A sewage and gas combined treatment system and method for sulfur-containing shale gas

Abstract

The present application relates to the technical field of sulfur-containing shale gas gathering and processing, in particular to a sewage and gas combined treatment system and method for sulfur-containing shale gas. The system has a high degree of integration, can separate sewage and gas while processing high-sulfur shale gas, and can realize combined treatment of sewage and gas, thereby effectively reducing the treatment cost and improving the treatment effect. Through the synergistic effect of the sodium hypochlorite dosing pry and the produced water flash evaporation and emptying pry, hydrogen sulfide and other harmful substances in the sewage can be effectively removed, and the pollution of the sewage to the environment is reduced. Through the setting of the foam displacement device, the liquid carrying capacity of the gas is improved, and the stable operation of the system is ensured. Through the setting of the ball collecting cylinder, the recovery and reuse of the cleaning ball are facilitated, the pipeline is ensured to be unobstructed, and the pipeline maintenance cost is reduced. Through the accurate control of each treatment link, the present application can realize efficient treatment of sulfur-containing shale gas sewage and gas, and has a wide application prospect and is easy to popularize.

Description

Technical Field

[0001] This invention relates to the field of sulfur-containing shale gas gathering, transportation and treatment technology, specifically to a combined wastewater and gas treatment system and method for sulfur-containing shale gas. Background Technology

[0002] Sulfur-bearing shale gas is an important natural gas resource. With the large-scale development of shale gas, its treatment has become a critical issue. The extraction process generates large amounts of wastewater and gases containing harmful substances such as hydrogen sulfide. Improper treatment can cause serious environmental pollution and pose safety hazards and quality problems for subsequent shale gas processing and utilization. Therefore, effective treatment and reuse of sulfur-bearing shale gas is extremely important. Current technologies have conducted some research and application of skid-mounted equipment for sulfur-bearing shale gas field development, but these are mainly single-unit skid-mounted units with limited functionality (wastewater and gas need to be treated separately).

[0003] Existing treatment technologies often separate wastewater and gas, resulting in complex processes, high costs, and poor treatment effects, failing to achieve efficient and synergistic treatment of wastewater and gas. Furthermore, with the continuous development of shale gas fields, the number of shale gas wells on the same platform is gradually increasing, and the wells generally exhibit inconsistent pressures. Existing skid-mounted equipment for shale gas field gathering and transportation has limited functionality and adaptability, and its high- and low-pressure shale gas separation function is incomplete, only applicable to wells with consistent pressure and pressure decay. Therefore, there is an urgent need to develop a system and method that can achieve the joint treatment of sulfur-containing shale gas wastewater and gas. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a combined wastewater and gas treatment system and method for sulfur-containing shale gas, which addresses the shortcomings of the prior art. The system is highly integrated and can separate wastewater and gas while treating high-sulfur shale gas, and perform combined treatment of wastewater and gas, which can effectively reduce treatment costs, improve treatment efficiency, and reduce environmental pollution.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] I. A combined wastewater and gas treatment system for sulfur-containing shale gas

[0007] This invention provides a combined wastewater and gas treatment system for sulfur-containing shale gas, mainly comprising: an air inlet pipe 100, a high and low pressure separator skid 200, a metering zone 300, a sodium hypochlorite dosing skid 400, a flash evaporation venting skid 500, a bubble discharge device 600, and a ball collection cylinder 700.

[0008] One end of the air inlet pipe 100 is connected to the shale gas wellhead, and the other end is connected to the air inlet of the high-low pressure separator skid 200. The high-low pressure separator skid 200 is equipped with two sets of cyclone separators for gas-liquid separation of sulfur-containing shale gas under different pressure conditions. The separated gas is discharged from the air outlet of the high-low pressure separator skid 200, and the separated wastewater is discharged from the liquid outlet of the high-low pressure separator skid 200. The metering zone 300 includes a gas flow meter and a liquid flow meter respectively installed at the air outlet and the liquid outlet.

