A high efficiency three-phase separation device

Abstract

The application discloses a kind of high-efficiency three-phase separation device, it is related to the technical field of three-phase separator, the present application is aimed at solving the problem of low separation efficiency of existing three-phase separator, the present application includes tank, the tank is provided with gas-liquid pre-separator, sand settling chamber, settling chamber, water chamber and oil chamber are arranged in the tank, the sand settling chamber is provided with rectifier between the settling chamber, the liquid outlet of the gas-liquid pre-separator is arranged in the sand settling chamber, negative pressure pump is communicated in the settling chamber;Heat exchange chamber is also provided in the settling chamber, the gas outlet of the gas-liquid pre-separator is communicated with the heat exchange chamber, heating coil is provided in the heat exchange chamber, heat exchange coil is provided in the settling chamber, the output end of the heating coil is communicated with the input end of the heat exchange coil, the input end of the heating coil is communicated with the output end of the heat exchange coil, circulating pump is also installed on the heating coil, the circulating pump is arranged outside the tank.

Description

Technical Field

[0001] This invention relates to the technical field of three-phase separators, and more specifically to a high-efficiency three-phase separation device. Background Technology

[0002] During oilfield extraction, the crude oil extracted from the well contains associated gas and water, as well as some coarse sand. Therefore, it is necessary to separate the oil, gas and water mixture to facilitate subsequent processing.

[0003] Three-phase separators are crucial process equipment in the petrochemical industry, enabling the separation of oil, gas, and water in downhole produced liquids. Traditional three-phase separation technology primarily utilizes the density differences between the three phases (oil, gas, and water) to achieve natural separation. However, in oil-water separation, relying mainly on natural gravity settling requires a settling time of 20-40 minutes, resulting in relatively low efficiency.

[0004] To address the aforementioned issues, existing technologies employ a combination of cyclone pre-separation and electrostatic coalescence coupling to improve separation efficiency. However, this approach is insufficient for demulsifying highly emulsified droplets (<10μm). Another approach utilizes a combination of ultrasonic and electric field demulsification, but these methods are often arranged separately within pipe sections or tanks. Consequently, the ultrasonic cavitation zone and the electric field coalescence zone do not overlap, limiting their synergistic efficiency.

[0005] In summary, the existing methods for improving three-phase separation technology are not ideal, and the external intervention methods used are relatively complex and costly. Summary of the Invention

[0006] To address the aforementioned problem of low separation efficiency in existing three-phase separators, this invention proposes a high-efficiency three-phase separation device, comprising a tank body with a gas-liquid pre-separator mounted on it. The tank body contains a sedimentation chamber, a settling chamber, a water chamber, and an oil chamber. A rectifier is installed between the sedimentation chamber and the settling chamber. The outlet of the gas-liquid pre-separator is located within the sedimentation chamber. A negative pressure pump is connected to the settling chamber to create a negative pressure environment within the tank. A heat exchange chamber is also located within the settling chamber, with the outlet of the gas-liquid pre-separator connected to it. A heating coil is installed within the heat exchange chamber, and a heat exchange coil is also installed within the settling chamber. The output and input ends of the heating coils are connected, forming a circulation loop. A circulation pump is also installed on the heating coils, located outside the tank body.

[0007] A further configuration of the present invention is as follows: the output end of the heating coil is connected to the input end of the heat exchange coil through a vertical pipe, and the input end of the heating coil is also connected to the output end of the heat exchange coil through the vertical pipe. A three-way valve is installed on both vertical pipes, and the two three-way valves are also connected to an external heat source water circuit.

[0008] A further feature of the present invention is that: an overflow slope is provided in the settling chamber, the side of the overflow slope near the rectifier is higher than the side of the overflow slope away from the rectifier, the overflow slope is located directly below the outlet of the gas-liquid pre-separator, and a sand discharge port is also provided in the settling chamber, the sand discharge port is located on the lower side of the overflow slope, and a sand control gate valve is installed on the sand discharge port.

[0009] A further feature of the present invention is that a plurality of sand-blocking teeth arranged in a stepped pattern are provided on the surface of the overflow slope, and the sand-blocking teeth are inclined.

[0010] A further feature of the present invention is that the output end of the sand-proof gate valve is detachably connected to a sand collection box.

