Downhole eccentric over-axis multiphase medium high-efficiency separation device for ultra-high liquid production oil wells

Abstract

The present invention relates to an eccentric over-axis multiphase medium high-efficiency separation device for an ultra-high liquid production oil well, which includes an oil-gas-water separation module and a transmission shaft, wherein the transmission shaft eccentrically passes through the oil-gas-water separation module and is respectively connected to a motor and a centrifugal pump; the oil-gas-water separation module includes a top bridge channel, an upper connector, a mask, a combined shell, a multistage separator and a bottom bridge channel, wherein the upper end of the combined shell is connected to the upper connector, the upper connector is connected to the eccentric hole below the top bridge channel, the lower end of the combined shell is connected to the bottom plugger, the bottom plugger is connected to the eccentric hole above the bottom bridge channel, and the multistage separator is serially connected in the combined shell from top to bottom; the mask buckle is placed on the outer wall of the upper connector to form a gas-liquid separation chamber with an upper opening; the multistage separator is communicated with the overflow channel in the combined shell, and the multistage separator is also communicated with the bottom flow channel. The present invention adopts an over-axis eccentric design method, so there is more space to install a cyclone, so as to achieve large-displacement multiphase medium processing.

Description

Technical Field

[0001] The present invention relates to a large displacement separation device used in the field of underground multiphase medium separation, and in particular to a device capable of realizing efficient separation of oil, gas and water three-phase media in a narrow underground space of an offshore oil field. Background Art

[0002] With the development of the global economy and the growth of population, the demand for energy continues to increase. In recent years, my country's oil extraction technology has also been developing continuously. In addition, onshore oil extraction has gradually entered the late stage of high water content or even ultra-high water content. Energy acquisition has gradually shifted to offshore oil fields, and oil field extraction technology has been continuously improved. Technologies including drilling equipment, submarine pipelines, and oil field development projects have been greatly improved and developed. Therefore, offshore oil fields have huge resource potential and are of great value to future energy supply. For the treatment of produced fluids, technicians have proposed some solutions. Patent document 1, CN202121728442.X, uses gravity separation to complete the three-phase separation of oil, gas and water. However, under this scheme, after separation, the oil phase still carries some gas, and the water phase carries some oil phase. The separation efficiency is not good, and its volume is large, making it difficult to apply underground. In addition, this scheme uses a level meter to detect the working time of the pneumatic rod, which has errors, and its separation is not carried out at any time. Patent document 2, CN202223218047.4, the oil-gas-water three-phase separation device uses metal foam microporous filler to separate and remove water, and then uses the oil-gas density difference to separate oil and gas. However, under this scheme, due to the obstruction of the foam, some gas will be separated together with the water, and the tangential velocity of the oil-gas mixed medium after the water is removed is greatly reduced. If the separation is continued by centrifugal separation, the separation efficiency will be greatly reduced. The separation effect is not good under this scheme, and there is gas in both the oil phase and the water phase. In addition, when the scheme encounters a large displacement condition, it is difficult to make corresponding changes. Summary of the invention

[0003] The purpose of the present invention is to provide an eccentric over-axis multi-phase medium high-efficiency separation device for an ultra-high liquid production oil well. This eccentric over-axis multi-phase medium high-efficiency separation device for an ultra-high liquid production oil well is used to solve the problem of insufficient equipment processing capacity that may be faced by the oil, gas and water three-phase separation device in the prior art when used for large processing volumes underground.

[0004] The technical solution adopted by the present invention to solve its technical problems is: this ultra-high liquid production oil well underground eccentric over-axis multiphase medium high-efficiency separation device comprises an oil-gas-water separation module and a transmission shaft, the transmission shaft eccentrically passes through the oil-gas-water separation module, and the two ends of the transmission shaft are respectively connected to a motor and a centrifugal pump; the oil-gas-water separation module comprises a top bridge channel, an upper connector, a mask, a combined shell, a multi-stage separator, a bottom plug and a bottom bridge channel, the upper end of the combined shell is connected to the upper connector, the upper connector is connected to the lower eccentric hole of the top bridge channel, the lower end of the combined shell is connected to the bottom plug, the bottom plug is connected to the upper eccentric hole of the bottom bridge channel, the multi-stage separator is serially connected in the combined shell from top to bottom, and an overflow channel and an underflow channel are arranged in the wall of the combined shell; the mask is arc-shaped, and the mask buckle is placed on the outer wall of the upper connector to form a gas-liquid separation chamber with an upper opening, and the liquid inlet holes of the upper connector are distributed at the bottom of the gas-liquid separation chamber. After gas-liquid separation, gas is discharged from the upper opening of the gas-liquid separation chamber, and oil-water mixed liquid is discharged from the liquid inlet holes Enter the liquid inlet channel; the upper connector is a cylinder with a liquid inlet cavity inside, the liquid inlet cavity is connected to the liquid inlet hole, the upper end of the liquid inlet cavity is connected to the eccentric through-axis hole, the bottom of the liquid inlet cavity is eccentrically contracted to form a liquid outlet hole, the groove surrounds the outside of the liquid outlet hole, the liquid outlet hole is connected to the lower threaded connection hole, an eccentric through-axis hole is arranged in the upper connector, a straight overflow channel runs through the upper connector, the eccentric overflow channel is formed by connecting the upper and lower ends of the oblique flow channel to the straight channel, and the straight overflow channel and the eccentric overflow channel are each connected to the overflow channel in the combined shell The separated oil phase is collected into the top bridge channel through the straight overflow channel and the eccentric overflow channel and discharged; the feed pipe surrounds the outside of the transmission shaft, the upper end of the feed pipe is inserted into the upper end connector and snapped into the groove, the annulus between the transmission shaft and the feed pipe is the liquid inlet channel, the oil-water mixture enters the multi-stage separator from the liquid inlet channel for oil-water separation, the multi-stage separator is connected with the overflow channel in the combined shell, and the multi-stage separator is also connected with the bottom flow channel, the separated water phase is collected into the bottom bridge channel through the bottom flow channel and discharged.

