Crude oil water cutting tank

Abstract

The utility model relates to a crude oil water cutting tank, which belongs to the field of oil field equipment and comprises a tank body, a heating coil, an oil inlet pipe, an oil outlet pipe, a water outlet pipe, a floating ball and a blow-down valve. A cavity is formed in the inner side of the tank body, and the heating coil is arranged at the bottom of the cavity and connected with an external heat source; the oil inlet pipe, the oil outlet pipe, the water outlet pipe and the blow-down valve are all arranged on the outer side wall of the tank body and are all communicated with the cavity; the oil inlet pipe is located on the upper portion of the tank body, and the oil outlet pipe, the water outlet pipe and the blow-down valve are all located on the lower portion of the tank body. The floating ball floats on crude oil in the cavity, and an oil discharge outlet is formed in the lower end of the floating ball and connected with an oil outlet pipe through a hose. According to the crude oil water cutting tank, water cutting treatment is carried out on crude oil exceeding the treatment capacity of the three-phase separator only by using a small amount of energy, and the water content of the crude oil reaches the standard.

Description

Technical Field

[0001] The utility model belongs to the field of oil field equipment, and in particular relates to a crude oil water cutting tank. Background Art

[0002] The produced products of oil fields are a mixture, and the natural gas, crude oil and associated water need to be separated and processed. In the existing technology, this is achieved through a wellhead three-phase separator. The separated crude oil is directly put into subsequent production, and part of the separated sludge is discharged with the associated water.

[0003] In the later period of oilfield service, the gas content in the oilfield decreased, and the produced products showed more water than oil. In addition, due to the use of recovery-aiding agents, the crude oil contained foam and colloid, which further increased the difficulty of oil-water separation. The produced products of some late oil wells exceeded the design parameters of the wellhead three-phase separator, making it difficult to completely separate the components in the produced products. The most significant manifestation was that the water content of the crude oil after separation was still too high. Utility Model Content

[0004] In order to solve the above problems existing in the prior art, the utility model provides a crude oil water cutting tank. The technical problem to be solved by the utility model is achieved through the following technical solutions:

[0005] The utility model provides a crude oil water cutting tank, comprising: a tank body, a heating coil, an oil inlet pipe, an oil outlet pipe, a water outlet pipe, a float and a drain valve; a cavity is arranged inside the tank body, the heating coil is arranged at the bottom of the cavity and is connected to an external heat source; the oil inlet pipe, the oil outlet pipe, the water outlet pipe and the drain valve are all arranged on the outer wall of the tank body and are all connected to the cavity; wherein the oil inlet pipe is located at the upper part of the tank body, the oil outlet pipe, the water outlet pipe and the drain valve are all located at the lower part of the tank body, and the height of the water outlet pipe is lower than the height of the oil outlet pipe; the float floats on the crude oil in the cavity, an oil drain port is arranged at the lower end of the float, and the oil drain port is connected to the oil outlet pipe through a hose.

[0006] In one embodiment of the present invention, the heating coil includes a plurality of sub-pipelines, which are sequentially connected to form a loop, and the connected sub-pipelines can move relative to each other.

[0007] In one embodiment of the utility model, the oil inlet pipe includes: a first interface, a first extension portion and a first turning portion, the first interface is arranged on the outer wall of the tank body, and the first extension portion and the first turning portion are both located in the cavity; wherein the first extension portion extends from top to bottom and is fixedly connected to the inner wall of the tank body, the first interface is connected to the upper end of the first extension portion, the lower end of the first extension portion is located below the midline of the tank body and is connected to the first turning portion, and the first turning portion faces the axial direction of the tank body.

[0008] In one embodiment of the utility model, the oil outlet pipe includes: a second interface, a second extension portion and a second turning portion, the second interface is arranged on the outer wall of the tank body, the second extension portion and the second turning portion are both located in the cavity, the two ends of the second extension portion are respectively connected to the second interface and the second turning portion, and the second turning portion extends obliquely toward the top of the tank body.

[0009] In one embodiment of the utility model, the water outlet pipe includes: a third interface, a third extension portion and a third turning portion, the third interface is arranged on the outer wall of the tank body, the third extension portion and the third turning portion are both located in the cavity, the two ends of the third extension portion are respectively connected to the third interface and the third turning portion, the third turning portion is an elbow, and the elbow extends toward the bottom of the tank body.

