Fracturing flow-back fluid treatment device and treatment process thereof

Abstract

The invention relates to the technical field of fracturing flow-back fluid treatment, and discloses a fracturing flow-back fluid treatment device and a treatment process thereof.The fracturing flow-back fluid treatment device comprises a tank body and a sewage pipe, the lower end of the sewage pipe is connected with a sewage inlet, the upper end of the sewage pipe is located in the tank body, and sewage obtained after gas-liquid mixing enters the sewage pipe from the sewage inlet; a branch pipe and a diversion pipe; the rotating shaft is fixedly connected with the flow guide pipe and rotationally mounted on the tank body, the distance between the lower end of the flow guide pipe and the rotating shaft is smaller than that between the upper end of the flow guide pipe and the rotating shaft, and the upper end of the flow guide pipe has a downward trend under the action of gravity; one end of the limiting rod is located in the tank body, the other end of the limiting rod is located outside the tank body, the limiting rod is installed on the tank body in a sealed and sliding mode, the sliding direction of the limiting rod is the same as the radial direction of the tank body, the limiting rod is provided with a reducing section, the reducing section makes contact with the outer pipe wall of the lower end of the flow guide pipe, and different outer diameters of the reducing section drive different inclination angles of the flow guide pipe. The oil phase purity of the top oil outlet and the water quality of the bottom water outlet can be improved.

Description

Technical Field

[0001] This application relates to the technical field of fracturing flowback fluid treatment, and in particular to a fracturing flowback fluid treatment device and its treatment process. Background Technology

[0002] Fracturing flowback fluid is a complex industrial wastewater discharged from the wellbore to the surface after hydraulic fracturing operations in oil and gas fields. It originates from a mixture of fracturing fluid injected into the formation, formation water, rock cuttings, and crude oil, as well as from well washing and the discharge of residual base fluid after the operation. It also contains various chemical agents added to the fracturing fluid, suspended solid particles, emulsified oils, and trace amounts of heavy metals. The water quality characteristics of fracturing flowback fluid are extremely complex composition, high pollutant concentration, extremely high COD and mineralization, high viscosity, severe emulsification, and system stability. These characteristics collectively make its treatment extremely difficult.

[0003] The entire treatment process for fracturing flowback fluid is as follows: First, chemicals are added to the raw fracturing flowback fluid to form a flocculation reaction, causing suspended solids and colloids in the water to form larger flocculent particles. After the flocculation reaction, the fluid enters the solid-liquid separation step, which mainly uses air flotation equipment. Air bubbles are used as carriers to adhere to the contaminants, making their buoyancy greater than their gravity and the resistance to buoyancy, thus causing the contaminants to float to the water surface and form oily scum. The scum can be scraped off by a scum scraper or discharged through an oil outlet pipe, thereby removing oil, suspended solids, and colloids.

[0004] The working principle of the aforementioned bubble cyclone flotation equipment can be detailed as follows: Oily wastewater enters from the bottom inlet, where guide vanes or pipes are installed. Under the action of these vanes or pipes, a vortex is formed. A bottom distributor generates bubbles, which rise and collide with and adhere to oil droplets in the cyclone wastewater, further separating the solid and liquid phases. Bubbles with an oil film float to the surface and are discharged from the oil outlet pipe, while the aqueous phase is discharged from the side wall outlet. As the inclination angle of the guide vane increases, the oil concentration in the discharged bubbles initially increases and then decreases. When the inclination angle of the guide vane is around 9°, the axial velocity of the oil and gas phases is highest at the center of the separation chamber, resulting in the best separation effect.

[0005] Regarding the aforementioned technologies, the guide pipe is fixedly installed inside the tank and guides the flow at a fixed angle. However, the oil concentration in the raw water of the fracturing flowback fluid fluctuates within a certain range. After the angle of the guide pipe is fixed, when the oil concentration is too high or too low, it affects the change of the axial velocity of the oil and gas phases, thus reducing the separation effect of the guide pipe. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides a fracturing flowback fluid treatment device and its treatment process.

