Water treatment system suitable for oilfield water injection

Abstract

The utility model relates to the technical field of oil fields, and discloses a water treatment system suitable for oil field water injection, through the structural design of a multi-stage filtering structure, liquid to be filtered is guided into a settling tank through a settling tank liquid inlet pipe, the liquid to be filtered is directly guided into the bottom of the settling tank due to the fact that the settling tank liquid inlet pipe is arranged at the relative position, and the water treatment efficiency is greatly improved. As the liquid level rises continuously along with the continuous increase of the liquid to be filtered, and the liquid outlet of the liquid inlet pipe of the sedimentation tank and the liquid inlet of the liquid outlet pipe of the sedimentation tank are arranged at an interval along the height direction of the sedimentation tank, when the liquid level rises to the liquid inlet of the liquid outlet pipe of the sedimentation tank, the liquid level rises continuously; the liquid to be filtered can enter the filtering stage through the liquid inlet of the liquid outlet pipe of the settling tank, and the settling stage is arranged in front of the filtering stage, so that the liquid to be filtered can be settled, the probability of blockage of meshes of the filtering stage is effectively reduced, and the filtering efficiency is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of oil fields, and more specifically, to a water treatment system suitable for oil field water injection. Background Art

[0002] After the oil field is put into development, with the increase of the exploitation time, the energy of the oil reservoir itself will be continuously consumed, resulting in the continuous decline of the oil reservoir pressure, a large amount of degassing of the underground crude oil, an increase in viscosity, a significant reduction in the oil well output, and even the well may stop spraying and production, causing a large amount of dead oil remaining underground and unable to be produced; in order to maintain the pressure of the oil reservoir and then increase the oil production, usually, water is continuously injected into the oil reservoir through a water injection device. As an important part of the existing water injection device, through the setting of the filtering structure, the impurity content in the injected water can be effectively blocked, thereby avoiding the impact on oil extraction.

[0003] For the existing common filtering structure, a filter screen is used as the filtering medium to intercept impurities. However, during the use process, if the mesh of the filter screen is set too large, there will be an incomplete filtering situation. If the mesh of the filter screen is set too small, it is prone to blockage and requires manual cleaning.

[0004] In view of this, this application is hereby proposed. Summary of the Utility Model

[0005] In view of the above problems, an embodiment of the utility model provides a water treatment system suitable for oil field water injection. The liquid to be filtered is introduced into the sedimentation tank through the liquid inlet pipe of the sedimentation tank. Due to the relative position setting of the liquid inlet pipe of the sedimentation tank, the liquid to be filtered is directly introduced to the bottom of the sedimentation tank. As the liquid to be filtered continuously increases, the liquid level continuously rises. And because the liquid outlet of the liquid inlet pipe of the sedimentation tank is spaced along the height direction of the sedimentation tank relative to the liquid inlet of the liquid outlet pipe of the sedimentation tank, when the liquid level rises to the liquid inlet of the liquid outlet pipe of the sedimentation tank, the liquid to be filtered can enter the filtration stage through the liquid inlet of the liquid outlet pipe of the sedimentation tank. By setting a sedimentation stage before the filtration stage, sedimentation of the liquid to be filtered can be realized, effectively reducing the probability of the occurrence of the situation of blockage of the mesh holes of the filtration stage and ensuring the filtration efficiency.

[0006] The utility model is realized through the following technical solutions:

[0007] An embodiment of the utility model provides a water treatment system suitable for oilfield water injection, which includes a multi-stage filtration structure. The multi-stage filtration structure includes a precipitation stage, and the precipitation stage includes a precipitation tank, the precipitation tank, an inlet pipe of the precipitation tank, and an outlet pipe of the precipitation tank. The outlet of the inlet pipe of the precipitation tank is arranged close to the bottom of the precipitation tank, and the inlet of the outlet pipe of the precipitation tank is arranged at an interval along the height direction of the precipitation tank relative to the outlet of the inlet pipe of the precipitation tank; a filtration stage, which is communicated with the outlet pipe of the precipitation tank and is used to filter the fluid after precipitation.

