A system for gas field produced water treatment and condensate recovery

Abstract

The utility model belongs to oil and gas field exploitation and sewage treatment technical field, concretely relates to a system for gas field produced water treatment and condensate oil recovery, including the raw water collection storehouse, primary separation membrane device, secondary separation membrane device, comprehensive reactor, tertiary separation membrane device and product water tank that set gradually, raw water collection storehouse, primary separation membrane device, secondary separation membrane device, comprehensive reactor, tertiary separation membrane device and product water tank all are connected with control system, the system passes through the raw water collection storehouse, primary separation membrane device, secondary separation membrane device, comprehensive reactor, tertiary separation membrane device and product water tank that set gradually, has formed the highly integrated gas field produced water treatment and condensate oil recovery system, combines control system, has realized the efficient separation of gas field produced water and condensate oil recovery, simultaneously multi -stage membrane separation process and physical chemistry treatment are combined, and the separation efficiency and processing effect are improved, and the chemical agent usage amount and operating cost are reduced simultaneously.

Description

Technical Field

[0001] This utility model belongs to the field of oil and gas field development and wastewater treatment technology, specifically relating to a system for treating produced water and recovering condensate oil from gas fields. Background Technology

[0002] In the development of gas fields, the treatment of produced water and the recovery of condensate are crucial aspects, directly impacting the economic benefits and environmental protection of gas field production. Currently, the main methods for treating produced water include reinjection, compliant discharge, and resource recovery. However, commonly used methods for condensate recovery, such as gravity separation and flotation, have significant drawbacks. Gravity separation is ineffective at separating small condensate droplets, leading to a large amount of condensate being discharged with the produced water, resulting in resource waste. While flotation can improve separation efficiency, it requires the addition of large amounts of chemical reagents, increasing treatment costs and potentially causing secondary pollution.

[0003] Traditional produced water treatment processes also face numerous challenges. Physical methods such as sedimentation and filtration are insufficient to effectively remove impurities such as fine suspended solids, colloids, and dissolved organic matter. If these impurities are not completely removed, they can clog the formation during reinjection, reducing injection efficiency and consequently affecting reservoir development. Chemical treatment methods, such as adding flocculants and bactericides, can remove some pollutants, but they introduce new chemical substances, leading to unstable produced water quality that fails to meet stringent reinjection standards.

[0004] As gas field development enters its mid-to-late stages, the volume of produced water continues to increase, and the water quality becomes increasingly complex. Produced water from gas fields typically has characteristics such as high content of petroleum-related substances, high content of suspended solids (SS), high content of organic matter (COD), and high mineralization. The treatment effect and capacity of traditional treatment technologies are no longer sufficient to meet actual needs.

[0005] Furthermore, traditional treatment processes are often complex, require large areas, and have high operating costs, limiting their application in space-constrained locations such as wellheads. In membrane treatment, although technologies such as ultrafiltration membranes demonstrate good separation performance, membrane fouling remains a bottleneck for their industrial application. Membrane fouling not only significantly reduces membrane flux, affecting treatment efficiency, but also generates waste liquid during chemical cleaning, increasing treatment costs and the risk of secondary pollution. Utility Model Content

[0006] To address the aforementioned shortcomings of existing technologies, this utility model provides a system for gas field produced water treatment and condensate oil recovery, which solves the problems of low separation efficiency, poor treatment effect, and high cost in existing gas field produced water treatment and condensate oil recovery technologies.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A system for treating produced water and recovering condensate from gas fields is provided, comprising a raw water collection tank, a primary separation membrane device, a secondary separation membrane device, a combined reactor, a tertiary separation membrane device, and a product water tank arranged sequentially. The raw water collection tank, the primary separation membrane device, the secondary separation membrane device, the combined reactor, the tertiary separation membrane device, and the product water tank are all connected to a control system. The first-stage membrane separation unit has a first inlet at its bottom, which is connected to the outlet of the raw water collection tank. The first-stage membrane separation unit has a first product water outlet at its top, which is connected to a second inlet. The second inlet is located at the bottom of the second-stage membrane separation unit. The second product water outlet is located at the top of the second-stage membrane separation unit and is connected to the inlet of the integrated reactor. The outlet of the integrated reactor is connected to a third inlet. The third inlet is located at the bottom of the third-stage membrane separation unit. The third product water outlet is located at the top of the third-stage membrane separation unit and is connected to the inlet of the product water tank.

[0008] The beneficial effects of adopting the above technical solution are as follows: the raw water collection tank can achieve preliminary separation of floating oil and water, improving the preliminary recovery efficiency of condensate oil; the primary separation membrane device can intercept condensate oil in different states, including suspended and emulsified states, through cross-flow filtration mode, improving the recovery rate of condensate oil and reducing resource waste; the secondary separation membrane device can more efficiently intercept the condensate oil remaining in the produced water of the primary separation membrane device, further enhancing the separation and recovery of condensate oil; the integrated reactor can purify the produced water of the secondary separation membrane device, removing harmful substances such as iron ions; the tertiary separation membrane device can perform deep filtration on the produced water treated by the integrated reactor, further removing the fine impurities remaining in the produced water, ensuring that the produced water meets extremely high water quality standards; the product water tank is used to store the product water treated by the tertiary separation membrane device.