[0007] Firstly, this application provides a fracturing flowback fluid treatment device, which adopts the following technical solution: A fracturing flowback fluid treatment device, comprising: The tank body has a wastewater inlet and a bottom outlet connected to its bottom, and an oil outlet at the top. The sewage pipe is connected to the sewage inlet at its lower end and located inside the tank at its upper end. The sewage, after being mixed with gas and liquid, enters the sewage pipe from the sewage inlet. Branch pipes are distributed circumferentially along the sewage pipe. One end of each branch pipe is connected to the sewage pipe, and the other end of each branch pipe is connected to the tank. Some sewage in the sewage pipe flows out from the upper end of the sewage pipe, and some sewage flows out from the branch pipes. A guide pipe is installed inside the tank. The guide pipe extends in a spiral direction along its length, and the lower end of the guide pipe is close to the outlet end of the branch pipe. A rotating shaft is fixedly connected to the guide pipe. The rotating shaft is rotatably mounted on the tank body. The distance between the lower end of the guide pipe and the rotating shaft is less than the distance between the upper end of the guide pipe and the rotating shaft. The upper end of the guide pipe tends to move downwards due to gravity. A limiting rod, with one end inside the tank and the other end outside the tank, is slidably and sealed on the tank. The sliding direction of the limiting rod is the same as the radial direction of the tank. The rod wall inside the tank is provided with a variable diameter section. The variable diameter section contacts the lower outer wall of the guide pipe. Different outer diameters of the variable diameter section drive the guide pipe to different tilt angles.

[0008] By adopting the above technical solution, the gas-liquid mixed fracturing flowback fluid enters the wastewater pipe from the wastewater inlet at the bottom of the tank. Part of the liquid flows directly into the upper part of the tank from the upper end of the wastewater pipe, while the rest is diverted to the middle and lower parts of the tank through circumferentially distributed branch pipes. The liquid discharged from the branch pipes impacts the lower end of the spirally extending guide pipe, forming an upward swirling flow under the guidance of the guide pipe. During this swirling process, the oil phase, due to its lower density, converges towards the center of the tank, while the water phase moves towards the tank wall. Simultaneously, the guide pipe is rotatably connected to the tank via a rotating shaft. Its lower end is closer to the rotating shaft, and its upper end tends to sink due to gravity, causing the lower end of the guide pipe to... The guide pipe is always in contact with the variable diameter section of the limiting rod. When the oil concentration of the oil phase discharged from the top oil outlet fluctuates, the operator slides the limiting rod outside the tank and uses the different outer diameters of the variable diameter section to drive the guide pipe to rotate around the axis and adjust the tilt angle. When the oil concentration in the wastewater is high, the limit rod can be adjusted to make the tilt angle of the guide pipe approach 9° (the optimal angle in the example) to improve the oil droplet capture efficiency. When the oil concentration is low, the tilt angle is finely adjusted to avoid energy waste caused by excessive swirling, and finally the optimal separation effect under different water qualities is achieved, improving the purity of the oil phase at the top oil outlet and the water quality at the bottom water outlet.

[0009] Optionally, a driving component is connected between the guide tube and the limiting rod. The driving component includes a driving rod and two connecting rings. The connecting rings are fixedly connected to both ends of the driving rod. A fixing rod is connected to the outer wall of the guide tube. One connecting ring is hinged to the fixing rod, and the other connecting ring is sleeved on the limiting rod. The inner ring wall of the connecting ring is in contact with the variable diameter section.

[0010] By adopting the above technical solution, the fixed rod outside the guide tube is hinged to a connecting ring, and another connecting ring is sleeved on the diameter-changing section of the limiting rod. The driving rod connects the two rings. When the limiting rod slides, the diameter-changing section pushes the sleeved connecting ring to move axially, and the force is transmitted to the fixed rod of the guide tube through the driving rod, causing the guide tube to rotate around the axis. Since the connecting ring and the fixed rod are hinged, it can adapt to the angle changes when the guide tube rotates.

[0011] Optionally, the limiting rod has multiple guide rods of different lengths installed on its wall. These guide rods are evenly spaced along the circumference of the limiting rod and their lengths gradually increase. Different guide rods correspond to different outer diameters of the variable diameter section. A positioning rod is connected to the end face of the connecting ring near the guide rod. The positioning rod has an arc-shaped groove, the groove wall of which is flush with the inner wall of the connecting ring. The positioning rod extends along the axial direction of the connecting ring, and is flush with the inner wall of the connecting ring. When the connecting ring and the variable diameter section remain stationary, the limiting rod is rotated. When the limiting rod and the positioning rod slide into contact, the rotation of the limiting rod stops. The remaining guide rods and the positioning rod are spaced apart.

[0012] By adopting the above technical solution, guide rods of different lengths correspond to different outer diameters of the variable diameter section (i.e., different inclination angles of the guide tube). After determining the optimal inclination angle by sliding the limiting rod, the limiting rod is rotated so that the guide rod matching the outer diameter of the current variable diameter section slides into the arc groove of the positioning rod (the arc groove is flush with the inner ring wall of the connecting ring to ensure a good fit). At this time, the other guide rods are spaced apart from the positioning rod, and only the target guide rod is positioned, thus achieving precise locking of the inclination angle of the guide tube. The cooperation between the guide rod with gradually changing length and the arc groove allows the operator to judge whether the positioning is in place by "whether the limiting rod rotates smoothly", simplifying the operation feedback. After the connecting ring and the guide rod come into contact, it does not affect the subsequent sliding of the limiting rod, thus balancing stability and flexibility.