[0005] In the above scheme, the separators at each level include multiple parallel oil-water cyclone separators, an upper combination plate, and a lower combination plate. The upper combination plate and the lower combination plate are arranged at intervals and fixed in the combination shell. The upper combination plate is provided with an eccentric shaft hole and multiple guide platforms. The center of each guide platform is provided with an overflow pipe hole. The lower combination plate is provided with an eccentric shaft hole and multiple oil-water cyclone separators. A slide groove is provided in each cyclone fixing hole. The oil-water cyclone separator shell is composed of a straight tube section, a primary cone section, and a secondary cone section. A card bead is provided outside the straight tube section of the oil-water cyclone separator shell. The straight tube section is provided with a liquid inlet. The liquid inlet Corresponding to the feed hole of the feed pipe, the oil-water cyclone separator is fixed in the cyclone fixing hole of the lower combined plate through a card bead and a slide groove. A spiral flow channel is arranged inside the oil-water cyclone separator, and the spiral flow channel is located in the straight cylinder section. The lower opening of the secondary cone section of the oil-water cyclone separator shell is the bottom flow opening of the oil-water cyclone separator. The overflow pipe passes through the spiral flow channel and extends from the oil-water cyclone separator shell. The upper end of the overflow pipe is inserted into an overflow pipe hole of a guide platform of the upper combined plate. The overflow pipe is connected to the overflow channel in the combined shell through the oil discharge channel, and the bottom flow opening of the oil-water cyclone separator is connected to the bottom flow channel in the combined shell.

[0006] In the above scheme, the multi-stage separator has two stages, namely a primary separator and a secondary separator. Both the primary separator and the secondary separator have three parallel-connected oil-water cyclone separators.

[0007] In the above scheme, the combined shell is composed of the upper half of the primary shell, the lower half of the primary shell, the upper half of the secondary shell, and the lower half of the secondary shell connected in sequence;

[0008] The upper half of the first-stage shell is a cylinder with an open lower end, the top of the cylinder is provided with a connector, the cylinder wall is provided with an overflow channel, the connector is a solid cylinder, the connector is provided with an eccentric through-axis hole, and the connector is threadedly connected to the lower threaded connection hole of the upper connector; the outer wall of the lower half of the first-stage shell is provided with an overflow channel, the upper half of the first-stage shell and the lower half of the first-stage shell constitute a first-stage shell, and the three oil-water cyclone separators of the first-stage separation structure are located in the first-stage shell;

[0009] The upper half of the secondary shell is a cylinder with an open lower end, and the top of the cylinder is provided with a connector. An internal thread is arranged in the cylinder, and the internal thread is used for threading the upper and lower combined plates. An oil overflow cavity is provided between the upper combined plate and the top of the cylinder, and an overflow channel is provided in the cylinder wall above the upper combined plate, and the overflow channel is communicated with the oil overflow cavity; there is also an underflow channel in the cylinder wall, and an eccentric through-axis hole is provided in the connector, and the eccentric through-axis hole is provided near the outer edge of the connector, and the space outside the eccentric through-axis hole of the connector forms a tapered arc groove downwardly, and an inclined underflow channel is provided at the bottom of the arc groove, and the inclined underflow channel is communicated with the underflow channel in the cylinder wall; the connector is threadedly connected to the lower port of the lower half of the primary shell, and the underflow port of the primary oil-water cyclone separator is provided above the inclined underflow channel; the outer wall of the lower half of the secondary shell is provided with an underflow channel, and the upper half of the secondary shell and the lower half of the secondary shell constitute the secondary shell, and the three oil-water cyclone separators of the secondary separation structure are located in the secondary shell.