[0009] The sodium hypochlorite dosing skid 400 is connected to the outlet of the high-low pressure separator skid 200 and is used to add sodium hypochlorite solution to the separated wastewater; the flash venting skid 500 is connected to the outlet of the sodium hypochlorite dosing skid 400 and is used to flash-evaporate the wastewater after sodium hypochlorite treatment; the two venting branches of the venting device 600 are respectively connected to the air outlet of the high-low pressure separator skid 200 and the venting pipe of the flash venting skid 500 and are used to inject venting agent to improve the liquid carrying capacity of the gas; the ball receiving cylinder 700 is installed at the end of the drainage pipe and is used to receive the cleaning balls during the cleaning operation.

[0010] Preferably, a pressure sensor and a flow control valve are installed on the air intake pipe 100. The flow control valve is used to dynamically adjust the air intake of the high and low pressure separator skid 200 according to the needs of different gathering and transportation processes during the normal production period and the pilot production period of shale gas.

[0011] The pressure sensor is used to monitor the intake pressure of the high-low pressure separator skid 200 in real time and determine the current pressure condition of the intake port, which includes low pressure condition and high pressure condition.

[0012] Preferably, the high-low pressure separator skid 200 is internally equipped with a first cyclone separator and a second cyclone separator. The gas-liquid separation of sulfur-containing shale gas under different pressure conditions includes:

[0013] When under high pressure, the first cyclone separator and the second cyclone separator start simultaneously, and the power of the cyclone motor is at the preset power level to increase the throughput of the separator skid and the gas-liquid separation speed.

[0014] When operating under low pressure, the first cyclone separator and the second cyclone separator are started alternately, and the power of the cyclone motor is at the preset power level 2 to reduce the energy consumption of the separator skid; wherein, the preset power level 1 is greater than the preset power level 2.

[0015] Preferably, the liquid outlet and air outlet of the high-low pressure separator skid 200 are both equipped with one-way valves, and the exterior of the high-low pressure separator skid is wrapped with a heat insulation layer.

[0016] Preferably, the sodium hypochlorite dosing skid 400 includes a storage tank, a metering pump, and a dosing pipeline. The storage tank is used to store sodium hypochlorite solution, and the metering pump controls the amount of sodium hypochlorite solution added in real time based on the wastewater flow information fed back by the liquid flow meter.

[0017] Preferably, the flash venting skid 500 is provided with a flash chamber, and a heating device is provided at the bottom of the flash chamber for heating the wastewater. The gas generated by flash venting is discharged through the venting pipe provided at the top of the flash venting skid 500, and the treated wastewater is transported to the wastewater treatment unit through the drainage pipe.

[0018] Preferably, the foaming and venting device 600 includes a foaming and venting agent storage tank, a foaming and venting injection pump, and two foaming and venting branches, which are respectively connected to the air outlet of the high and low pressure separator skid 200 and the venting pipe of the flash venting skid 500.

[0019] The foaming branch pipeline is made of corrosion-resistant material, and the foaming injection pump is a variable frequency pump, which controls the injection rate of the foaming agent in real time based on the gas flow information fed back by the gas flow meter.

[0020] Preferably, the ball collecting cylinder 700 is installed at the end of the drainage pipe, and the ball collecting cylinder 700 is provided with a quick-opening blind plate to facilitate the removal and placement of the cleaning ball.

[0021] II. A method for combined treatment of wastewater and gas containing sulfur shale gas

[0022] Based on the same inventive concept, the present invention also provides a method for the combined treatment of wastewater and gas containing sulfur shale gas, based on the wastewater and gas combined treatment system described above, comprising the following steps:

[0023] Step S1, Shale Gas Transportation: Sulfur-containing shale gas is transported to the inlet of the high and low pressure separator skid through the inlet pipeline, and the inlet pressure and flow rate are monitored and dynamically adjusted in real time by pressure sensors and flow control valves.

[0024] Step S2, high and low pressure gas-liquid separation: The two sets of cyclone separators in the high and low pressure separator skid operate synchronously or alternately according to the current pressure conditions of the air inlet, so as to perform gas-liquid separation of sulfur-containing shale gas under different pressure conditions.

[0025] Step S3, gas-liquid two-phase metering: The gas flow rate at the gas outlet and the liquid flow rate at the liquid outlet of the high-low pressure separator are monitored in real time using a gas flow meter and a liquid flow meter, and the metering data is fed back to the control system.