[0011] A further configuration of the present invention is as follows: the water chamber and the oil chamber are symmetrically arranged about the axis of the tank body; a weir plate is provided between the water chamber, the oil chamber and the settling chamber; the water chamber and the settling chamber are connected by an adjusting weir pipe; the weir plate has a weir opening corresponding to the oil chamber, so as to allow the upper layer of oil in the settling chamber to flow into the oil inlet chamber through the weir opening; a water outlet is provided at the bottom of the water chamber and an oil outlet is provided at the bottom of the oil chamber.

[0012] A further feature of the present invention is that a weir tongue is slidably connected inside the weir opening, and the weir tongue is sealed to the bottom edge and the left and right sides of the weir opening.

[0013] A further feature of the present invention is that an adjusting rod is rotatably connected to the bottom of the weir tongue, the adjusting rod extends through the weir plate and out of the tank body, and an adjusting seat is threadedly connected to the adjusting rod, the adjusting seat being fixedly connected to the outer wall of the tank body.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. By using a negative pressure pump to create a negative pressure environment within the tank, the apparent viscosity of the crude oil decreases, and the oil-water interfacial tension also decreases under negative pressure. This helps to demulsify emulsions. Furthermore, combined with micro-heating, it can replace some chemical demulsifiers, thus reducing their usage. Additionally, negative pressure reduces gas phase density, makes the flow rate more controllable, and stabilizes the gas-liquid separation interface, avoiding the problem of secondary liquid droplet entrainment when gas flows through the tank at high speed under normal pressure.

[0016] 2. By setting up an overflow slope, sand and gravel in the mixture can be blocked on the side of the overflow slope away from the rectifier, preventing them from flowing into the rectifier and settling chamber. At the same time, with the sand-blocking teeth, fine sand and gravel can be further blocked. The combination of the sand-proof gate valve and the sand collection box can avoid the need for shutdown to discharge sand.

[0017] 3. By setting up a weir tongue that can slide up and down, the height of the weir tongue can be adaptively adjusted according to the thickness of the oil layer, thereby controlling the oil phase liquid level and preventing the oil layer from being too thin and being entrained by the gas phase turbulence, or the oil layer from being too thick and compressing the water phase space. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of the present invention is shown. Figure 1 .

[0019] Figure 2 A schematic diagram of the structure of the present invention is shown. Figure 2 .

[0020] Figure 3 A partial cross-sectional view of the present invention is shown. Figure 1 .

[0021] Figure 4 A partial cross-sectional view of the present invention is shown. Figure 2 .

[0022] Figure 5 A partial cross-sectional view of the present invention is shown. Figure 3 .

[0023] Figure 6 A cross-sectional view along the AA direction is shown.

[0024] Figure 7 A cross-sectional view along the BB direction is shown.

[0025] Figure 8 A schematic diagram of the weir tongue structure is shown.

[0026] Attached reference numerals: 1. Tank body; 11. Settling chamber; 111. Overflow slope; 1111. Sand-blocking teeth; 112. Sand discharge port; 1121. Sand-proof gate valve; 12. Settling chamber; 121. Heat exchange coil; 13. Water chamber; 14. Oil chamber; 15. Rectifier; 16. Heat exchange chamber; 161. Heating coil; 2. Gas-liquid pre-separator; 3. Negative pressure pump; 4. Vertical pipe; 41. Three-way valve; 5. Weir plate; 51. Weir mouth; 52. Weir tongue; 521. Adjusting rod; 53. Adjusting weir pipe. Detailed Implementation

[0027] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0028] This invention proposes a high-efficiency three-phase separation device, comprising a tank 1, on which a gas-liquid pre-separator 2 is installed. An inlet is connected to the side wall of the gas-liquid pre-separator 2, through which a mixed liquid can be conveyed into the gas-liquid separator. The mixed liquid undergoes preliminary gas-liquid phase separation within the gas-liquid pre-separator 2. An outlet for gas and an outlet for liquid are respectively located at the top and bottom of the gas-liquid pre-separator 2. The separated gas phase flows out through the outlet for gas, and the separated liquid phase flows out through the outlet for liquid. The outlet for gas is located on the outside of the tank 1, and the outlet for liquid is located inside the tank 1.

[0029] The tank body 1 is provided with a sedimentation chamber 11, a settling chamber 12, a water chamber 13 and an oil chamber 14. A rectifier 15 is installed between the sedimentation chamber 11 and the settling chamber 12, and the rectifier 15 is filled with coalescing packing.

