cylinders. One of the double-walled hollow semi-circular cylinders is equipped with a methanol inlet pipe, and the other double-walled hollow semi-circular cylinder is equipped with a methanol outlet pipe. Both the methanol inlet pipe and the methanol outlet pipe are located on the outer wall of the double-walled hollow semi-circular cylinder located outside the outer shell. The two double-walled hollow semi-circular cylinders located inside the outer shell are connected by a connecting pipe, so that the two double-walled hollow semi-circular cylinders are not only connected in series, but also can be pulled out of the outer shell without obstruction.
[0008] A further technical solution is: a hoop is fitted on the outside of the double-walled hollow semi-circular cylinder located inside the outer shell, and a straightening block is fixed to the outside of the hoop, with the straightening block abutting against the outer shell.
[0009] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0010] 1. This application utilizes the waste heat from the exhaust gas of its own equipment—the diesel engine—to heat low-temperature (-30℃) methanol to above 15℃, thus solving the problem that injecting low-temperature methanol in winter actually accelerates and aggravates blockages in wellbores or gas production pipelines.
[0011] 2. The double-walled hollow heat exchanger in this application is composed of two double-walled hollow semi-circular cylinders. When carbon deposits from exhaust gas adhere to its inner and outer surfaces, it is extracted from the outer shell, separating the two double-walled hollow semi-circular cylinders, making it easier to clean the carbon deposits on the surface.
[0012] 3. The double-walled hollow semi-circular cylinder of this application has exhaust gas flowing through both the inner and outer walls, which allows the methanol flowing through the double-walled hollow semi-circular cylinder to absorb heat energy from both sides, accelerate its heating rate, and ensure that the temperature reaches the standard when the methanol flows out. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of Embodiment 1.
[0014] Figure 2This is a schematic diagram of the structure of Embodiment 2.
[0015] In the diagram: 1. Methanol injection pump; 2. Diesel engine; 3. Exhaust pipe; 4. Outer casing; 5. Sealed space; 6. Double-walled hollow semi-circular cylinder; 7. Methanol outlet pipe; 8. Natural gas pipeline; 9. Straightening block; 10. Hoop; 11. Methanol inlet pipe; 12. Connecting pipeline. Detailed Implementation
[0016] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model 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 utility model and are not intended to limit the present utility model.
[0017] It should be noted that since the location of the natural gas pipeline 8 is uncertain and the availability of power at the location of the blockage cannot be guaranteed, and since the diesel engine 2 has low operating costs and can adapt to harsh low-temperature environments, the existing alcohol injection pump 1 is almost entirely driven by the diesel engine 2.
[0018] Example 1: As Figure 1 As shown, this embodiment includes a natural gas pipeline 8, an alcohol injection pump 1, a diesel engine 2, a housing 4, and a double-walled hollow heat exchanger. The double-walled hollow heat exchanger has a sealed space 5 between its two walls. One end of the sealed space 5 is provided with a methanol inflow pipe 11, which is connected to the outlet end of the alcohol injection pump 1. The other end of the sealed space 5 is provided with a methanol outflow pipe 7, which is connected to the natural gas pipeline 8. The housing 4 is fitted onto the outside of the double-walled hollow heat exchanger. An annular flow space is left between the housing 4 and the outer wall of the double-walled hollow heat exchanger. The double-walled hollow heat exchanger has a central channel. The exhaust pipe of the diesel engine 2 is connected to the central channel of the double-walled hollow heat exchanger. An exhaust pipe 3 is connected to the end of the housing 4 near the diesel engine 2. The high-temperature exhaust gas from diesel engine 2 first contacts the inner wall of the double-walled hollow heat exchanger, transferring heat from the inside to the double-walled hollow heat exchanger. After reaching the end of the double-walled hollow heat exchanger, the high-temperature exhaust gas returns through the annular flow space between the outer shell 4 and the outer wall of the double-walled hollow heat exchanger. At this point, the high-temperature exhaust gas can contact the outer wall of the double-walled hollow heat exchanger, transferring heat energy from the outside to the double-walled hollow heat exchanger. Therefore, this embodiment can transfer heat energy to the double-walled hollow heat exchanger from both sides, increasing the temperature rise rate of the methanol flowing inside the double-walled hollow heat exchanger and ensuring that the methanol reaches the required temperature when it flows out.
