Well opening device for high-pressure low-yield gas well
By employing a two-stage throttle valve design for pressure reduction and temperature increase in the wellhead opening device for high-pressure, low-yield gas wells, the problem of gas pipeline freezing and blockage caused by low temperature and high pressure at the wellhead is solved, achieving efficient temperature control and energy management. This device is suitable for wellhead equipment in high-pressure, low-yield gas wells.
Patent Information
- Application Number
- CN202520002163.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2035-01-02
AI Technical Summary
Low wellhead temperature and high pressure in high-pressure, low-production gas wells lead to hydrate blockage in downstream gas production pipelines, affecting normal gas well production. This is difficult to handle and seriously impacts the stable operation of the gas field.
The system employs two throttling valves to reduce pressure and two heating methods, using a heat exchanger to heat the natural gas to above 20°C, thus preventing freezing and blockage of downstream gas pipelines. Energy utilization is regulated using a flow control valve.
It effectively avoids freezing and blockage of downstream gas pipelines, reduces the volume of heat exchangers, improves heat exchange efficiency, avoids energy waste, and is suitable for use in well sites.
Smart Images
Figure CN223510900U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to natural gas exploitation wellhead device technical field especially relates to high pressure low yield gas well opening device. BACKGROUND
[0002] For conventional reservoir, gas well gas production is high, carries the geothermal fast, opens the well 5h or so, wellhead temperature reaches 50 DEG C above, at this time the gas can pass through wellhead throttle valve pressure regulating and directly enters the gas gathering pipeline. Since the temperature of the natural gas entering the downstream gas gathering pipeline is not lower than 20 DEG C, hydrate is not formed, and such gas well can operate normally. For the tight gas reservoir, due to the low porosity and low permeability of such reservoir, the daily gas production is low, the geothermal is carried slowly, and in addition, the wellhead pressure is high at the initial stage of well opening, and the wellhead needs to be throttled to reduce pressure before entering the gas gathering pipeline. For such gas well, due to the low temperature of the gas at the wellhead and the high pressure at the wellhead, the temperature of the natural gas after throttling is 5 DEG C lower, and under the conditions of high pressure and low temperature, a large amount of hydrate is formed in the downstream gas gathering pipeline, resulting in serious blockage of the gas gathering pipeline, and the gas well cannot be produced normally, and is forced to shut down. In addition, the treatment of the frozen blockage of the gas gathering pipeline of such gas well is difficult, which seriously affects the stable operation and efficient development of the gas field. SUMMARY
[0003] To solve the problems in the background art, the utility model provides a high pressure low yield gas well opening device, which heats the gas temperature to above 20 DEG C through two times of throttle valve pressure reduction and two times of temperature rise, to avoid the frozen blockage of the downstream gas pipeline.
[0004] The utility model provides a technical scheme: a high pressure low yield gas well opening device, including gas pipeline, primary throttle valve, heat exchanger and secondary throttle valve, the heat exchanger includes shell and communication pipeline, two ends in the shell are fixedly connected with sealing plate A and sealing plate B respectively, sealing plate A and sealing plate B are sealedly connected with the shell, the space between sealing plate A and sealing plate B is called primary pressure reduction chamber, the space between sealing plate B and the shell is called secondary pressure reduction chamber, two sealing plate A are provided with heat exchange pipe A, two ends of heat exchange pipe A are communicated with primary pressure reduction chamber respectively, heat exchange pipe B is provided in heat exchange pipe A, and the flow clearance is left between heat exchange pipe B and heat exchange pipe A, two ends of heat exchange pipe B are communicated with secondary pressure reduction chamber respectively, one primary pressure reduction chamber is communicated with gas pipeline, primary throttle valve is arranged on gas pipeline, another primary pressure reduction chamber is communicated with the secondary pressure reduction chamber adjacent to one, and secondary throttle valve is arranged on communication pipeline, and another secondary pressure reduction chamber is connected with gas pipeline.
[0005] The gas from the wellhead first passes through a primary throttle valve to reduce its pressure by 20%. The depressurized natural gas immediately enters the primary depressurization chamber, and then passes through heat exchange pipe A to be heated to a temperature of not less than 40°C. It then passes through a secondary throttle valve to reduce its pressure by 80%. The depressurized natural gas enters the secondary depressurization chamber through a connecting pipeline, and then passes through heat exchange pipe B to be heated to a temperature of not less than 20°C. Finally, the natural gas is output through the gas transmission pipeline.