[0013] Optionally, an indicator rod is installed on the rod wall outside the tank body of the limiting rod. The indicator rod and the guide rod are correspondingly arranged. A positioning block is slidably connected to the outside of the tank body. The sliding direction of the positioning block is the same as the radial direction of the tank body. When the guide rod and the positioning rod are in contact, the positioning block is slid to insert the corresponding indicator rod into the positioning block.

[0014] By adopting the above technical solution, when the guide rod and the positioning rod are in contact and positioned, the corresponding indicator rod on the outside of the tank is exactly aligned with the positioning block; the operator slides the positioning block to insert the indicator rod into the positioning block, thus completing the mechanical locking; since the indicator rod and the guide rod are in one-to-one correspondence, the operator can intuitively judge the current tilt angle of the guide pipe by observing "which indicator rod is in contact with the positioning block".

[0015] Optionally, a reset component is installed on the outer wall of the tank, the positioning block is connected to the reset component, and the reset component drives the positioning block to always tend to move closer to the indicator rod.

[0016] By adopting the above technical solution, the elastic force of the reset component pushes the positioning block to move automatically toward the indicator rod, and the initial fit can be completed without the operator actively applying force. When unlocking, the positioning block can be pulled to overcome the elastic force.

[0017] Optionally, when the guide rod and the positioning rod come into contact, the limiting rod is driven to slide, and the guide rod slides along the length direction of the positioning rod.

[0018] By adopting the above technical solution, the tilt angle of the guide tube remains unchanged, and the limit rod continues to slide without affecting the tilt angle of the guide tube.

[0019] Optionally, the inner wall of the tank is provided with multiple partition rings along the height direction, the sewage pipe is located inside the partition rings, the inner wall of the partition rings and the sewage pipe are spaced apart, the inner wall of the partition rings is connected to a sleeve, the lower end of the sleeve is spaced apart from the other partition rings, the partition rings divide the tank into a main separation chamber and a secondary separation chamber, the main separation chamber is located at the top of the tank, the upper end of the sewage pipe is located in the main separation chamber, the inner wall of the sleeve is evenly spaced with guide plates, each of the secondary separation chambers is provided with a branch pipe and a guide pipe, the branch pipe is connected to the sleeve, the sleeve is connected to an air inlet pipe, and the tank is connected to an oil outlet pipe in each of the secondary separation chambers.

[0020] By adopting the above technical solution, the separator ring divides the tank into multiple chambers. The upper end of the sewage pipe is located in the main separation chamber. After preliminary separation in the main chamber, part of the liquid flows down the casing into the secondary separation chamber. The guide plate on the inner wall of the casing guides the liquid to form a secondary vortex. The air inlet pipe introduces gas into the casing to enhance the flotation effect. Each secondary separation chamber is equipped with a branch pipe, a guide pipe, and an independent oil outlet pipe to achieve graded separation and graded oil discharge. The graded separation design solves the problems of limited single-chamber processing capacity and incomplete separation of high-concentration liquids in one step. Through coarse separation in the main chamber and fine separation in the secondary chambers, the oil phase recovery rate is improved and the COD value of the effluent is reduced. The cooperation between the casing and the guide plate enhances the vortex stability of the liquid and avoids liquid interference between the multiple chambers. The independent oil outlet pipe can discharge oil according to the oil phase concentration of each chamber, improving the overall purity of the final oil. At the same time, the gas supplementation of the air inlet pipe enhances the adhesion effect of oil droplets and bubbles, which is suitable for severely emulsified backflow liquid.

[0021] Optionally, a sampling tube is connected inside the limiting rod, and a sampling hole is opened at one end of the limiting rod near the sleeve. One end of the sampling tube is connected to the sampling hole, and the other end of the sampling tube is located outside the tank and connected to a storage tube.

[0022] By adopting the above technical solution, a sampling hole is opened at the end of the limiting rod near the sleeve. One end of the sampling tube is connected to the sampling hole, and the other end extends to the outside of the tank to connect to the storage tube. The operator can obtain the liquid sample of the current chamber at any time through the storage tube, detect the oil concentration, judge the separation effect of the chamber, and then adjust the position of the corresponding limiting rod and optimize the tilt angle of the guide tube. Real-time sampling makes the tilt angle adjustment more targeted, which can ensure that each chamber is in the optimal separation state.

[0023] Optionally, the oil outlet pipe is sealed and slides on the tank body, and a linkage rod is connected between the oil outlet pipe and the limiting rod. The linkage rod is located outside the tank body, and the linkage rod and the limiting rod are rotatably connected by a bearing.

