Downhole multi-phase separation injection and production equipment

Abstract

The application discloses a downhole multiphase separation injection and production equipment, which comprises a first separation device, a sand removal cavity shell of the first separation device comprises a first centrifugal cavity section and a first separation cavity section arranged in sequence from top to bottom, a liquid inlet and a sand filter inlet are respectively arranged on the first centrifugal cavity section and the first separation cavity section, a first oil outlet channel extending through the first centrifugal cavity section from top to bottom and to the upper end of the first centrifugal cavity section is arranged on a first centrifugal separator arranged in the first centrifugal cavity section, a sand removal outer cylinder assembly is arranged outside the first separation cavity section and is provided with a first mounting hole for exposing the lower end opening of the first separation cavity section, a sand discharge port is arranged at the lower end of the sand removal outer cylinder assembly, an oil filter cavity shell is arranged in the first separation cavity section and is provided with an oil filter hole on the side wall, and the upper end of the oil filter cavity shell is in communication with the first oil outlet channel, so that three-phase separation of oil, water and sand is realized, sand removal through the cancellation of a filter screen is achieved, sand accumulation and blockage are avoided, and the oil filter cavity shell is not easy to be damaged and has a long service life.

Description

Technical Field

[0001] This invention belongs to the field of oil production technology, and in particular relates to a downhole multiphase separation injection and production device. Background Technology

[0002] Petroleum has advantages such as high energy density (the calorific value of petroleum is 50% higher than that of standard coal for the same weight), convenient transportation and storage, and relatively low atmospheric pollution after combustion. Fuel oil refined from petroleum is the primary fuel for transportation vehicles, power plant boilers, and various kilns in the metallurgical and building materials industries. Liquefied petroleum gas (LPG) and piped gas, made from petroleum, are high-quality fuels for urban residents. Aircraft, tanks, ships, rockets, and other spacecraft also consume large quantities of petroleum fuel. Therefore, many countries classify petroleum as a strategic resource.

[0003] Oil extraction refers to the act of digging and extracting oil from places where oil reserves exist. However, in some areas, wells often have excessively high sand content, so filter screens are commonly used in injection and production equipment to remove sand. But over time, the filter screens can become clogged with accumulated sand, which not only hinders downhole sand removal but also makes the filter screens prone to damage due to sand accumulation. Summary of the Invention

[0004] To address the aforementioned defects or deficiencies, this invention provides a downhole multiphase separation injection and production device, aiming to solve the technical problem that filter screens are easily clogged and damaged by accumulated sand when using screen desanding.

[0005] To achieve the above objectives, the present invention provides a downhole multiphase separation injection and production device, wherein the downhole multiphase separation injection and production device includes a first separation device, the first separation device including a sand removal chamber shell, a sand removal outer cylinder assembly, and an oil filter chamber shell; the sand removal chamber shell includes a first centrifugal chamber section and a first separation chamber section arranged sequentially from top to bottom, the first centrifugal chamber section is provided with a liquid inlet, the side wall of the first separation chamber section is provided with a sand filter port, and the first centrifugal chamber section is provided with a first centrifuge below the liquid inlet to centrifuge and separate the sand phase in the sand-containing mixture entering from the liquid inlet to the sand filter port. A centrifuge is also provided with a first oil outlet channel that runs vertically through and extends to the upper end of the first centrifugal chamber section; a sand removal outer cylinder assembly is sleeved on the outside of the first separation chamber section and has a first mounting hole at its lower end for the lower opening of the first separation chamber section to be exposed; the sand removal outer cylinder assembly and the first separation chamber section enclose a sand removal chamber that communicates with the sand filter port; the lower end of the sand removal outer cylinder assembly has a sand discharge port that communicates with the sand removal chamber; an oil filter chamber shell is located inside the first separation chamber section and has oil filter holes on its side wall; the upper end of the oil filter chamber shell has an oil outlet opening that communicates with the first oil outlet channel.

[0006] In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes a second separation device. The second separation device includes an oil-water separation chamber shell, which includes a second centrifugal chamber section and a second separation chamber section arranged sequentially from top to bottom. The upper end of the second centrifugal chamber section is connected to the lower end of the sand removal outer cylinder assembly, and the upper opening of the second centrifugal chamber section communicates with the lower opening of the first separation chamber section. The lower end of the second separation chamber section is open. A second centrifuge is provided in the second centrifugal chamber section to separate the sand-discharging mixture entering from the lower opening of the first separation chamber section. The second centrifuge is provided with a second oil outlet channel that runs vertically through the second centrifuge. The second oil outlet channel extends upward and passes through the lower opening of the first separation chamber section and the oil filter chamber shell in sequence to enter the first oil outlet channel.

[0007] In one embodiment of the present invention, the second separation device further includes an oil-water separation outer cylinder and an electric valve seat. The oil-water separation outer cylinder is sleeved on the outside of the oil-water separation chamber shell and its upper end is connected to the lower end of the desanding outer cylinder assembly. The upper end of the electric valve seat is connected to the lower end of the oil-water separation outer cylinder, so as to form a flushing chamber by enclosing the oil-water separation outer cylinder and the oil-water separation chamber shell. The electric valve seat has an inlet valve port, a first outlet valve port and a second outlet valve port. The inlet valve port is connected to the lower end opening of the second separation chamber section. The first outlet valve port and the second outlet valve port are respectively connected to the downhole space and the flushing chamber in a one-to-one correspondence. The valve core on the electric valve seat is used to select one of the first outlet valve port and the second outlet valve port to communicate with the inlet valve port. The lower end of the desanding outer cylinder assembly is provided with a flushing port that connects the flushing chamber and the desanding chamber.