[0006] A further technical solution is as follows: the downstream connecting pipeline of the secondary throttle valve is divided into two branches, referred to as the first branch and the second branch, respectively. The first branch is connected to the secondary pressure reducing chamber, and the second branch is connected to the gas transmission pipeline. An adjustment valve is installed on the second branch.
[0007] When the natural gas output temperature on the gas pipeline is significantly higher than 20°C, it represents a waste of energy. In this case, by adjusting the flow rate valve, some natural gas is allowed to bypass the heat exchanger tube B for heating. This portion of natural gas, along with the natural gas heated by passing through the heat exchanger tube B, converges on the gas pipeline, thereby lowering the natural gas temperature on the pipeline to just above 20°C, thus avoiding energy waste.
[0008] A further technical solution is to install thermometer A on the connecting pipeline upstream of the second throttle valve and thermometer B on the gas transmission pipeline.
[0009] A further technical solution is that the heat exchange tube A and the heat exchange tube B are arranged coaxially.
[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0011] 1. Compared with the prior art, this application reduces the pressure twice through the throttle valve and heats the natural gas to above 20°C twice through the heat exchanger set at the wellhead, thereby avoiding freezing and blockage of the downstream natural gas pipeline.
[0012] 2. This application uses one heat exchanger for two heat exchanges, avoiding the use of two heat exchangers, reducing the overall volume of the heat exchanger, avoiding the occupation of a large space, and is very suitable for well site use.
[0013] 3. The heat exchanger of this application has low heat loss and high heat exchange efficiency during the two heat exchange processes.
[0014] 4. The input temperature of the gas pipeline in this application can be adjusted to avoid energy waste. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this utility model.
[0016] In the diagram: 1. Incoming gas pipeline; 2. Primary throttle valve; 3. Gas delivery pipeline; 4. Thermometer B; 5. Flow control valve; 6. Second branch pipe; 7. Secondary throttle valve; 8. Connecting pipeline; 9. Thermometer A; 10. First branch pipe; 11. Secondary pressure reducing chamber; 12. Primary pressure reducing chamber; 13. Heat exchanger tube B; 14. Heat exchanger tube A; 15. Shell; 16. Sealing plate A; 17. Sealing plate B. Detailed Implementation
[0017] 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.
[0018] As shown in the figure, this embodiment includes an incoming gas pipeline 1, a primary throttling valve 2, a heat exchanger, and a secondary throttling valve 7.
[0019] The heat exchanger includes a shell 15 and a connecting pipeline 8. Sealing plates A and B are fixedly connected to both ends of the shell 15, respectively. Sealing plates A and B are sealed to the shell 15. The space between sealing plates A and B is called the primary pressure-reducing chamber 12, and the space between sealing plate B and the shell 15 is called the secondary pressure-reducing chamber 11. A heat exchange tube A14 is arranged between the two sealing plates A, with both ends of heat exchange tube A14 connected to the primary pressure-reducing chamber 12. A heat exchange tube B13 is arranged inside heat exchange tube A14. B13 is coaxial with heat exchange tube A14, and a flow gap is left between heat exchange tube B13 and heat exchange tube A14. Both ends of heat exchange tube B13 are connected to the secondary pressure reduction chamber 11. One of the primary pressure reduction chambers 12 is connected to the incoming gas pipeline 1, and the primary throttle valve 2 is installed on the incoming gas pipeline 1. The other primary pressure reduction chamber 12 is connected to an adjacent secondary pressure reduction chamber 11 through a connecting pipeline 8. The secondary throttle valve 7 is installed on the connecting pipeline 8. The other secondary pressure reduction chamber 11 is connected to a gas transmission pipeline 3.
[0020] The heat exchanger has an inlet and an outlet. The high-temperature medium inside the shell 15 exchanges heat with the natural gas in the heat exchange tube A14, and the natural gas in the heat exchange tube A14 exchanges heat with the natural gas in the heat exchange tube B13.
