Natural gas high-pressure drainage and medium-pressure sand removal integrated separation method and device

Abstract

The application discloses a natural gas high-pressure drainage and medium-pressure sand removal integrated separation method and device, which comprises the following steps: obtaining and recording natural gas preliminary processing information, and presetting A-level and B-level gas processing requirement grades. When the grade is A-level, open the gas pipe and high-pressure chip catcher communication valve; when the grade is B-level, close the gas pipe and high-pressure chip catcher communication valve, and open the gas pipe and sand removal separation device communication valve, and B-level natural gas enters the sand removal separation device for three-phase separation, and the separated natural gas is metered and externally transported, and sand and gas field water are discharged to a sewage pool. The method realizes efficient separation and treatment of natural gas, and improves the efficiency and economy of natural gas exploitation and utilization.

Description

Technical Field

[0001] This invention relates to the technical field of natural gas desanding equipment, and in particular to an integrated method and apparatus for high-pressure drainage and medium-pressure desanding of natural gas. Background Technology

[0002] In the field of shale gas extraction, shale gas wells face severe challenges in gas-liquid-solid three-phase separation during surface drainage and production due to high initial reservoir pressure, large flowback fluid volume, and significant sand content. In traditional processes, surface treatment systems for each stage of shale gas well fracturing, drainage, and production are often constructed in stages. For example, a separate temporary sand removal and separation device is required during the initial high-pressure drainage stage, while a medium-pressure treatment device needs to be deployed separately during the production stage. This segmented construction method not only leads to repeated investment in surface facilities but also incurs high costs due to temporary equipment leasing.

[0003] Especially in the separation process, traditional sand removal equipment has obvious technical bottlenecks: 1. Insufficient separation efficiency: Conventional gravity separation devices have limited effect on separating micron-sized sand particles in shale gas and cannot adapt to the high flow rate conditions in the early stage of high-pressure drainage, resulting in frequent damage to downstream equipment (such as throttling manifolds and gas pipelines) due to sand erosion. 2. Poor process continuity: The separation equipment in the drainage stage and the production stage is incompatible, requiring shutdown and process switching, which affects the continuity of gas production, and manual intervention increases operational risks; 3. Low level of automation: Traditional equipment lacks the ability to monitor and automatically handle sand deposition and equipment blockage during the separation process, requiring frequent shutdowns for cleaning, which reduces production efficiency.

[0004] Secondly, from the initial drainage stage, the wellhead pressure of shale gas wells is usually in the high-pressure range of 10-15 MPa. At this time, the reservoir energy is sufficient, the natural gas sand content is high (up to 5 kg / m³), and the flowback fluid volume is large, requiring coordinated treatment by high-pressure cuttings skids and choke manifold skids. As the drainage time increases (usually lasting 6-12 months), the reservoir energy gradually decreases, and the wellhead pressure gradually decreases to below 8 MPa. At this time, the liquid and sand content of the natural gas is significantly reduced (the sand content can be reduced to 30% or less of the initial value). However, the traditional drainage process still requires the raw gas to be extracted from the wellhead to the high-pressure cuttings skid and then reduced to medium pressure for sand removal. The drainage time is long, and because the liquid and sand content of the natural gas is significantly reduced at this time, there is no need for the operation of the high-pressure cuttings skid.

[0005] Furthermore, existing gas-solid separation equipment for high-pressure fluids mostly employs a single filtration or gravity sedimentation principle, without fully integrating centrifugal separation mechanisms to optimize structural design. For example, although some sand removal devices are equipped with filter cartridges, the velocity distribution of the fluid within the separation chamber and the centrifugal effect are not considered, resulting in rapid filter cartridge clogging and significant reduction in separation efficiency under high sand content conditions.

[0006] Therefore, how to design an integrated device that can adapt to the drainage and production needs of shale gas wells throughout their entire life cycle and improve separation efficiency through a dual mechanism of centrifugal force and filtration, so as to achieve a seamless connection between high-pressure drainage and medium-pressure production, has become an urgent technical problem to be solved. Summary of the Invention

[0007] In order to solve the above-mentioned technical problems, the present invention provides an integrated method and apparatus for separating high-pressure natural gas drainage and medium-pressure sand removal.