[0008] In this solution, the water treatment system for oilfield water injection includes a multi-stage filtration structure. The multi-stage filtration structure includes a precipitation stage and a filtration stage. The precipitation stage and the filtration stage are communicated with each other. The precipitation stage includes a precipitation tank, an inlet pipe of the precipitation tank, and an outlet pipe of the precipitation tank. The outlet of the inlet pipe of the precipitation tank is arranged at an interval along the height direction of the precipitation tank relative to the inlet of the outlet pipe of the precipitation tank, and the outlet of the inlet pipe of the precipitation tank is relatively close to the bottom of the precipitation tank. When using this multi-stage filtration structure for filtration, the liquid to be filtered is introduced into the precipitation tank through the inlet pipe of the precipitation tank. Due to the relative position setting of the inlet pipe of the precipitation tank, the liquid to be filtered is directly introduced to the bottom of the precipitation tank. As the liquid to be filtered continuously increases, the liquid level continuously rises. And because the outlet of the inlet pipe of the precipitation tank is arranged at an interval along the height direction of the precipitation tank relative to the inlet of the outlet pipe of the precipitation tank, when the liquid level rises to the inlet of the outlet pipe of the precipitation tank, the liquid to be filtered can enter the filtration stage through the inlet of the outlet pipe of the precipitation tank. By setting the precipitation stage before the filtration stage, precipitation of the liquid to be filtered can be realized, effectively reducing the probability of clogging of the mesh holes of the filtration stage and ensuring the filtration efficiency.

[0009] Furthermore, a buffer structure is arranged at the outlet of the inlet pipe of the precipitation tank, and the buffer structure is arranged at an interval relative to the end face of the outlet of the inlet pipe of the precipitation tank.

[0010] Furthermore, the buffer structure includes an arc-shaped plate. One side of the arc-shaped plate is a convex side, and the convex side is used to contact the liquid discharged from the outlet of the inlet pipe of the precipitation tank; the buffer structure further includes flat plates. There are two flat plates, and the two flat plates are respectively arranged at both ends of the arc-shaped plate, and the projections of both ends of the arc-shaped plate on the plane where the two flat plates are located are on the flat plates.

[0011] Furthermore, the outlet pipe of the precipitation tank is arranged on the tank wall of the precipitation tank, and an inclined port structure is further arranged at the inlet of the outlet pipe of the precipitation tank. Among them, the end of the inclined port structure far from the bottom of the precipitation tank is arranged farther from the tank wall of the precipitation tank than the other end.

[0012] Further, a control valve is also provided on the liquid outlet pipe of the sedimentation tank, and the control valve is used to open or close the liquid outlet pipe of the sedimentation tank.

[0013] Further, a liquid level sensor is also provided on the tank wall of the sedimentation tank. The liquid level sensor is arranged relative to the inclined opening structure away from the bottom of the sedimentation tank, and the liquid level sensor is signal-connected to the control valve for realizing the opening and closing control of the control valve.

[0014] Further, the filtration stage includes a liquid inlet pipe of the filtration tank. The liquid inlet pipe of the filtration tank is communicated with the liquid outlet pipe of the sedimentation tank, and the liquid inlet pipe of the filtration tank is a bent pipe structure. Wherein, the bottom of the bent pipe structure is arranged relatively close to the bottom of the sedimentation tank compared with any end of the bent pipe structure.

[0015] Further, the filtration stage also includes a filtration tank. The filtration tank has an inner cavity provided with a filter screen structure. The filter screen structure divides the inner cavity into a first cavity and a second cavity. The first cavity and the second cavity are arranged at intervals along the gravity direction; wherein, the first cavity is connected to the liquid inlet pipe of the filtration tank, and a liquid outlet pipe of the filtration tank is provided in the second cavity. The liquid outlet pipe of the filtration tank is arranged on the side wall of the filtration tank, and the liquid inlet of the liquid outlet pipe of the filtration tank is arranged relatively close to the filter screen structure.

[0016] Further, the liquid outlet of the liquid inlet pipe of the filtration tank is arranged at the bottom of the filtration tank, and an auxiliary liquid discharge pipe is also provided at the bottom of the filtration tank. Both the auxiliary liquid discharge pipe and the liquid inlet pipe of the filtration tank are communicated with the first cavity; wherein, the bottom of the filtration tank is an inclined structure, and the liquid outlet of the liquid inlet pipe of the filtration tank is arranged relatively close to the top of the filtration tank compared with the liquid inlet of the auxiliary liquid discharge pipe.

[0017] Further, an oilfield water injection pipe is also included, and the oilfield water injection pipe is communicated with the water outlet pipe of the filtration stage.