[0024] By adopting the above technical solution, the linkage rod connects the oil outlet pipe and the limit rod, and the linkage rod and the limit rod are connected by a bearing. When the limit rod slides radially, it drives the linkage rod to move synchronously, so that the oil outlet pipe slides together with the limit rod, adjusting the position of the oil outlet pipe in the tank body, so that the oil outlet is always close to the oil core area in the chamber. When the limit rod rotates, the bearing ensures that the linkage rod does not rotate with it, avoiding the oil outlet pipe from rotating and affecting the oil discharge stability.

[0025] Secondly, this application provides a fracturing flowback fluid treatment process, which adopts the following technical solution: A fracturing flowback fluid treatment process is provided, which involves processing the fluid after gas-liquid mixing through a sewage pipe into the tank. Part of the sewage flows out from the top of the sewage pipe, and part flows out from a branch pipe. The sewage is guided upward by a guide pipe and swirls upward, converging into an oil core area at the center of the tank. The oil is discharged through the top oil outlet, and the separated water phase is discharged from the bottom water outlet. During the separation process, the limit rod is controlled to slide according to the oil concentration of the oil phase discharged from the top oil outlet. The guide pipe and the variable diameter section are in contact with different outer diameters, and the inclination angle of the guide pipe is adjusted to change the axial velocity of the oil and gas phases.

[0026] By adopting the above technical solution, after the process starts, the gas-liquid mixture is diverted into the tank through the sewage pipe. Under the action of the guide pipe, it forms an upward swirling flow. The oil phase converges into an oil core area and is discharged from the top, while the water phase is discharged from the bottom. The operator monitors the oil concentration of the oil phase at the top oil outlet in real time (e.g., through sampling and testing). If the concentration is lower than the set value, it is determined that the inclination angle of the guide pipe deviates from the optimal value. The external limit rod of the tank is slid to make the guide pipe contact the larger outer diameter of the variable diameter section, increasing the inclination angle. If the concentration is too high but the processing volume is insufficient, the inclination angle is finely adjusted to reduce the swirling intensity and balance the separation effect and processing efficiency. In view of the characteristics of the fluctuation of the oil concentration in the fracturing flowback fluid, the process ensures that the separation effect is always at an optimal level through dynamic adjustment.

[0027] In summary, this application includes at least one of the following beneficial effects: 1. By adjusting the inclination angle of the guide tube, combined with staged separation and real-time monitoring, efficient and stable separation of fracturing flowback fluid is achieved; 2. The sliding limit rod can not only adjust the tilt angle of the guide pipe, but also change the position of the oil outlet pipe. Real-time sampling makes the tilt angle adjustment more targeted, and the oil outlet is always close to the oil core area, increasing the oil output. Attached Figure Description

[0028] Figure 1 This is a cross-sectional view of the overall structure of an embodiment of this application; Figure 2 This is a partial schematic diagram of an embodiment of this application; Figure 3 This is a cross-sectional view illustrating the fit between the guide tube and the rotating shaft in an embodiment of this application; Figure 4 This is a partial structural cross-sectional view of an embodiment of this application; Figure 5 This is a schematic diagram illustrating the variable diameter section cooperation between the driving component and the limiting rod in an embodiment of this application; Figure 6 This is a front view illustrating the cooperation between the guide rod and the positioning rod in an embodiment of this application; Figure 7 This is a schematic diagram illustrating the cooperation between the indicator rod and the positioning block in an embodiment of this application; Figure 8 This is a schematic diagram illustrating the structure of the oil pipe and the limiting rod in an embodiment of this application.

[0029] Explanation of reference numerals in the attached drawings: 10. Tank body; 11. Sewage inlet; 12. Bottom outlet; 131. Top oil outlet; 132. Safety valve interface; 133. Level gauge port; 14. Separating ring; 15. Sleeve; 151. Guide plate; 16. Positioning block; 17. Reset component; 101. Main separation chamber; 102. Secondary separation chamber; 20. Sewage pipe; 30. Branch pipe; 40. Guide pipe; 41. Rotating shaft; 42. Fixing rod; 50. Air inlet pipe; 60. Limiting rod; 601. Stop block; 61. Variable diameter section; 62. Installation section; 63. Guide rod; 64. Indicator rod; 65. Sampling pipe; 66. Storage pipe; 70. Driving component; 71. Driving rod; 72. Connecting ring; 80. Positioning rod; 81. Arc groove; 90. Oil outlet pipe; 91. Linkage rod. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1 - Appendix Figure 8 This application will be described in further detail.

[0031] In a first aspect, embodiments of this application disclose a fracturing flowback fluid treatment device.