[0008] The technical solution of this invention is implemented as follows: A method for integrating high-pressure natural gas drainage and medium-pressure sand removal includes the following steps: S1, Obtain the information required for the initial processing of natural gas and tabulate it as a searchable table of historical production information; S2 is a preset gas processing requirement level for natural gas wellheads, including Level A and Level B. S3, based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is A, the valve connecting the gas transmission pipeline of the natural gas wellhead to the high-pressure debris catching skid is opened; after the high-pressure debris catching skid performs preliminary sand removal, the natural gas is depressurized through the throttling manifold skid; finally, it enters the sand removal separation device for three-stage separation. S4. Based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is B, the valve connecting the gas transmission pipe of the natural gas wellhead to the high-pressure debris sled is closed, and the valve connecting the gas transmission pipe of the natural gas wellhead to the sand removal and separation device is opened. S5. Based on step S3 or S4, natural gas with a gas processing requirement of level B at the natural gas wellhead is detected to enter the desanding separation device. The gas-liquid-solid three-phase separation is carried out through the desanding separation device. The separated natural gas is metered and then transported out, while the sand and gas field water are discharged to the sewage pond.

[0009] Preferably, in step S2, the preset natural gas wellhead gas processing requirement level specifically refers to: Data acquired through sensor detection The natural gas wellhead pressure is ≥8MPa, and the rating is Class A. Sand content ≥ 500mg / m³, grade A; The natural gas wellhead pressure is <8MPa and the sand content is <500mg / m³, class B. The natural gas wellhead pressure is <0.5MPa, classified as level C, which is an abnormal value.

[0010] Preferably, the separation method further includes the following steps: S6. Based on the three-phase separated natural gas obtained in step S3 or step S5, the sand content of the natural gas is detected in real time. If it is greater than 200 mg / m³, it is returned to the sand removal separation device for secondary sand removal.

[0011] By implementing the above technical solution and adding a secondary sand removal mechanism, closed-loop control of separation quality is achieved. When the sand content exceeds the standard, secondary treatment is automatically triggered, ensuring that the sand content of the final exported natural gas is stabilized below 200 mg / m³, and the separation efficiency is increased to over 98%, effectively guaranteeing the safety of subsequent pipelines and equipment.

[0012] Preferably, the separation method further includes the following steps: S7. Based on the historical drainage information table established in step S1, establish a linear correlation model, predict the sand content through the natural gas wellhead pressure, and control the opening and closing of the valve connecting the gas pipeline and the sand removal device at the natural gas wellhead and the valve connecting the gas pipeline and the high-pressure debris catcher at the natural gas wellhead within the predicted time.

[0013] By introducing a linear correlation model prediction mechanism through the above technical solution, forward-looking valve control is achieved. Based on the linear relationship between pressure and sand content, valve status is adjusted in advance, reducing the process switching response time from a lag state of real-time detection to 60-120 minutes earlier. This reduces equipment shock caused by sudden parameter changes and lowers the valve switching failure rate by 40%.

[0014] More preferably, the linear correlation model includes the following construction method: Data preprocessing removes outliers, fills in missing values, and converts pressure and sand content into dimensionless values ​​(e.g., Z-score standardization) to avoid the impact of dimensional differences on model accuracy. There is a linear relationship between sand content S and wellhead pressure P, i.e., S = aP + b + ε, where a is the slope, b is the intercept, and ε is the random error term. By fitting the optimal parameters a and b through historical data, the error between the predicted value S^ and the actual sand content S is minimized. Input historical dataset, Where i is the sample number and n is the sample size.

[0015] Optimization goal: Minimize mean squared error (MSE):

[0016] Parameter calculation formula

[0017] Wherein are pressures and The sample mean of sand content; Get the current wellhead pressure P now Substitute into the model to calculate and predict sand content If it is necessary to predict the sand content in the next t minutes, the predicted value can be adjusted by combining the pressure change trend: , where k is the pressure change rate (MPa / minute), calculated by moving average of historical data; Preset sand content threshold S thr , Open the high-pressure debris collection skid valve and close the sand removal and separation device valve; Close the high-pressure debris collection skid valve and open the sand removal and separation device valve; Parameters a and b are refitted daily using the latest data to adapt to changes in the gas well production stage.

[0018] More preferably, the prediction of natural gas sand content within t minutes is based on a linear correlation model, where t minutes specifically refers to 60-120 minutes. Based on the correspondence between the predicted sand content value and the detected value within this time period, if the error is within ±100 mg / m³, the prediction is considered correct; if the error is higher than ±100 mg / m³, the prediction is considered incorrect. The linear correlation model is then back-calculated based on the detected value within this time period, and the linear correlation model is modified until the error of the next prediction value is within ±100 mg / m³.

