A coal bed gas pipe string fouling simulation device

Abstract

The utility model discloses a kind of coal-bed gas pipe column scale simulation devices, belong to pipe wall scale analysis technical field.The device includes simulation gas system, temperature control unit, liquid storage tank, circulating pump and vertical pipe column, by the simulation formation gas of simulation gas system delivery and the simulation formation liquid in liquid storage tank mixed formation simulation formation fluid, and by temperature control unit regulation and control fluid temperature, the utility model is equipped with sampling hole in vertical pipe column side wall, and piece is inlaid in sampling hole and with its gap cooperation, and its curvature radius is consistent with pipe column inner wall, ensure that the pipe column inner diameter is consistent after piece embedding;Annular anticorrosive and scale prevention coating is set to arc piece opposite pipe wall side, back is sealedly connected with pipe column outer wall by second arc piece.The device is seamlessly attached to arc piece and pipe wall, eliminates the interference of traditional suspension piece to fluid flow, makes piece surface scale environment and real pipe wall height consistent, significantly improves the accuracy of scale experimental data.

Description

Technical Field

[0001] This utility model relates to the field of pipe wall scaling analysis technology and also to the field of coalbed methane pipeline technology, specifically a coalbed methane pipeline scaling simulation device. Background Technology

[0002] As produced water flows from the reservoir to the wellbore, the temperature decreases, causing various scaling ions in the produced water to precipitate and adsorb onto the coalbed methane tubing. This leads to discontinuous coalbed methane production, reduced output, and pump jamming due to the loose scale detaching. Furthermore, it can cause under-deposit corrosion, resulting in tubing perforation and failure, severely impacting normal production safety. Scaling within the tubing not only increases production costs but also creates safety hazards, significantly affecting coalbed methane production. Therefore, it is necessary to design appropriate experimental equipment to study the influencing factors of scaling.

[0003] Currently, there are various experimental devices for testing the scaling process in pipelines. The main process includes a storage tank, a circulation pump, and a test pipeline connected in sequence. The circulation pump circulates the test fluid into the test pipeline, causing scaling to form on the inner wall of the pipeline. Finally, the test pipeline is disassembled to determine the mass of the scaling. Some devices also use a plate in the test pipeline to investigate the scaling process by removing the plate. However, there are some problems. For example, the plate is usually suspended in the pipeline, and the fluid impacts the plate, causing the fluid pattern at the plate wall to be inconsistent with that on the inner wall of the pipeline. The fluid changes its flow direction after impacting the plate, resulting in a decrease in the flow velocity at the plate. Utility Model Content

[0004] To address the aforementioned problems, this invention provides a coalbed methane tubular scaling simulation device.

[0005] The specific solution of this utility model is as follows:

[0006] A coalbed methane tubing column scaling simulation device includes a simulated gas system, a temperature control unit, and a storage tank, a circulation pump, and a vertical tubing column connected in sequence. The circulation pump is used to deliver simulated formation liquid from the storage tank into the vertical tubing column. The simulated gas system is used to deliver simulated formation gas into the vertical tubing column. The simulated formation gas and simulated formation liquid mix to form simulated formation fluid. The temperature control unit is used to control the temperature of the fluid inside the vertical tubing column. The vertical tubing column has a sampling hole on its side wall, into which an arc-shaped bracket is embedded. The arc-shaped bracket fits the sampling hole with a clearance, and the radius of curvature of the arc-shaped bracket is consistent with the radius of curvature of the inner wall of the vertical tubing column, thus ensuring that the inner diameter of the vertical tubing column is equal at all points after the arc-shaped bracket is embedded in the sampling hole. The side of the arc-shaped bracket facing the inner wall of the vertical tubing column has an annular anti-corrosion and anti-scaling coating. The side of the arc-shaped bracket facing away from the inner wall of the vertical tubing column is fixed to a second arc-shaped component, and the second arc-shaped component is sealed to the outer wall of the vertical tubing column.

[0007] In one specific embodiment of this utility model, the second arc-shaped component is attached to the outer wall of the vertical column, and a magnet is fixed on the side of the second arc-shaped component away from the arc-shaped hanging piece, so as to fix the annular hanging piece and the second arc-shaped component together by magnetic attraction; an annular sealing ring is provided on the side of the second arc-shaped component facing the arc-shaped hanging piece, and the projection of the arc-shaped hanging piece on the second arc-shaped component is located in the hollow part of the annular sealing ring.