[0026] Step S4, wastewater dosing and flash evaporation treatment: The wastewater separated by the high and low pressure separator skid enters the sodium hypochlorite dosing skid. The sodium hypochlorite dosing skid dynamically adjusts the amount of sodium hypochlorite solution added by the metering pump according to the liquid flow information fed back by the liquid flow meter. The wastewater after sodium hypochlorite treatment enters the flash evaporation venting skid for flash evaporation treatment, so that the volatile gases in the wastewater are discharged through the vent pipe at the top of the flash evaporation venting skid.

[0027] Step S5, foaming and venting injection: The foaming agent is injected into the outlet of the high and low pressure separator skid and the venting pipe of the flash venting skid through the foaming and venting device to reduce the resistance during gas flow and enhance the liquid carrying capacity of the gas. The foaming and venting device dynamically adjusts the injection rate of the foaming agent through a frequency converter pump based on the gas flow information fed back by the gas flow meter.

[0028] Step S6, System Pipeline Cleaning: According to the preset cleaning cycle, a cleaning ball is periodically sent into the pipeline to push the impurities in the pipeline into the ball collection tube. After cleaning is completed, the cleaning ball is removed by opening the quick-opening blind flange on the ball collection tube, and the cleaned impurities are collected and processed.

[0029] The specific method for dynamically adjusting the amount of sodium hypochlorite solution added is as follows:

[0030] Q = Q0 + L × C1

[0031] In the formula, Q is the real-time addition amount of sodium hypochlorite solution, Q0 is the minimum addition amount of sodium hypochlorite solution, L is the liquid flow rate value fed back by the liquid flow meter, and C1 is the addition amount conversion coefficient.

[0032] The injection rate of the dynamically adjustable foaming agent is specifically calculated as follows:

[0033] V = V0 - G × C2

[0034] In the formula, V is the real-time injection rate of the foaming agent, V0 is the maximum injection rate of the foaming agent, G is the gas flow rate value fed back by the gas flow meter, and C2 is the rate conversion coefficient.

[0035] Compared with the prior art, the present invention has the following main advantages:

[0036] 1. This invention, through the rational arrangement of the metering zone, high and low pressure separator skid, sodium hypochlorite dosing skid, flash evaporation venting skid, bubble discharge device and ball collection cylinder, has a high degree of functional integration. It can separate wastewater and gas while treating high sulfur shale gas, and carry out joint treatment of wastewater and gas, which can effectively reduce treatment costs, improve treatment effect and reduce environmental pollution.

[0037] 2. The high and low pressure separator of this invention adopts two sets of cyclone separation devices, which can meet the gas-liquid separation requirements under different wellhead pressure conditions during the normal production period and the treatment period of high sulfur shale gas, providing a good foundation for subsequent processing; through the setting of the gas-liquid two-phase metering zone, the flow rates of gas and liquid can be accurately measured, which facilitates the monitoring and management of the entire processing process.

[0038] 3. This invention effectively removes harmful substances such as hydrogen sulfide from wastewater by using the synergistic effect of the sodium hypochlorite dosing skid and the produced water flash evaporation venting skid, thus reducing the pollution of the environment. The bubble discharge device reduces the resistance during gas flow, improves the liquid carrying capacity of the gas, and ensures the stable operation of the system. The pig collection tube facilitates the recovery and reuse of the pigging pig, ensuring the smooth flow of the pipeline and reducing pipeline maintenance costs.

[0039] 4. This invention, through precise control of each processing stage, can achieve efficient treatment of sulfur-containing shale gas wastewater and gas, with good economic and environmental benefits. It has broad application prospects and is easy to promote. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a combined wastewater and gas treatment system for sulfur-containing shale gas according to an embodiment of the present invention;

[0041] Figure 2 This is a flowchart of a method for combined treatment of wastewater and gas containing sulfur shale gas, as described in an embodiment of the present invention.