[0019] More preferably, in step S3, when the gas processing requirement level at the natural gas wellhead is A, the valve connecting the gas transmission pipeline at the natural gas wellhead and the high-pressure debris-collecting skid is opened. Specifically, natural gas is output from the natural gas wellhead through the pipeline to the high-pressure debris-collecting skid. Since the natural gas is still under high pressure at this time, after the sand is removed by the high-pressure debris-collecting skid, it enters the throttling manifold skid for pressure reduction. After the pressure is reduced to meet the pressure requirements of the sand removal and separation device, it enters the sand removal and separation device. The sand removal and separation device performs three-phase separation on the natural gas. The separated natural gas is metered and then transported out, while the sand and gas field water are discharged to the sewage pond.

[0020] The above technical solution clarifies the processing flow under high-pressure conditions, enabling the staged treatment of high-pressure natural gas. The high-pressure debris skid first removes large particles and high-concentration sand particles, then reduces the pressure and allows the gas to enter the sand separation device. This avoids the impact of high pressure on the sand separation device, and the staged treatment ensures more thorough sand separation. Under high-pressure conditions, the sand removal rate increases from 85% using traditional methods to 98%, protecting downstream equipment.

[0021] More preferably, in step S5, the natural gas with a gas processing requirement of grade B at the natural gas wellhead enters the desanding separation device. Specifically, the natural gas is in a medium-pressure state at this time, and the sand content is lower than that of natural gas in a high-pressure state. It can directly enter the desanding separation device through the pipeline without entering the high-pressure cuttings skid and the throttling manifold skid.

[0022] By employing the above technical solutions, the processing flow under medium-pressure conditions is optimized, achieving a balance between energy consumption and efficiency. Medium-pressure natural gas directly enters the sand removal and separation unit, bypassing the high-pressure debris collection skid and the throttling manifold skid, reducing equipment investment and energy consumption. The processing flow is shortened by 30%, and energy consumption is reduced by 25%, while ensuring separation efficiency under medium-pressure conditions, enabling the system to operate efficiently under various operating conditions.

[0023] An integrated separation device for high-pressure natural gas drainage and medium-pressure sand removal, comprising a high-pressure debris collection skid, a throttling manifold skid, and a sand removal and separation device; The sand removal and separation device includes a base and a horizontal separator set and fixed on the base; The horizontal separator includes a cylinder, with an air inlet assembly at the top of one end and an air outlet assembly at the other end. The air intake assembly includes an air outlet pipe, a swirl assembly, and an air intake pipe; The air outlet assembly includes a second air inlet pipe, a second air outlet pipe, and a demister; The intake pipe is connected to the throttle manifold and is equipped with a valve; The gas inlet pipe is connected to the gas outlet pipe of the natural gas wellhead and is equipped with a valve; The high-pressure debris-collecting skid is connected to the throttling manifold skid, and the throttling manifold skid is connected to the sand removal and separation device.

[0024] Through the above technical solutions, an integrated separation device structure is constructed, achieving functional integration and process connection. The various devices are connected sequentially, and the horizontal separator structure is optimized. The cyclone assembly enhances the centrifugal separation effect, and the demister improves gas dryness. This reduces the device's footprint, makes the process connection more compact, and improves separation efficiency compared to traditional independent devices, facilitating on-site installation and maintenance.

[0025] Preferably, the outlet pipe of the horizontal separator is connected to the second inlet pipe, and a valve is provided thereon.

[0026] By adding a connection structure between the outlet pipe and the second inlet pipe, the above technical solution enables gas circulation and flexible control. The gas circulation path can be adjusted according to the separation effect, and substandard gases can be separated a second time. At the same time, valve control makes the process more flexible, adapting to different operating conditions, further improving separation quality, and ensuring the quality of exported natural gas.

[0027] Preferably, the integrated separation device further includes a natural gas pipeline assembly; The first pipeline runs from the natural gas wellhead to the high-pressure debris catcher skid, and is equipped with control valves and sensors; The second pipeline runs from the high-pressure chip catcher to the throttling manifold, and is equipped with control valves and sensors. The third pipeline runs from the throttling manifold to the sand removal and separation device, and is equipped with control valves and sensors; The fourth pipeline runs from the natural gas wellhead to the high-pressure debris catcher, and is equipped with control valves and sensors.

[0028] Through the above technical solution, a complete natural gas pipeline assembly and sensor control components are configured, achieving fully automated and intelligent control of the entire process. Valves and sensors are installed in each pipeline to monitor parameters such as gas flow and pressure in real time. Combined with the automatic adjustment of valve states by the control system, the operating parameters of the unit are always kept within the optimal range, increasing the degree of automation, reducing manual intervention, and ensuring the safety and reliability of the process.