[0030] A negative pressure pump 3 is connected to the settling chamber 12 through a pipe. The negative pressure pump 3 can draw the settling chamber 12 to a negative pressure state, and the negative pressure range is -0.02 to -0.06 MPa. It should be noted that when the settling chamber 12 is drawn to a negative pressure state, the sand chamber 11 and the oil chamber 14 are also kept in a negative pressure state.

[0031] According to Henry's Law, the solubility of a gas in a liquid phase decreases as pressure decreases. Therefore, under negative pressure, gas will continuously precipitate from the liquid phase in the settling chamber 11, settling chamber 12, and oil chamber 14, allowing for more thorough and rapid separation of the gas within the liquid mixture. It should be noted that the negative pressure pump 3, during the negative pressure extraction process, can also discharge the gas precipitated within the tank 1. Alternatively, an additional mist eliminator can be installed on the tank 1, with a valve on the mist eliminator to periodically vent gas from the tank 1. The on / off state of the mist eliminator is selected according to the usage requirements. If the negative pressure pump 3 can meet the venting needs of the tank 1 in actual operation, the venting valve of the mist eliminator need not be opened.

[0032] At the same time, under negative pressure, the surface viscosity of crude oil decreases, the sedimentation rate of the aqueous phase increases, further accelerating the separation rate of oil and water and reducing the sedimentation residence time.

[0033] The tank body 1 is also equipped with a heat exchange chamber 16, and the heat exchanger is located in the settling chamber 12. The outlet of the gas-liquid pre-separator 2 is connected to the heat exchanger, and the associated gas flowing out of the gas-liquid pre-separator 2 is transported into the heat exchange chamber 16. The heat exchanger is equipped with a heating coil 161, and the settling chamber 12 is equipped with a heat exchange coil 121. The output end of the heating coil 161 is connected to the input end of the heat exchange coil 121 through a vertical pipe 4, and the input end of the heating coil 161 is connected to the output end of the heat exchange coil 121 through a vertical pipe 4 to form a circulation loop. The heating coil 161 and the heat exchange coil 121 are filled with liquid heat exchange medium.

[0034] The heating coil 161 exchanges heat with the associated gas within the heat exchange chamber 16. The heat exchange medium absorbs the sensible heat and part of the latent heat from the associated gas, causing its temperature to rise. Then, the heat exchange medium flows into the heat exchange coil 121, providing micro-heating to the liquid phase in the settling chamber 12. This not only cools the associated gas but also directly feeds heat back to the liquid phase for micro-thermal demulsification. It should be noted that the micro-heating temperature range is 40-60℃, meaning the temperature within the settling chamber 12 is heated to 40-60℃.

[0035] A circulation pump is also installed on the heating coil 161 to drive the heat exchange medium to circulate within the heating coil 161 and the heat exchange coil 121. The circulation pump is located on the outside of the tank 1.

[0036] Typically, the temperature of the incoming fluid at the wellhead is 40-70℃. After separation by the gas-liquid pre-separator 2, the associated gas output from the top will still have a temperature of 40-60℃. The associated gas separated by a traditional three-phase separator needs to be air-cooled or water-cooled to consume the heat load in the associated gas. This application utilizes the micro-heating in the settling chamber 12 to utilize this part of the heat load, which not only eliminates the need for air cooling of the associated gas in the first stage, but also eliminates the need for heat tracing of the liquid phase. The external energy consumption is close to zero, which greatly saves process costs.

[0037] By utilizing negative pressure and micro-heating, the oil-water settling time, oil content in the effluent, and demulsifier dosage can be significantly reduced. See the table below for a comparison of parameters between the proposed process and traditional processes:

[0038] Both vertical pipes 4 are also equipped with three-way valves 41. The two three-way valves 41 are also connected to an external heat source water circuit. That is, when the heat of the associated gas is insufficient to meet the micro-heating requirements, the heating requirements in the settling chamber 12 can be met by controlling the use of the external heat source water circuit through the three-way valves 41.

[0039] An overflow slope 111 is also installed in the settling chamber 11. The overflow slope 111 is located at the bottom of the settling chamber 11, with the side of the overflow slope 111 closest to the rectifier 15 and the side of the overflow slope 111 away from the rectifier 15. The overflow slope 111 is located directly below the outlet of the gas-liquid pre-separator 2. The liquid phase separated by the gas-liquid pre-separator 2 can flow onto the overflow slope 111. Since the overflow slope 111 is inclined, the liquid phase mixture will first flow to the lower side of the overflow slope 111 and gradually accumulate, and the liquid level will continuously rise. When the liquid level exceeds the higher side of the overflow slope 111, the liquid phase mixture will overflow through the overflow slope 111 and flow into the settling chamber 12. Since the sand and gravel in the mixture are relatively heavy, the sand and gravel will be deposited at the lower side of the overflow slope 111 and will not overflow into the settling chamber 12.