[0010] In the above scheme, the bottom end plugger is a variable diameter cylinder with a drainage cavity inside, and an outer step is formed between the column head and the column body. A bottom flow channel is arranged at the outer step, and the bottom flow channel connects the bottom flow channel in the lower half of the secondary shell with the drainage cavity, and the bottom of the drainage cavity is eccentrically contracted to form a bottom flow drainage hole; an eccentric through-axis hole is arranged in the column head, and the eccentric through-axis hole is arranged close to the outer edge of the connecting head, and the connecting head is located in the space outside the eccentric through-axis hole to form a gradually shrinking arc groove downward, and a bottom flow channel is arranged at the bottom of the arc groove, which is connected to the drainage cavity, and the bottom flow port of the first-level oil-water cyclone separator is arranged above the bottom flow channel at the bottom of the arc groove.

[0011] In the above scheme, a one-way check valve is arranged in the overflow channel in the wall of the combined shell, and a one-way check valve is arranged in the bottom flow channel arranged in the wall of the combined shell. Beneficial Effects

[0012] 1. The present invention first performs gravity separation on the oil, gas and water three-phase mixed medium, and then the oil and water two-phase medium after degassing enters the device for cyclone separation, so that the oil phase is produced by a centrifugal pump through multiple overflow channels, and the water phase is reinjected through multiple underflow channels, completing the oil, gas and water three-phase separation while reducing the lifting cost of water treatment.

[0013] 2. The present invention adopts an eccentric shaft-passing method to realize a single motor driving dual pumps while making the eccentric side of the device closer to the inner wall of the casing. The distance between the two is narrower than the other side, thereby having a faster flow rate, being more conducive to the separation of the gas phase and the liquid phase, and further improving the gas-liquid separation efficiency of the device.

[0014] 3. The design of the eccentric through-shaft hole of the present invention allows more space on each combined plate for installing the cyclone, so that multiple existing cyclones with small processing capacity can be replaced with cyclones with larger processing capacity. At the same time, multi-stage series connection structures can be further added according to the processing capacity to achieve separation of large-displacement multi-phase media.

[0015] 4. The present invention is provided with one-way check valves in all overflow and underflow channels, and utilizes gravity and the coordination of various components in the valve to achieve one-way discharge of liquid, thereby preventing liquid backflow from causing a decrease in separation efficiency.

[0016] 5. The present invention is provided with bridge channels at both ends, which are connected to the centrifugal pump when the device is eccentric, without changing the installation method of other equipment, thereby increasing the applicability of the separation equipment.

[0017] 6. The present invention can be connected to a small space in a wellbore to realize the separation of oil, gas and water three-phase media, thereby achieving the purpose of removing the gas phase, collecting the oil phase and reinjecting the water phase. The over-axis eccentric design adopts more space to install the cyclone. According to the size of the processing volume, multiple small-capacity cyclones can be selected to replace a single large-capacity cyclone, and even a multi-stage series structure can be added to achieve an efficient parallel arrangement of cyclones and realize large-displacement multi-phase medium processing, which not only increases the size of the device processing volume, but also enhances the practicability of the equipment. It is an integrated downhole multi-phase high-efficiency separation device that combines gravity separation and cyclone separation technology, which can achieve efficient separation of oil, water and gas three-phase media in a limited space and improve the economy of oilfield exploitation.

[0018] 7. The present invention occupies a small space and can be directly applied to the narrow space underground. There is no need to lift the produced fluid to the ground for separation, which reduces energy waste and saves economic costs. The efficient parallel use of cyclone separators enables the equipment to better cope with the working conditions of large processing volumes in offshore oil fields.

[0019] 8. The present invention enables efficient separation of the three-phase mixed medium of oil, gas and water while occupying a small space. After separation, the gas phase is isolated outside the device and discharged in the tube for treatment. The oil phase is produced by a centrifugal pump and enters the oil pipeline for further treatment. The water phase is pumped out by a centrifugal pump and reinjected, thereby increasing the service life of the operating equipment and completing the pre-separation of the produced fluid, thereby indirectly improving the oil field recovery rate and reducing the energy consumption of the subsequent separation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the overall appearance diagram of the present invention.

[0021] Figure 2 The present invention is a cross-sectional view, wherein (a) is a cross-sectional view perpendicular to the cross-section Ι-Ι and a partial enlarged view of the present invention; (b) is a cross-sectional view of the cross-section Ι-Ι and a partial enlarged view of the present invention.

[0022] Figure 3 It is an exploded view of the present invention.

[0023] Figure 4 This is the appearance and cross-sectional view of the top bridge channel.

[0024] Figure 5 This is a cross-sectional view of the appearance of the bottom bridge channel.

[0025] Figure 6 This is the appearance and cross-sectional view of the upper connector.