[0029] The present invention has the following beneficial effects: The graded treatment achieves efficient sand removal through the graded collaboration of a high-pressure debris-collecting skid and a sand removal separation device. Under high-pressure conditions (Grade A), large particles and high-concentration sand particles are first removed by the high-pressure debris-collecting skid. After throttling and depressurization, the natural gas enters the sand removal separation device for fine separation, increasing the sand removal rate from 85% in traditional methods to over 98% under high pressure. Under medium-pressure conditions (Grade B), natural gas directly enters the sand removal separation device. Its internal cyclone components work in conjunction with a demister to achieve a 95% separation efficiency for sand particles larger than 10μm. The sand content of the exported natural gas is ultimately stably controlled below 200mg / m³, effectively preventing sand particles from eroding and wearing downstream pipelines, compressors, and other equipment. The secondary sand removal mechanism forms a quality closed loop. The added secondary sand removal process can reprocess natural gas with excessive sand content after three-phase separation. When the sand content is detected to be >200mg / m³, a cyclic separation is automatically triggered, further increasing the separation efficiency to over 98%. This mechanism solves the problem of unstable one-time separation effect in traditional processes, and is especially suitable for shale gas drainage scenarios with large fluctuations in sand content, ensuring that the quality of exported natural gas continuously meets the standards.

[0030] The secondary desanding mechanism forms a quality closed loop. The added secondary desanding process can reprocess natural gas with excessive sand content after three-phase separation. When the sand content is detected to be >200mg / m³, it automatically triggers cyclic separation, further improving the separation efficiency to over 98%. This mechanism solves the problem of unstable one-time separation effect in traditional processes, and is particularly suitable for shale gas drainage scenarios with large fluctuations in sand content, ensuring that the quality of exported natural gas continuously meets standards. The integrated design is compatible with all stages of drainage. The device adopts a series layout of high-pressure cuttings skid, choke manifold skid, and desanding separation device, which can automatically switch processes according to wellhead pressure and sand content: full-process processing is activated in the initial stage of high-pressure drainage (Level A), and in the medium-pressure production stage (Level B), the high-pressure cuttings skid and choke manifold skid are skipped, and the process directly enters the desanding separation device. This design breaks the traditional phased construction model, avoids the repeated investment in initial temporary desanding equipment and later medium-pressure equipment, reduces the construction cost of surface facilities by more than 30%, and reduces equipment rental costs, saving millions of yuan per well over its entire life cycle. Energy consumption is significantly reduced under medium-pressure conditions. The process is optimized for Class B medium-pressure conditions, with natural gas directly entering the sand removal and separation unit without passing through the high-pressure debris collection skid and the throttling manifold skid, thus shortening the processing flow and reducing energy consumption.

[0031] High-pressure staged treatment protects downstream equipment. Under high-pressure conditions, over 90% of large sand particles are removed first by a high-pressure debris-collecting skid, and then the pressure is reduced to a medium-pressure range by a throttling manifold skid. This avoids direct impact of high-pressure sand-laden gas on the sand removal and separation device and downstream equipment. Actual measurement data shows that after adopting this solution, the wear rate of equipment such as throttling valves and gas pipelines is reduced, the maintenance cycle is extended from 3 months in the traditional process to 6-8 months, the annual equipment maintenance cost per well is reduced, and automated monitoring reduces equipment failures. The sensor network and automated control system equipped with the device can monitor parameters such as pressure, flow rate, and sand content in real time. When equipment abnormalities are detected (such as blockage of the high-pressure debris-collecting skid filter element or excessive sand deposition in the sand removal and separation device), automatic warnings are issued and backwashing or sand discharge procedures are triggered. This function advances equipment failure warning time by more than 30 minutes, reduces equipment failure rate by 40%, reduces unplanned downtime by 70%, and further reduces maintenance costs. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an integrated separation method for high-pressure natural gas drainage and medium-pressure sand removal according to the present invention.

[0033] Figure 2 This is a schematic diagram of the overall separation device for high-pressure natural gas drainage and medium-pressure sand removal according to the present invention.

[0034] Figure 3 This is a schematic diagram of the sand removal separation device of the integrated separation device for high-pressure natural gas drainage and medium-pressure sand removal according to the present invention.

[0035] Figure 4 This is a schematic diagram of the pipeline connection of the sand separation device in the integrated separation device for high-pressure natural gas drainage and medium-pressure sand removal of the present invention.

[0036] Figure 5 This is a schematic diagram of the high-pressure debris-collecting skid and the throttling manifold skid used in the natural gas high-pressure drainage and medium-pressure desanding integrated separation device of the present invention for processing natural gas.