[0040] The sedimentation chamber 11 is also equipped with a sand discharge port 112, which is located at the lower side of the overflow slope 111. The deposited sand and gravel are discharged from the sedimentation chamber 11 through the sand discharge port 112. A sand control gate valve 1121 is installed on the sand discharge port 112. Opening the sand control gate valve 1121 allows the deposited sand and gravel to be discharged. The output end of the sand control gate valve 1121 is also threadedly connected to a sand collection box. During the separation process, the sand control gate valve 1121 is in a normally open state. The deposited sand and gravel will flow into the sand collection box along the sand discharge port 112 and the sand control gate valve 1121. When the sand collection box is full, the sand control gate valve 1121 is closed, and the sand collection box is then disassembled to clean the sand and gravel inside. After cleaning the sand and gravel, the sand collection box is reinstalled back onto the sand control gate valve 1121. This achieves the purpose of sand discharge without stopping the machine.

[0041] It should be noted that several stepped sand-blocking teeth 1111 are also installed on the slope surface of the overflow slope 111. The sand-blocking teeth 1111 are also installed at an angle. The sand-blocking teeth 1111 can block the fine sand and gravel in the mixture and prevent the fine sand and gravel from overflowing out of the sedimentation chamber 11 with the mixture.

[0042] The water chamber 13 and the oil chamber 14 are symmetrically arranged about the axis of the tank body 1. A weir plate 5 is also installed between the water chamber 13 and the oil chamber 14 and the settling chamber 12. The water chamber 13 and the settling chamber 12 are connected by an adjusting weir pipe 53, and the inlet of the adjusting weir pipe 53 is located at the bottom of the tank body 1.

[0043] The weir plate 5 is also provided with a weir opening 51 corresponding to the oil chamber 14, so that the upper layer of oil in the settling chamber 12 can flow into the oil chamber 14 through the weir opening 51. The bottom of the water chamber 13 is provided with a water outlet, and the bottom of the oil chamber 14 is provided with an oil outlet.

[0044] A weir tongue 52 is slidably connected vertically within the weir opening 51. The left and right sides of the weir opening 51 have grooves made of PTFE material, and the weir tongue 52 is slidably connected within these grooves. The weir tongue 52 is sealed to the lower edge and both sides of the weir opening 51 to ensure airtightness. Adjusting the weir tongue 52 vertically changes the overflow height of the oil layer, thereby adjusting the thickness of the oil layer within the settling chamber 12.

[0045] An adjusting rod 521 is rotatably connected to the bottom of the weir tongue 52. The adjusting rod 521 passes through the weir plate 5 and extends out of the tank body 1. An adjusting seat is welded on the outer wall of the tank body 1. The adjusting seat has an internal thread. The adjusting rod 521 is threadedly connected to the adjusting seat. When the adjusting rod 521 is rotated, the height of the weir tongue 52 can be adjusted, and the height of the weir tongue 52 can be adjusted according to the oil layer thickness.

[0046] It should be noted that the adjusting rod 521 and the weir plate 5 are coaxially sleeved and sealed. The adjusting rod 521 is threadedly connected to the adjusting seat. This ensures the sealing of the tank 1 and prevents leakage.

[0047] It should also be noted that a handwheel can be installed at the end of the adjusting rod 521 extending from the tank body 1, allowing manual adjustment of the weir tongue 52. Alternatively, a drive motor can be connected to one end of the adjusting rod 521, driving the adjusting rod to rotate and thus adjusting the weir tongue 52. This application only uses the installation of a handwheel as an example; in actual use, the driving method can be adapted to meet specific needs.

[0048] In summary, this invention utilizes a negative pressure pump 3 to create a negative pressure environment within tank 1, which reduces the apparent viscosity of the crude oil and decreases the oil-water interfacial tension. This negative pressure helps demulsify the emulsion. Furthermore, combined with micro-heating, it can replace some chemical demulsifiers, thus reducing their usage. Additionally, the negative pressure reduces the gas phase density, makes the flow rate more controllable, and stabilizes the gas-liquid separation interface, avoiding the problem of secondary liquid droplet entrainment when gas flows at high speed through tank 1 under normal pressure.