[0042] In the diagram: 100 - air inlet pipe, 200 - high and low pressure separator skid, 300 - metering area, 400 - sodium hypochlorite dosing skid, 500 - flash venting skid, 600 - bubble discharge device, 700 - ball collection tube. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0044] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0045] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0046] Example 1: This example provides a combined wastewater and gas treatment system for sulfur-containing shale gas, such as... Figure 1 As shown, it mainly includes: an air intake pipe 100, a high and low pressure separator skid 200, a metering area 300, a sodium hypochlorite dosing skid 400, a flash venting skid 500, a bubble discharge device 600, and a ball collecting cylinder 700.

[0047] The air intake pipe 100 is connected at one end to the shale gas wellhead and at the other end to the air inlet of the high-low pressure separator skid 200. The high-low pressure separator skid 200 is equipped with two sets of cyclone separators for gas-liquid separation of sulfur-containing shale gas under different pressure conditions. The separated gas is discharged from the air outlet of the high-low pressure separator skid 200, and the separated wastewater is discharged from the liquid outlet of the high-low pressure separator skid 200. The metering zone 300 includes a gas flow meter and a liquid flow meter respectively installed at the air outlet and liquid outlet.

[0048] The sodium hypochlorite dosing skid 400 is connected to the outlet of the high-low pressure separator skid 200 and is used to add sodium hypochlorite solution to the separated wastewater; the flash venting skid 500 is connected to the outlet of the sodium hypochlorite dosing skid 400 and is used to flash-evaporate the wastewater after sodium hypochlorite treatment; the two venting branches of the venting device 600 are respectively connected to the air outlet of the high-low pressure separator skid 200 and the venting pipe of the flash venting skid 500 and are used to inject venting agent to improve the liquid carrying capacity of the gas; the ball receiving cylinder 700 is installed at the end of the drainage pipe and is used to receive the cleaning balls during the cleaning operation.

[0049] Furthermore, a pressure sensor and a flow control valve are installed on the air intake pipe 100. The flow control valve is used to dynamically adjust the air intake of the high and low pressure separator skid 200 according to the needs of different gathering and transportation processes during the normal production period and the pilot production period of shale gas.

[0050] The pressure sensor is used to monitor the intake pressure of the high-low pressure separator skid 200 in real time and determine the current pressure condition of the intake port, which includes low pressure condition and high pressure condition.

[0051] Furthermore, the high-low pressure separator skid 200 is internally equipped with a first cyclone separation device and a second cyclone separation device. The gas-liquid separation of sulfur-containing shale gas under different pressure conditions includes:

[0052] When under high pressure, the first cyclone separator and the second cyclone separator start simultaneously, and the power of the cyclone motor is at the preset power level to increase the throughput of the separator skid and the gas-liquid separation speed.

[0053] When operating under low pressure, the first cyclone separator and the second cyclone separator are started alternately, and the power of the cyclone motor is at the preset power level 2 to reduce the energy consumption of the separator skid; wherein, the preset power level 1 is greater than the preset power level 2.

[0054] Furthermore, the liquid outlet and air outlet of the high-low pressure separator skid 200 are both equipped with one-way valves, and the exterior of the high-low pressure separator skid is wrapped with a heat insulation layer.

[0055] Furthermore, the sodium hypochlorite dosing skid 400 includes a storage tank, a metering pump, and a dosing pipeline. The storage tank is used to store sodium hypochlorite solution, and the metering pump controls the amount of sodium hypochlorite solution added in real time based on the wastewater flow information fed back by the liquid flow meter.

[0056] Furthermore, the flash venting skid 500 is equipped with a flash chamber, and a heating device is installed at the bottom of the flash chamber for heating the wastewater. The gas generated by flash venting is discharged through the venting pipe installed at the top of the flash venting skid 500, and the treated wastewater is transported to the wastewater treatment unit through the drainage pipe.

[0057] Furthermore, the foaming and venting device 600 includes a foaming and venting agent storage tank, a foaming and venting injection pump, and two foaming and venting branches, which are respectively connected to the air outlet of the high and low pressure separator skid 200 and the venting pipe of the flash venting skid 500.

[0058] The foaming branch pipeline is made of corrosion-resistant material, and the foaming injection pump is a variable frequency pump, which controls the injection rate of the foaming agent in real time based on the gas flow information fed back by the gas flow meter.