[0037] In the diagram: 1-High-pressure debris collection skid; 2-Throttle manifold skid; 3-Desand separation device; 4-First pipe; 5-Second pipe; 6-Third pipe; 7-Fourth pipe; 31-Intake assembly; 32-Outtake assembly; 33-Second intake pipe; 34-Outtake pipe; 35-Intake pipe; 36-Second outlet pipe; 37-Swirl assembly. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] like Figures 1-5 As shown, the present invention provides an integrated separation method for high-pressure natural gas drainage and medium-pressure sand removal, comprising the following steps: S1, Obtain the information required for the initial processing of natural gas and tabulate it as a searchable table of historical production information; S2 is a preset gas processing requirement level for natural gas wellheads, including Level A and Level B. S3, based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is A, the valve connecting the gas transmission pipeline and the high-pressure cuttings skid at the natural gas wellhead is opened; after preliminary sand removal by the high-pressure cuttings skid, the natural gas is depressurized by the throttling manifold skid; finally, it enters the sand removal separation device for three-stage separation; after preliminary sand removal by the high-pressure cuttings skid, the natural gas is depressurized by the throttling manifold skid; finally, it enters the sand removal separation device for three-stage separation; S4. Based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is B, the valve connecting the gas transmission pipe of the natural gas wellhead to the high-pressure debris sled is closed, and the valve connecting the gas transmission pipe of the natural gas wellhead to the sand removal and separation device is opened. S5. Based on step S3 or S4, natural gas with a gas processing requirement of level B at the natural gas wellhead is detected to enter the desanding separation device. The gas-liquid-solid three-phase separation is carried out through the desanding separation device. The separated natural gas is metered and then transported out, while the sand and gas field water are discharged to the sewage pond.

[0041] Preferably, in step S2, the preset natural gas wellhead gas processing requirement level specifically refers to: Data acquired through sensor detection The natural gas wellhead pressure is ≥8MPa, and the rating is Class A. Sand content ≥ 500mg / m³, grade A; The natural gas wellhead pressure is <8MPa and the sand content is <500mg / m³, class B. The natural gas wellhead pressure is <0.5MPa, classified as level C, which is an abnormal value.

[0042] The above technical solution establishes a multi-parameter grading standard, enabling accurate determination of processing grades. Combining pressure and sand content as dual indicators avoids misjudgments based solely on pressure parameters, improving the matching degree between grade classification and actual sand separation requirements by 30%, and providing an accurate basis for subsequent valve switching and separation processes.

[0043] Preferably, the separation method further includes the following steps: S6. Based on the three-phase separated natural gas obtained in step S3 or step S5, the sand content of the natural gas is detected in real time. If it is greater than 200 mg / m³, it is returned to the sand removal separation device for secondary sand removal.

[0044] By implementing the above technical solution and adding a secondary sand removal mechanism, closed-loop control of separation quality is achieved. When the sand content exceeds the standard, secondary treatment is automatically triggered, ensuring that the sand content of the final exported natural gas is stabilized below 200 mg / m³, and the separation efficiency is increased to over 98%, effectively guaranteeing the safety of subsequent pipelines and equipment.

[0045] Preferably, the separation method further includes the following steps: S7. Based on the historical drainage information table established in step S1, establish a linear correlation model, predict the sand content through the natural gas wellhead pressure, and control the opening and closing of the valve connecting the gas pipeline and the sand removal device at the natural gas wellhead and the valve connecting the gas pipeline and the high-pressure debris catcher at the natural gas wellhead within the predicted time.

[0046] By introducing a linear correlation model prediction mechanism through the above technical solution, forward-looking valve control is achieved. Based on the linear relationship between pressure and sand content, valve status is adjusted in advance, reducing the process switching response time from a lag state of real-time detection to 60-120 minutes earlier. This reduces equipment shock caused by sudden parameter changes and lowers the valve switching failure rate by 40%.

[0047] More preferably, the linear correlation model includes the following construction method: Data preprocessing Outlier removal: Filter out abrupt changes in pressure or sand content (such as sensor malfunction values) using the 3σ principle (mean ± 3 standard deviations).

[0048] Missing value imputation: Linear interpolation or forward imputation methods are used to supplement short-term missing data, while long-term missing data requires manual verification.

[0049] Data standardization: Convert pressure and sand content into dimensionless values ​​(such as Z-score standardization) to avoid the impact of dimensional differences on model accuracy.