[0010] In one embodiment of the utility model, the crude oil cut-off tank also includes: an oil-water interface meter, a radar level gauge and a breathing valve. The oil-water interface meter, the radar level gauge and the breathing valve are respectively arranged at intervals on the top of the tank body, and the oil-water interface meter, the radar level gauge and the breathing valve are all arranged in the vertical direction; the lower end of the breathing valve is connected to a flame arrester.

[0011] In one embodiment of the utility model, the crude oil water cutting tank further comprises: an upper manhole and a lower manhole; the upper manhole is vertically arranged on the top of the tank body; the lower manhole is horizontally arranged on the outer side wall of the tank body and is located at the lower part of the tank body.

[0012] In one embodiment of the present invention, the floating ball is an ellipsoid, and the length of the minor axis of the ellipsoid is smaller than the diameter of the upper manhole and the lower manhole.

[0013] In one embodiment of the utility model, an internal ladder is arranged on the inner side wall of the tank body, and the internal ladder is located below the upper manhole and extends to the lower manhole.

[0014] In one embodiment of the utility model, the crude oil water cutting tank further comprises: an electrostatic terminal, which is arranged on the outer side wall of the tank body and located at the lower part of the tank body.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The utility model of the crude oil water cut tank is used to cut water from the crude oil that exceeds the processing capacity of the three-phase separator. The crude oil is heated by the heating coil, and the oil and water in the tank are separated by standing after heating. The upper layer is floated and drained by the float ball, and the outlet pipe is set at the bottom of the tank to drain the bottom, thereby achieving the standard water content of the crude oil. In addition, no chemical agent is added during the water cut process, and only a small amount of energy is used. The oil and water separation is mainly achieved by heating and standing, which is simple and reliable.

[0017] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural schematic diagram of a crude oil water cut-off tank provided by an embodiment of the utility model;

[0019] Figure 2 It is a bottom perspective schematic diagram of a crude oil water cut-off tank provided by an embodiment of the utility model;

[0020] Figure 3 It is a structural schematic diagram of another crude oil water cutting tank with safety accessories provided by an embodiment of the utility model;

[0021] Figures 4a to 4c It is a schematic diagram of the reinforcement structure of the crude oil water cutting tank provided by the embodiment of the utility model.

[0022] Icons: 1-tank body; 2-heating coil; 3-oil inlet pipe; 31-first interface; 32-first extension; 33-first turning part; 4-oil outlet pipe; 41-second interface; 42-second extension; 43-second turning part; 5-water outlet pipe; 51-third interface; 52-third extension; 53-third turning part; 6-float; 61-oil drain port; 62-hose; 7-oil-water interface meter; 8-radar level gauge; 9-breathing valve; 10-drain valve; 11-upper manhole; 12-lower manhole; 13-static terminal; 14-internal ladder; 20-safety accessories; 30-angle steel reinforcement ring; 40-diagonal brace. DETAILED DESCRIPTION

[0023] In order to further explain the technical means and effects adopted by the utility model to achieve the predetermined utility model purpose, the crude oil water cutting tank proposed according to the utility model is described in detail below in combination with the accompanying drawings and specific implementation methods.

[0024] The above and other technical contents, features and effects of the utility model are clearly presented in the following detailed description of the specific implementation mode in conjunction with the accompanying drawings. Through the description of the specific implementation mode, the technical means and effects adopted by the utility model to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation, and are not used to limit the technical solution of the utility model.

[0025] Embodiment 1

[0026] The crude oil water cut-off tank of this embodiment can be connected in series to the rear end of the three-phase separator, and can be used to cut off water from the crude oil processed by the three-phase separator.