[0059] Furthermore, the ball collecting cylinder 700 is installed at the end of the drainage pipe, and the ball collecting cylinder 700 is equipped with a quick-opening blind plate to facilitate the removal and placement of the cleaning ball.

[0060] Example 2: This example provides a combined wastewater and gas treatment system for sulfur-containing shale gas, which has functions such as gas-liquid two-phase metering, high and low pressure shale gas distribution, gas-liquid separation, and high-efficiency wet desulfurization.

[0061] The high-low pressure separator skids are configured as follows: For 8 wells, under low-pressure conditions (operating pressure 2.0 MPa), with an average gas production of 25,000 cubic meters per well, the separator processes 20 × 10⁴ Nm³ / d of gas and 360 m³ / d of liquid; under high-pressure conditions (operating pressure 4.0 MPa), with an average gas production of 50,000 cubic meters per well, the separator processes 40 × 10⁴ Nm³ / d of gas and 360 m³ / d of liquid. For 14 wells, under low-pressure conditions (operating pressure 2.0 MPa), with an average gas production of 25,000 cubic meters per well, the separator processes 35 × 10⁴ Nm³ / d of gas and 600 m³ / d of liquid; under high-pressure conditions (operating pressure 4.0 MPa), with an average gas production of 50,000 cubic meters per well, the separator processes 70 × 10⁴ Nm³ / d of gas and 600 m³ / d of liquid.

[0062] One-way valves are installed at both the air outlet and liquid outlet of the high-low pressure separator skid to prevent gas-liquid backflow and ensure that the gas-liquid can smoothly enter the subsequent processing stage after separation, maintaining the stable operation of the system. At the same time, the high-low pressure separator skid is wrapped with an insulation layer, which can effectively reduce heat loss and avoid the gas-liquid separation effect being affected by temperature changes.

[0063] The gas-liquid two-phase metering zone is used to separately meter the separated gas and liquid, and includes a gas flow meter and a liquid flow meter. The gas flow meter is installed on the pipeline between the gas outlet of the high-low pressure separator skid and the subsequent processing equipment to accurately measure the gas flow rate; the liquid flow meter is installed on the pipeline between the liquid outlet of the high-low pressure separator skid and the sodium hypochlorite dosing skid to accurately measure the liquid flow rate.

[0064] The sodium hypochlorite dosing skid: After passing through high and low pressure separation, the fluid enters the dosing skid for desulfurization. Sodium hypochlorite has strong oxidizing properties and can undergo a redox reaction with sulfur-containing substances such as hydrogen sulfide in wastewater, oxidizing hydrogen sulfide to elemental sulfur or sulfate, thereby removing sulfur-containing substances from the wastewater. The sodium hypochlorite dosing skid is equipped with a dosing pump, a storage tank, and other equipment. The amount of sodium hypochlorite solution added is precisely controlled by a control system to ensure the treatment effect.

[0065] The flash venting skid is designed for a maximum flow rate of 300 m³ / d from one well during the initial trial production phase. The integrated skid-mounted water treatment capacity is considered for two wells operating simultaneously, resulting in a total flow rate of 600 m³ / d. The produced water flash separator is DN2000×6000mm. The produced water flash venting skid is connected to a sodium hypochlorite dosing skid and is used for flash evaporation treatment of the wastewater after sodium hypochlorite treatment. Inside the produced water flash venting skid, the wastewater rapidly evaporates under low pressure, causing some of the water and dissolved gases to escape, further reducing the volume and pollutant content of the wastewater. The gas generated during flash evaporation is discharged through a venting pipe, while the treated wastewater is transported to the subsequent wastewater treatment unit.

[0066] The bubble discharge device is connected to the gas outlet separated by the high-low pressure separator skid, and is used to further process the separated gas. The bubble discharge device is equipped with a foam generator and a filter. After the gas enters the bubble discharge device, it comes into full contact with the foam generated by the foam generator. The foam can adsorb small particles, droplets and some sulfur-containing substances in the gas. Then, the foam is separated from the purified gas by the filter, so that the gas is further purified.