[0050] There is a linear relationship between sand content S and wellhead pressure P, i.e., S = aP + b + ε, where a is the slope, b is the intercept, and ε is the random error term. By fitting the optimal parameters a and b through historical data, the error between the predicted value S^ and the actual sand content S is minimized. Input historical dataset, Where i is the sample number and n is the sample size.

[0051] Optimization goal: Minimize mean squared error (MSE):

[0052] Parameter calculation formula

[0053] Wherein are pressures and The sample mean of sand content; Get the current wellhead pressure P now Substitute into the model to calculate and predict sand content If it is necessary to predict the sand content in the next t minutes, the predicted value can be adjusted by combining the pressure change trend: , where k is the pressure change rate (MPa / minute), calculated by moving average of historical data; Preset sand content threshold S thr , Open the high-pressure debris collection skid valve and close the sand removal and separation device valve; Close the high-pressure debris collection skid valve and open the sand removal and separation device valve; Parameters a and b are refitted daily using the latest data to adapt to changes in the gas well production stage.

[0054] Through the above technical solutions and a systematic model building method, dynamic optimization of prediction accuracy was achieved. Data preprocessing improved the quality of input data, least squares fitting ensured model accuracy, and daily parameter updates enabled the model to adapt to different production stages of gas wells. The prediction error was controlled within ±100 mg / m³, achieving an accuracy rate of 90% and ensuring the reliability of valve control.

[0055] More preferably, the prediction of natural gas sand content within t minutes is based on a linear correlation model, where t minutes specifically refers to 60-120 minutes. Based on the correspondence between the predicted sand content value and the detected value within this time period, if the error is within ±100 mg / m³, the prediction is considered correct; if the error is higher than ±100 mg / m³, the prediction is considered incorrect. The linear correlation model is then back-calculated based on the detected value within this time period, and the linear correlation model is modified until the error of the next prediction value is within ±100 mg / m³.

[0056] By establishing a clear prediction time range and error correction mechanism, the model's self-evolution capability is achieved. A prediction time of 60-120 minutes balances foresight with data stability, and error back-calculation correction continuously improves the model's prediction accuracy. After 3-5 iterations, the prediction error can be stably controlled within ±100 mg / m³, reducing manual intervention and enhancing the system's intelligence level.

[0057] More preferably, in step S3, when the gas processing requirement level at the natural gas wellhead is A, the valve connecting the gas transmission pipeline at the natural gas wellhead and the high-pressure debris-collecting skid is opened. Specifically, natural gas is output from the natural gas wellhead through the pipeline to the high-pressure debris-collecting skid. Since the natural gas is still under high pressure at this time, after the sand is removed by the high-pressure debris-collecting skid, it enters the throttling manifold skid for pressure reduction. After the pressure is reduced to meet the pressure requirements of the sand removal and separation device, it enters the sand removal and separation device. The sand removal and separation device performs three-phase separation on the natural gas. The separated natural gas is metered and then transported out, while the sand and gas field water are discharged to the sewage pond.

[0058] The above technical solution clarifies the processing flow under high-pressure conditions, enabling the staged treatment of high-pressure natural gas. The high-pressure debris skid first removes large particles and high-concentration sand particles, then reduces the pressure and allows the gas to enter the sand separation device. This avoids the impact of high pressure on the sand separation device, and the staged treatment ensures more thorough sand separation. Under high-pressure conditions, the sand removal rate increases from 85% using traditional methods to 98%, protecting downstream equipment.

[0059] More preferably, in step S5, the natural gas with a gas processing requirement of grade B at the natural gas wellhead enters the desanding separation device. Specifically, the natural gas is in a medium-pressure state at this time, and the sand content is lower than that of natural gas in a high-pressure state. It can directly enter the desanding separation device through the pipeline without entering the high-pressure cuttings skid and the throttling manifold skid.

[0060] By employing the above technical solutions, the processing flow under medium-pressure conditions is optimized, achieving a balance between energy consumption and efficiency. Medium-pressure natural gas directly enters the sand removal and separation unit, bypassing the high-pressure debris collection skid and the throttling manifold skid, reducing equipment investment and energy consumption. The processing flow is shortened by 30%, and energy consumption is reduced by 25%, while ensuring separation efficiency under medium-pressure conditions, enabling the system to operate efficiently under various operating conditions.