[0008] In one embodiment of the present invention, the sand removal outer cylinder assembly includes a sand removal outer cylinder body and a sand discharge cylinder seat. The sand removal outer cylinder body is sleeved on the outside of the first separation chamber section and its upper end is connected to the lower end of the first centrifugal chamber section. The upper end of the sand discharge cylinder seat is connected to the lower end of the sand removal outer cylinder body, so as to form a sand removal chamber by surrounding the sand removal outer cylinder body and the first separation chamber section. The sand discharge cylinder seat is provided with a first mounting hole that is connected to the lower end opening of the first separation chamber section. The sand discharge cylinder seat is also provided with a sand settling tank around the outside of the first mounting hole. The sand discharge port and the flushing port are arranged sequentially at intervals along the circumferential direction of the outer side wall of the sand settling tank and are all connected to the sand settling tank.

[0009] In one embodiment of the present invention, there are at least two sand discharge ports and at least two flushing ports. The at least two sand discharge ports and at least two flushing ports are arranged alternately along the circumference of the outer side wall of the settling tank. Each flushing port includes a transverse section and a vertical section. The transverse section extends laterally outward from the outer side wall of the settling tank. The vertical section extends vertically downward from the end of the transverse section away from the settling tank to penetrate the sand discharge cylinder seat. The sand discharge port extends laterally outward from the outer side wall of the settling tank to penetrate the sand discharge cylinder seat. All transverse sections are obliquely arranged in the same direction in the radial direction of the settling tank. All sand discharge ports are obliquely arranged in a direction different from the transverse sections in the radial direction of the settling tank.

[0010] In one embodiment of the present invention, the bottom walls of both the transverse section and the sand discharge port are flush with the bottom of the settling tank.

[0011] In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes a downdrive pump group, which is located at the lower end of the electric valve cylinder seat and its upper end communicates with the first outlet valve port.

[0012] In one embodiment of the present invention, the second centrifuge includes a second main body and a guide rod. The second main body is placed in a second centrifuge chamber and is provided with a second spiral flow channel extending from top to bottom. The second spiral flow channel is used to separate the sand-discharging mixture into oil and water. The guide rod extends from the upper end of the second main body and passes through the lower opening of the first separation chamber and the oil filter chamber shell in sequence, extending into the first oil outlet channel. The upper and lower ends of the second oil outlet channel respectively penetrate the guide rod and the second main body and are located inside the second spiral flow channel.

[0013] In one embodiment of the present invention, the guide rod is provided with an external thread section, and the inner wall of the lower end of the oil filter chamber is provided with an internal thread section that is threadedly connected to the external thread section.

[0014] In one embodiment of the present invention, the diameter of the second separation chamber section gradually decreases from the second centrifugal chamber section downwards.

[0015] In one embodiment of the present invention, the diameter of the first separation chamber section gradually decreases from the first centrifugal chamber section downwards, and there are multiple filter ports, which are arranged sequentially at intervals along the circumference of the first separation chamber section, and each filter port is arranged to extend along the height direction of the first separation chamber section.

[0016] In one embodiment of the present invention, the oil filter chamber includes a chamber body portion, the diameter of which is gradually reduced from top to bottom, and the chamber body portion is provided with multiple rows of oil filter holes, which are arranged sequentially at intervals along the circumference of the chamber body portion.

[0017] In one embodiment of the present invention, the first centrifuge includes a first main body and a docking column. The first main body is located below the liquid inlet and is provided with a first spiral flow channel extending from top to bottom. The first spiral flow channel is used to centrifuge the sand phase in the sand-containing mixture. The docking column extends from the upper end of the first main body and docks with a second mounting hole opened at the upper end of the first centrifugal chamber section. The upper and lower ends of the first oil outlet channel respectively penetrate the docking column and the first main body and are located inside the first spiral flow channel.

[0018] In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes an upper drive pump group, which is located at the upper end of the first centrifugal chamber section and its lower end communicates with the first oil outlet channel.

[0019] Through the above technical solutions, the downhole multiphase separation injection and production equipment provided in this embodiment of the invention has the following beneficial effects:

[0020] When using the aforementioned downhole multiphase separation injection-production equipment, since the first separation device includes a sand removal chamber shell, a sand removal outer cylinder assembly, and an oil filter chamber shell, the sand-containing mixture, under the downhole high-pressure environment, enters the space above the first centrifuge section through the inlet via pressure difference, and then enters the first centrifuge, where it undergoes centrifugal separation. Because the sand phase in the sand-containing mixture has the highest density and the oil phase has the lowest density, after being accelerated by centrifugation and exiting the first centrifuge, the sand phase in the sand-containing mixture is thrown onto the inner wall of the first separation chamber section, while the oil phase is thrown onto the outer wall of the oil filter chamber shell. Since the side wall of the first separation chamber section has sand-filtering ports, the sand... The sand phase enters the sand removal chamber formed by the sand removal outer cylinder assembly and the first separation chamber section through the sand filter port. The lower end of the sand removal outer cylinder assembly is provided with a sand discharge port that communicates with the sand removal chamber, so the sand phase can be discharged from the equipment through the sand discharge port. In addition, the side wall of the oil filter chamber shell is provided with an oil filter hole, so the oil phase will enter the interior of the oil filter chamber shell through the oil filter hole and enter the first oil outlet channel from the upper oil outlet opening, so as to be discharged from the equipment through the first oil outlet channel. The water phase in the sand-containing mixture will carry a small amount of oil phase and be discharged from the lower opening of the first separation chamber section. Thus, not only is the three-phase separation of oil, water and sand in the sand-containing mixture achieved, but by eliminating the sand removal method of the filter screen, the problem of sand accumulation and blockage is avoided, while also having the advantages of not being easily damaged and having a long service life.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. Those skilled in the art can obtain other drawings based on the structures shown in these drawings without any inventive effort. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of a downhole multiphase separation injection and production device according to an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure of AA;

[0025] Figure 3 This is a schematic diagram of the structure of the first separation device and the upper drive pump group according to an embodiment of the present invention;

[0026] Figure 4 This is an exploded structural diagram of the sand removal chamber shell and the sand removal outer cylinder assembly according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the oil filter chamber shell according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of the sand discharge cylinder seat according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic cross-sectional view of the transverse section of the sand discharge cylinder seat according to an embodiment of the present invention;