[0009] This system, through a series of interconnected components including a raw water collection tank, a primary separation membrane device, a secondary separation membrane device, a combined reactor, a tertiary separation membrane device, and a product water tank, combined with a control system, achieves automated operation. It effectively solves the problems of low separation efficiency, poor treatment effect, and high cost in existing gas field produced water treatment and condensate recovery technologies. At the same time, by focusing on physical separation, it reduces the use of chemical agents, avoids secondary pollution, improves resource utilization and treatment efficiency, ensures that the produced water meets the standards for reinjection, and guarantees the stability and sustainability of gas field production.

[0010] Furthermore, the top of the raw water collection tank is equipped with a first liquid inlet and a floating oil collection device. The floating oil collection device is connected to the input end of the condensate collection tank through an oil collection weir and a first pipeline. The bottom side of the raw water collection tank is equipped with an outlet, which is connected to the first inlet through a fourth pipeline. The fourth pipeline is equipped with a first water inlet pump and a filter. The first water inlet pump is located near the outlet.

[0011] The beneficial effects of adopting the above technical solution are as follows: The first inlet and floating oil collection device set at the top of the raw water collection tank can effectively collect the floating oil on the surface of the raw water through the oil collection weir, and transport it to the condensate oil collection tank through the first pipeline, realizing the preliminary and efficient separation and recovery of the floating oil; At the same time, the outlet set on one side of the bottom of the raw water collection tank is connected to the primary separation membrane device through the fourth pipeline equipped with the first water inlet pump and filter, which not only ensures the stable delivery of raw water, but also filters out larger particles of impurities through the filter, avoiding the primary separation membrane device from being blocked by large particles in the raw water, improving the overall separation efficiency and operational stability of the system, and reducing the treatment cost.

[0012] Furthermore, a first concentrate inlet is provided on one side of the top of the condensate oil collection tank. The first concentrate inlet is connected to a guide plate, which is located inside the condensate oil collection tank. An oil separator is provided inside the condensate oil collection tank. An oil outlet is provided on one side above the oil separator, and a first liquid outlet is provided on one side below the oil separator.

[0013] The beneficial effects of adopting the above technical solution are as follows: the guide plate is used to guide the flow of the concentrate entering from the first concentrate inlet to promote the natural stratification of condensate oil and water. At the same time, the oil separator can effectively isolate the upper layer of condensate oil from the lower layer of water and other impurities, ensuring that high-purity condensate oil products can be collected through the oil outlet. The first outlet is used to discharge the small amount of water that may be contained in the lower layer, thereby improving the recovery purity and efficiency of condensate oil and reducing subsequent processing costs.

[0014] Furthermore, both the first-stage separation membrane device and the second-stage separation membrane device are equipped with a first concentrate outlet at their top, and the first concentrate outlet is connected to the first concentrate inlet through a fifth pipeline; The third inlet of the three-stage separation membrane device is connected to the second outlet through the sixth pipeline. The second outlet is located on one side of the bottom of the integrated reactor. The sixth pipeline is equipped with a second inlet pump. The top of the three-stage separation membrane device is equipped with a second concentrate outlet, which is connected to the return port through a seventh pipeline. The return port is located at the top of the raw water collection tank. The primary, secondary, and tertiary separation membrane units are all equipped with ceramic membrane modules.

[0015] The beneficial effects of adopting the above technical solution are as follows: The first concentrate outlet at the top of the primary and secondary separation membrane devices is connected to the condensate collection tank via the fifth pipeline, realizing the direct recovery of the efficiently retained condensate concentrate and reducing resource waste; the tertiary separation membrane device is connected to the integrated reactor via the sixth pipeline, and the second inlet pump on the sixth pipeline ensures a stable water supply. At the same time, the second concentrate outlet at the bottom of the tertiary separation membrane device returns to the raw water collection tank via the seventh pipeline, forming a circulation treatment mechanism, which improves the overall treatment efficiency and water quality adaptability of the system; in addition, the primary, secondary, and tertiary separation membrane devices all use polyceramic membrane modules, which have excellent anti-fouling and oil-resistant properties, ensuring the stable operation and efficient separation of the separation membrane devices in complex water quality, thereby significantly improving the reliability and economy of the system.

[0016] Furthermore, a second liquid inlet is provided at the top of the integrated reactor. The second liquid inlet is connected to the second product water outlet through a second pipeline. An acid inlet and an alkali inlet are provided in sequence on one side of the second liquid inlet. The acid inlet and the alkali inlet are connected to an external reagent storage tank.

[0017] The beneficial effects of adopting the above technical solution are as follows: The second inlet at the top of the integrated reactor is connected to the second product water outlet of the secondary separation membrane device through the second pipeline, ensuring that the pre-purified produced water can smoothly enter the integrated reactor for further treatment; at the same time, the acid and alkali dosing ports arranged sequentially on one side of the second inlet are connected to the external reagent storage tank, which allows the system to accurately add acid and alkali reagents according to the real-time pH value of the produced water, thereby effectively adjusting the water quality to the range required for reinjection, avoiding poor treatment effect and equipment corrosion problems caused by pH deviation, and improving the stability and reliability of the overall treatment process.