[0061] Example 2

[0062] An integrated separation device for high-pressure natural gas drainage and medium-pressure sand removal, comprising, in sequence, a high-pressure debris-collecting skid 1, a throttling manifold skid 2, and a sand removal and separation device 3; The sand removal and separation device 3 includes a base and a horizontal separator set and fixed on the base; The horizontal separator includes a cylinder 30, with an air inlet assembly 31 at the top of one end and an air outlet assembly 32 at the other end. The air intake assembly 31 includes an air outlet pipe 34, a swirl assembly 37, and an air intake pipe 35; The air outlet assembly 32 includes a second air inlet pipe 33, a second air outlet pipe 36, and a demister; The intake pipe 35 is connected to the throttle manifold 2 and is equipped with a valve; The gas inlet pipe 35 is connected to the gas outlet pipe of the natural gas wellhead and is equipped with a valve; The high-pressure debris-collecting skid 1 is connected to the throttling manifold skid 2, and the throttling manifold skid 2 is connected to the sand removal and separation device 3.

[0063] Through the above technical solutions, an integrated separation device structure is constructed, achieving functional integration and process connection. The various devices are connected sequentially, and the horizontal separator structure is optimized. The cyclone assembly 37 enhances the centrifugal separation effect, and the demister improves gas dryness. This reduces the device's footprint, makes the process connection more compact, and improves separation efficiency compared to traditional independent devices, facilitating on-site installation and maintenance.

[0064] Preferably, the outlet pipe 34 of the horizontal separator is connected to the second inlet pipe 33 and is equipped with a valve.

[0065] By adding a connection structure between the outlet pipe 34 and the second inlet pipe 33 through the above technical solution, gas circulation and flexible control are achieved. The gas circulation path can be adjusted according to the separation effect, and substandard gases can be separated a second time. At the same time, valve control makes the process more flexible, adapts to different operating conditions, further improves the separation quality, and ensures the quality of exported natural gas.

[0066] Preferably, the integrated separation device further includes a natural gas pipeline assembly; The first pipeline 4 runs from the natural gas wellhead to the high-pressure debris catcher 1, and is equipped with control valves and sensors; The second pipeline 5 runs from the high-pressure chip catcher 1 to the throttling manifold 2, and is equipped with control valves and sensors; The third pipeline 6 extends from the throttling manifold 2 to the sand removal and separation device 3, and is equipped with control valves and sensors; The fourth pipeline 7 runs from the natural gas wellhead to the high-pressure debris catcher 1, and is equipped with control valves and sensors.

[0067] Through the above technical solution, a complete natural gas pipeline assembly and sensor control components are configured, achieving fully automated and intelligent control of the entire process. Valves and sensors are installed in each pipeline to monitor parameters such as gas flow and pressure in real time. Combined with the automatic adjustment of valve states by the control system, the operating parameters of the unit are always kept within the optimal range, increasing the degree of automation, reducing manual intervention, and ensuring the safety and reliability of the process.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for integrating high-pressure natural gas drainage and medium-pressure sand removal, characterized in that, Includes the following steps: S1. Obtain the information required for the initial processing of natural gas and tabulate it as a searchable table of historical production information; S2 is a preset gas processing requirement level for natural gas wellheads, including Level A and Level B. S3, based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is A, the valve connecting the gas transmission pipeline of the natural gas wellhead to the high-pressure debris catching skid is opened; after the high-pressure debris catching skid performs preliminary sand removal, the natural gas is depressurized through the throttling manifold skid; finally, it enters the sand removal separation device for three-phase separation. S4. Based on the gas processing requirement level of the natural gas wellhead obtained in step S2, when the gas processing requirement level of the natural gas wellhead is B, the valve connecting the gas transmission pipe of the natural gas wellhead to the high-pressure debris sled is closed, and the valve connecting the gas transmission pipe of the natural gas wellhead to the sand removal and separation device is opened. S5, based on step S4, natural gas with a gas processing requirement of grade B at the natural gas wellhead is detected to enter the sand removal and separation device. Gas-liquid-solid three-phase separation is carried out through the sand removal and separation device. The separated natural gas is metered and then transported out, while sand and gas field water are discharged to the sewage pond. The separation method further includes the following steps: S6. Based on the three-phase separated natural gas obtained in step S3 or step S5, the sand content of the natural gas is detected in real time. If it is greater than 200 mg / m³, it is returned to the sand removal separation device for secondary sand removal. The separation method further includes the following steps: S7. Based on the historical drainage information table established in step S1, establish a linear correlation model, predict the sand content through the natural gas wellhead pressure, and control the opening and closing of the valve connecting the gas pipeline and the sand removal separation device at the natural gas wellhead and the valve connecting the gas pipeline and the high-pressure debris catching skid at the natural gas wellhead within the predicted time. The linear correlation model is constructed as follows: Data preprocessing removes outliers, fills in missing values, and converts pressure and sand content into dimensionless values ​​to avoid dimensional differences affecting model accuracy. There is a linear relationship between sand content S and wellhead pressure P, i.e., S = aP + b + ε, where a is the slope, b is the intercept, and ε is the random error term. The optimal parameters a and b are fitted using historical data to ensure the predicted value... The error with the actual sand content S is the smallest; Input historical dataset, Where i is the sample number and n is the sample size; Optimization goal: Minimize mean squared error (MSE). Parameter calculation formula , ; in and These are the sample mean values ​​for pressure and sand content, respectively. Get the current wellhead pressure P now Substitute into the model to calculate and predict sand content If it is necessary to predict the sand content in the next t minutes, the predicted value can be adjusted by combining the pressure change trend: , where k is the pressure change rate, calculated by moving average of historical data; Preset sand content threshold S thr , Open the high-pressure debris collection skid valve and close the sand removal and separation device valve; Close the high-pressure debris collection skid valve and open the sand removal and separation device valve; Parameters a and b are refitted daily using the latest data to adapt to changes in the gas well production stage; The prediction of sand content in natural gas within t minutes is based on a linear correlation model, where t minutes specifically refers to 60-120 minutes. The prediction value corresponds to the detected value within this time period. If the error is within ±100 mg / m³, the prediction is considered correct. If the error is higher than ±100 mg / m³, the prediction is considered incorrect. The linear correlation model is then back-calculated based on the detected value within this time period, and the linear correlation model is modified until the error of the next prediction value is within ±100 mg / m³.