[0008] In one specific embodiment of this utility model, a nested plexiglass column is coaxially sleeved inside the vertical column. The nested plexiglass column is composed of multiple layers of plexiglass coaxially sleeved together, and each layer can be separated. Therefore, the diameter of the nested plexiglass column can be changed by peeling, thereby changing the cross-sectional area of ​​the annular cavity between the inner wall of the vertical column and the nested plexiglass column, and adjusting the flow rate of the simulated fluid inside the vertical column.

[0009] As a specific embodiment of this utility model, the vertical column is provided with an acrylic glass observation window and equipped with a camera. The camera is used to observe the scaling condition of the arc-shaped hanging plate through the acrylic glass observation window.

[0010] As a specific embodiment of this utility model, the temperature control unit includes a cooling chip and a heating chip, and a temperature control device electrically connected to the cooling chip and the heating chip for controlling the load of the cooling chip and the heating chip.

[0011] As a specific embodiment of this utility model, the simulated gas system includes a natural gas cylinder and a carbon dioxide cylinder. The natural gas cylinder is connected to the injection conduit of the vertical column through a natural gas control valve; the carbon dioxide cylinder is connected to the injection conduit of the vertical column through a carbon dioxide control valve. Pressure gauges and flow meters are installed upstream of both the natural gas control valve and the carbon dioxide control valve to measure the pressure and flow rate of the two. In this way, by controlling the carbon dioxide and natural gas content in the simulated liquid, the conditions inside the coalbed methane column can be better simulated.

[0012] Compared with existing technologies, this invention has the following advantages: The arc-shaped hanging plate of this invention is embedded in the inner wall of the vertical tube column, eliminating the interference of traditional suspended hanging plates on fluid flow, making the scaling environment on the hanging plate surface highly consistent with the actual tube wall, significantly improving the accuracy of scaling experimental data, and providing a reliable tool for the study of scaling mechanism of coalbed methane tube columns and the optimization of scaling prevention schemes. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a coalbed methane tubular scaling simulation device in one embodiment of this utility model;

[0014] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle hanging plate;

[0015] Figure 3 yes Figure 1 Schematic diagram of the structure of the second arc-shaped component;

[0016] In the diagram, 1 is a simulated gas system; 2 is a temperature control unit; 3 is a storage tank; 4 is a circulating pump; 5 is a vertical tubing column; 6 is a testing instrument; 7 is an arc-shaped hanging plate; 8 is a second arc-shaped component; 9 is a magnet; 10 is an annular sealing ring; 11 is a nested acrylic tubing column; 12 is an acrylic observation window; 13 is a camera; 101 is a natural gas cylinder; 102 is a carbon dioxide cylinder; and 71 is a coating. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0018] The tubing in this embodiment refers to conventional tubing, which consists of single tubes connected together by a threaded structure and is connected before being run into the well.

[0019] Example

[0020] Please refer to Figures 1-3 This illustration shows the overall structure of a specific embodiment of the coalbed methane tubing scaling simulation device of this invention. The device includes a simulated gas system 1, a temperature control unit 2, a storage tank 3, a circulation pump 4, and a vertical tubing string 5. The storage tank 3 contains simulated formation water containing minerals that easily form scale on the tubing string walls, such as calcium carbonate and calcium sulfate. The specific composition can be configured according to the composition of the coalbed methane produced water. The circulation pump 4 is used to inject the simulated formation water into the vertical tubing string 5 for a more realistic simulation. To simulate the fluid composition in the tubing string, a simulated gas system 1 was set up to deliver simulated formation gas into the vertical tubing string 5. The simulated formation gas is usually prepared by mixing natural gas and carbon dioxide in a certain proportion. After the simulated formation gas and simulated formation liquid are mixed, they form simulated formation fluid. The temperature control unit 2 is used to control the temperature of the fluid in the vertical tubing string 5. In addition, a detection instrument 6 is also provided to detect the temperature, ion concentration, pH value, etc. of the fluid in the vertical tubing string 5. These are all standard configurations of scaling simulation devices and will not be described in detail here.