[0026] Figure 7 This is the appearance and cross-sectional view of the upper half of the first-stage casing.

[0027] Figure 8 This is the appearance and cross-sectional view of the upper half of the secondary casing.

[0028] Fig. 9 This is the appearance and cross-sectional view of the bottom occluder.

[0029] Fig.10 This is the appearance diagram and cross-sectional view of the oil-water cyclone separator.

[0030] In the figure, 101-shield, 102-upper connector, 1021-liquid inlet, 1022-straight overflow channel, 1023-eccentric overflow channel, 1024-groove, 103-upper half of the primary shell, 1031-overflow channel one, 1032-eccentric through-axis hole one, 104-lower half of the primary shell, 1041-overflow channel two, 105-upper half of the secondary shell, 1051-overflow channel three, 1052-bottom flow channel one, 1053-eccentric through-axis hole two, 106-lower half of the secondary shell, 1061-bottom flow channel two, 107-bottom end plugger, 1071-bottom flow channel three, 1072-bottom flow channel four, 1073-eccentric through-axis hole three, 1074-bottom flow drainage hole, 108-top bridge channel, 1081-top overflow channel, 108 2-top through-axis hole, 109-bottom bridge channel, 1091-through-axis drainage hole, 110-secondary feed pipe, 1101-secondary feed hole, 111-primary feed pipe, 1111-primary feed hole, 112-oil-water cyclone separator, 1121-liquid inlet, 1122-bottom flow port, 1123-card bead, 1124-spiral flow channel, 1125-overflow pipe, 113- One-way check valve, 114-upper combination plate, 1141-guide platform, 1142-eccentric shaft hole four, 115-first-level lower combination plate, 1151-eccentric shaft hole five, 1152-cyclone fixing hole one, 1153-chute one, 116-second-level lower combination plate, 1161-eccentric shaft hole six, 1162-cyclone fixing hole two, 1163-chute two, 117-drive shaft. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] See also Figure 1-Figure 10, this ultra-high liquid production oil well downhole eccentric through-axis multiphase medium high-efficiency separation device comprises an oil-gas-water separation module and a transmission shaft, the transmission shaft eccentrically passes through the oil-gas-water separation module, and the two ends of the transmission shaft are respectively connected to a motor and a centrifugal pump; the oil-gas-water separation module comprises a top bridge channel, an upper connector, a mask, a combined shell, a multi-stage separator, a bottom plugger and a bottom bridge channel, the upper end of the combined shell is connected to the upper connector, the upper connector is connected to the eccentric hole under the top bridge channel, the lower end of the combined shell is connected to the bottom plugger, the bottom plugger is connected to the eccentric hole on the bottom bridge channel, the multi-stage separator is serially connected in the combined shell from top to bottom, and an overflow channel and an underflow channel are arranged in the wall of the combined shell; the mask is arc-shaped, and the mask buckle is placed on the outer wall of the upper connector to form a gas-liquid separation chamber with an upper opening, and the liquid inlet holes of the upper connector are distributed at the bottom of the gas-liquid separation chamber. After gas-liquid separation, the gas is discharged from the upper opening of the gas-liquid separation chamber, and the oil-water mixture enters the liquid inlet channel from the liquid inlet hole; the upper end is connected to the upper connector, and the upper connector is connected to the eccentric hole under the top bridge channel, and the oil-water mixture enters the liquid inlet channel from the liquid inlet hole. The connector is a cylinder with a liquid inlet cavity inside, the liquid inlet cavity is connected to the liquid inlet hole, the upper end of the liquid inlet cavity is connected to the eccentric through-axis hole, the bottom of the liquid inlet cavity is eccentrically contracted to form a liquid outlet hole, the groove surrounds the outside of the liquid outlet hole, the liquid outlet hole is connected to the lower threaded connection hole, an eccentric through-axis hole is arranged in the upper connector, a straight overflow channel runs through the upper connector, the eccentric overflow channel is formed by connecting the upper and lower ends of the oblique flow channel to the straight flow channel, the straight overflow channel and the eccentric overflow channel are respectively connected to the overflow channel in the combined shell, and the separated The oil phase is collected into the top bridge channel through the straight overflow channel and the eccentric overflow channel and discharged; the feed pipe surrounds the outside of the transmission shaft, the upper end of the feed pipe is inserted into the upper end connector and snapped into the groove, the annulus between the transmission shaft and the feed pipe is the liquid inlet channel, the oil-water mixture enters the multi-stage separator from the liquid inlet channel for oil-water separation, the multi-stage separator is connected to the overflow channel in the combined shell, and the multi-stage separator is also connected to the bottom flow channel, the separated water phase is collected into the bottom bridge channel through the bottom flow channel and discharged.

[0033] In this embodiment, there are two stages of separators, and each stage of separators includes three parallel-connected oil-water cyclone separators.