[0032] This application discloses a fracturing flowback fluid treatment device. (Refer to...) Figure 1 A fracturing flowback fluid treatment device includes a tank 10, and a wastewater pipe 20 and a guide pipe 40 installed inside the tank 10. The bottom wall of the tank 10 is connected to a wastewater inlet 11 and a bottom outlet 12. The top of the tank 10 is provided with a top oil outlet 131, a safety valve interface 132, and a level gauge port 133. Branch pipes 30 are spaced apart on the outer periphery of the top of the wastewater pipe 20, and are distributed circumferentially along the wastewater pipe 20. The gas-liquid mixture enters the tank 10 through the wastewater pipe 20. Part of the wastewater in the wastewater pipe 20 flows out from the upper end of the wastewater pipe 20, and part flows out from the branch pipes 30. The guide pipe 40 extends in a spiral direction, with its lower end close to the outlet of the branch pipe 30. After passing through the guide pipe 40, the wastewater spirals upward, causing the wastewater to separate into an aqueous phase and an oil phase. The oil phase concentrates in the middle region of the tank 10, forming an oil core area, and flows out from the top oil outlet 131.

[0033] Reference Figure 1 and Figure 2The tank 10 is equipped with multiple separating rings 14. A gap exists between the sewage pipe 20 and the inner wall of the separating rings 14. The separating rings 14 divide the tank 10 into a main separation chamber 101 and a secondary separation chamber 102. The main separation chamber 101 is located at the top of the tank 10. The lower end of the sewage pipe 20 is connected to the sewage inlet 11, and the upper end is located within the main separation chamber 101. The first separation of sewage occurs within the main separation chamber 101. A sleeve 15 is connected to the inner wall of the separating rings 14. A gap exists between the sleeve 15 and the inner wall of the sewage pipe 20. The aqueous phase after the first separation is graded from top to bottom along the height direction of the tank 10. The aqueous phase passes through the gap between the sleeve 15 and the sewage pipe 20 and enters the next separation chamber 102. A guide plate 151 is installed on the inner wall of the sleeve 15, allowing the sewage to continue mixing after passing through the sleeve 15.

[0034] Reference Figure 1 The aqueous phase formed in the main separation chamber 101 enters the next secondary separation chamber 102 for further separation. A casing 15 is connected to an air inlet pipe 50, which introduces gas into the casing 15 to enhance the flotation effect. Branch pipes 30 and guide pipes 40 are installed in the main separation chamber 101 and secondary separation chamber 102 respectively. One end of the branch pipe 30 in the main separation chamber 101 is connected to the sewage pipe 20, and the other end is connected to the tank 10. The branch pipe 30 in the secondary separation chamber 102 is connected to the casing 15, and the other end is connected to the tank 10. The guide pipe 40 is installed inside the tank 10, and is correspondingly arranged with the branch pipe 30. Sewage flows out of the branch pipe 30 and enters the guide pipe 40. The sewage treatment method is the same in both the main separation chamber 101 and the secondary separation chamber 102. There are three branch pipes 30 corresponding to one separation chamber, and the number of guide pipes 40 is also set accordingly.

[0035] Reference Figure 3 The tank body 10 is rotatably connected to a rotating shaft 41, which is fixedly connected to a guide pipe 40. A small gap is left between the guide pipe 40 and the inner wall of the tank body 10, allowing the guide pipe 40 to rotate around the rotating shaft 41. The distance between the lower inclined end of the guide pipe 40 and the rotating shaft 41 is less than the distance between the upper inclined end of the guide pipe 40 and the rotating shaft 41, so the upper inclined end of the guide pipe 40 always tends downwards under the influence of gravity. The diameter of the guide pipe 40 is larger than the diameter of the branch pipe 30. Therefore, when the guide pipe 40 rotates slightly with the rotating shaft 41, it can receive the sewage discharged from the branch pipe 30, causing the sewage to spiral upwards along the guide pipe 40.

[0036] Reference Figure 4 and Figure 5The tank body 10 is also sealed with a sliding limit rod 60, the sliding direction of which is the same as the radial direction of the tank body 10. The limit rod 60 and the guide pipe 40 are arranged in a one-to-one correspondence. One of the limit rods 60 located in the secondary separation chamber 102 is sleeved on the air inlet pipe 50. The air inlet pipe 50 and the limit rod 60 are coaxial. When the limit rod 60 rotates, the air inlet pipe 50 remains stationary, forming a relative sliding connection with the air inlet pipe 50. One end of the limit rod 60 is located inside the tank body 10, and the other end is located outside the tank body 10. The rod wall of the limit rod 60 inside the tank body 10 is provided with a stop block 601 and a diameter-changing section 61. The stop block 601 prevents the limit rod 60 from detaching from the tank body 10. The diameter-changing section 61 gradually shortens its outer diameter along the length of the limit rod 60, resulting in different inclination angles at the lower end of the guide pipe 40 due to the different outer diameter trends of the diameter-changing section 61.