[0018] Furthermore, an air inlet is provided on one side of the bottom of the integrated reactor. One end of the air inlet is connected to an external compressed air device, and the other end of the air inlet is connected to an aeration device. The aeration device is located at the bottom of the integrated reactor and includes several aeration heads evenly arranged. A first sludge discharge port is provided on the other side of the bottom of the integrated reactor and is connected to a sludge thickening tank.

[0019] The beneficial effects of adopting the above technical solution are as follows: The air inlet on one side of the bottom of the integrated reactor is connected to the external compressed air device and the internal aeration device. Air can be introduced into the integrated reactor through the evenly distributed aeration heads, which enhances the mixing and oxidation reaction of the produced water and the reagent, and effectively removes pollutants such as iron ions from the produced water. At the same time, the first sludge discharge port on the other side of the bottom is connected to the sludge thickening tank, which can discharge the sludge generated during the reaction in a timely manner, avoid the accumulation of sludge in the integrated reactor, ensure the continuous and efficient operation of the integrated reactor, and further improve the produced water treatment effect and system stability.

[0020] Furthermore, the integrated reactor is equipped with a stirring device, which includes a stirring shaft connected to the output end of a drive motor located at the top of the integrated reactor; the stirring shaft is equipped with several stirring blades.

[0021] The beneficial effects of adopting the above technical solution are as follows: The stirring device installed inside the integrated reactor can generate a uniform and strong stirring effect by driving the stirring shaft and several stirring blades through the drive motor, ensuring that the extracted water and the added reagents are fully mixed and reacted, thereby improving the efficiency and effect of other treatment processes such as acid-base adjustment and oxidation reaction, and ensuring the effective removal of impurities and iron ions from the extracted water.

[0022] Furthermore, the top of the sludge thickening tank is provided with a sludge inlet, which is connected to the first sludge discharge outlet. A fourth water outlet is provided on one side of the bottom of the sludge thickening tank. The fourth water outlet is connected to the fourth water inlet through a third pipeline. The fourth water inlet is located on one side of the raw water collection chamber.

[0023] The beneficial effects of adopting the above technical solution are as follows: the sludge thickening tank is connected to the first sludge discharge port of the integrated reactor through the sludge inlet, effectively collecting the sludge generated during the treatment process. The fourth water outlet set at the bottom of the sludge thickening tank returns the filter liquid separated during the thickening process to the raw water collection chamber for recycling through the third pipeline, realizing the recycling of water resources and the reduction of sludge discharge. This not only reduces the pressure of wastewater discharge on the environment, but also reduces the waste of water resources and improves the overall sustainability of the system.

[0024] Furthermore, a fifth water inlet is provided on one side of the top of the product water tank, and the fifth water inlet is connected to the third product water outlet through an eighth pipeline. A return port is provided on one side of the bottom of the product water tank, and the return port is connected to the second liquid inlet through a return pipeline.

[0025] The beneficial effects of adopting the above technical solution are as follows: the fifth water inlet at the top of the product water tank is connected to the third product water outlet of the three-stage separation membrane device through the eighth pipeline, which ensures the stable storage of the deeply purified product water; in addition, if the water quality in the product water tank fluctuates, the water can be transported back to the integrated reactor for further treatment through the return pipeline until the water quality stabilizes and meets the standards, which not only improves the flexibility of the system, but also ensures the reliability of the reinjected water quality.

[0026] Furthermore, it also includes a detection component, which is electrically connected to the control system. The detection component includes a level sensor, a pressure sensor, a flow sensor, a pH sensor, and an online water quality analyzer. The level sensor is installed inside the raw water collection tank; the pressure sensor is installed on the primary, secondary, and tertiary separation membrane devices; the pH sensor is installed inside the integrated reactor and the product water tank; the flow sensor is installed on the ninth, second, and eighth pipelines; the ninth pipeline is located between the first product water inlet and the second inlet water inlet; and a third inlet water pump is installed on the ninth pipeline; the online water quality analyzer is installed inside the product water tank.

[0027] The beneficial effects of adopting the above technical solution are as follows: the detection component integrates a liquid level sensor, a pressure sensor, a flow sensor, a pH sensor, and an online water quality analyzer, and is connected to the control system. This enables real-time monitoring of the liquid level in the raw water collection tank, the operating pressure and flow rate of each stage of the separation membrane device, and the pH value and water quality in the integrated reactor and product water tank. This provides comprehensive data support for the system, ensuring the stability of the treatment process and the compliance of water quality standards. At the same time, it can promptly detect and adjust abnormal parameters, thereby effectively improving the system's treatment efficiency and reducing the cost of manual intervention and operational risks.

[0028] In summary, the system for gas field produced water treatment and condensate oil recovery provided by this utility model has the following beneficial effects: (1) The system forms a highly integrated gas field produced water treatment and condensate oil recovery system by sequentially connecting the raw water collection tank, the primary separation membrane device, the secondary separation membrane device, the integrated reactor, the tertiary separation membrane device and the product water tank. Combined with the automated control system, it realizes efficient separation of gas field produced water and recovery of condensate oil. At the same time, the multi-stage membrane separation process relies entirely on physical separation, without the need to add chemical reagents. The concentrate can be fully recycled and reused, constructing a low-energy-consumption cycle system that takes into account both "resource recovery and cost control". It significantly improves the recovery rate of condensate oil, reduces resource waste, and reduces the amount of chemical reagents used and operating costs.