[0027] like Figure 1 and Figure 2 As shown, the present embodiment provides a crude oil water cut-off tank, comprising: a tank body 1, a heating coil 2, an oil inlet pipe 3, an oil outlet pipe 4, a water outlet pipe 5, a float 6 and a drain valve 10; a cavity is arranged on the inner side of the tank body 1, the heating coil 2 is arranged at the bottom of the cavity, and is connected to an external heat source; the oil inlet pipe 3, the oil outlet pipe 4, the water outlet pipe 5 and the drain valve 10 are all arranged on the outer wall of the tank body 1, and are all connected to the cavity; wherein, the oil inlet pipe 3 is located at the upper part of the tank body 1, the oil outlet pipe 4, the water outlet pipe 5 and the drain valve 10 are all located at the lower part of the tank body 1, and the height of the water outlet pipe 5 is lower than the height of the oil outlet pipe 4; the float 6 floats on the crude oil in the cavity, and an oil drain port 61 is arranged at the lower end of the float 6, and the oil drain port 61 is connected to the oil outlet pipe 4 through a hose 62.

[0028] The principle is that the crude oil treated by the three-phase separator enters the tank body 1 through the oil inlet pipe 3, and the heating coil 2 is connected to the external heat source to heat the crude oil in the tank body 1. After heating and standing, the crude oil in the tank body 1 has oil-water stratification. It is easy to understand that the density of crude oil is lower than the density of water, so after the oil-water stratification occurs, the crude oil layer should be located above the water layer, that is, in the tank body 1, the crude oil is located above and the water settles below. The float 6 has the ability to float on the liquid surface and can float on the liquid surface in the tank body 1, that is, the float 6 floats on the crude oil and can rise and fall with the change of the liquid level in the tank body 1. The float 6 discharges oil through the oil discharge port 61 and is connected to the oil outlet pipe 4 through the hose 62 to discharge oil. The water in the tank body 1 is discharged through the water outlet pipe 5, and the height of the water outlet pipe 5 is set lower than the height of the oil outlet pipe 4, which uses the density difference between crude oil and water to ensure that the water and oil are discharged separately after stratification.

[0029] Exemplarily, the main body material of the tank body 1 may be 316 stainless steel.

[0030] like Figure 1 As shown, the oil inlet pipe 3 includes: a first interface 31, a first extension portion 32 and a first turning portion 33, the first interface 31 is arranged on the outer wall of the tank body 1, and the first extension portion 32 and the first turning portion 33 are both located in the cavity; wherein, the first extension portion 32 extends from top to bottom and is fixedly connected to the inner wall of the tank body 1, the first interface 31 is connected to the upper end of the first extension portion 32, the lower end of the first extension portion 32 is located below the midline of the tank body 1 and connected to the first turning portion 33, and the first turning portion 33 is facing the axial direction of the tank body 1.

[0031] Optionally, the tank body 1 can be a vertical storage tank, the oil inlet pipe 3 is located at the upper part of the vertical storage tank, the oil outlet pipe 4 and the water outlet pipe 5 are both located at the lower part of the vertical storage tank, and the crude oil enters the cavity from the first interface 31 of the upper oil inlet pipe 3, flows downward from the first extension portion 32 to below the midline of the tank body 1, turns horizontally through the first turning portion 33 and is discharged into the cavity.

[0032] Exemplarily, the first interface 31 is welded to the outer wall of the tank body 1, the first extension portion 32 is fixed to the inner wall of the tank body 1 by welding, and the first interface 31, the first extension portion 32 and the first turning portion 33 are also fixedly connected as a whole by welding.

[0033] The principle is that the crude oil newly discharged into the cavity is located in the lower layer of the tank body 1 through the first extension portion 32, and when the oil is discharged through the oil discharge port 61 of the float 6, the newly discharged crude oil and the stratified crude oil do not affect each other.

[0034] like Figure 1 and Figure 2 As shown, the heating coil 2 includes a plurality of sub-pipelines, which are connected in sequence to form a loop, and the connected sub-pipelines can move relative to each other.

[0035] Preferably, the heating coil 2 is arranged at the bottom of the cavity, and the distance from the bottom plate of the tank body 1 can be 15 cm. When impacted by the injection of external heat source, the connected sub-pipelines can move relative to each other and float slightly in the crude oil in a semi-fixed form to reduce the impact of the external heat source.

[0036] In addition, in this embodiment, the medium of the external heat source and the specific structural form of the heating coil 2 are not limited. For example, the medium of the external heat source can be steam or heat transfer oil; the heating coil 2 can form a frame-shaped loop through a plurality of sub-pipelines. Furthermore, the material of the heating coil 2 can be set to be the same as the main material of the tank body 1, and the wall thickness of the sub-pipelines and the connection positions between the sub-pipelines can bear the pressure of the external heat source, and leave a safety and corrosion margin.