[0030] Figure 8 This is a schematic cross-sectional view of the longitudinal section of the sand discharge cylinder seat according to an embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the structure of the second separation device and the lower drive pump group according to an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of the structure of a second centrifuge according to an embodiment of the present invention;

[0033] Figure 11 This is a schematic diagram of the structure of the electric valve cylinder seat in drainage mode according to an embodiment of the present invention;

[0034] Figure 12 This is a schematic diagram of the structure of the electric valve seat in flushing mode according to an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 100 Sand removal chamber shell 110 First centrifuge chamber section

[0037] 111 Liquid inlet 112 End cap base

[0038] 120 First separation chamber section 121 Filter sand port

[0039] 130 First centrifuge 131 First main body

[0040] 132 Connecting column 133 First spiral flow channel

[0041] 134 Second mounting hole; 135 First oil outlet channel

[0042] 200 Sand removal outer cylinder assembly 210 Sand removal outer cylinder body

[0043] 220 Sand discharge cylinder seat 221 First mounting hole

[0044] 222 Settling tank 223 Sand discharge port

[0045] 224 Rinse port 225 Lateral inlet segment

[0046] 226 Vertical section 230 Sand removal chamber

[0047] 300 Oil filter housing 310 Upper part

[0048] 311 Oil outlet opening; 320 Cavity shell main body.

[0049] 321 Oil filter hole 330 Lower assembly

[0050] 400 Oil-water separation chamber shell 410 Second centrifuge chamber section

[0051] 420 Second separation chamber section 430 Second centrifuge

[0052] 431 Second main body section 432 Guide rod section

[0053] 433 Second spiral flow channel; 434 Second oil outlet channel

[0054] 435 External thread section 500 Oil-water separator outer cylinder

[0055] 501 Flushing chamber; 600 Electric valve seat

[0056] 601 Valve Inlet 602 First Valve Outlet

[0057] 603 Second outlet valve port 610 Valve core

[0058] 700 Down-drive Pump Set 800 Up-drive Pump Set Detailed Implementation

[0059] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0060] The downhole multiphase separation injection and production equipment of the present invention will now be described with reference to the accompanying drawings.

[0061] like Figures 1 to 3 As shown, the present invention provides a downhole multiphase separation injection-production device, wherein the downhole multiphase separation injection-production device includes a first separation device, the first separation device comprising:

[0062] In addition to the sand chamber shell 100, it includes a first centrifugal chamber section 110 and a first separation chamber section 120 arranged sequentially from top to bottom. The first centrifugal chamber section 110 is provided with a liquid inlet 111, and the first separation chamber section 120 is provided with a sand filter port 121 on its side wall. The first centrifugal chamber section 110 is provided with a first centrifuge 130 below the liquid inlet 111 to centrifuge and separate the sand phase in the sand-containing mixture entering from the liquid inlet 111 to the sand filter port 121. The first centrifuge 130 is also provided with a first oil outlet channel 135 that runs vertically through and extends to the upper end of the first centrifugal chamber section 110.

[0063] The outer casing assembly 200 is sleeved on the outside of the first separation chamber section 120 and has a first mounting hole 221 at its lower end for the lower end opening of the first separation chamber section 120 to be exposed. The outer casing assembly 200 and the first separation chamber section 120 enclose a sand removal chamber 230 that communicates with the sand filter port 121. The lower end of the outer casing assembly 200 has a sand discharge port 223 that communicates with the sand removal chamber 230.

[0064] The oil filter chamber shell 300 is located inside the first separation chamber section 120 and has an oil filter hole 321 on its side wall. The upper end of the oil filter chamber shell 300 is provided with an oil outlet opening 311 that communicates with the first oil outlet channel 135.

[0065] When using the aforementioned downhole multiphase separation injection and production equipment, since the first separation device includes a sand removal chamber shell 100, a sand removal outer cylinder assembly 200, and an oil filter chamber shell 300, the sand-containing mixture, under the downhole high-pressure environment, enters the space above the first centrifuge section 130 (located above the first centrifuge 130) through the inlet 111 via pressure difference, and then enters the first centrifuge 130 where it undergoes centrifugal separation. Because the sand phase in the sand-containing mixture has the highest density and the oil phase has the lowest density, after centrifugal acceleration and exiting the first centrifuge 130 into the first separation chamber section 120, the sand phase in the sand-containing mixture is thrown onto the inner wall of the first separation chamber section 120, and the oil phase is thrown onto the outer wall of the oil filter chamber shell 300. Since the first separation chamber section 120 has a sand filter port 121, the sand phase will naturally... The sand filter port 121 enters the sand removal chamber 230 formed between the sand removal outer cylinder assembly 200 and the first separation chamber section 120. The lower end of the sand removal outer cylinder assembly 200 is provided with a sand discharge port 223 that communicates with the sand removal chamber 230, so the sand phase can be discharged from the equipment through the sand discharge port 223. In addition, the side wall of the oil filter chamber shell 300 is provided with an oil filter hole 321, so the oil phase will enter the interior of the oil filter chamber shell 300 through the oil filter hole 321 and enter the first oil outlet channel 135 through the oil outlet opening 311 at the upper end, so as to be discharged from the equipment through the first oil outlet channel 135. The water phase in the sand-containing mixture will carry a small amount of oil phase and be discharged from the lower opening of the first separation chamber section 120. Thus, not only is the oil-water-sand three-phase separation of the sand-containing mixture achieved, but also by eliminating the sand removal method of the filter screen, the sand accumulation and blockage phenomenon is avoided, while also having the advantages of being not easily damaged and having a long service life.