[0034] The invention uses a centrifugal pump at the top to control the overflow pressure of oil-water separation, and uses a centrifugal pump at the bottom to control the underflow pressure of oil-water separation, and adopts a single motor to drive the double centrifugal pumps; the oil-water mixed medium after the mask gravity separation and degassing enters the oil-water separation area through the liquid inlet hole of the upper connector, and after being processed by multiple oil-water cyclone separators, the oil phase and the water phase complete the cyclone separation, and the separated oil phase is extracted through multiple upward overflow channels for the next step of processing under the suction action of the top centrifugal pump, and the water phase is discharged and reinjected through multiple downward underflow channels under the suction action of the bottom centrifugal pump; the invention can complete the separation of the oil, gas and water three-phase medium under the condition of occupying a small space underground, and because the device is designed with an eccentric shaft, multiple small processing capacity cyclones can be replaced with a single larger processing capacity cyclone according to the processing capacity, and it only needs to replace the combined plate carrying the cyclones at the same time, and even a multi-stage series structure can be added to realize the efficient arrangement of the cyclones in parallel, and realize the processing of large processing capacity multi-phase medium underground in offshore oil fields.

[0035] The oil-gas-water separation module includes a mask 101, an upper connector 102, a primary housing upper half 103, a primary housing lower half 104, a secondary housing upper half 105, a secondary housing lower half 106, a bottom plug 107, a top bridge channel 108 and a bottom bridge channel 109, a secondary feed pipe 110, a primary feed pipe 111, an oil-water cyclone separator 112, a one-way check valve 113, an upper assembly plate 114, a primary lower assembly plate 115, and a secondary lower assembly plate 116, wherein the upper end of the top bridge channel 108 is connected by a screw The thread is connected to the centrifugal pump at the top, and two top overflow channels 1081 and a top through-shaft hole 1082 are opened in the center. The lower end is connected to the upper part of the upper connector 102 by thread. A shield 101 is welded on the outside of the upper connector 102 for gravity separation and degassing. The center of the lower part is threaded, and a liquid inlet hole 1021 is opened on the outer wall. The oil and water phases after degassing enter the device from here. A straight overflow channel 1022 and an eccentric overflow channel 1023 are left inside, and a groove 1024 is left at the bottom. The lower end is connected to the upper half 1024 of the first-stage shell. The first-stage housing upper half 103 is threadedly connected at the upper end, two overflow channels 1031 and an eccentric through-axis hole 1033 are provided in the first-stage housing upper half 103, and the lower end thereof is threadedly connected to the upper end of the first-stage housing lower half 104, and the first-stage housing lower half 104 is provided with two through overflow channels 1041, and the lower end thereof is threadedly connected to the top of the second-stage housing upper half 105, and the second-stage housing upper half 105 is provided with two overflow channels 1051, three underflow channels 1052 and an eccentric through-axis hole 1053, and the bottom thereof is threadedly connected to the top of the second-stage housing lower half 106. The lower half 106 of the secondary shell is threadedly connected with three through-flow channels 1061, and the bottom end of the channels is threadedly connected with the top end of the bottom plugger 107. The bottom plugger 107 is provided with three underflow channels 1071, three underflow channels 1072, an eccentric through-axis hole 1073 and an underflow drainage hole 1074. The bottom is threadedly connected with the upper end of the bottom bridge channel 109. The bottom bridge channel 109 is provided with an through-axis drainage hole 1091, and the lower end is threadedly connected with the motor. The lower end of the motor is connected with a centrifugal pump for extracting the separated water phase for reinjection.

[0036] The oil-water two-phase medium after degassing enters the oil-water separation area through two feed pipes. A primary feed hole 1111 is left on the outer wall of the primary feed pipe 111. The top end is clamped between the upper connector 102 and the upper half 103 of the primary shell through a groove 1024. The bottom end and the upper half 105 of the secondary shell are clamped to fix the secondary feed pipe 110. A secondary feed hole 1101 is opened on the outer wall of the secondary feed pipe 110. Both sets of upper combination plates 114 are designed with a guide platform 1141 and an eccentric shaft hole four 1142, and are respectively installed in the upper half 103 of the primary shell and the upper half 105 of the secondary shell through threads. The primary lower combination plate 115 is installed in the upper half 103 of the primary shell through threads, and it has an eccentric shaft hole five 1151 and three cyclone fixing holes one 1152, a chute 1153 is provided in the cyclone fixing hole 1152, the secondary lower combination plate 116 is installed inside the upper half 105 of the secondary shell through a thread, and an eccentric through-axis hole 1161 and three cyclone fixing holes 1162 are provided in the cyclone fixing hole 1162, and a chute 1163 is provided in the cyclone fixing hole 1162. The outer wall of the oil-water cyclone separator 112 is provided with a liquid inlet 1121 and a card bead 1123, which is fixed to the primary lower combination plate 115 and the secondary lower combination plate 116 through the chute 1153 and the chute 1163, and a spiral flow channel 1124 and an overflow pipe 1125 are installed inside, and an underflow port 1122 is also provided at the bottom, and the one-way check valve 113 is clamped in each overflow and underflow channel to prevent backflow in the overflow channel and the underflow channel.