[0021] The key feature of this invention lies in the rearrangement of the hanging plates. Traditional hanging plates are suspended inside the vertical tube column 5, with multiple surfaces in contact with the fluid. As the fluid flows, it impacts the bottom of the hanging plates, affecting the flow pattern around them and resulting in a different flow pattern compared to the actual tube wall, thus impacting test results. In this invention, the vertical tube column 5 has sampling holes on its side wall, into which an arc-shaped hanging plate 7 is embedded. The arc-shaped hanging plate 7 fits snugly with the sampling hole, facilitating its installation and removal. The radius of curvature of the arc-shaped hanging plate 7 matches the radius of curvature of the inner wall of the vertical tube column 5; therefore, after the arc-shaped hanging plate 7 is embedded in the sampling hole, the inner diameter of the vertical tube column 5 is equal at all points. Figure 1 and Figure 2 As shown, the side of the arc-shaped hanging plate 7 facing the inner wall of the vertical tube column 5 is provided with an annular anti-corrosion and anti-scaling coating 71. A scaling zone is formed in the middle outside the coating coverage area. This can prevent the scale on the arc-shaped hanging plate 7 from connecting with the structure inside the vertical tube column 5, which would damage the scale on the arc-shaped hanging plate 7 when it is removed later (which would lead to changes in the quality and shape of the scale). In addition, the side of the arc-shaped hanging plate 7 facing away from the inner wall of the vertical tube column 5 is fixed to the second arc-shaped member 8. The second arc-shaped member 8 is sealed to the outer wall of the vertical tube column 5, thereby preventing fluid leakage inside the vertical tube column 5.

[0022] In this invention, the arc-shaped hanging plate 7 is embedded in the vertical tubular column 5, which can maintain the fluid flow state at the hanging plate as the same as that of the real tubular column, obtain real scaling data, and the arc-shaped hanging plate 7 can be taken out through the sampling port for observation, weighing and other operations, which is simple to operate.

[0023] In this invention, the sampling hole needs to be blocked by the second arc-shaped component 8. In some embodiments, such as... Figure 1 and Figure 3 As shown, the side wall of the second arc-shaped component 8 facing the arc-shaped hanging piece 7 is attached to the outer wall of the vertical column 5. A magnet 9 is fixed to the side of the second arc-shaped component 8 opposite to the arc-shaped hanging piece 7, used to fix the two (arc-shaped hanging piece 7 and the second arc-shaped component 8) together through magnetic attraction, facilitating the insertion and removal of the arc-shaped hanging piece 7 into the sampling hole. An annular sealing ring 10 is provided on the side of the second arc-shaped component 8 facing the arc-shaped hanging piece 7. The projection of the arc-shaped hanging piece 7 onto the second arc-shaped component 8 is located within the hollow portion of the annular sealing ring 10. In specific operation, the second arc-shaped component 8 is fixed to the outer wall of the vertical column 5 and presses against the annular sealing ring 10 to prevent leakage. There are many specific fixing methods, such as fixing with screws or straps.

[0024] During the experiment, the fluid flow rate has a significant impact on scaling. The fluid flow rate in the vertical column 5 can usually be adjusted by changing the flow rate of the circulating pump 4. However, this involves adjusting the flow rate of the circulating pump 4 and the flow rate of the simulated gas system 1, which is complex. Adjusting the cross-sectional area of ​​the fluid flow in the vertical column 5 is simpler. Therefore, in some embodiments, a nested plexiglass column 11 is coaxially fitted inside the vertical column 5. The nested plexiglass column 11 is composed of multiple layers of plexiglass coaxially fitted together, and the layers can be separated. Therefore, the diameter of the nested plexiglass column 11 can be changed by peeling, thereby changing the cross-sectional area of ​​the annular cavity between the inner wall of the vertical column 5 and the nested plexiglass column 11, and adjusting the flow rate of the simulated fluid in the vertical column 5.

[0025] In some embodiments, the vertical column 5 has multiple inlets to ensure uniform distribution of fluid in the annular cavity between the vertical column 5 and the nested plexiglass column 11. In other embodiments, an annular groove 14 is provided on the upper outer wall of the vertical column 5 to allow gas-liquid separation of fluid at the upper end of the vertical column 5. The separated liquid overflows along the upper end of the vertical column 5 into the annular groove. The bottom of the annular groove is higher than the storage tank 3 but lower than the upper end of the vertical column 5. Therefore, the fluid in the annular groove can flow into the storage tank 3 by gravity for continued use, and the separated gas is directly discharged to a safe discharge port, such as a flare.

[0026] As is well known, the scaling rate varies under different experimental conditions. When setting experimental conditions for testing, the scaling situation on the arc-shaped hanging plate 7 is not clear. Therefore, the arc-shaped hanging plate 7 is often removed for observation after a certain period of time. The determination of the interval time relies entirely on experience. Therefore, it is necessary to set up an observation system to visually observe the scaling situation. This can at least help us not to remove the arc-shaped hanging plate 7 when no scale appears, thereby saving experimental time. Therefore, in some embodiments, the plexiglass column 11 is made of transparent material, and the vertical column 5 is equipped with an plexiglass observation window 12 and a camera 13. The camera 13 is used to observe the scaling situation of the arc-shaped hanging plate 7.