[0066] See Figures 1 to 3 ,as well as Figure 9In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes a second separation device, which includes an oil-water separation chamber shell 400. The oil-water separation chamber shell 400 includes a second centrifugal chamber section 410 and a second separation chamber section 420 arranged sequentially from top to bottom. The upper end of the second centrifugal chamber section 410 is connected to the lower end of the sand removal outer cylinder assembly 200, and the upper opening of the second centrifugal chamber section 410 communicates with the lower opening of the first separation chamber section 120. The lower end of the second separation chamber section 420 is open. A second centrifuge 430 is provided in the second centrifugal chamber section 410 to separate the sand-discharging mixture entering from the lower opening of the first separation chamber section 120. The second centrifuge 430 is provided with a second oil outlet channel 434 that runs vertically through the second centrifuge section 430. The second oil outlet channel 434 extends upward and passes through the lower opening of the first separation chamber section 120 and the oil filter chamber shell 300 in sequence to enter the first oil outlet channel 135. That is, by adding a second separation device, the aqueous phase and a small amount of oil phase of the sand discharge mixture discharged from the lower end opening of the first separation chamber 120 can be separated into oil and water for a second time, so as to improve the oil-water separation efficiency and achieve higher economic benefits.

[0067] Specifically, the sand-discharging mixture, containing an aqueous phase and a small amount of oil phase, first enters the second centrifugal section 410 of the oil-water separation chamber shell 400 through the lower opening of the first separation chamber section 120, and then enters the second centrifuge 430, where it can undergo centrifugal separation. Since the density of the oil phase in the sand-discharging mixture is greater than that of the aqueous phase, after the sand-discharging mixture is accelerated by centrifugation and exits from the second centrifuge 430 into the second separation chamber section 420, the oil phase in the sand-discharging mixture will flow from the lower end to the upper end of the second oil outlet channel 434 and merge with the oil phase that has undergone initial separation in the first centrifuge 130 and be discharged from the equipment. The aqueous phase in the sand-discharging mixture flows downward and is discharged from the lower opening of the second separation chamber section 420, thereby completing the secondary oil-water separation.

[0068] See Figures 1 to 3 ,as well as Figures 9 to 12In one embodiment of the present invention, the second separation device further includes an oil-water separation outer cylinder 500 and an electric valve seat 600. The oil-water separation outer cylinder 500 is sleeved on the outside of the oil-water separation chamber shell 400 and its upper end is connected to the lower end of the sand removal outer cylinder assembly 200. The upper end of the electric valve seat 600 is connected to the lower end of the oil-water separation outer cylinder 500, so as to form a flushing chamber 501 by the oil-water separation outer cylinder 500 and the oil-water separation chamber shell 400. The electric valve seat 600 has an inlet valve port 601, a first outlet valve port 602 and a second outlet valve port 603. The inlet valve port 601 is connected to the lower opening of the second separation chamber section 420. The first outlet valve port 602 and the second outlet valve port 603 are respectively connected to the downhole space and the flushing chamber 501 in a one-to-one correspondence. The valve core 610 on the electric valve seat 600 is used to select one of the first outlet valve port 602 and the second outlet valve port 603 to communicate with the inlet valve port 601; wherein, as Figures 6 to 8 As shown, the lower end of the sand removal outer cylinder assembly 200 is provided with a flushing port 224 that connects the flushing chamber 501 and the sand removal chamber 230. The addition of the oil-water separation outer cylinder 500 not only protects the oil-water separation chamber shell 400, but also forms a flushing chamber 501 with the oil-water separation chamber shell 400 and the electric valve seat 600. The addition of the electric valve seat 600 and the flushing port 224 allows the valve core 610 on the electric valve seat 600 to select the second outlet port 603 and the inlet port 601 when there is excessive sand accumulation at the lower end of the desanding chamber 230. This allows the water phase, after secondary oil-water separation, to enter the inlet port 601 from the lower opening of the second separation section 420, and then enter the flushing chamber 501 through the second outlet port 603. The water phase then flows upward along the flushing chamber 501 and enters the desanding chamber 230 through the flushing port 224 to backflush the sand phase. Finally, the sand phase is carried out from the sand discharge port 223, thus achieving efficient sand removal.

[0069] Specifically, the electric valve seat 600 has two operating modes. When the valve core 610 of the electric valve seat 600 connects the first outlet 602 with the inlet 601, the electric valve seat 600 is in drainage mode. The water phase after secondary oil-water separation enters the inlet 601 from the lower opening of the second separation chamber section 420 and can be directly discharged through the first outlet 602. When there is too much sand phase accumulation at the lower end of the sand removal chamber 230, the valve core of the electric valve seat 600... When the second outlet valve port 603 is connected to the inlet valve port 601, the electric valve seat 600 is in flushing mode. After the water phase, which has undergone secondary oil-water separation, enters the inlet valve port 601 through the lower opening of the second separation chamber section 420, it can enter the flushing chamber 501 through the second outlet valve port 603 and flow upward along the flushing chamber 501. It then enters the sand removal chamber 230 through the flushing port 224 to backflush the sand phase and finally carries the sand phase out of the sand discharge port 223.

[0070] More specifically, the upper end of the electric valve cylinder seat 600 protrudes upward along the periphery of the valve inlet 601 and is provided with a first extension portion. The outer side wall of the first extension portion is threadedly connected to the inner side wall of the second separation chamber section 420. The upper end of the electric valve cylinder seat 600 is provided with a second extension portion extending upward. The inner wall of the second extension portion is threadedly connected to the outer side wall of the oil-water separation outer cylinder 500.