[0037] like Figure 1 As shown, the oil outlet pipe 4 includes: a second interface 41, a second extension portion 42 and a second turning portion 43. The second interface 41 is arranged on the outer wall of the tank body 1. The second extension portion 42 and the second turning portion 43 are both located in the cavity. The two ends of the second extension portion 42 are respectively connected to the second interface 41 and the second turning portion 43. The second turning portion 43 extends obliquely toward the top of the tank body 1.

[0038] Exemplarily, the second interface 41 of the oil outlet pipe 4 is fixed to the outer wall of the tank body 1 by welding, and the distance between its central axis and the bottom plate of the tank body 1 can be 0.2m. The second interface 41, the second extension portion 42 and the second turning portion 43 are fixedly connected as a whole by welding. The length of the second extension portion 42 in the cavity is at least 0.2m, and the second turning portion 43 is inclined 45° toward the top of the tank body 1 and extends at least 0.1m.

[0039] like Figure 1 As shown, the water outlet pipe 5 includes: a third interface 51, a third extension portion 52 and a third turning portion 53. The third interface 51 is arranged on the outer wall of the tank body 1. The third extension portion 52 and the third turning portion 53 are both located in the cavity. The two ends of the third extension portion 52 are respectively connected to the third interface 51 and the third turning portion 53. The third turning portion 53 is an elbow, and the elbow extends toward the bottom of the tank body 1.

[0040] Exemplarily, the third interface 51 of the water outlet pipe 5 is fixed to the outer wall of the tank body 1 by welding, and the distance between the central axis thereof and the bottom plate of the tank body 1 can be 0.1m. The third interface 51, the third extension portion 52 and the third turning portion 53 are fixedly connected as a whole by welding. The length of the third extension portion 52 in the cavity is at least 0.4m. The third turning portion 53 is a 90° elbow facing the bottom of the tank body 1, and the distance between the end face of the elbow and the bottom plate of the tank body 1 is at least 1 times the pipe diameter of the elbow.

[0041] Preferably, the interfaces of the oil inlet pipe 3, the oil outlet pipe 4 and the water outlet pipe 5 are all flanges, and anti-static jumpers are used between the flanges. Gaskets can be provided on the flanges, and the gaskets can be 316 stainless steel graphite wound gaskets.

[0042] like Figure 1 and Figure 2 As shown, the crude oil cut-off tank also includes: an oil-water interface meter 7, a radar level gauge 8 and a breathing valve 9. The oil-water interface meter 7, the radar level gauge 8 and the breathing valve 9 are respectively arranged at intervals on the top of the tank body 1, and the oil-water interface meter 7, the radar level gauge 8 and the breathing valve 9 are all arranged in the vertical direction; the lower end of the breathing valve 9 is connected to a flame arrester.

[0043] Exemplarily, the tank body 1 includes a tank body and a top cover, the top cover is a cap-shaped structure and is fixedly connected to the tank body; the oil inlet pipe 3, the oil outlet pipe 4, the water outlet pipe 5 and the drain valve 10 are all arranged on the tank body, and the oil-water interface meter 7, the radar level meter 8 and the breathing valve 9 are respectively arranged on the top cover. Exemplarily, the oil-water interface meter 7 is arranged on one side of the top cover, and the distance from the edge can be 0.3m; the breathing valve 9 is located at the highest point of the top cover and on the central axis of the tank body 1, and the radar level meter 8 is arranged between the oil-water interface meter 7 and the breathing valve 9.

[0044] like Figure 1 and Figure 2 As shown, the crude oil water cut-off tank further includes: an upper manhole 11 and a lower manhole 12 , the upper manhole 11 is vertically arranged on the top of the tank body 1 , and the lower manhole 12 is horizontally arranged on the outer side wall of the tank body 1 and is located at the lower part of the tank body 1 .

[0045] Furthermore, an internal ladder 14 is provided on the inner wall of the tank body 1 . The internal ladder 14 is located below the upper manhole 11 and extends to the lower manhole 12 .