2. The integrated separation method for high-pressure natural gas drainage and medium-pressure sand removal according to claim 1, characterized in that, In step S2, the preset natural gas wellhead gas processing requirement level specifically refers to: Data acquired through sensor detection The natural gas wellhead pressure is ≥8MPa, and the rating is Class A. Sand content ≥ 500mg / m³, grade A; The natural gas wellhead pressure is <8MPa and the sand content is <500mg / m³, class B; The natural gas wellhead pressure is <0.5MPa, classified as level C, which is an abnormal value.

3. The integrated separation method for high-pressure natural gas drainage and medium-pressure sand removal according to claim 1, characterized in that, In step S3, when the gas processing requirement level at the natural gas wellhead is A, the valve connecting the gas pipeline at the natural gas wellhead and the high-pressure debris-collecting skid is opened. Specifically, natural gas is output from the natural gas wellhead through the pipeline to the high-pressure debris-collecting skid. Since the natural gas is still under high pressure at this time, after the sand is removed by the high-pressure debris-collecting skid, it enters the throttling manifold skid for pressure reduction. After the pressure is reduced to meet the pressure requirements of the sand removal and separation device, it enters the sand removal and separation device. The sand removal and separation device performs three-phase separation on the natural gas. The separated natural gas is metered and then transported out, while the sand and gas field water are discharged to the sewage pond.

4. The integrated separation method for high-pressure natural gas drainage and medium-pressure sand removal according to claim 1, characterized in that, In step S5, the natural gas with a gas processing requirement of grade B at the natural gas wellhead enters the desanding separation device. Specifically, the natural gas is in a medium-pressure state and has a sand content lower than that of natural gas in a high-pressure state. It can directly enter the desanding separation device through the pipeline without entering the high-pressure cuttings skid and the throttling manifold skid.

5. A natural gas high-pressure drainage and medium-pressure desanding integrated separation device, applied to the natural gas high-pressure drainage and medium-pressure desanding integrated separation method as described in any one of claims 1-4, characterized in that, The sequence consists of a high-pressure debris collection skid, a throttling manifold skid, and a sand removal and separation device; The sand removal and separation device includes a base and a horizontal separator set and fixed on the base; The horizontal separator includes a cylinder, with an air inlet assembly at the top of one end and an air outlet assembly at the other end. The air intake assembly includes a first air outlet pipe, a swirl assembly, and a first air intake pipe; The air outlet assembly includes a second air inlet pipe, a second air outlet pipe, and a demister; The first intake pipe is connected to the throttle manifold and is equipped with a valve; The first intake pipe is connected to the first outlet pipe of the natural gas wellhead, and a valve is installed thereon; The high-pressure debris-collecting skid is connected to the throttling manifold skid, and the throttling manifold skid is connected to the sand removal and separation device.

6. The integrated high-pressure natural gas drainage and medium-pressure sand removal separation device according to claim 5, characterized in that, The second air outlet pipe of the horizontal separator is connected to the first air inlet pipe and is equipped with a valve.

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