[0027] In some embodiments, there are two temperature control units 2, which respectively control the temperature in the liquid storage tank 3 and the vertical tubing 5. Each temperature control unit 2 includes a cooling plate and a heating plate inserted into the fluid, as well as a temperature control device electrically connected to the cooling plate and the heating plate. The temperature control device receives data from the temperature sensor and controls the load on the cooling plate and the heating plate, thereby controlling the temperature.

[0028] In some embodiments, the simulated gas system 1 includes a natural gas cylinder 101 and a carbon dioxide cylinder 102. The natural gas cylinder 101 is connected to the injection conduit of the vertical column 5 through a natural gas control valve; the carbon dioxide cylinder 102 is connected to the injection conduit of the vertical column 5 through a carbon dioxide control valve. Pressure gauges and flow meters are installed upstream of both the natural gas control valve and the carbon dioxide control valve to measure their pressure and flow rate. In this way, by controlling the carbon dioxide and natural gas content in the simulated liquid, the conditions inside the coalbed methane column can be better simulated.

[0029] In some embodiments, multiple arc-shaped hanging plates 7 can be provided so that they can be removed under different conditions at different times to analyze the evolution of scale on the steel plate surface.

[0030] The above are merely preferred embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this utility model should be included within the protection scope of this utility model.

Claims

1. A coalbed methane tubing column scaling simulation device, comprising a simulated gas system, a temperature control unit, and a storage tank, a circulation pump, and a vertical tubing column connected in sequence, wherein the circulation pump is used to deliver simulated formation liquid from the storage tank into the vertical tubing column, the simulated gas system is used to deliver simulated formation gas into the vertical tubing column, the simulated formation gas and the simulated formation liquid are mixed to form a simulated formation fluid, and the temperature control unit is used to control the temperature of the fluid in the vertical tubing column, characterized in that... The vertical tubular column has a sampling hole on its side wall, into which an arc-shaped hanging piece is embedded. The arc-shaped hanging piece is in clearance fit with the sampling hole, and the radius of curvature of the arc-shaped hanging piece is consistent with the radius of curvature of the inner wall of the vertical tubular column, so that the inner diameter of the vertical tubular column is equal at all points after the arc-shaped hanging piece is embedded in the sampling hole. The side of the arc-shaped hanging piece facing the inner wall of the vertical tubular column is provided with an annular anti-corrosion and anti-scaling coating. The side of the arc-shaped hanging piece facing away from the inner wall of the vertical tubular column is fixed to a second arc-shaped component, and the second arc-shaped component is sealed to the outer wall of the vertical tubular column.

2. The coalbed methane tubing scaling simulation device according to claim 1, characterized in that, The second arc-shaped component is attached to the outer wall of the vertical column. A magnet is fixed on the side of the second arc-shaped component away from the arc-shaped hanging piece, so as to fix the annular hanging piece and the second arc-shaped component together by magnetic attraction. An annular sealing ring is provided on the side of the second arc-shaped component facing the arc-shaped hanging piece. The projection of the arc-shaped hanging piece on the second arc-shaped component is located in the hollow part of the annular sealing ring.

3. The coalbed methane tubing scaling simulation device according to claim 1, characterized in that, The vertical column is coaxially fitted with a nested plexiglass column, which is composed of multiple layers of plexiglass coaxially fitted together, and the layers can be separated.

4. The coalbed methane tubing scaling simulation device according to claim 1, characterized in that, The vertical tube column is equipped with an acrylic glass observation window and a camera. The camera is used to observe the scaling condition of the arc-shaped hanging plate through the acrylic glass observation window.

5. The coalbed methane tubing scaling simulation device according to claim 1, characterized in that, The temperature control unit includes: Cooling element; Heating element; A temperature control device electrically connected to the cooling element and the heating element is used to control the load on the cooling element and the heating element.

6. The coalbed methane tubing scaling simulation device according to claim 1, characterized in that, The simulated gas system includes a natural gas cylinder and a carbon dioxide cylinder. The natural gas cylinder is connected to the injection line of the vertical column through a natural gas control valve. The carbon dioxide cylinder is connected to the injection line of the vertical column through a carbon dioxide control valve. Pressure gauges and flow meters are installed upstream of both the natural gas control valve and the carbon dioxide control valve.

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