[0018] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0019] An embodiment of the present utility model provides a water treatment system suitable for oilfield water injection. The water treatment system for oilfield water injection includes a multi-stage filtration structure. The multi-stage filtration structure includes a precipitation stage and a filtration stage. The precipitation stage and the filtration stage are communicated with each other. The precipitation stage includes a precipitation tank, a liquid inlet pipe of the precipitation tank, and a liquid outlet pipe of the precipitation tank. The liquid outlet of the liquid inlet pipe of the precipitation tank is spaced along the height direction of the precipitation tank relative to the liquid inlet of the liquid outlet pipe of the precipitation tank. And the liquid outlet of the liquid inlet pipe of the precipitation tank is relatively close to the bottom of the precipitation tank. When using the multi-stage filtration structure for filtration, the liquid to be filtered is introduced into the precipitation tank through the liquid inlet pipe of the precipitation tank. Due to the relative position setting of the liquid inlet pipe of the precipitation tank, the liquid to be filtered is directly introduced to the bottom of the precipitation tank. As the liquid to be filtered continuously increases, the liquid level continuously rises. And because the liquid outlet of the liquid inlet pipe of the precipitation tank is spaced along the height direction of the precipitation tank relative to the liquid inlet of the liquid outlet pipe of the precipitation tank, when the liquid level rises to the liquid inlet of the liquid outlet pipe of the precipitation tank, the liquid to be filtered can enter the filtration stage through the liquid inlet of the liquid outlet pipe of the precipitation tank. By setting the precipitation stage in front of the filtration stage, precipitation of the liquid to be filtered can be realized, and the probability of blockage of the mesh holes of the filtration stage can be effectively reduced, ensuring the filtration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts:

[0021] Figure 1 is a schematic structural diagram of the water treatment system provided by the embodiment of the present utility model;

[0022] Figure 2 is Figure 1 a partial enlarged view of area A in

[0023] Figure 3 is a schematic diagram of the cooperation between the liquid inlet pipe of the precipitation tank and the buffer structure provided by the embodiment of the present utility model.

[0024] Markings in the drawings and corresponding component names:

[0025] 100 - precipitation stage, 110 - precipitation tank, 111 - liquid level sensor, 120 - liquid inlet pipe of the precipitation tank, 121 - arc plate, 122 - flat plate, 130 - liquid outlet pipe of the precipitation tank, 131 - control valve, 200 - filtration stage, 210 - liquid inlet pipe of the filtration tank, 220 - filtration tank, 230 - liquid outlet pipe of the filtration tank, 240 - auxiliary drain pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are only a part rather than all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0027] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. However, it is obvious to those of ordinary skill in the art that the present utility model does not have to employ these specific details. In other instances, well-known structures, circuits, materials, or methods have not been described in detail in order to avoid obscuring the present utility model.

[0028] Throughout the specification, references to "one embodiment", "embodiment", "an example", or "example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present utility model. Thus, the appearances of the phrases "one embodiment", "embodiment", "an example", or "example" throughout the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0029] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present utility model.

[0030] Embodiment

[0031] Such as Figure 1As shown in the figure, an embodiment of the present utility model provides a water treatment system suitable for oilfield water injection, including a multi-stage filtration structure. The multi-stage filtration structure includes a precipitation stage 100, and the precipitation stage 100 includes a precipitation tank 110, a precipitation tank inlet pipe 120, and a precipitation tank outlet pipe 130. The outlet of the precipitation tank inlet pipe 120 is arranged near the bottom of the precipitation tank 110, and the inlet of the precipitation tank outlet pipe 130 is arranged at an interval along the height direction of the precipitation tank 110 relative to the outlet of the precipitation tank inlet pipe 120; a filtration stage 200, which is communicated with the precipitation tank outlet pipe 130 and is used to filter the fluid after precipitation.

[0032] Among them, as those skilled in the art should know, the outlet of the precipitation tank inlet pipe 120 is arranged near the bottom of the precipitation tank 110. When injecting the liquid to be filtered into the inner cavity of the precipitation tank 110 through the precipitation tank inlet pipe 120, the liquid is discharged directly from the bottom of the precipitation tank 110, which can ensure the stability of the liquid in the precipitation tank 110, thereby realizing the precipitation of impurities with a larger mass.