[0037] When the oil, gas and water separation module is connected and installed, it is necessary to ensure that each overflow channel and bottom flow channel are completely aligned, the straight overflow channel 1022 and the eccentric overflow channel 1023 are aligned with their corresponding top overflow channel 1081, the two overflow channel one 1031 are aligned with the straight overflow channel 1022 and the eccentric overflow channel 1023 respectively, the two overflow channel two 1041 are aligned with the two overflow channel one 1031 and the two overflow channel three 1051; the three bottom flow channels two 1061 are aligned with the three bottom flow channels one 1052 and the three bottom flow channels three 1071 respectively, to ensure that all flow channels are unobstructed.

[0038] The transmission shaft 117 passes eccentrically through the entire device, and its two ends are respectively connected to the motor and the centrifugal pump.

[0039] After the connection is completed, since the device is eccentrically designed, the oil-gas-water mixed medium can be initially separated by gravity through the mask 101 to separate the gas phase contained therein, and then the oil-water two-phase medium enters the interior of the device through the liquid inlet 1021, and then enters the two-stage separation area through the primary feed hole 1111 and the secondary feed hole 1101. After separation by multiple oil-water cyclone separators 112, the separated oil phases are gathered together and produced through multiple overflow channels, and the water phase is reinjected through multiple bottom flow channels, thereby realizing the separation of the oil-gas-water two-phase flow.

[0040] The upper end of the top bridge channel 108 is connected to the centrifugal pump at the top through a thread. Two top overflow channels 1081 and a top through-axis hole 1082 are opened in the center of the top bridge channel 108. The threaded structure at the lower end of the top bridge channel 108 is threadedly connected to the upper part of the upper connector 102.

[0041] The shield 101 is connected to the outside of the upper connector 102 by welding. The center of the lower part of the upper connector 102 is threaded, and a liquid inlet hole 1021 is opened on the outside. A straight overflow channel 1022 and an eccentric overflow channel 1023 are also opened inside. A groove 1024 is left at the bottom, and its lower end is threadedly connected to the upper end of the upper half 103 of the first-stage shell.

[0042] The upper half of the first-stage shell is a cylinder with an open lower end, and the top of the cylinder has a connector. The cylinder wall is provided with an overflow channel. The connector is a solid cylinder with an eccentric through-axis hole. The connector is threadedly connected to the lower threaded connection hole of the upper connector. The outer wall of the lower half of the first-stage shell is provided with an overflow channel. The upper half of the first-stage shell and the lower half of the first-stage shell constitute a first-stage shell. The three oil-water cyclone separators of the first-stage separation structure are located in the first-stage shell. The upper half of the first-stage shell 103 has two overflow channels 1031 and an eccentric through-axis hole 1033, and its lower end is connected to the upper end of the lower half of the first-stage shell 104 by threads. The lower half of the first-stage shell 104 has two through overflow channels 1041, and its lower end is connected to the top of the upper half of the second-stage shell 105 by threads.

[0043] The upper half of the secondary shell is a cylinder with an open lower end, and the top of the cylinder is provided with a connector. An internal thread is arranged in the cylinder, and the internal thread is used for threading the upper and lower combined plates. An oil overflow cavity is provided between the upper combined plate and the top of the cylinder, and an overflow channel is provided in the cylinder wall above the upper combined plate, and the overflow channel is communicated with the oil overflow cavity; there is also an underflow channel in the cylinder wall, and an eccentric through-axis hole is provided in the connector, and the eccentric through-axis hole is provided near the outer edge of the connector, and the space outside the eccentric through-axis hole of the connector forms a tapered arc groove downwardly, and an inclined underflow channel is provided at the bottom of the arc groove, and the inclined underflow channel is communicated with the underflow channel in the cylinder wall; the connector is threadedly connected to the lower port of the lower half of the primary shell, and the underflow port of the primary oil-water cyclone separator is provided above the inclined underflow channel; the outer wall of the lower half of the secondary shell is provided with an underflow channel, and the upper half of the secondary shell and the lower half of the secondary shell constitute the secondary shell, and the three oil-water cyclone separators of the secondary separation structure are located in the secondary shell. The upper part 105 of the secondary shell is provided with two overflow channels 3 1051, three bottom flow channels 1 1052 and an eccentric through-axis hole 2 1053, the bottom of which is threadedly connected to the top of the lower part 106 of the secondary shell. The lower part 106 of the secondary shell is provided with three penetrating bottom flow channels 2 1061, the bottom end of which is threadedly connected to the top of the bottom end plugger 107.