[0071] like Figures 1 to 8 As shown, in one embodiment of the present invention, the sand removal outer cylinder assembly 200 includes a sand removal outer cylinder body 210 and a sand discharge cylinder seat 220. The sand removal outer cylinder body 210 is sleeved on the outside of the first separation chamber section 120 and its upper end is connected to the lower end of the first centrifugal chamber section 110. The upper end of the sand discharge cylinder seat 220 is connected to the lower end of the sand removal outer cylinder body 210, so as to form a sand removal chamber 230 by surrounding the sand removal outer cylinder body 210 and the first separation chamber section 120. The sand discharge cylinder seat 220 is provided with a first mounting hole 221 that is connected to the lower end opening of the first separation chamber section 120. The sand discharge cylinder seat 220 is also provided with a sand settling trough 222 around the outside of the first mounting hole 221. The sand discharge port 223 and the flushing port 224 are arranged sequentially at intervals along the circumference of the outer side wall of the sand settling trough 222 and are all connected to the sand settling trough 222. Specifically, the outer casing 210 of the sand removal cylinder can be configured as the side portion of the outer casing assembly 200, and the sand discharge cylinder seat 220 can be configured as the lower end portion of the outer casing assembly 200. The outer casing assembly 200 is divided into the outer casing 210 and the sand discharge cylinder seat 220. This facilitates connection with the lower end of the first separation chamber section 120, the upper end of the oil-water separation chamber shell 400, and the upper end of the oil-water separation outer casing 500, respectively. It also facilitates the formation of the settling tank 222, the sand discharge port 223, and the flushing port 224. Furthermore, the setting of the settling tank 222 on the sand discharge cylinder seat 220 allows sand to fall into the settling tank 222, while the sand discharge port 223 and the flushing port 224 are both located on the outer wall of the settling tank 222, facilitating sand discharge.

[0072] Furthermore, the inner wall of the upper end of the sand removal outer cylinder body 210 is threadedly connected to the outer wall of the lower end of the first centrifugal cavity section 110 of the sand removal chamber shell 100. The upper periphery of the sand discharge cylinder seat 220 has a first enclosure extending upward, and the inner wall of the first enclosure is threadedly connected to the outer wall of the lower end of the sand removal outer cylinder body 210. The inner wall of the first mounting hole 221 on the sand discharge cylinder seat 220 is threadedly connected to the outer wall of the lower end of the first separation chamber section 120. At the same time, the lower end of the sand discharge cylinder seat 220 is provided with a second enclosure and a second enclosure with gradually increasing diameter from the inside to the outside outside of the first mounting hole 221. The inner wall of the second enclosure can be threadedly connected to the outer wall of the upper end of the oil-water separation chamber shell 400, and the inner wall of the third enclosure can be threadedly connected to the outer wall of the upper end of the oil-water separation outer cylinder 500.

[0073] In one embodiment of the present invention, there are at least two sand discharge ports 223 and at least two flushing ports 224. The at least two sand discharge ports 223 and the at least two flushing ports 224 are arranged alternately along the circumference of the outer side wall of the settling tank 222. Each flushing port 224 includes a transverse section 225 and a vertical section 226. The transverse section 225 extends laterally outward from the outer side wall of the settling tank 222, and the vertical section 226 extends vertically downward from the end of the transverse section 225 away from the settling tank 222 to penetrate the sand discharge cylinder seat 220, so that the water phase in the flushing chamber 501 can enter the flushing port 224 through the vertical section 226 and be self-flushed through the transverse section 225. The water phase entering the settling tank 222 through the flushing port 224 backwashes the sand phase inside the settling tank 222. The sand discharge port 223 extends laterally outward from the outer wall of the settling tank 222 to penetrate the sand discharge cylinder seat 220. All the transverse port sections 225 are obliquely set in the same direction in the radial direction of the settling tank 222, which makes the flow direction of the water phase entering the settling tank 222 from all the flushing ports 224 the same and forms a circulation in the settling tank 222. All the sand discharge ports 223 are obliquely set in a different direction in the radial direction of the settling tank 222 than the transverse port sections 225. This setting makes it easier for the water phase circulation in the settling tank 222 to push out the sand phase at the sand discharge port 223.

[0074] Specifically, such as Figure 7 As shown, all transverse inlets 225 are obliquely arranged in the radial direction from the inside to the outside of the settling tank 222 in a counterclockwise direction. This causes the water phase entering the settling tank 222 from all transverse inlets 225 to form a circulation in the clockwise direction of the settling tank 222. All sand discharge outlets 223 are obliquely arranged in the radial direction from the inside to the outside of the settling tank 222 in a clockwise direction. The outflow direction of the sand discharge outlets 223 is the same as the flow direction of the water phase circulation in the settling tank 222, which facilitates the water phase to push the sand phase to discharge sand.

[0075] In one embodiment of the present invention, the bottom walls of both the transverse inlet section 225 and the sand discharge outlet 223 are flush with the bottom of the settling tank 222. This arrangement avoids energy loss of the aqueous phase during backwashing, further improving sand discharge efficiency.

[0076] See Figure 1 , Figure 2 and Figure 9 In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes a downdrive pump assembly 700, which is located at the lower end of the electric valve seat 600 and its upper end communicates with the first outlet valve port 602. The addition of the downdrive pump assembly 700 facilitates the rapid pumping and reinjection of the aqueous phase discharged from the first outlet valve port 602 back into the downhole formation. Further, the downdrive pump assembly 700 may include, but is not limited to, a centrifugal pump assembly or a screw pump assembly.

[0077] See Figure 1 , Figure 2 , Figure 9 and Figure 10 In one embodiment of the present invention, the second centrifuge 430 includes a second main body 431 and a guide rod 432. The second main body 431 is placed inside the second centrifugal chamber section 410 and is provided with a second spiral flow channel 433 extending from top to bottom. The second spiral flow channel 433 is used for oil-water separation of the sand discharge mixture. The guide rod 432 extends from the upper end of the second main body 431 and passes through the lower end opening of the first separation chamber section 120 and the oil filter chamber shell 300 in sequence, extending into the first oil outlet channel 135. The upper and lower ends of the second oil outlet channel 434 respectively penetrate the guide rod 432 and the second main body 431 and are located inside the second spiral flow channel 433. By providing the second spiral flow channel 433 on the second main body 431, oil-water separation of the sand discharge mixture can be easily achieved, and the second centrifuge 430 can achieve centrifugal motion without driving, which also facilitates the setting of the second oil outlet channel 434. Of course, the second centrifuge 430 in this invention can also be other suitable centrifuges with centrifugation function.