[0033] In this solution, the water treatment system for oilfield water injection includes a multi-stage filtration structure. The multi-stage filtration structure includes a precipitation stage 100 and a filtration stage 200. The precipitation stage 100 and the filtration stage 200 are communicated with each other. The precipitation stage 100 includes a precipitation tank 110, a precipitation tank inlet pipe 120, and a precipitation tank outlet pipe 130. The outlet of the precipitation tank inlet pipe 120 is arranged at an interval along the height direction of the precipitation tank 110 relative to the inlet of the precipitation tank outlet pipe 130, and the outlet of the precipitation tank inlet pipe 120 is relatively close to the bottom of the precipitation tank 110. When using this multi-stage filtration structure for filtration, the liquid to be filtered is introduced into the precipitation tank 110 through the precipitation tank inlet pipe 120. Due to the relative position setting of the precipitation tank inlet pipe 120, the liquid to be filtered is directly introduced to the bottom of the precipitation tank 110. As the liquid to be filtered continuously increases, the liquid level continuously rises. And because the outlet of the precipitation tank inlet pipe 120 is arranged at an interval along the height direction of the precipitation tank 110 relative to the inlet of the precipitation tank outlet pipe 130, when the liquid level rises to the inlet of the precipitation tank outlet pipe 130, the liquid to be filtered can enter the filtration stage 200 through the inlet of the precipitation tank outlet pipe 130. By setting the precipitation stage 100 in front of the filtration stage 200, the precipitation of the liquid to be filtered can be realized, effectively reducing the probability of the occurrence of the situation of clogging of the mesh holes of the filtration stage 200 and ensuring the filtration efficiency.

[0034] Such as Figure 3As shown, in some embodiments, a buffer structure is further provided at the liquid outlet of the liquid inlet pipe 120 of the sedimentation tank, and the buffer structure is spaced apart from the end face of the liquid outlet of the liquid inlet pipe 120 of the sedimentation tank.

[0035] Further, the buffer structure includes an arc-shaped plate 121. One side of the arc-shaped plate 121 is a convex side, and the convex side is used to contact the liquid discharged from the liquid outlet of the liquid inlet pipe 120 of the sedimentation tank. The buffer structure further includes flat plates 122. There are two flat plates 122, and the two flat plates 122 are respectively arranged at both ends of the arc-shaped plate 121, and the projections of both ends of the arc-shaped plate 121 on the plane where the two flat plates 122 are located are located on the flat plates 122.

[0036] Among them, through the setting of the buffer structure, by arranging the buffer structure on the extension line of the liquid outlet of the liquid inlet pipe 120 of the sedimentation tank, it can effectively buffer the water flow entering through the liquid inlet pipe 120 of the sedimentation tank, and can effectively reduce the problem that the internal water body of the sedimentation tank 110 is stirred due to the too large water flow speed, thus ensuring the sedimentation effect.

[0037] Among them, the arc-shaped plate 121 structure is adopted, and the convex side of the arc-shaped plate 121 is close to the liquid outlet. When the water flow strikes the arc-shaped plate 121, due to the guiding effect of the arc-shaped plate 121, the water flow can be made to flow downward, avoiding stirring the upper layer of water body.

[0038] Specifically, the buffer structure further includes flat plates 122. There are two flat plates 122, and the two flat plates 122 are respectively arranged at both ends of the arc-shaped plate 121, and the projections of both ends of the arc-shaped plate 121 on the plane where the two flat plates 122 are located are located on the flat plates 122; that is, the water flow guided by the arc-shaped plate 121 can directly strike the flat plates 122. As those skilled in the art should know, after passing through the sedimentation stage 100, impurities can be deposited at the bottom of the sedimentation tank 110. However, due to the structural design of the arc-shaped plate 121, in order to ensure the guiding of the water flow, there is a possibility that the water flow downward disturbs the bottom impurities. Through the structural design of the flat plates 122, the flat plates 122 can further block the water flow, thereby ensuring the stability of the bottom impurities.

[0039] In some embodiments, the liquid outlet pipe 130 of the sedimentation tank is arranged on the tank wall of the sedimentation tank 110, and an inclined opening structure is further provided at the liquid inlet of the liquid outlet pipe 130 of the sedimentation tank. Among them, the end of the inclined opening structure far from the bottom of the sedimentation tank 110 is arranged farther away from the tank wall of the sedimentation tank 110 than the other end.