[0067] The pig collection tube is located at the end of the pipeline in the system and is used to receive the pig cleaning balls. After the system has been running for a period of time, the pipeline needs to be cleaned. By sending the pig cleaning balls into the pipeline, the pig cleaning balls, propelled by gas or liquid, clean out impurities and dirt in the pipeline, and finally enter the pig collection tube for convenient collection and processing of the pig cleaning balls and the cleaned impurities.

[0068] Example 3, based on the same inventive concept, this example also provides a method for the combined treatment of wastewater and gas from sulfur-containing shale gas, based on the wastewater and gas combined treatment system described above, such as... Figure 2 As shown, it includes the following steps:

[0069] Step S1, Shale Gas Transportation: Sulfur-containing shale gas is transported to the inlet of the high and low pressure separator skid through the inlet pipeline, and the inlet pressure and flow rate are monitored and dynamically adjusted in real time by pressure sensors and flow control valves.

[0070] Step S2, high and low pressure gas-liquid separation: The two sets of cyclone separators in the high and low pressure separator skid operate synchronously or alternately according to the current pressure conditions of the air inlet, so as to perform gas-liquid separation of sulfur-containing shale gas under different pressure conditions.

[0071] Step S3, gas-liquid two-phase metering: The gas flow rate at the gas outlet and the liquid flow rate at the liquid outlet of the high-low pressure separator are monitored in real time using a gas flow meter and a liquid flow meter, and the metering data is fed back to the control system.

[0072] Step S4, wastewater dosing and flash evaporation treatment: The wastewater separated by the high and low pressure separator skid enters the sodium hypochlorite dosing skid. The sodium hypochlorite dosing skid dynamically adjusts the amount of sodium hypochlorite solution added by the metering pump according to the liquid flow information fed back by the liquid flow meter. The wastewater after sodium hypochlorite treatment enters the flash evaporation venting skid for flash evaporation treatment, so that the volatile gases in the wastewater are discharged through the vent pipe at the top of the flash evaporation venting skid.

[0073] Step S5, foaming and venting injection: The foaming agent is injected into the outlet of the high and low pressure separator skid and the venting pipe of the flash venting skid through the foaming and venting device to reduce the resistance during gas flow and enhance the liquid carrying capacity of the gas. The foaming and venting device dynamically adjusts the injection rate of the foaming agent through a frequency converter pump based on the gas flow information fed back by the gas flow meter.

[0074] Step S6, System Pipeline Cleaning: According to the preset cleaning cycle, a cleaning ball is periodically sent into the pipeline to push the impurities in the pipeline into the ball collection tube. After cleaning is completed, the cleaning ball is removed by opening the quick-opening blind flange on the ball collection tube, and the cleaned impurities are collected and processed.

[0075] The specific method for dynamically adjusting the amount of sodium hypochlorite solution added is as follows:

[0076] Q = Q0 + L × C1

[0077] In the formula, Q is the real-time addition amount of sodium hypochlorite solution, Q0 is the minimum addition amount of sodium hypochlorite solution, L is the liquid flow rate value fed back by the liquid flow meter, and C1 is the addition amount conversion coefficient.

[0078] The injection rate of the dynamically adjustable foaming agent is specifically calculated as follows:

[0079] V = V0 - G × C2

[0080] In the formula, V is the real-time injection rate of the foaming agent, V0 is the maximum injection rate of the foaming agent, G is the gas flow rate value fed back by the gas flow meter, and C2 is the rate conversion coefficient.

[0081] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0082] In summary:

[0083] 1. This invention, through the rational arrangement of the metering zone, high and low pressure separator skid, sodium hypochlorite dosing skid, flash evaporation venting skid, bubble discharge device and ball collection cylinder, has a high degree of functional integration. It can separate wastewater and gas while treating high sulfur shale gas, and carry out joint treatment of wastewater and gas, which can effectively reduce treatment costs, improve treatment effect and reduce environmental pollution.