[0037] Reference Figure 5 A driving component 70 is connected between the guide tube 40 and the limiting rod 60. The driving component 70 includes a driving rod 71 and two connecting rings 72. The two connecting rings 72 are fixedly connected to both ends of the driving rod 71. A fixing rod 42 is connected to the outer wall of the guide tube 40. One connecting ring 72 is hinged to the fixing rod 42, and the other connecting ring 72 is sleeved on the limiting rod 60. Since the upper end of the guide tube 40 always tends to move downward due to gravity, the lower end of the guide tube 40 always tends to move upward, driving the connecting ring 72 to abut against the rod wall of the limiting rod 60.

[0038] By sliding the limiting rod 60, the variable diameter section 61 contacts the connecting ring 72 with different outer diameters. By changing the height position of the connecting ring 72, the tilt angle of the guide tube 40 can be finely adjusted.

[0039] Reference Figure 5 and Figure 6 Furthermore, the limiting rod 60 also includes an installation section 62. The maximum outer diameter of the installation section 62 is smaller than the minimum outer diameter of the diameter-changing section 61. Multiple guide rods 63 of different lengths are installed on the wall of the installation section 62. These guide rods 63 are evenly spaced along the circumference of the limiting rod 60, forming an angle between adjacent guide rods 63. Different guide rods 63 correspond to different outer diameters of the diameter-changing section 61. A positioning rod 80 is connected to the end face of the connecting ring 72 near the guide rods 63. The positioning rod 80 has an arc-shaped groove 81, the inner wall of which is flush with the inner ring wall of the connecting ring 72. The positioning rod 80 extends along the axial direction of the connecting ring 72.

[0040] Reference Figure 6After the inner ring wall of the connecting ring 72 abuts against the variable diameter section 61 and remains unchanged, the tilt angle of the guide tube 40 is determined. Then, the limiting rod 60 is rotated so that the limiting rod 60 and the positioning rod 80, which have the same outer diameter as the variable diameter section 61, slide into contact. When the limiting rod 60 slides, the height of the connecting ring 72 remains unchanged. The other guide rods 63 and positioning rods 80 are spaced apart.

[0041] Reference Figure 4 and Figure 7 To allow operators to visually assess the contact between the guide rod 63 and the positioning rod 80, an indicator rod 64 is installed on the outer wall of the limiting rod 60 outside the tank body 10. The indicator rod 64 corresponds to and has the same length as the guide rod 63. A positioning block 16 is slidably connected to the outer wall of the tank body 10. The sliding direction of the positioning block 16 is the same as that of the limiting rod 60, allowing it to slide alongside the limiting rod 60. When the guide rod 63 and the positioning rod 80 contact, the corresponding indicator rod 64 also approaches the positioning block 16. Sliding the positioning block 16 creates an insertion relationship between the positioning block 16 and the indicator rod 64, restricting the limiting rod 60 from further rotation. However, the limiting rod 60 can move synchronously with the positioning block 16 towards the tank body 10. By sliding the positioning block 16 away from the indicator rod 64, the limiting rod 60 can continue to rotate.

[0042] Reference Figure 4 and Figure 7 An installation block and a reset element 17 are installed on the outer wall of the tank body 10. The reset element 17 is installed in the groove of the installation block. The reset element 17 is a compression spring. The positioning block 16 extends into the groove and is connected to the compression spring. The compression spring drives the positioning block 16 to always tend to approach the indicator rod 64.

[0043] Reference Figure 4 Each limiting rod 60 is connected to a sampling tube 65. A sampling hole is provided at the end of the limiting rod 60 near the sleeve 15. One end of the sampling tube 65 communicates with the sampling hole, and the other end of the sampling tube 65 is located outside the tank body 10 and connected to a storage tube 66. A valve is installed between the sampling tube 65 and the storage tube 66. The storage tube 66 and the valve are detachably threaded together for easy removal of the storage tube 66. Opening the valve allows extraction of either the aqueous or oil phase from the tank body 10 through the sampling tube 65. The oil content of the extracted liquid determines whether the limiting rod 60 is near the oil core or the wastewater. Closing the valve prevents wastewater from flowing into the storage tube 66.

[0044] Reference Figure 4 and Figure 8The oil outlet pipe 90 is sealed and slides on the tank body 10. One end of the oil outlet pipe 90 inside the tank body 10 is flush with one end of the limiting rod 60. A linkage rod 91 is connected between the oil outlet pipe 90 and the limiting rod 60. The linkage rod 91 is located outside the tank body 10. The linkage rod 91 is rotatably connected to the limiting rod 60 through a bearing, so that the rotation of the limiting rod 60 does not affect the oil outlet pipe 90. However, when the limiting rod 60 slides, the oil outlet pipe 90 slides synchronously. It can be determined whether to push the oil outlet pipe 90 closer to the sleeve 15 according to the oil content of the storage tube 66.