[0040] Specifically, through the setting of the bevel structure, the length of the side of the bevel structure close to the top of the sedimentation tank 110 is set relative to the other side away from the tank wall of the sedimentation tank 110. As those skilled in the art should understand, during the filtration process, there are impurities floating on the water surface in the water to be filtered. By adopting the structural design of the bevel structure, it can play a certain role in blocking this part of the impurities, thereby further reducing the probability of clogging of the mesh holes of the subsequent filtration tank 220.

[0041] In some embodiments, a control valve 131 is further provided on the liquid outlet pipe 130 of the sedimentation tank, and the control valve 131 is used to realize the conduction or closing of the liquid outlet pipe 130 of the sedimentation tank.

[0042] As Figure 2 shown, in some embodiments, a liquid level sensor 111 is further provided on the tank wall of the sedimentation tank 110. The liquid level sensor 111 is arranged relative to the bevel structure away from the bottom of the sedimentation tank 110, and the liquid level sensor 111 is signal-connected to the control valve 131 for realizing the opening and closing control of the control valve 131.

[0043] Specifically, through the structural design of the control valve 131 and the liquid level sensor 111, the conduction of the liquid outlet pipe 130 of the sedimentation tank can be realized targeted. After the liquid level is higher than the liquid inlet of the liquid outlet pipe 130 of the sedimentation tank, the control valve 131 is opened. At this time, the liquid inlet of the liquid outlet pipe 130 of the sedimentation tank is lower than the water surface, which can further reduce the probability of floating impurities entering the filtration stage 200.

[0044] In some embodiments, the filtration stage 200 includes a filtration tank liquid inlet pipe 210, the filtration tank liquid inlet pipe 210 is communicated with the liquid outlet pipe 130 of the sedimentation tank, and the filtration tank liquid inlet pipe 210 is a bent pipe structure. Among them, the bottom of the bent pipe structure is set relatively close to the bottom of the sedimentation tank 110 relative to any end of the bent pipe structure.

[0045] Specifically, through the bent pipe structure design, further precipitation can be realized at the bottom of the bent pipe structure, thereby further reducing the probability of clogging of the mesh holes of the filtration stage 200.

[0046] In some embodiments, the filtration stage 200 further includes a filtration tank 220 having an inner cavity provided with a filter mesh structure. The filter mesh structure divides the inner cavity into a first cavity and a second cavity, and the first cavity and the second cavity are arranged at intervals along the gravity direction. Among them, the first cavity is connected to the liquid inlet pipe 210 of the filtration tank, and the second cavity is provided with a liquid outlet pipe 230 of the filtration tank 220. The liquid outlet pipe 230 of the filtration tank 220 is arranged on the side wall of the filtration tank 220, and the liquid inlet of the liquid outlet pipe 230 of the filtration tank 220 is arranged relatively close to the filter mesh structure.

[0047] Among them, by setting the position of the liquid inlet of the liquid outlet pipe 230 of the filtration tank 220, the transfer of the filtered liquid can be realized immediately at the first time of filtration, ensuring the water injection efficiency.

[0048] In some embodiments, the liquid outlet of the liquid inlet pipe 210 of the filtration tank is arranged at the bottom of the filtration tank 220, and an auxiliary drain pipe 240 is further arranged at the bottom of the filtration tank 220. Both the auxiliary drain pipe 240 and the liquid inlet pipe 210 of the filtration tank are communicated with the first cavity. Among them, the bottom of the filtration tank 220 is of an inclined structure, and the liquid outlet of the liquid inlet pipe 210 of the filtration tank is arranged relatively close to the top of the filtration tank 220 compared with the liquid inlet of the auxiliary drain pipe 240.

[0049] Specifically, through the structural design of the filtration tank 220, when cleaning is required, the impurities attached to the filter mesh structure can fall to the bottom of the filtration tank 220 due to gravity. And because the auxiliary drain pipe 240 is arranged at the bottom of the filtration tank 220, the impurities can be further removed through the auxiliary drain pipe 240. And by adopting an inclined structure, it can ensure the accumulation at the inlet of the auxiliary drain pipe 240.

[0050] Furthermore, it further includes an oilfield water injection pipe, and the oilfield water injection pipe is communicated with the water outlet pipeline of the filtration stage 200.