[0049] By setting up the overflow slope 111, the sand and gravel in the mixture can be blocked on the side of the overflow slope 111 away from the rectifier 15, preventing them from flowing into the rectifier 15 and the settling chamber 12. At the same time, in conjunction with the sand-blocking teeth 1111, fine sand and gravel can be further blocked. The sand-proof gate valve 1121 and the sand collection box can avoid the need for shutdown to discharge sand.

[0050] By setting a weir tongue 52 that can slide up and down, the height of the weir tongue 52 can be adaptively adjusted according to the thickness of the oil layer, thereby controlling the oil phase liquid level and preventing the oil layer from being too thin and being entrained by the gas phase turbulence, or the oil layer from being too thick and compressing the water phase space.

[0051] Although the invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0052] In the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0055] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A high-efficiency three-phase separation device, comprising a tank (1), a gas-liquid pre-separator (2) disposed on the tank (1), a sedimentation chamber (11), a settling chamber (12), a water chamber (13), and an oil chamber (14) disposed inside the tank (1), a rectifier (15) disposed between the sedimentation chamber (11) and the settling chamber (12), and the liquid outlet of the gas-liquid pre-separator (2) disposed inside the sedimentation chamber (11), characterized in that: The settling chamber (12) is connected to a negative pressure pump (3) for pumping the tank (1) to a negative pressure state; the settling chamber (12) is also provided with a heat exchange chamber (16), the outlet of the gas-liquid pre-separator (2) is connected to the heat exchange chamber (16), the heat exchange chamber (16) is provided with a heating coil (161), the settling chamber (12) is provided with a heat exchange coil (121), the output end of the heating coil (161) is connected to the input end of the heat exchange coil (121), and the input end of the heating coil (161) is connected to the output end of the heat exchange coil (121) to form a circulation loop. The heating coil (161) is also equipped with a circulation pump, which is located on the outside of the tank (1).

2. The high-efficiency three-phase separation device according to claim 1, characterized in that: The output end of the heating coil (161) is connected to the input end of the heat exchange coil (121) through a vertical pipe (4). The input end of the heating coil (161) is also connected to the output end of the heat exchange coil (121) through the vertical pipe (4). A three-way valve (41) is installed on both vertical pipes (4). The two three-way valves (41) are also connected to an external heat source water circuit.

3. The high-efficiency three-phase separation device according to claim 1, characterized in that: An overflow slope (111) is provided in the sedimentation chamber (11). The side of the overflow slope (111) closest to the rectifier (15) is higher than the side of the overflow slope away from the rectifier (15). The overflow slope (111) is located directly below the outlet of the gas-liquid pre-separator (2). A sand discharge port (112) is also provided in the sedimentation chamber (11). The sand discharge port (112) is located on the lower side of the overflow slope (111). A sand control gate valve (1121) is installed on the sand discharge port (112).

4. The high-efficiency three-phase separation device according to claim 3, characterized in that: The surface of the overflow slope (111) is provided with a number of sand-blocking teeth (1111) arranged in a stepped manner, and the sand-blocking teeth (1111) are inclined.

5. The high-efficiency three-phase separation device according to claim 3, characterized in that: The output end of the sand control gate valve (1121) is detachably connected to a sand collection box.

6. The high-efficiency three-phase separation device according to claim 1, characterized in that: The water chamber (13) and the oil chamber (14) are symmetrically arranged about the axis of the tank body (1). A weir plate (5) is provided between the water chamber (13), the oil chamber (14) and the settling chamber (12). The water chamber (13) and the settling chamber (12) are connected by an adjusting weir pipe (53). The weir plate (5) has a weir opening (51) corresponding to the oil chamber (14) so ​​that the upper layer of oil in the settling chamber (12) can flow into the oil chamber (14) through the weir opening (51). A water outlet is provided at the bottom of the water chamber (13) and an oil outlet is provided at the bottom of the oil chamber (14).

7. The high-efficiency three-phase separation device according to claim 6, characterized in that: The weir mouth (51) is slidably connected to the weir tongue (52) inside, and the weir tongue (52) is sealed to the bottom edge and the left and right sides of the weir mouth (51).

8. The high-efficiency three-phase separation device according to claim 7, characterized in that: An adjusting rod (521) is rotatably connected to the bottom of the weir tongue (52). The adjusting rod (521) extends through the weir plate (5) and out of the tank body (1). An adjusting seat is threaded onto the adjusting rod (521). The adjusting seat is fixedly connected to the outer wall of the tank body (1).

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