[0046] Exemplarily, the upper manhole 11 is welded and fixed on the top cover of the tank body 1 in the vertical direction, and the lower manhole 12 is welded on the tank body in the horizontal direction. The outer diameters of the upper manhole 11 and the lower manhole 12 are not less than 500 mm, and the distance between the lower side wall of the lower manhole 12 and the bottom plate of the tank body 1 is at least 0.3 m; the upper manhole 11 and the lower manhole 12 are respectively arranged corresponding to the internal ladder 14 to meet the maintenance requirements. Further, the drain valve 10 is arranged below the lower manhole 12, and the bottom plate close to the tank body 1 is welded to the inner wall of the tank body. The material of the drain valve 10 can be the same as the main material of the tank body 1.

[0047] Preferably, the drain valve 10 may be a fluorine-lined ball valve that is resistant to sediment deposition and corrosion.

[0048] like Figure 1 As shown, the float 6 is an ellipsoid, and the length of the minor axis of the ellipsoid is smaller than the diameters of the upper manhole 11 and the lower manhole 12 .

[0049] Exemplarily, the float 6 can be made of 316 stainless steel thin-walled stamping and butt welding, with a fixed clamping plate arranged at the bottom, the oil drain port 61 arranged on the fixed clamping plate, and the hose 62 is connected to the oil drain port 61. The hose 62 can be a PVC steel wire hose.

[0050] like Figure 1 As shown, the crude oil water cut tank further includes: an electrostatic terminal 13 , which is arranged on the outer side wall of the tank body 1 and located at the lower part of the tank body 1 .

[0051] Exemplarily, the electrostatic terminal 13 is welded to the outer wall of the tank body 1, and the distance between its central axis and the bottom plate of the tank body 1 can be 0.5m. The material of the electrostatic terminal 13 is consistent with the main material of the tank body 1. The electrostatic terminal 13 is not painted, and the grounding resistance is ≤5Ω. Optionally, the electrostatic terminal 13 is also connected to a ground wire.

[0052] like Figure 3 As shown, the tank body and the top cover of the tank body 1 are both connected with safety accessories 20, but the specific structural form is not limited; illustratively, it can be a ladder and guardrail that meets safety standards, or it can be a spiral ladder or a top corridor.

[0053] In this embodiment, the tank body 1 and each pipe structure are provided with a reinforcement structure, such as Figure 4a As shown, an angle steel reinforcement ring 30 is provided on the outer side of the tank body and the top cover of the tank body 1. Figure 4b As shown, diagonal braces 40 are provided at the pipe openings and pipe walls of the oil inlet pipe 3, the oil outlet pipe 4 and the water outlet pipe 5. For example, the lower side of the pipe opening of the water outlet pipe 5 is connected to the tank body 1 through the diagonal brace 40. Figure 4c There may be two diagonal braces 40, and the angle between the two diagonal braces 40 may be 60°, connecting the water pipe 5 and the tank body 1 respectively.

[0054] It is worth noting that the crude oil cut-off tank of this embodiment can realize the interface detection inside the tank according to the oil-water interface meter 7 and the radar level meter 8, and realize automatic control of continuous oil and water discharge by connecting to an external control device, and then determine the update cycle according to the amount of sediment deposition, and perform regular cleaning through the drain valve 10, the upper manhole 11 and the lower manhole 12. Multiple groups of crude oil cut-off tanks can also be grouped to realize interactive operation.

[0055] The utility model of the crude oil water cut tank is used to cut water from the crude oil that exceeds the processing capacity of the three-phase separator. The crude oil is heated by the heating coil, and the oil and water in the tank are separated by standing after heating. The upper layer is floated and drained by the float ball, and the outlet pipe is set at the bottom of the tank to drain the bottom, thereby achieving the standard water content of the crude oil. In addition, no chemical agent is added during the water cut process, and only a small amount of energy is used. The oil and water separation is mainly achieved by heating and standing, which is simple and reliable.

[0056] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant is intended to cover non-exclusive inclusion, so that the article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or device including the elements. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The orientation or position relationship indicated by "up", "down", "left", "right", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the 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 therefore cannot be understood as a limitation to the utility model.