[0078] Furthermore, the sand-discharging mixture, containing an aqueous phase and a small amount of oil phase, first enters the second centrifugal section 410 of the oil-water separation chamber shell 400 through the lower opening of the first separation chamber section 120, and then enters the second spiral flow channel 433 of the second main body 431 for centrifugal separation. Since the density of the oil phase in the sand-discharging mixture is greater than that of the aqueous phase, after the sand-discharging mixture is accelerated by centrifugation and exits from the second spiral flow channel 433 into the second separation chamber section 420, the oil phase in the sand-discharging mixture will flow from the lower end of the second oil outlet channel 434 to the upper end and merge with the oil phase that has been initially separated by the first centrifuge 130 and be discharged from the equipment. The aqueous phase in the sand-discharging mixture flows downward and is discharged from the lower opening of the second separation chamber section 420, thereby completing the secondary oil-water separation.

[0079] Furthermore, the second spiral flow channel 433 is formed on the outer side wall of the second main body 431, and the second main body 431 is interference-fitted into the second centrifugal cavity section 410 so that the inner side wall of the second centrifugal cavity section 410 seals the lateral side of the second spiral flow channel 433.

[0080] In one embodiment of the present invention, the guide rod portion 432 is provided with an external thread section 435, and the inner wall of the lower end of the oil filter chamber shell 300 is provided with an internal thread section that is threadedly connected to the external thread section 435. The addition of the external thread section 435 and the internal thread section ensures the connection strength between the two and also ensures the sealing of the lower end of the oil filter chamber shell 300. Specifically, the oil filter chamber shell 300 includes an upper part 310, a chamber body part 320, and a lower part 330 arranged sequentially from top to bottom. The upper part 310 forms an oil outlet opening 311. The lower end of the first body part 131 of the first centrifuge 130 extends downward between the first oil outlet channel 135 and the first spiral flow channel 133 and is provided with a connecting plate. The inner side wall of the upper part 310 is threadedly connected to the outer side wall of the connecting plate. Since the diameter of the connecting plate is larger than the diameter of the first oil outlet channel 135, the oil outlet opening 311 can be connected to the first oil outlet channel 135. Multiple oil filter holes 321 are spaced apart on the chamber body part 320. The lower rotating part is open and has an internal thread section.

[0081] In one embodiment of the present invention, the diameter of the second separation chamber section 420 is gradually reduced from the second centrifugal chamber section 410 downwards, so as to enhance the internal swirling intensity of the second separation chamber section 420, thereby making it easier to separate the oil and water phases inside.

[0082] like Figures 2 to 4 As shown, in one embodiment of the present invention, the diameter of the first separation chamber section 120 gradually decreases downward from the first centrifugal chamber section 110, and there are multiple sand filter ports 121. These multiple sand filter ports 121 are arranged sequentially at intervals along the circumference of the first separation chamber section 120, and each sand filter port 121 extends along the height direction of the first separation chamber section 120. This allows the sand filter ports 121 to form upward-sloping openings, facilitating the smooth entry of the centrifuged sand phase into the sand removal chamber 230. Specifically, the upper end of the sand filter port 121 is located at a position corresponding to the lower part of the chamber body 320 of the oil filter chamber shell 300.

[0083] See Figure 2 , Figure 3 and Figure 5 In one embodiment of the present invention, the oil filter chamber shell 300 includes a chamber body 320, the diameter of which gradually decreases from top to bottom, and the chamber body 320 is provided with multiple rows of oil filter holes 321, which are arranged sequentially at intervals along the circumference of the chamber body 320. That is, the oil filter chamber shell 300 is shaped to conform to the first separation chamber section 120, so that there is sufficient space between the first separation chamber section 120 and the oil filter chamber shell 300 for oil-water-sand three-phase separation.

[0084] Please see again Figures 2 to 4In one embodiment of the present invention, the first centrifuge 130 includes a first main body 131 and a docking column 132. The first main body 131 is located below the liquid inlet 111 and is provided with a first spiral flow channel 133 extending from top to bottom. The first spiral flow channel 133 is used for centrifugal separation of the sand phase in the sand-containing mixture. The docking column 132 extends from the upper end of the first main body 131 and docks with a second mounting hole 134 opened at the upper end of the first centrifugal chamber section 110. The upper and lower ends of the first oil outlet channel 135 respectively penetrate the docking column 132 and the first main body 131 and are located inside the first spiral flow channel 133. By providing the first spiral flow channel 133 on the first main body 131, the oil-water-sand separation of the sand-containing mixture can be easily realized, and the first centrifuge 130 can achieve centrifugal movement without driving, which also facilitates the setting of the first oil outlet channel 135. Of course, the first centrifuge 130 in the present invention can also be other suitable centrifuges with centrifugal function.

[0085] Furthermore, under the high-pressure environment downhole, the sand-containing mixture first enters the space above the first main body 131 of the first centrifugal chamber section 110 through the pressure difference from the inlet 111, and then enters the first spiral flow channel 133, where it can undergo centrifugal separation. Since the sand phase in the sand-containing mixture has the highest density and the oil phase has the lowest density, after the sand-containing mixture is accelerated by centrifugation and exits from the first spiral flow channel 133 into the first separation chamber section 120, the sand phase in the sand-containing mixture will be thrown onto the inner wall of the first separation chamber section 120, and the oil phase in the sand-containing mixture will be thrown onto the outer wall of the oil filter chamber shell 300, and then exit from the sand filter port 121. The sand phase enters the sand removal chamber 230 formed by the sand removal outer cylinder assembly 200 and the first separation chamber section 120. The lower end of the sand removal outer cylinder assembly 200 is provided with a sand discharge port 223 that communicates with the sand removal chamber 230, so that the sand phase can be discharged from the equipment through the sand discharge port 223. In addition, the side wall of the oil filter chamber shell 300 is provided with an oil filter hole 321, so that the oil phase will enter the interior of the oil filter chamber shell 300 through the oil filter hole 321 and enter the first oil outlet channel 135 through the oil outlet opening 311 at the upper end, so as to be discharged from the equipment through the second mounting hole 134. The water phase in the sand-containing mixture will carry a small amount of oil phase and be discharged from the lower opening of the first separation chamber section 120 to the second separation device.