[0029] (2) The raw water collection tank in this system achieves preliminary separation of floating oil and water through the floating oil collection device, which reduces the load on subsequent treatment. In addition, the guide plate inside the raw water collection tank promotes the aggregation of floating oil and improves the separation efficiency; at the same time, the raw water collection tank ensures the residence time of raw water, making the preliminary separation more complete and providing stable water quality conditions for subsequent treatment.

[0030] (3) This system is designed with a three-stage progressive separation process to address the multi-form distribution characteristics of condensate oil in produced water from gas fields, which consists of "surface floating oil + suspended oil + emulsified oil". This solves the problem that traditional single processes cannot fully recover the condensate oil. At the same time, through the three-stage gradient separation design, the system achieves "full-form interception" of condensate oil, significantly improving the recovery rate and resource utilization rate. It also ensures the stability and reliability of the treatment effect and effectively meets the treatment needs under different water quality conditions. The first-stage separation membrane device can initially remove most of the condensate oil and suspended solids in the produced water; the second-stage separation membrane device can further intercept residual condensate oil, improving the recovery rate; the third-stage separation membrane device can further remove residual condensate oil. The water treated by the integrated reactor undergoes deep purification to ensure that the water quality meets the standards. In addition, when traditional membrane methods recover condensate oil, the membrane flux is prone to a sharp drop due to oil adhesion, requiring frequent cleaning. In this system, the primary, secondary, and tertiary separation membrane units are all equipped with polyceramic membrane modules. Polyceramic membrane modules have excellent antifouling and oil resistance properties. Through the selection of polyceramic membrane modules and the optimization of operating parameters, a balance between "high rejection rate and low fouling rate" is achieved, effectively resolving the contradiction between "membrane fouling and oil retention". This ensures the stable operation and efficient separation of the separation membrane units in complex water conditions, thereby significantly improving the reliability and economy of the system.

[0031] (4) The integrated reactor in this system integrates functions such as acid-base adjustment, oxidation reaction and reaction parameter control. It can achieve comprehensive purification of produced water quality through real-time monitoring and precise control. At the same time, it uses a physical method of forced stirring combined with air aeration to remove iron ions, avoiding the introduction of chemical agents, achieving in-situ pollution-free treatment, and improving the quality of reinjected water.

[0032] (5) The product water tank in the system can store water that has been deeply purified and meets the standards. The water quality monitoring system installed inside the product water tank can monitor water quality indicators in real time, ensuring the stability of the reinjected water quality. In addition, if the water quality in the product water tank fluctuates, the water can be transported back to the integrated reactor for further treatment through the return pipeline until the water quality is stable and meets the standards. This not only improves the flexibility of the system, but also ensures the reliability of the reinjected water quality.

[0033] (6) The condensate collection tank in the system collects the concentrate retained by the primary and secondary separation membrane devices and the floating oil separated from the raw water collection tank into the condensate collection tank, realizing the centralized collection and subsequent treatment of condensate oil, avoiding the waste of condensate oil and environmental pollution, improving the resource recovery rate, and at the same time facilitating the recycling of condensate oil, enhancing the economy and sustainability of the system.

[0034] (7) The sludge thickening tank in the system can reduce the volume of sludge and reduce the cost of subsequent treatment. At the same time, the filter liquid generated during the thickening process is returned to the raw water collection tank for reprocessing, realizing the recycling of water resources and thus reducing the pressure of wastewater discharge on the environment. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of this utility model; The components include: 1. Raw water collection tank; 11. First inlet; 12. Floating oil recovery device; 13. First pipeline; 14. Outlet; 15. Fourth pipeline; 16. First inlet pump; 17. Filter; 18. Return port; 19. Fourth inlet; 110. Level sensor; 2. Primary separation membrane device; 21. First inlet; 22. First product outlet; 23. First concentrate outlet; 24. Fifth pipeline; 25. Pressure sensor; 26. Ninth pipeline; 27. Flow sensor; 3. Secondary separation membrane device; 31. Second inlet; 32. Second product outlet; 4. Integrated reactor; 41. Second outlet; 42. Second inlet pump; 43. Second inlet; 44. Second pipeline; 45. Acid dosing port; 46. 47. Alkali inlet; 48. Air inlet; 49. Aeration device; 410. Aeration head; 411. First sludge discharge port; 412. Drive motor; 413. Stirring shaft; 414. Stirring blade; 5. Three-stage separation membrane device; 51. Third water inlet; 52. Third product water inlet; 53. Sixth pipeline; 54. Second concentrate outlet; 55. Seventh pipeline; 6. Product water tank; 61. Fifth water inlet; 62. Eighth pipeline; 63. Reinjection port; 64. Return pipeline; 65. pH sensor; 7. Condensate oil collection tank; 71. First concentrate inlet; 72. Baffle plate; 73. Oil separator; 74. Oil outlet; 75. First outlet; 8. Sludge thickening tank; 81. Sludge inlet; 82. Fourth product water inlet; 83. Third pipeline. Detailed Implementation

[0036] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0037] like Figure 1 As shown, the system for gas field produced water treatment and condensate oil recovery provided by this utility model includes a raw water collection tank 1, a primary separation membrane device 2, a secondary separation membrane device 3, a comprehensive reactor 4, a tertiary separation membrane device 5, and a product water tank 6 arranged in sequence. The raw water collection tank 1, the primary separation membrane device 2, the secondary separation membrane device 3, the comprehensive reactor 4, the tertiary separation membrane device 5, and the product water tank 6 are all connected to the control system.