[0045] The implementation principle of a fracturing flowback fluid treatment device according to an embodiment of this application is as follows: The gas-liquid mixed fracturing flowback fluid first enters the wastewater pipe 20 from the wastewater inlet 11 at the bottom of the tank 10. Part of the liquid flows directly into the main separation chamber 101 at the top of the tank 10, while part enters the main separation chamber 101 through the circumferentially distributed branch pipes 30 of the wastewater pipe 20. The liquid discharged from the branch pipes 30 enters the spirally extended guide pipe 40, forming a stable upward swirling flow under the guidance of the guide pipe 40. Due to the density difference, the oil phase converges towards the center of the tank 10 to form an oil core area, while the water phase moves towards the tank wall, achieving preliminary oil-water separation. The oil phase separated in the main separation chamber 101 exits from the top oil outlet 131, while the water phase enters each of the secondary separation chambers 102 to continue swirling and flotation. The separated oil phase is discharged from the oil outlet pipe 90, and the water phase is discharged from the bottom water outlet 12, achieving staged separation and staged oil discharge, improving separation efficiency and stability.

[0046] Secondly, this application discloses a fracturing flowback fluid treatment process.

[0047] A fracturing flowback fluid treatment process is carried out according to the aforementioned fracturing flowback fluid treatment device. The gas-liquid mixture enters the tank 10 through the sewage pipe 20. Part of the sewage in the sewage pipe 20 flows out from the upper end of the sewage pipe 20, and part of the sewage flows out from the branch pipe 30. The sewage is guided upward by the guide pipe 40 and swirls upward, converging into an oil core area in the center of the tank 10. The oil is discharged through the top oil outlet 131, and the separated water phase is discharged from the bottom water outlet 12. During the separation process, the limit rod 60 is controlled to slide according to the oil concentration of the oil phase discharged from the top oil outlet 131. The guide pipe 40 and the variable diameter section 61 are in contact with different outer diameters, and the tilt angle of the guide pipe 40 is adjusted to change the axial velocity of the oil and gas phases.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A fracturing flowback fluid treatment device, characterized in that, include: The tank (10) has a sewage inlet (11) and a bottom outlet (12) connected to its bottom, and a top oil outlet (131) is provided on the top of the tank (10). The sewage pipe (20) is connected at its lower end to the sewage inlet (11) and at its upper end inside the tank (10). The sewage after gas-liquid mixing enters the sewage pipe (20) from the sewage inlet (11). Branch pipes (30) are distributed circumferentially along the sewage pipe (20). One end of the branch pipe (30) is connected to the sewage pipe (20), and the other end of the branch pipe (30) is connected to the tank (10). Some sewage in the sewage pipe (20) flows out from the upper end of the sewage pipe (20), and some sewage flows out from the branch pipe (30). A guide pipe (40) is installed inside the tank (10). The length of the guide pipe (40) extends in a spiral direction, and the lower end of the guide pipe (40) is close to the outlet end of the branch pipe (30). A rotating shaft (41) is fixedly connected to the guide pipe (40). The rotating shaft (41) is rotatably mounted on the tank body (10). The distance between the lower end of the guide pipe (40) and the rotating shaft (41) is less than the distance between the upper end of the guide pipe (40) and the rotating shaft (41). The upper end of the guide pipe (40) tends to move downwards due to gravity. The limiting rod (60) has one end inside the tank (10) and the other end outside the tank (10). It is sealed and slidably installed on the tank (10). The sliding direction of the limiting rod (60) is the same as the radial direction of the tank (10). The limiting rod (60) has a variable diameter section (61) on its rod wall inside the tank (10). The variable diameter section (61) contacts the lower outer wall of the guide pipe (40). The different outer diameters of the variable diameter section (61) drive the guide pipe (40) to different tilt angles.

2. The fracturing flowback fluid treatment device according to claim 1, characterized in that, A driving component (70) is connected between the guide tube (40) and the limiting rod (60). The driving component (70) includes a driving rod (71) and two connecting rings (72). The connecting rings (72) are fixedly connected to both ends of the driving rod (71). A fixing rod (42) is connected to the outer wall of the guide tube (40). One connecting ring (72) is hinged to the fixing rod (42), and the other connecting ring (72) is sleeved on the limiting rod (60). The inner ring wall of the connecting ring (72) is in contact with the variable diameter section (61).