[0021] The gas from the wellhead first passes through the first-stage throttle valve 2, where its pressure is reduced by 20%. The depressurized natural gas immediately enters the first-stage depressurization chamber 12, and then passes through the heat exchange pipe A14 to be heated to a temperature of not less than 40°C. After that, it passes through the second-stage throttle valve 7, where its pressure is reduced by 80%. The depressurized natural gas then enters the second-stage depressurization chamber 11 through the connecting pipeline 8, and then passes through the heat exchange pipe B13 to be heated to a temperature of not less than 20°C. Finally, the natural gas is output through the gas transmission pipeline 3.
[0022] Although this application involves two heat exchanges, it uses the same heat exchanger, which helps to reduce the size of the heat exchanger and avoids occupying a large amount of wellhead space. Furthermore, the heat exchanger in this application exhibits low heat loss and high heat exchange efficiency during the two heat exchange processes.
[0023] When the natural gas output temperature on gas pipeline 3 exceeds 20°C significantly, it represents a waste of energy. Therefore, this embodiment includes a flow control valve 5. The downstream connecting pipeline 8 of the secondary throttling valve 7 splits into two branches, referred to as the first branch 10 and the second branch 6. The first branch 10 connects to the secondary pressure-reducing chamber 11, and the second branch 6 connects to gas pipeline 3. A flow control valve 5 is installed on the second branch 6. By using the flow control valve 5, a portion of the natural gas bypasses the heat exchanger tube B13 to avoid heating. This portion of natural gas, along with the heated natural gas that passes through heat exchanger tube B13, converges on gas pipeline 3, thereby lowering the natural gas temperature on gas pipeline 3 to just above 20°C, thus preventing energy waste.
[0024] Install thermometer A9 on the connecting pipeline 8 upstream of the second throttle valve, and install thermometer B4 on the gas transmission pipeline 3. Observe the temperature through the thermometers and adjust the heat exchange parameters of the heat exchanger accordingly.
[0025] In summary, this application heats the natural gas to above 20°C by reducing pressure with two throttling valves and raising temperature with two heat exchangers, thereby preventing freezing and blockage of downstream natural gas pipelines.
Claims
1. A well-opening device for high-pressure, low-yield gas wells, characterized in that: The system includes an incoming gas pipeline (1), a primary throttle valve (2), a heat exchanger, and a secondary throttle valve (7). The heat exchanger includes a shell (15) and a connecting pipeline (8). A sealing plate A (16) and a sealing plate B (17) are fixedly connected to both ends of the shell (15). The sealing plates A (16) and B (17) are respectively sealed to the shell (15). The space between the sealing plates A (16) and B (17) is called the primary pressure-reducing chamber (12), and the space between the sealing plate B (17) and the shell (15) is called the secondary pressure-reducing chamber (11). A heat exchange tube A (14) is installed between the two sealing plates A (16). The two ends of the heat exchange tube A (14) are respectively... A heat exchange tube B (13) is installed inside the heat exchange tube A (14) and a flow gap is left between the heat exchange tube B (13) and the heat exchange tube A (14). The two ends of the heat exchange tube B (13) are connected to the secondary pressure reduction chamber (11). One of the primary pressure reduction chambers (12) is connected to the gas pipeline (1). A primary throttle valve (2) is installed on the gas pipeline (1). The other primary pressure reduction chamber (12) is connected to an adjacent secondary pressure reduction chamber (11) through a connecting pipeline (8). The secondary throttle valve (7) is installed on the connecting pipeline (8). The other secondary pressure reduction chamber (11) is connected to a gas transmission pipeline (3).
2. The high-pressure, low-yield gas well opening device according to claim 1, characterized in that: The downstream connecting pipeline (8) of the secondary throttle valve (7) is divided into two branches, referred to as the first branch (10) and the second branch (6), respectively. The first branch (10) is connected to the secondary pressure reducing chamber (11), and the second branch (6) is connected to the gas transmission pipeline (3). A flow regulating valve (5) is installed on the second branch (6).
3. The high-pressure, low-yield gas well opening device according to claim 1, characterized in that: Install thermometer A (9) on the connecting line (8) upstream of the second throttle valve, and install thermometer B (4) on the gas transmission line.
4. The high-pressure, low-yield gas well opening device according to claim 1, characterized in that: The heat exchange tube A (14) and heat exchange tube B (13) are arranged coaxially.