[0038] The system includes a raw water collection tank 1, which enables preliminary separation of floating oil and water, improving the initial recovery efficiency of condensate oil; a primary separation membrane device 2, which can intercept condensate oil in different states, including suspended and emulsified states, through cross-flow filtration, improving the recovery rate of condensate oil and reducing resource waste; a secondary separation membrane device 3, which can more efficiently intercept the condensate oil remaining in the produced water from the primary separation membrane device 2, further enhancing the separation and recovery of condensate oil; a comprehensive reactor 4, which can purify the produced water from the secondary separation membrane device 3, removing harmful substances such as iron ions; a tertiary separation membrane device 5, which can perform deep filtration on the produced water treated by the comprehensive reactor 4, further removing the fine impurities remaining in the produced water, ensuring that the produced water meets extremely high water quality standards; and a product water tank 6, which is used to store the product water treated by the tertiary separation membrane device 5.

[0039] like Figure 1 As shown, the top of the raw water collection tank 1 is provided with a first inlet 11 and a floating oil collection device 12. The floating oil collection device 12 is connected to the input end of the condensate collection tank 7 through an oil collection weir and a first pipeline 13. The bottom side of the raw water collection tank 1 is provided with an outlet 14. The outlet 14 is connected to the first inlet 21 through a fourth pipeline 15. The fourth pipeline 15 is provided with a first water pump 16 and a filter 17. The first water pump 16 is located on the side near the outlet 14.

[0040] The first inlet 11 and the floating oil collection device 12, located at the top of the raw water collection tank 1, can effectively collect the floating oil on the surface of the raw water through the oil collection weir and transport it to the condensate oil collection tank 7 through the first pipeline 13, thus achieving preliminary and efficient separation and recovery of the floating oil. At the same time, the outlet 14 located on one side of the bottom of the raw water collection tank 1 is connected to the primary separation membrane device 2 through the fourth pipeline 15, which is equipped with the first water inlet pump 16 and the filter 17. This ensures the stable delivery of raw water and also filters out larger particles of impurities through the filter 17, preventing the primary separation membrane device from being blocked by large particles in the raw water. This improves the overall separation efficiency and operational stability of the system and reduces the processing cost.

[0041] like Figure 1 As shown, a first concentrated liquid inlet 71 is provided on one side of the top of the condensate oil collection tank 7. The first concentrated liquid inlet 71 is connected to a guide plate 72, which is located inside the condensate oil collection tank 7. An oil separator 73 is provided inside the condensate oil collection tank 7. An oil outlet 74 is provided on the upper side of the oil separator 73, and a first liquid outlet 75 is provided on the lower side of the oil separator 73. The guide plate 72 is used to guide the flow of concentrated liquid entering from the first concentrated liquid inlet 71 to promote the natural stratification of condensate oil and water. At the same time, the oil separator 73 can effectively isolate the upper layer of condensate oil from the lower layer of water and other impurities, ensuring that high-purity condensate oil product can be collected through the oil outlet 74. The first liquid outlet 75 is used to discharge the small amount of water that may be contained in the lower layer, thereby improving the recovery purity and efficiency of condensate oil and reducing subsequent processing costs.

[0042] like Figure 1 As shown, the first-stage separation membrane device 2 has a first inlet 21 at its bottom, which is connected to the outlet of the raw water collection tank 1. The first-stage separation membrane device 2 has a first concentrate outlet 23 and a first product water outlet 22 at its top. The first concentrate outlet 23 is connected to the first concentrate inlet 71 via a fifth pipeline 24. The second-stage separation membrane device 3 has a second inlet 31 at its bottom, which is connected to the first product water outlet 22. The second-stage separation membrane device 3 has a first concentrate outlet 23 and a second product water outlet 32 ​​at its top. The second product water outlet 32 ​​is connected to the inlet of the integrated reactor 4. The first concentrate outlet 23 at the top of the first-stage separation membrane device 2 and the second-stage separation membrane device 3 is connected to the condensate oil collection tank 7 via a fifth pipeline 24, which realizes the direct recovery of the efficiently retained condensate oil concentrate and reduces resource waste.