[0086] Furthermore, the first spiral flow channel 133 is formed on the outer side wall of the first main body 131, and the first main body 131 is interference-fitted into the first centrifugal cavity section 110, so that the inner side wall of the first centrifugal cavity section 110 laterally seals the first spiral flow channel 133.

[0087] See Figure 2 and Figure 3In one embodiment of the present invention, the upper end of the first centrifugal chamber section 110 is provided with an end cap cylinder seat 112, the end cap cylinder seat 112 is provided with a second mounting hole 134, the inner side wall of the end cap cylinder seat 112 is threadedly connected to the outer side wall of the upper end of the first offline chamber section, the outer side wall of the docking column portion 132 is threadedly connected to the inner side wall of the second mounting hole 134, and the upper end of the guide rod portion 432 of the second centrifuge 430 can extend into the second mounting hole 134 of the end cap cylinder seat 112.

[0088] In one embodiment of the present invention, the downhole multiphase separation injection and production equipment further includes an upper drive pump assembly 800, which is located at the upper end of the first centrifugal chamber section 110 and its lower end communicates with the first oil outlet channel 135. The addition of the upper drive pump assembly 800 facilitates the rapid suction and lifting of the oil phase discharged from the first oil outlet channel 135 to the surface. Further, the upper drive pump assembly 800 may include, but is not limited to, a centrifugal pump assembly or a screw pump assembly. Specifically, the upper drive pump assembly 800 is threadedly connected to the upper end of the end cap cylinder seat 112.

[0089] Specifically, the downhole multiphase separation injection and production equipment provided by this invention has the following advantages:

[0090] 1. The first separation device proposed in this invention performs hydrocyclone separation on the sand-containing mixture, causing the denser sand phase to be discharged along the structural wall, preventing the sand phase from interfering with the subsequent oil-water separation. It does not have complex components or easily damaged parts, and the equipment has the advantages of long service life while having the function of removing sand.

[0091] 2. The first and second separation devices proposed in this invention achieve a reasonable arrangement of sand removal and multi-stage oil-water separation in the proposed structural layout, realizing efficient sand removal. The internal primary oil filtration structure is used for initial oil phase recovery, followed by secondary cyclone separation, achieving efficient oil-water separation, improving the oil-water separation efficiency of the equipment, increasing the oilfield recovery rate, and having high economic benefits.

[0092] 3. The present invention provides a flushing structure between the first separation device and the second separation device. When the sand phase accumulates and blocks the equipment, the accumulated sand phase is discharged through the flushing structure, thereby increasing the applicability of the equipment.

[0093] In summary, the downhole multiphase separation injection and production equipment proposed in this application can be connected to the confined space of the wellbore, achieving efficient separation of oil, water, and sand three-phase media. Through a multi-stage oil-water separation and flushing structure, the separation efficiency is improved, and the practicality of the equipment is enhanced. It is a highly efficient integrated downhole multiphase separation equipment that can achieve efficient separation of oil, water, and sand three-phase media in a limited space, thereby improving the economic efficiency of oilfield development.

[0094] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0095] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0097] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A downhole multiphase separation injection-production device, characterized in that, The downhole multiphase separation injection-production equipment includes a first separation device, which comprises: Except for the sand chamber shell (100), it includes a first centrifugal chamber section (110) and a first separation chamber section (120) arranged sequentially from top to bottom. The first centrifugal chamber section (110) is provided with a liquid inlet (111), and the first separation chamber section (120) is provided with a sand filter port (121) on its side wall. The first centrifugal chamber section (110) is provided with a first centrifuge (130) below the liquid inlet (111) to centrifuge and separate the sand phase in the sand-containing mixture entering from the liquid inlet (111) to the sand filter port (121). The first centrifuge (130) is also provided with a first oil outlet channel (135) that runs vertically through and extends to penetrate the upper end of the first centrifugal chamber section (110). The sand removal outer cylinder assembly (200) is sleeved on the outside of the first separation chamber section (120) and has a first mounting hole (221) at its lower end for exposing the lower opening of the first separation chamber section (120). The sand removal outer cylinder assembly (200) and the first separation chamber section (120) enclose a sand removal chamber (230) that communicates with the sand filter port (121). The lower end of the sand removal outer cylinder assembly (200) has a sand discharge port (223) that communicates with the sand removal chamber (230). The oil filter chamber shell (300) is located inside the first separation chamber section (120) and has oil filter holes (321) on its side wall. The upper end of the oil filter chamber shell (300) is provided with an oil outlet opening (311) that communicates with the first oil outlet channel (135).

2. The downhole multiphase separation injection and production equipment according to claim 1, characterized in that, The downhole multiphase separation injection-production equipment further includes a second separation device, which comprises: The oil-water separation chamber shell (400) includes a second centrifugal chamber section (410) and a second separation chamber section (420) arranged sequentially from top to bottom. The upper end of the second centrifugal chamber section (410) is connected to the lower end of the sand removal outer cylinder assembly (200), and the upper opening of the second centrifugal chamber section (410) communicates with the lower opening of the first separation chamber section (120). The lower end of the second separation chamber section (420) is open. A second centrifuge (430) is provided in the second centrifugal chamber section (410) to separate the sand-discharging mixture entering from the lower opening of the first separation chamber section (120) into oil and water. The second centrifuge (430) is provided with a second oil outlet channel (434) that runs vertically through the second centrifuge. The second oil outlet channel (434) extends upward and passes through the lower opening of the first separation chamber section (120) and the oil filter chamber shell (300) in sequence to enter the first oil outlet channel (135).