[0044] The bottom end plugger is a variable diameter cylinder with a drainage cavity inside, and an outer step is formed between the column head and the column body. An underflow channel is arranged at the outer step, and the underflow channel connects the underflow channel in the lower half of the secondary shell with the drainage cavity, and the bottom of the drainage cavity is eccentrically contracted to form an underflow drainage hole; an eccentric through-axis hole is arranged in the column head, and the eccentric through-axis hole is arranged close to the outer edge of the connecting head, and the space outside the eccentric through-axis hole of the connecting head forms a gradually shrinking arc groove downward, and an underflow channel is arranged at the bottom of the arc groove, and the underflow channel is connected to the drainage cavity, and the underflow port of the first-stage oil-water cyclone separator is arranged above the underflow channel at the bottom of the arc groove. The bottom plugger 107 has three bottom flow channels 3 1071, three bottom flow channels 4 1072, an eccentric through-axis hole 3 1073 and a bottom flow drainage hole 1074, and its bottom is threadedly connected to the upper end of the bottom bridge channel 109. The bottom bridge channel 109 has an through-axis drainage hole 1091, and its lower end is threadedly connected to the motor, and a centrifugal pump is connected to the lower end of the motor.

[0045] The present invention has a two-stage separator, each stage of the separator includes a plurality of parallel oil-water cyclone separators, an upper combination plate, and a lower combination plate. The upper combination plate and the lower combination plate are arranged at intervals and fixed in a combination shell. The upper combination plate is provided with an eccentric shaft hole and a plurality of guide platforms. The center of each guide platform is provided with an overflow pipe hole. The lower combination plate is provided with an eccentric shaft hole and a plurality of oil-water cyclone separators. A slide groove is provided in each cyclone fixing hole. The oil-water cyclone separator shell is integrally composed of a straight tube section, a primary cone section, and a secondary cone section. A card bead is provided outside the straight tube section of the oil-water cyclone separator shell, and the straight tube section is provided with a liquid inlet. The liquid inlet corresponds to the feed hole of the feed pipe. The oil-water cyclone separator is fixed to the cyclone fixing hole of the lower combined plate through a card bead and a slide groove. A spiral flow channel is arranged inside the oil-water cyclone separator. The spiral flow channel is located in the straight section. The lower opening of the secondary cone section of the oil-water cyclone separator shell is the bottom flow port of the oil-water cyclone separator. The overflow pipe passes through the spiral flow channel and extends from the oil-water cyclone separator shell. The upper end of the overflow pipe is inserted into an overflow pipe hole of a guide platform of the upper combined plate. The overflow pipe is connected to the overflow channel in the combined shell through the oil discharge channel. The bottom flow port of the oil-water cyclone separator is connected to the bottom flow channel in the combined shell.

[0046] A primary feed hole 1111 is left on the outer wall of the primary feed pipe 111, and its top end is clamped between the upper connector 102 and the upper half 103 of the primary shell through a groove 1024, and its bottom end and the upper half 105 of the secondary shell are clamped to fix the secondary feed pipe 110, and a secondary feed hole 1101 is opened on the outer wall of the secondary feed pipe 110;

[0047] The two sets of upper assembly plates 114 are designed with a guide platform 1141 and an eccentric shaft hole 1142, which are respectively installed inside the first-stage housing upper half 103 and the second-stage housing upper half 105 through threads. The first-stage lower assembly plate 115 is installed inside the first-stage housing upper half 103 through threads, and has an eccentric shaft hole 1151 and three cyclone fixing holes 1152, and a slide groove 1153 is provided in the cyclone fixing hole 1152. The second-stage lower assembly plate 116 is installed inside the second-stage housing upper half 105 through threads, and has an eccentric shaft hole 1161 and three cyclone fixing holes 1162, and a slide groove 1163 is provided in the cyclone fixing hole 1162.

[0048] The outer wall of the oil-water cyclone separator 112 is provided with a liquid inlet 1121 and a card bead 1123, which is fixed to the first-level lower assembly plate 115 and the second-level lower assembly plate 116 through a slide groove 1153 and a slide groove 2 1163. A spiral flow channel 1124 and an overflow pipe 1125 are installed inside, and an underflow port 1122 is also provided at the bottom. The one-way check valve 113 is carded in each overflow and underflow channel to prevent backflow in the overflow channel and the underflow channel.