[0043] like Figure 1As shown, the top of the integrated reactor 4 is equipped with a second inlet 43, which is connected to the second product water outlet 32 ​​via a second pipeline 44. An acid inlet 45 and an alkali inlet 46 are sequentially arranged on one side of the second inlet 43, and are connected to an external reagent storage tank. The second inlet 43 at the top of the integrated reactor 4 is connected to the second product water outlet 32 ​​of the secondary separation membrane device 3 via the second pipeline 44, ensuring that the pre-purified produced water can smoothly enter the integrated reactor 4 for further treatment. Simultaneously, the acid inlet 45 and alkali inlet 46 sequentially arranged on one side of the second inlet 43 are connected to an external reagent storage tank, allowing the system to accurately add acid and alkali reagents according to the real-time pH value of the produced water, thereby effectively adjusting the water quality to the range required for reinjection. This avoids poor treatment results and equipment corrosion problems caused by pH deviation, improving the stability and reliability of the overall treatment process.

[0044] like Figure 1 As shown, an air inlet 47 is provided on one side of the bottom of the integrated reactor 4. One end of the air inlet 47 is connected to an external compressed air device, and the other end is connected to an aeration device 48. The aeration device 48 is located at the bottom of the integrated reactor 4 and includes several evenly distributed aeration heads 49. A first sludge discharge port 410 is provided on the other side of the bottom of the integrated reactor 4 and is connected to a sludge thickening tank 8. The air inlet 47 on one side of the bottom of the integrated reactor 4 is connected to the external compressed air device and the internal aeration device 48, allowing air to be introduced into the integrated reactor 4 through the evenly distributed aeration heads 49. This enhances the mixing and oxidation reaction of the produced water and the reagents, effectively removing pollutants such as iron ions from the produced water. At the same time, the first sludge discharge port 410 on the other side of the bottom is connected to the sludge thickening tank 8, which can promptly discharge the sludge generated during the reaction process, preventing sludge accumulation in the integrated reactor 4, ensuring the continuous and efficient operation of the integrated reactor 4, and further improving the produced water treatment effect and system stability.

[0045] like Figure 1 As shown, the integrated reactor 4 is equipped with a stirring device, which includes a stirring shaft 412 connected to the output end of a drive motor 411, which is located at the top of the integrated reactor 4. Several stirring blades 413 are provided on the stirring shaft 412. In use, the stirring device inside the integrated reactor 4 drives the stirring shaft 412 and several stirring blades 413 to rotate through the drive motor 411, which can produce a uniform and strong stirring effect, ensuring that the extracted water and the added reagents are fully mixed and reacted, thereby improving the efficiency and effect of other treatment processes such as acid-base adjustment and oxidation reaction, and ensuring the effective removal of impurities and iron ions from the extracted water.

[0046] like Figure 1As shown, the top of the three-stage membrane separation device 5 is equipped with a second concentrate outlet 54 and a third inlet 51. The second concentrate outlet 54 is connected to a reflux port 18 via a seventh pipe 55, which is located at the top of the raw water collection chamber 1. The third inlet 51 is connected to a second outlet 41 via a sixth pipe 53, which is located on one side of the bottom of the integrated reactor 4. A second inlet pump 42 is installed on the sixth pipe 53. The top of the three-stage membrane separation device 5 is equipped with a third product water outlet 52, which is connected to the inlet of the product water tank 6. The three-stage membrane separation device 5 is connected to the integrated reactor 4 via the sixth pipe 53, and the second inlet pump 42 installed on the sixth pipe 53 ensures a stable water supply. Water is simultaneously returned to the raw water collection chamber 1 via the second concentrate outlet 54 at the bottom of the tertiary separation membrane device 5 through the seventh pipeline 55, forming a circulating treatment mechanism that improves the overall treatment efficiency and water quality adaptability of the system. In addition, the primary separation membrane device 2, the secondary separation membrane device 3, and the tertiary separation membrane device 5 all use polyceramic membrane modules. The filtration accuracy of the primary separation membrane device 2 is 0.1μm, the filtration accuracy of the secondary separation membrane device 3 is 0.05μm, and the filtration accuracy of the tertiary separation membrane device 5 is 5nm. Moreover, the polyceramic membrane modules have excellent anti-fouling and oil resistance properties, ensuring the stable operation and efficient separation of the separation membrane devices in complex water quality, thereby significantly improving the reliability and economy of the system.

[0047] like Figure 1 As shown, the sludge thickening tank 8 has a sludge inlet 81 at its top, which is connected to the first sludge discharge outlet 410. A fourth water outlet 82 is located on one side of the bottom of the sludge thickening tank 8, and this fourth water outlet 82 is connected to a fourth water inlet 19 via a third pipeline 83. The fourth water inlet 19 is located on one side of the raw water collection chamber 1. The sludge thickening tank 8 is connected to the first sludge discharge outlet 410 of the integrated reactor 4 via the sludge inlet 81, effectively collecting the sludge generated during the treatment process. The fourth water outlet 82 at the bottom of the sludge thickening tank 8 returns the filtrate separated during the thickening process to the raw water collection chamber 1 for recycling via the third pipeline 83. This achieves the recycling of water resources and the reduction of sludge discharge, reducing the environmental pressure from wastewater discharge, minimizing water waste, and improving the overall sustainability of the system.