[0084] 2. The high and low pressure separator of this invention adopts two sets of cyclone separation devices, which can meet the gas-liquid separation requirements under different wellhead pressure conditions during the normal production period and the treatment period of high sulfur shale gas, providing a good foundation for subsequent processing; through the setting of the gas-liquid two-phase metering zone, the flow rates of gas and liquid can be accurately measured, which facilitates the monitoring and management of the entire processing process.

[0085] 3. This invention effectively removes harmful substances such as hydrogen sulfide from wastewater by using the synergistic effect of the sodium hypochlorite dosing skid and the produced water flash evaporation venting skid, thus reducing the pollution of the environment. The bubble discharge device reduces the resistance during gas flow, improves the liquid carrying capacity of the gas, and ensures the stable operation of the system. The pig collection tube facilitates the recovery and reuse of the pigging pig, ensuring the smooth flow of the pipeline and reducing pipeline maintenance costs.

[0086] 4. This invention, through precise control of each processing stage, can achieve efficient treatment of sulfur-containing shale gas wastewater and gas, with good economic and environmental benefits. It has broad application prospects and is easy to promote.

[0087] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0088] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0089] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A combined wastewater and gas treatment system for sulfur-containing shale gas, characterized in that: It includes an intake pipe (100), a high and low pressure separator skid (200), a metering zone (300), a sodium hypochlorite dosing skid (400), a flash venting skid (500), a bubble discharge device (600), and a ball collecting cylinder (700). One end of the air intake pipe (100) is connected to the shale gas wellhead, and the other end is connected to the air inlet of the high-low pressure separator skid (200). The high-low pressure separator skid (200) is equipped with two sets of cyclone separators for gas-liquid separation of sulfur-containing shale gas under different pressure conditions. The separated gas is discharged from the air outlet of the high-low pressure separator skid (200), and the separated wastewater is discharged from the liquid outlet of the high-low pressure separator skid (200). The metering area (300) includes a gas flow meter and a liquid flow meter installed at the air outlet and liquid outlet, respectively. The sodium hypochlorite dosing skid (400) is connected to the outlet of the high-low pressure separator skid (200) and is used to add sodium hypochlorite solution to the separated wastewater; the flash venting skid (500) is connected to the outlet of the sodium hypochlorite dosing skid (400) and is used to flash treat the wastewater after sodium hypochlorite treatment; the two venting branches of the venting device (600) are respectively connected to the air outlet of the high-low pressure separator skid (200) and the venting pipe of the flash venting skid (500) and are used to inject venting agent to improve the liquid carrying capacity of the gas; the ball receiving cylinder (700) is installed at the end of the drainage pipe and is used to receive the cleaning balls during the cleaning operation; A pressure sensor and a flow control valve are installed on the air intake pipe (100). The flow control valve is used to dynamically adjust the air intake of the high and low pressure separator skid (200) according to the needs of different gathering and transportation processes during the normal production period and the pilot production period of shale gas. The pressure sensor is used to monitor the intake pressure of the high and low pressure separator skid (200) in real time and determine the current pressure condition of the intake port, including low pressure condition and high pressure condition. The high-low pressure separator skid (200) is equipped with a first cyclone separator and a second cyclone separator. The gas-liquid separation of sulfur-containing shale gas under different pressure conditions includes: When under high pressure, the first cyclone separator and the second cyclone separator start simultaneously, and the power of the cyclone motor is at the preset power level to increase the throughput of the separator skid and the gas-liquid separation speed. When operating under low pressure, the first cyclone separator and the second cyclone separator are started alternately, and the power of the cyclone motor is at the preset power level 2 to reduce the energy consumption of the separator skid; wherein, the preset power level 1 is greater than the preset power level 2.

2. The combined wastewater and gas treatment system for sulfur-containing shale gas according to claim 1, characterized in that, The liquid outlet and air outlet of the high-low pressure separator skid (200) are both equipped with one-way valves, and the outside of the high-low pressure separator skid is wrapped with a heat insulation layer.

3. The combined wastewater and gas treatment system for sulfur-containing shale gas according to claim 1, characterized in that, The sodium hypochlorite dosing skid (400) includes a storage tank, a metering pump, and a dosing pipeline. The storage tank is used to store sodium hypochlorite solution, and the metering pump controls the amount of sodium hypochlorite solution added in real time based on the sewage flow information fed back by the liquid flow meter.