[0019] As can be seen from the above, this embodiment uses the waste heat of the exhaust gas from its own equipment—diesel engine 2—to heat the low-temperature (-30℃) methanol to above 15℃, thus solving the problem that injecting low-temperature methanol in winter would accelerate or aggravate the blockage of the wellbore or gas production pipeline.
[0020] Because diesel generator exhaust contains carbon deposits, these deposits accumulate over time and adhere to the surface of the double-walled hollow heat exchanger. If not cleaned in time, they will significantly affect the heat transfer efficiency.
[0021] To facilitate regular cleaning of carbon deposits, the double-walled hollow heat exchanger described in this embodiment has one end located outside the outer shell 4 and the other end located inside the outer shell 4. The double-walled hollow heat exchanger is composed of two double-walled hollow semi-circular cylinders 6. Each double-walled hollow semi-circular cylinder 6 has a methanol inlet pipe 11 and a methanol outlet pipe 7 at both ends. The methanol inlet pipe 11 is located on the outer wall of the double-walled hollow semi-circular cylinder 6 outside the outer shell 4, and the methanol outlet pipe 7 is located on the inner wall of the double-walled hollow semi-circular cylinder 6 inside the outer shell 4. This not only allows the two double-walled hollow semi-circular cylinders 6 to be arranged in parallel but also allows them to be pulled out of the outer shell 4 without obstruction. When surface carbon deposits need to be cleaned, the two double-walled hollow semi-circular cylinders 6 are pulled out and separated, making it easy to clean the carbon deposits on both the inner and outer surfaces of the double-walled hollow semi-circular cylinders 6.
[0022] Example 2: Figure 2 As shown, unlike Embodiment 1, in this embodiment, one of the double-walled hollow semi-circular cylinders 6 is equipped with a methanol inlet pipe 11, and the other double-walled hollow semi-circular cylinder 6 is equipped with a methanol outlet pipe 7. Both the methanol inlet pipe 11 and the methanol outlet pipe 7 are located on the outer wall of the double-walled hollow semi-circular cylinder 6 outside the outer shell 4. The two double-walled hollow semi-circular cylinders 6 located inside the outer shell 4 are connected by a connecting pipe 12, which not only allows the two double-walled hollow semi-circular cylinders 6 to be connected in series, but also allows the two double-walled hollow semi-circular cylinders 6 to be pulled out of the outer shell 4 without obstruction. The parallel connection of the two double-walled hollow semi-circular cylinders 6 results in a longer flow path and more complete heat exchange.
[0023] In the two embodiments described above, a clamping band 10 is fitted on the outer side of the double-walled hollow semi-circular cylinder 6 located inside the outer shell 4. The clamping band 10 prevents the two double-walled hollow semi-circular cylinders 6 from separating, ensuring that the two double-walled hollow semi-circular cylinders 6 are always assembled into a cylindrical shape. A straightening block 9 is fixed to the outer side of the clamping band 10. The straightening block 9 abuts against the outer shell 4. The straightening block 9 ensures that the cylinder formed by the two double-walled hollow semi-circular cylinders 6 is coaxial with the outer shell 4, ensuring uniform exhaust gas flow, thereby ensuring uniform temperature rise.