[0048] like Figure 1As shown, a fifth inlet 61 is provided on one side of the top of the product water tank 6. The fifth inlet 61 is connected to the third product water outlet 52 through the eighth pipeline 62. A return port 63 is provided on one side of the bottom of the product water tank 6. The return port 63 is connected to the second liquid inlet 43 through the return pipeline 64. The fifth inlet 61 at the top of the product water tank 6 is connected to the third product water outlet 52 of the three-stage separation membrane device 5 through the eighth pipeline 62, which ensures the stable storage of the deeply purified product water. In addition, if the water quality in the product water tank 6 fluctuates, the water can be transported back to the integrated reactor 4 through the return pipeline 64 for further treatment until the water quality stabilizes and meets the standards. This improves the flexibility of the system and ensures the reliability of the returned water quality.

[0049] like Figure 1 As shown, it also includes a detection component, which is electrically connected to the control system. The detection component includes a level sensor 110, a pressure sensor 25, a flow sensor 27, a pH sensor 65, and an online water quality analyzer. The level sensor 110 is installed inside the raw water collection tank 1. The pressure sensor 25 is installed on the primary separation membrane device 2, the secondary separation membrane device 3, and the tertiary separation membrane device 5. The pH sensor 65 is installed inside the integrated reactor 4 and the product water tank 6. The flow sensor 27 is installed on the ninth pipeline 26, the second pipeline 44, and the eighth pipeline 62. The ninth pipeline 26 is located between the first product water inlet 22 and the second inlet 31. A third inlet pump 28 is installed on the product tank 6; an online water quality monitor is installed inside the product tank 6; the detection components integrate a level sensor 110, a pressure sensor 25, a flow sensor 27, a pH sensor 65, and the online water quality monitor, and are connected to the control system. This enables real-time monitoring of the liquid level in the raw water collection chamber 1, the operating pressure and flow rate of each stage of the separation membrane device, the pH value and water quality in the integrated reactor 4 and the product tank 6, providing comprehensive data support for the system, ensuring the stability of the treatment process and the compliance of water quality standards, and enabling timely detection and adjustment of abnormal parameters, thereby effectively improving the system's treatment efficiency and reducing the cost of manual intervention and operational risks.

[0050] The method of using this utility model is as follows: The produced water from the gas field to be treated enters the raw water collection tank 1 through the first inlet 11. The floating oil recovery device 12 inside the raw water collection tank 1 initially recovers the surface condensate oil and sends it to the condensate oil collection tank 7. The produced water, after initial filtration in the raw water collection tank 1, enters the primary separation membrane device 2 and the secondary separation membrane device 3 sequentially through the first inlet pump 16 for cross-flow filtration. The retained concentrate is input into the condensate oil collection tank 7 through the fifth pipeline 24. The effluent from the secondary separation membrane device 3 is input into the integrated reactor 4 through the second pipeline 44. Under the synergistic effect of stirring, aeration, and automatic acid / alkali addition, iron ion oxidation, suspended solids flocculation, and pH adjustment are completed. After the integrated reactor… The sludge generated after treatment by reactor 4 is discharged into sludge thickening tank 8 through the first sludge discharge port 410. The filtrate obtained after treatment by sludge compression tank is returned to raw water collection tank 1 for recycling through the fourth product water port 82 and the third pipeline 83. The effluent from integrated reactor 4 is sent to the three-stage separation membrane device 5 for deep purification by the second inlet pump 42. The concentrate obtained after treatment by the three-stage separation membrane device 5 is returned to raw water collection tank 1 through the seventh pipeline 55 for continued recycling. The effluent obtained after treatment by the three-stage separation membrane device 5 is stored in product water tank 6. When the online water quality monitor detects fluctuations in the water quality in product water tank 6, it is returned to integrated reactor 4 for further treatment through return pipeline 64.

[0051] In summary, the system for gas field produced water treatment and condensate oil recovery provided by this utility model forms a highly integrated gas field produced water treatment and condensate oil recovery system by sequentially connecting the raw water collection tank 1, the primary separation membrane device 2, the secondary separation membrane device 3, the integrated reactor 4, the tertiary separation membrane device 5, and the product water tank 6. Combined with an automated control system, it achieves efficient separation of gas field produced water and recovery of condensate oil. At the same time, the combination of multi-stage membrane separation technology and physicochemical treatment significantly improves separation efficiency and treatment effect, while reducing the amount of chemical reagents used and operating costs.

Claims

1. A system for gas field produced water treatment and condensate recovery, characterized by: The system includes a raw water collection tank (1), a primary separation membrane device (2), a secondary separation membrane device (3), a combined reactor (4), a tertiary separation membrane device (5), and a product water tank (6), arranged sequentially. The raw water collection tank (1), the primary separation membrane device (2), the secondary separation membrane device (3), the combined reactor (4), the tertiary separation membrane device (5), and the product water tank (6) are all connected to the control system. The first-stage separation membrane device (2) is provided with a first inlet (21) at its bottom end, which is connected to the outlet of the raw water collection tank (1). The first-stage separation membrane device (2) is provided with a first product water outlet (22) at its top end, which is connected to a second inlet (31). The second inlet (31) is located at the bottom end of the second-stage separation membrane device (3). The second product water outlet (32) is located at the top end of the second-stage separation membrane device (3). The second product water outlet (32) is connected to the inlet of the integrated reactor (4). The outlet of the integrated reactor (4) is connected to a third inlet (51). The third inlet (51) is located at the bottom end of the third-stage separation membrane device (5). The third product water outlet (52) is located at the bottom end of the third-stage separation membrane device (5). The third product water outlet (52) is connected to the inlet of the product water tank (6).