4. The combined wastewater and gas treatment system for sulfur-containing shale gas according to claim 1, characterized in that, The flash venting skid (500) is equipped with a flash chamber, and a heating device is provided at the bottom of the flash chamber for heating the wastewater. The gas generated by flash venting is discharged through the venting pipe provided at the top of the flash venting skid (500), and the treated wastewater is transported to the wastewater treatment unit through the drainage pipe.

5. The combined wastewater and gas treatment system for sulfur-containing shale gas according to claim 1, characterized in that, The foaming device (600) includes a foaming agent storage tank, a foaming injection pump and two foaming branches, which are respectively connected to the outlet of the high and low pressure separator skid (200) and the venting pipe of the flash venting skid (500). The foaming branch pipeline is made of corrosion-resistant material, and the foaming injection pump is a variable frequency pump, which controls the injection rate of the foaming agent in real time based on the gas flow information fed back by the gas flow meter.

6. The combined wastewater and gas treatment system for sulfur-containing shale gas according to claim 4, characterized in that, The ball collecting cylinder (700) is installed at the end of the drainage pipe, and the ball collecting cylinder (700) is equipped with a quick-opening blind plate to facilitate the removal and placement of the cleaning ball.

7. A method for combined treatment of wastewater and gas containing sulfur shale gas, based on the combined wastewater and gas treatment system according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1, Shale Gas Transportation: Sulfur-containing shale gas is transported to the inlet of the high and low pressure separator skid through the inlet pipeline, and the inlet pressure and flow rate are monitored and dynamically adjusted in real time by pressure sensors and flow control valves. Step S2, high and low pressure gas-liquid separation: The two sets of cyclone separators in the high and low pressure separator skid operate synchronously or alternately according to the current pressure conditions of the air inlet, so as to perform gas-liquid separation of sulfur-containing shale gas under different pressure conditions. Step S3, gas-liquid two-phase metering: The gas flow rate at the gas outlet and the liquid flow rate at the liquid outlet of the high-low pressure separator are monitored in real time using a gas flow meter and a liquid flow meter, and the metering data is fed back to the control system. Step S4, wastewater dosing and flash evaporation treatment: The wastewater separated by the high and low pressure separator skid enters the sodium hypochlorite dosing skid. The sodium hypochlorite dosing skid dynamically adjusts the amount of sodium hypochlorite solution added by the metering pump according to the liquid flow information fed back by the liquid flow meter. The wastewater after sodium hypochlorite treatment enters the flash evaporation venting skid for flash evaporation treatment, so that the volatile gases in the wastewater are discharged through the vent pipe at the top of the flash evaporation venting skid. Step S5, foaming and venting injection: The foaming agent is injected into the outlet of the high and low pressure separator skid and the venting pipe of the flash venting skid through the foaming and venting device to reduce the resistance during gas flow and enhance the liquid carrying capacity of the gas. The foaming and venting device dynamically adjusts the injection rate of the foaming agent through a frequency converter pump based on the gas flow information fed back by the gas flow meter. Step S6, System Pipeline Cleaning: According to the preset cleaning cycle, a cleaning ball is periodically sent into the pipeline to push the impurities in the pipeline into the ball collection tube. After cleaning is completed, the cleaning ball is removed by opening the quick-opening blind flange on the ball collection tube, and the cleaned impurities are collected and processed.

8. The wastewater and gas combined treatment method according to claim 7, characterized in that, The specific formula for dynamically adjusting the amount of sodium hypochlorite solution added is as follows: Q = Q0 + L × C1 In the formula, Q is the real-time addition amount of sodium hypochlorite solution, Q0 is the minimum addition amount of sodium hypochlorite solution, L is the liquid flow rate value fed back by the liquid flow meter, and C1 is the addition amount conversion coefficient. The injection rate of the dynamically adjustable foaming agent is specifically calculated as follows: V = V0 - G × C2 In the formula, V is the real-time injection rate of the foaming agent, V0 is the maximum injection rate of the foaming agent, G is the gas flow rate value fed back by the gas flow meter, and C2 is the rate conversion coefficient.

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