3. The downhole multiphase separation injection and production equipment according to claim 2, characterized in that, The second separation device further includes: The oil-water separator outer cylinder (500) is sleeved on the outside of the oil-water separator chamber shell (400) and its upper end is connected to the lower end of the sand removal outer cylinder assembly (200). An electric valve seat (600) is provided, the upper end of which is connected to the lower end of the oil-water separation outer cylinder (500) to form a flushing chamber (501) by the oil-water separation outer cylinder (500) and the oil-water separation chamber shell (400). The electric valve seat (600) has an inlet valve port (601), a first outlet valve port (602) and a second outlet valve port (603). The inlet valve port (601) is connected to the lower opening of the second separation chamber section (420). The first outlet valve port (602) and the second outlet valve port (603) are respectively connected to the downhole space and the flushing chamber (501). The valve core (610) on the electric valve seat (600) is used to select one of the first outlet valve port (602) and the second outlet valve port (603) to communicate with the inlet valve port (601). The lower end of the sand removal outer cylinder assembly (200) is provided with a flushing port (224) that connects the flushing chamber (501) and the sand removal chamber (230).

4. The downhole multiphase separation injection and production equipment according to claim 3, characterized in that, The sand removal outer cylinder assembly (200) includes a sand removal outer cylinder body (210) and a sand discharge cylinder seat (220). The sand removal outer cylinder body (210) is sleeved on the outside of the first separation chamber section (120) and its upper end is connected to the lower end of the first centrifugal chamber section (110). The upper end of the sand discharge cylinder seat (220) is connected to the lower end of the sand removal outer cylinder body (210), so that it, together with the sand removal outer cylinder body (210) and the first separation chamber section (120), forms the sand removal outer cylinder body (210) and the sand discharge cylinder seat (220). The sand removal chamber (230) has a first mounting hole (221) on the sand discharge cylinder seat (220) that aligns with the lower opening of the first separation chamber section (120). The sand discharge cylinder seat (220) is also provided with a sand settling trough (222) around the outside of the first mounting hole (221). The sand discharge port (223) and the flushing port (224) are arranged sequentially at intervals along the circumference of the outer side wall of the sand settling trough (222) and are both connected to the sand settling trough (222).

5. The downhole multiphase separation injection and production equipment according to claim 4, characterized in that, The number of sand discharge ports (223) and flushing ports (224) is at least two. At least two sand discharge ports (223) and at least two flushing ports (224) are alternately arranged along the circumference of the outer wall of the settling tank (222). Each flushing port (224) includes a transverse section (225) and a vertical section (226). The transverse section (225) extends laterally outward from the outer wall of the settling tank (222), and the vertical section (226) extends laterally outward from the transverse section (225). 225) The end away from the settling tank (222) extends vertically downward to penetrate the sand discharge cylinder seat (220). The sand discharge port (223) extends laterally outward from the outer wall of the settling tank (222) to penetrate the sand discharge cylinder seat (220). All the lateral openings (225) are obliquely arranged in the same direction in the radial direction of the settling tank (222). All the sand discharge ports (223) are obliquely arranged in a different direction from the lateral openings (225) in the radial direction of the settling tank (222).

6. The downhole multiphase separation injection and production equipment according to claim 5, characterized in that, The bottom walls of the transverse section (225) and the sand discharge port (223) are flush with the bottom of the sedimentation tank (222).

7. The downhole multiphase separation injection and production equipment according to claim 3, characterized in that, The downhole multiphase separation injection and production equipment also includes a downdrive pump group (700), which is located at the lower end of the electric valve cylinder seat (600) and its upper end communicates with the first outlet valve port (602).

8. The downhole multiphase separation injection and production equipment according to claim 2, characterized in that, The second centrifuge (430) includes a second main body (431) and a guide rod (432). The second main body (431) is placed in the second centrifuge chamber (410) and is provided with a second spiral flow channel (433) extending from top to bottom. The second spiral flow channel (433) is used to separate the sand discharge mixture into oil and water. The guide rod (432) extends out from the upper end of the second main body (431) and passes through the lower end opening of the first separation chamber (120) and the oil filter chamber shell (300) in sequence, extending into the first oil outlet channel (135). The upper and lower ends of the second oil outlet channel (434) respectively penetrate the guide rod (432) and the second main body (431) and are located inside the second spiral flow channel (433).

9. The downhole multiphase separation injection and production equipment according to claim 8, characterized in that, The guide rod (432) is provided with an external thread section (435), and the inner wall of the lower end of the oil filter chamber (300) is provided with an internal thread section that is threadedly connected to the external thread section (435).

10. The downhole multiphase separation injection and production equipment according to claim 2, characterized in that, The diameter of the second separation chamber section (420) gradually decreases from the second centrifugal chamber section (410) downwards.

11. The downhole multiphase separation injection and production equipment according to any one of claims 1 to 10, characterized in that, The diameter of the first separation chamber section (120) gradually decreases from the first centrifugal chamber section (110) downwards, and there are multiple sand filter ports (121). The multiple sand filter ports (121) are arranged sequentially at intervals along the circumference of the first separation chamber section (120), and each sand filter port (121) is arranged to extend along the height direction of the first separation chamber section (120).

12. The downhole multiphase separation injection and production equipment according to any one of claims 1 to 10, characterized in that, The oil filter chamber housing (300) includes a chamber housing body (320), the diameter of which is gradually reduced from top to bottom, and the chamber housing body (320) is provided with multiple rows of oil filter holes (321), which are arranged sequentially at intervals along the circumference of the chamber housing body (320).

13. The downhole multiphase separation injection and production equipment according to any one of claims 1 to 10, characterized in that, The first centrifuge (130) includes a first main body (131) and a docking column (132). The first main body (131) is located below the liquid inlet (111) and is provided with a first spiral flow channel (133) extending from top to bottom. The first spiral flow channel (133) is used to centrifuge the sand phase in the sand-containing mixture. The docking column (132) extends from the upper end of the first main body (131) and docks with the second mounting hole (134) opened at the upper end of the first centrifuge chamber section (110). The upper and lower ends of the first oil outlet channel (135) respectively penetrate the docking column (132) and the first main body (131) and are located inside the first spiral flow channel (133).

14. The downhole multiphase separation injection and production equipment according to any one of claims 1 to 10, characterized in that, The downhole multiphase separation injection and production equipment also includes an upper drive pump group (800), which is located at the upper end of the first centrifugal chamber section (110) and its lower end is connected to the first oil outlet channel (135).

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