2. The system for gas field produced water treatment and condensate oil recovery according to claim 1, characterized in that: The top of the raw water collection tank (1) is provided with a first liquid inlet (11) and a floating oil collection device (12). The floating oil collection device (12) is connected to the input end of the condensate collection tank (7) through an oil collection weir and a first pipeline (13). The bottom side of the raw water collection tank (1) is provided with a water outlet (14). The water outlet (14) is connected to the first water inlet (21) through a fourth pipeline (15). The fourth pipeline (15) is provided with a first water pump (16) and a filter (17). The first water pump (16) is located near the water outlet (14).

3. The system for gas field produced water treatment and condensate recovery of claim 2, wherein: The top side of the condensate oil collection tank (7) is provided with a first concentrate inlet (71), which is connected to a guide plate (72). The guide plate (72) is located inside the condensate oil collection tank (7). The inside of the condensate oil collection tank (7) is provided with an oil separator (73). An oil outlet (74) is provided on the upper side of the oil separator (73), and a first liquid outlet (75) is provided on the lower side of the oil separator (73).

4. The system for gas field produced water treatment and condensate recovery of claim 1, wherein: The top of both the primary separation membrane device (2) and the secondary separation membrane device (3) is provided with a first concentrate outlet (23), and the first concentrate outlet (23) is connected to the first concentrate inlet (71) through the fifth pipeline (24). The third inlet (51) of the three-stage separation membrane device (5) is connected to the second outlet (41) through the sixth pipeline (53). The second outlet (41) is located on one side of the bottom end of the integrated reactor (4). A second water pump (42) is installed on the sixth pipeline (53). The top of the three-stage separation membrane device (5) is provided with a second concentrated liquid outlet (54), which is connected to the return port (18) through a seventh pipeline (55). The return port (18) is located at the top of the raw water collection tank (1). The primary separation membrane device (2), the secondary separation membrane device (3), and the tertiary separation membrane device (5) are all equipped with ceramic membrane components.

5. The system for gas field produced water treatment and condensate recovery of claim 1, wherein: The top of the integrated reactor (4) is provided with a second liquid inlet (43), which is connected to the second water outlet (32) through a second pipeline (44). An acid inlet (45) and an alkali inlet (46) are provided on one side of the second liquid inlet (43), and the acid inlet (45) and the alkali inlet (46) are connected to an external reagent storage tank.

6. The system for gas field produced water treatment and condensate recovery of claim 5, wherein: An air inlet (47) is provided on one side of the bottom of the integrated reactor (4). One end of the air inlet (47) is connected to an external compressed air device, and the other end of the air inlet (47) is connected to an aeration device (48). The aeration device (48) is located at the bottom of the integrated reactor (4) and includes several aeration heads (49) evenly arranged. A first sludge discharge port (410) is provided on the other side of the bottom of the integrated reactor (4). The first sludge discharge port (410) is connected to a sludge thickening tank (8).

7. The system for gas field produced water treatment and condensate recovery of claim 5, wherein: The integrated reactor (4) is equipped with a stirring device inside. The stirring device includes a stirring shaft (412), which is connected to the output end of a drive motor (411). The drive motor (411) is located at the top of the integrated reactor (4). Several stirring blades (413) are provided on the stirring shaft (412).

8. The system for gas field produced water treatment and condensate recovery of claim 6, wherein: The top of the sludge thickening tank (8) is provided with a sludge inlet (81), which is connected to the first sludge discharge outlet (410). The bottom side of the sludge thickening tank (8) is provided with a fourth water outlet (82), which is connected to a fourth water inlet (19) through a third pipeline (83). The fourth water inlet (19) is located on one side of the raw water collection chamber (1).

9. The system for gas field produced water treatment and condensate recovery of claim 1, wherein: The product water tank (6) has a fifth water inlet (61) on one side of the top, and the fifth water inlet (61) is connected to the third water outlet (52) through the eighth pipeline (62). The product water tank (6) has a return port (63) on one side of the bottom, and the return port (63) is connected to the second liquid inlet (43) through the return pipeline (64).

10. The system for gas field produced water treatment and condensate recovery of claim 1, wherein: It also includes a detection component, which is electrically connected to the control system. The detection component includes a level sensor (110), a pressure sensor (25), a flow sensor (27), a pH sensor (65), and an online water quality analyzer. The level sensor (110) is located inside the raw water collection tank (1). The pressure sensor (25) is located on the first-stage separation membrane device (2), the second-stage separation membrane device (3), and the third-stage separation membrane device (5). The pH sensor (65) is located inside the integrated reactor (4) and the product water tank (6). The flow sensor (27) is located on the ninth pipeline (26), the second pipeline (44), and the eighth pipeline (62). The ninth pipeline (26) is located between the first product water outlet (22) and the second inlet water outlet (31). A third inlet water pump (28) is installed on the ninth pipeline (26). The online water quality analyzer is located inside the product water tank (6).

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