3. The fracturing flowback fluid treatment device according to claim 2, characterized in that, The limiting rod (60) has multiple guide rods (63) of different lengths installed on its wall. The multiple guide rods (63) are evenly spaced along the circumference of the limiting rod (60) and their lengths gradually increase. Different guide rods (63) correspond to different outer diameters of the variable diameter section (61). The connecting ring (72) is connected to a positioning rod (80) near the end face of the guide rod (63). The positioning rod (80) has an arc-shaped groove (81). The inner wall of the connecting ring (72) is flush with the inner wall of the connecting ring (72). The positioning rod (80) extends along the axial direction of the connecting ring (72). The inner wall of the connecting ring (72) is flush with the inner wall. When the connecting ring (72) and the variable diameter section (61) remain stationary, the limiting rod (60) is rotated. When the limiting rod (60) and the positioning rod (80) slide into contact, the rotation of the limiting rod (60) is stopped. The remaining guide rods (63) and the positioning rods (80) are spaced apart.

4. The fracturing flowback fluid treatment device according to claim 3, characterized in that, The limiting rod (60) is located on the rod wall outside the tank (10) and an indicator rod (64) is installed. The indicator rod (64) and the guide rod (63) are correspondingly arranged. A positioning block (16) is slidably connected to the outside of the tank (10). The sliding direction of the positioning block (16) is the same as the radial direction of the tank (10). When the guide rod (63) and the positioning rod (80) are in contact, the positioning block (16) is slid to make the corresponding indicator rod (64) insert into the positioning block (16).

5. The fracturing flowback fluid treatment device according to claim 4, characterized in that, A reset member (17) is installed on the outer wall of the tank (10). The positioning block (16) is connected to the reset member (17). The reset member (17) drives the positioning block (16) to always tend to approach the indicator rod (64).

6. The fracturing flowback fluid treatment device according to claim 4, characterized in that, When the guide rod (63) and the positioning rod (80) come into contact, the limiting rod (60) is driven to slide, and the guide rod (63) slides along the length direction of the positioning rod (80).

7. The fracturing flowback fluid treatment device according to claim 6, characterized in that, The tank (10) has multiple partition rings (14) arranged along its height on its inner wall. The sewage pipe (20) is located inside the partition rings (14). There is a gap between the inner wall of the partition rings (14) and the sewage pipe (20). A sleeve (15) is connected to the inner wall of the partition rings (14). The lower end of the sleeve (15) is spaced apart from the other partition rings (14). The partition rings (14) divide the tank (10) into a main separation chamber (101) and a secondary separation chamber (102). The main separation chamber (101) The upper end of the sewage pipe (20) is located at the top of the tank (10), and the upper end of the sewage pipe (20) is located in the main separation chamber (101). The inner wall of the sleeve (15) is evenly spaced with guide plates (151). Each of the secondary separation chambers (102) is provided with a branch pipe (30) and a guide pipe (40). The branch pipe (30) is connected to the sleeve (15). The sleeve (15) is connected to an air inlet pipe (50). The tank (10) is connected to an oil outlet pipe (90) in each of the secondary separation chambers (102).

8. The fracturing flowback fluid treatment device according to claim 7, characterized in that, The limiting rod (60) is connected to a sampling tube (65). A sampling hole is provided at one end of the limiting rod (60) near the sleeve (15). One end of the sampling tube (65) is connected to the sampling hole. The other end of the sampling tube (65) is located outside the tank (10) and is connected to a storage tube (66).

9. A fracturing flowback fluid treatment device according to claim 8, characterized in that, The oil outlet pipe (90) is sealed and slides on the tank body (10). A linkage rod (91) is connected between the oil outlet pipe (90) and the limiting rod (60). The linkage rod (91) is located outside the tank body (10). The linkage rod (91) and the limiting rod (60) are rotatably connected by a bearing.

10. A fracturing flowback fluid treatment process, wherein the fracturing flowback fluid is treated by a fracturing flowback fluid treatment device according to any one of claims 1-9, characterized in that, After the gas-liquid mixture is mixed, the fluid enters the tank (10) through the sewage pipe (20). Some sewage in the sewage pipe (20) flows out from the upper end of the sewage pipe (20), and some sewage flows out from the branch pipe (30). The sewage flows upward through the guide pipe (40) and gathers into an oil core area in the center of the tank (10). The oil is discharged through the top oil outlet (131). The separated water phase is discharged from the bottom water outlet (12). During the separation process, the limit rod (60) is controlled to slide according to the oil concentration of the oil phase discharged from the top oil outlet (131). The guide pipe (40) and the variable diameter section (61) are in contact with different outer diameters. The tilt angle of the guide pipe (40) is adjusted to change the axial velocity of the oil and gas phases.

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