[0024] The operating steps of the two embodiments described above are as follows: High-temperature exhaust gas from the matching diesel engine at 85°C is introduced into two double-walled hollow semi-circular cylinders 6. The high-temperature exhaust gas and low-temperature methanol undergo thorough heat exchange through the inner and outer walls of the double-walled hollow semi-circular cylinders 6, ultimately raising the temperature of the low-temperature methanol from -30°C to 15°C, while the temperature of the high-temperature exhaust gas decreases from 85°C to 35°C. The exhaust gas is then discharged from the exhaust gas discharge pipe 3. At this point, the heated methanol can enter the wellhead or gas production pipeline without causing ice blockage. The heated methanol can fully exert its function of preventing and unblocking natural gas hydrates.
Claims
1. A device for unblocking a natural gas pipeline, injecting methanol, and raising the temperature, comprising a natural gas pipeline (8), characterized in that: It also includes an alcohol injection pump (1), a diesel engine (2), an outer casing (4), and a double-walled hollow heat exchanger. The double-walled hollow heat exchanger has a sealed space (5) between its two walls. A methanol inflow pipe (11) is provided at one end of the sealed space (5), and the methanol inflow pipe (11) is connected to the outlet end of the alcohol injection pump (1). A methanol outflow pipe (7) is provided at the other end of the sealed space (5), and the methanol outflow pipe (7) is connected to the natural gas pipeline (8). The outer casing (4) is fitted onto the outside of the double-walled hollow heat exchanger. An annular flow space is left between the outer casing (4) and the outer wall of the double-walled hollow heat exchanger. The double-walled hollow heat exchanger has a central channel. The exhaust pipe of the diesel engine (2) is connected to the central channel of the double-walled hollow heat exchanger. An exhaust pipe (3) is connected to the end of the outer casing (4) near the diesel engine (2).
2. The natural gas pipeline unblocking and methanol injection temperature-raising device according to claim 1, characterized in that: One end of the double-walled hollow heat exchanger is located outside the outer shell (4), and the other end of the double-walled hollow heat exchanger is located inside the outer shell (4). The double-walled hollow heat exchanger is composed of two double-walled hollow semi-circular cylinders (6). Each double-walled hollow semi-circular cylinder (6) is provided with a methanol inflow pipe (11) and a methanol outflow pipe (7) at both ends. The methanol inflow pipe (11) is located on the outer wall of the double-walled hollow semi-circular cylinder (6) located outside the outer shell (4), and the methanol outflow pipe (7) is located on the inner wall of the double-walled hollow semi-circular cylinder (6) located inside the outer shell (4). This not only allows the two double-walled hollow semi-circular cylinders (6) to be connected in parallel, but also allows the two double-walled hollow semi-circular cylinders (6) to be pulled out from the outer shell (4) without obstruction.
3. The natural gas pipeline unblocking and methanol injection temperature-raising device according to claim 1, characterized in that: One end of the double-walled hollow heat exchanger is located outside the outer shell (4), and the other end is located inside the outer shell (4). The double-walled hollow heat exchanger is composed of two double-walled hollow semi-circular cylinders (6). One of the double-walled hollow semi-circular cylinders (6) is provided with a methanol inlet pipe (11), and the other double-walled hollow semi-circular cylinder (6) is provided with a methanol outlet pipe (7). Both the methanol inlet pipe (11) and the methanol outlet pipe (7) are located on the outer wall of the double-walled hollow semi-circular cylinder (6) located outside the outer shell (4). The two double-walled hollow semi-circular cylinders (6) located inside the outer shell (4) are connected by a connecting pipe (12), so that not only are the two double-walled hollow semi-circular cylinders (6) connected in series, but the two double-walled hollow semi-circular cylinders (6) can also be pulled out from the outer shell (4) without obstruction.
4. A natural gas pipeline unblocking, methanol injection, and temperature-raising device according to any one of claims 2 or 3, characterized in that: A hoop (10) is fitted on the outside of a double-walled hollow semi-circular cylinder (6) located inside the outer shell (4). A straightening block (9) is fixed to the outside of the hoop (10) and abuts against the outer shell (4).