[0057] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A crude oil water cut-off tank, characterized in that: include: A tank body (1), a heating coil (2), an oil inlet pipe (3), an oil outlet pipe (4), a water outlet pipe (5), a floating ball (6) and a drain valve (10); A cavity is provided inside the tank body (1), and the heating coil (2) is provided at the bottom of the cavity and connected to an external heat source; the oil inlet pipe (3), the oil outlet pipe (4), the water outlet pipe (5) and the drain valve (10) are all provided on the outer wall of the tank body (1) and are all connected to the cavity; wherein the oil inlet pipe (3) is located at the upper part of the tank body (1), the oil outlet pipe (4), the water outlet pipe (5) and the drain valve (10) are all located at the lower part of the tank body (1), and the height of the water outlet pipe (5) is lower than the height of the oil outlet pipe (4); The float (6) floats on the crude oil in the cavity. An oil discharge port (61) is provided at the lower end of the float (6), and the oil discharge port (61) is connected to the oil outlet pipe (4) via a hose (62).

2. The crude oil water cut-off tank according to claim 1, characterized in that: The heating coil (2) comprises a plurality of sub-pipelines, which are connected in sequence to form a loop, and the connected sub-pipelines can move relative to each other.

3. The crude oil cut-off tank according to claim 1, characterized in that: The oil inlet pipe (3) comprises: a first interface (31), a first extension portion (32) and a first turning portion (33), wherein the first interface (31) is arranged on the outer side wall of the tank body (1), and the first extension portion (32) and the first turning portion (33) are both located in the cavity; The first extension portion (32) extends from top to bottom and is fixedly connected to the inner wall of the tank body (1); the first interface (31) is connected to the upper end of the first extension portion (32); the lower end of the first extension portion (32) is located below the midline of the tank body (1) and is connected to the first steering portion (33); the first steering portion (33) faces the axial direction of the tank body (1).

4. The crude oil cut-off tank according to claim 1, characterized in that: The oil outlet pipe (4) comprises: a second interface (41), a second extension portion (42) and a second turning portion (43); the second interface (41) is arranged on the outer wall of the tank body (1); the second extension portion (42) and the second turning portion (43) are both located in the cavity; two ends of the second extension portion (42) are respectively connected to the second interface (41) and the second turning portion (43); the second turning portion (43) extends obliquely toward the top of the tank body (1).

5. The crude oil cut-off tank according to claim 1, characterized in that: The water outlet pipe (5) comprises: a third interface (51), a third extension portion (52) and a third turning portion (53); the third interface (51) is arranged on the outer wall of the tank body (1); the third extension portion (52) and the third turning portion (53) are both located in the cavity; two ends of the third extension portion (52) are respectively connected to the third interface (51) and the third turning portion (53); the third turning portion (53) is an elbow, and the elbow extends toward the bottom of the tank body (1).

6. The crude oil cut-off tank according to claim 1, characterized in that: Also includes: An oil-water interface meter (7), a radar level gauge (8) and a breathing valve (9), wherein the oil-water interface meter (7), the radar level gauge (8) and the breathing valve (9) are respectively arranged at intervals on the top of the tank body (1), and the oil-water interface meter (7), the radar level gauge (8) and the breathing valve (9) are all arranged in a vertical direction; and a flame arrester is connected to the lower end of the breathing valve (9).

7. The crude oil cut-off tank according to claim 1, characterized in that: Also includes: An upper manhole (11) and a lower manhole (12); the upper manhole (11) is vertically arranged on the top of the tank body (1); the lower manhole (12) is horizontally arranged on the outer wall of the tank body (1) and is located at the lower part of the tank body (1).

8. The crude oil water cut-off tank according to claim 7, characterized in that: The floating ball (6) is an ellipsoid, and the length of the minor axis of the ellipsoid is smaller than the diameters of the upper manhole (11) and the lower manhole (12).

9. The crude oil cut-off tank according to claim 7, characterized in that: An internal ladder (14) is provided on the inner side wall of the tank body (1), and the internal ladder (14) is located below the upper manhole (11) and extends to the lower manhole (12).

10. The crude oil cut-off tank according to claim 1, characterized in that: Also includes: An electrostatic terminal (13), wherein the electrostatic terminal (13) is arranged on the outer wall of the tank body (1) and is located at the lower part of the tank body (1).

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