[0051] The above specific embodiments have further detailed the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water treatment system applicable to oilfield water injection, characterized in that, including a multi-stage filtration structure, the multi-stage filtration structure comprising: a precipitation stage (100), the precipitation stage (100) including a precipitation tank (110), the precipitation tank (110), a precipitation tank inlet pipe (120), and a precipitation tank outlet pipe (130), an outlet of the precipitation tank inlet pipe (120) being disposed near the bottom of the precipitation tank (110), and an inlet of the precipitation tank outlet pipe (130) being spaced apart from the outlet of the precipitation tank inlet pipe (120) in the height direction of the precipitation tank (110); a filtration stage (200), the filtration stage (200) being in communication with the precipitation tank outlet pipe (130) for filtering the fluid after precipitation.

2. The water treatment system applicable to oilfield water injection according to claim 1, wherein A buffer structure is further provided at the outlet of the precipitation tank inlet pipe (120), the buffer structure being spaced apart from the end face of the outlet of the precipitation tank inlet pipe (120).

3. The water treatment system applicable to oilfield water injection according to claim 2, wherein The buffer structure includes an arc-shaped plate (121), one side of the arc-shaped plate (121) being a convex side for contacting the liquid discharged from the outlet of the precipitation tank inlet pipe (120); the buffer structure further includes flat plates (122), there being two flat plates (122), the two flat plates (122) being respectively disposed at two ends of the arc-shaped plate (121), and projections of two ends of the arc-shaped plate (121) on the plane where the two flat plates (122) are located being located on the flat plates (122).

4. A water treatment system applicable to oilfield water injection according to claim 1, characterized in that, The precipitation tank outlet pipe (130) is disposed on the tank wall of the precipitation tank (110), and an inclined port structure is further provided at the inlet of the precipitation tank outlet pipe (130), wherein one end of the inclined port structure away from the bottom of the precipitation tank (110) is disposed away from the tank wall of the precipitation tank (110) relative to the other end.

5. A water treatment system applicable to oilfield water injection according to claim 4, characterized in that, The precipitation tank outlet pipe (130) is further provided with a control valve (131) for opening or closing the precipitation tank outlet pipe (130).

6. The water treatment system suitable for oilfield water injection according to claim 5, characterized in that, A liquid level sensor (111) is further provided on the tank wall of the precipitation tank (110), the liquid level sensor (111) being disposed away from the bottom of the precipitation tank (110) relative to the inclined port structure, and the liquid level sensor (111) being in signal connection with the control valve (131) for controlling the opening and closing of the control valve (131).

7. A water treatment system applicable to oilfield water injection according to any one of claims 1-6, characterized in that, The filtration stage (200) includes a filtration tank inlet pipe (210), the filtration tank inlet pipe (210) being in communication with the precipitation tank outlet pipe (130), and the filtration tank inlet pipe (210) being a bent pipe structure, wherein the bottom of the bent pipe structure is disposed relatively closer to the bottom of the precipitation tank (110) than any one end of the bent pipe structure.

8. A water treatment system applicable to oil field water injection according to claim 7, characterized in that, The filtration stage (200) further includes a filtration tank (220), the filtration tank (220) having an inner cavity provided with a filter mesh structure, the filter mesh structure dividing the inner cavity into a first cavity and a second cavity, the first cavity and the second cavity being spaced apart along the gravity direction; wherein, the first cavity is connected to the liquid inlet pipe (210) of the filtration tank, the second cavity is provided with a liquid outlet pipe (230) of the filtration tank, the liquid outlet pipe (230) of the filtration tank is provided on the side wall of the filtration tank (220), and the liquid inlet of the liquid outlet pipe (230) of the filtration tank is arranged relatively close to the filter mesh structure.

9. A water treatment system applicable to oilfield water injection according to claim 8, characterized in that, The liquid outlet of the liquid inlet pipe (210) of the filtration tank is arranged at the bottom of the filtration tank (220), and an auxiliary drain pipe (240) is further provided at the bottom of the filtration tank (220), both the auxiliary drain pipe (240) and the liquid inlet pipe (210) of the filtration tank are communicated with the first cavity; wherein, the bottom of the filtration tank (220) is of an inclined structure, and the liquid outlet of the liquid inlet pipe (210) of the filtration tank is arranged relatively close to the top of the filtration tank (220) compared to the liquid inlet of the auxiliary drain pipe (240).

10. A water treatment system applicable to oilfield water injection according to claim 1, characterized in that, It further includes an oilfield water injection pipe, and the oilfield water injection pipe is communicated with the water outlet pipe of the filtration stage (200).

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