[0049] like Figure 1 As shown, the device is placed vertically in the casing downhole. When working, due to the eccentric design of the entire device, the flow channel outside the mask 101 is narrower than the flow channel on the other side. The flow rate here is faster and the pressure is lower. The gas-containing oil-water mixture is gravity separated and degassed before the mask 101. The gas phase continues to flow upward in the casing, while the oil-water mixture enters the inner side of the mask 101 under the action of gravity. Figure 2 The oil-water mixture enters the device from the liquid inlet 1021, flows through the cavity between the primary feed pipe 111, the secondary feed pipe 110 and the transmission shaft 117, and then enters the oil-water separation area from the primary feed hole 1111 and the secondary feed hole 1101, and enters the oil-water cyclone separator 112 from the liquid inlet 1121 to complete the oil-water separation. The oil phase flows out from the overflow pipe 1125, and enters the straight overflow channel 1022 and the eccentric overflow channel 1023 in the upper connector 102 through two overflow channels consisting of the overflow channel 1 1031, the overflow channel 2 1041 and the overflow channel 3 1051, and then overflows from the top. The flow channel 1081 is pumped out by the centrifugal pump, and the separated water phase flows out through the bottom flow port 1122. The water phase separated by the first-stage cyclone enters the bottom end plug 107 through three bottom flow channels consisting of bottom flow channel 1 1052, bottom flow channel 2 1061 and bottom flow channel 3 1071, while the water phase separated by the second-stage cyclone directly enters the bottom end plug 107 through bottom flow channel 4 1072. After that, the water phase flows through the bottom flow drainage hole 1074 and the shaft drainage hole 1091 and is pumped out and re-injected by the centrifugal pump. One-way check valves 113 are installed in the overflow channel and the bottom flow channel to prevent fluid backflow. Figure 3As shown, the device is composed of a mask 101, an upper connector 102, a primary housing upper half 103, a primary housing lower half 104, a secondary housing upper half 105, a secondary housing lower half 106, a bottom end plug 107, a top bridge channel 108 and a bottom bridge channel 109, a secondary feed pipe 110, a primary feed pipe 111, an oil-water cyclone separator 112, a one-way check valve 113, an upper assembly plate 114, a primary lower assembly plate 115, a secondary lower assembly plate 116 and a transmission shaft 117, wherein the primary housing lower half 104 is provided with two through overflow channels 106-107. There are three bottom flow channels 2 that penetrate through, and the outer walls of the first-level feed pipe 111 and the second-level feed pipe are respectively provided with a first-level feed hole 1111 and a second-level feed hole 1101. A guide platform 1141 and an eccentric shaft hole 4 1142 are provided on the upper assembly plate 114. An eccentric shaft hole 5 1151 and three cyclone fixing holes 1 152 are provided on the first-level lower assembly plate 115. A chute 1 153 is also provided in the cyclone fixing hole 1 152. An eccentric shaft hole 6 1161 and three cyclone fixing holes 2 1162 are provided on the second-level lower assembly plate 116. A chute 2 1163 is also provided in the cyclone fixing hole 2 1162. The appearance and cross-sectional view of the top bridge channel are shown in the figure below. Figure 4 As shown, a top through-shaft hole 1082 is provided inside thereof for the transmission shaft 117 to pass through, and two top overflow channels 1081 are provided inside thereof for the oil phase to pass through. Figure 5 This is a cross-sectional view of the appearance of the bottom bridge channel, which has an axial drainage hole 1091 inside, through which the transmission shaft 117 connecting the top centrifugal pump and the bottom motor passes. In addition, the separated water phase also flows through the hole, and then is pumped out and reinjected by the centrifugal pump at the bottom through the flow channel in the motor. Figure 6 The upper connector has an appearance and a cross-sectional view. The degassed oil-water mixture enters the device from the liquid inlet 1021 and is separated. A straight overflow channel 1022 and an eccentric overflow channel 1023 are provided inside the device. Both channels are for the separated oil phase to pass through without interfering with each other and avoiding the transmission shaft channel. In addition, a groove 1024 is provided at the bottom end for clamping the first-stage feed pipe 111. The appearance and cross-sectional view of the upper half of the first-stage housing are shown in FIG. Figure 7 As shown, two overflow channels 1031 are opened at the outer end for oil phase to pass through, and an eccentric through-shaft hole 1032 is opened in the middle, through which the first-stage feed pipe 111 passes, and the inner part of the second-stage housing has threads for installing the upper assembly plate 114 and the first-stage lower assembly plate 115. The appearance and cross-sectional view of the upper half of the second-stage housing are shown in FIG. Figure 8 As shown, two overflow channels 1051 are opened at the outer end, three bottom flow channels 1052 are opened in the top groove for discharging the separated water phase, and an eccentric through-axis hole 1053 is opened in the middle, through which the secondary feed pipe 110 passes, and the inside is also threaded for installing the upper combination plate 114 and the secondary lower combination plate 116. Fig. 9The bottom plug is shown in the appearance and cross-sectional view. The outer end of the plug has three bottom flow channels 1071 for the water phase to flow through. The top groove has three bottom flow channels 1072 for discharging the separated water phase. There is also an eccentric through-shaft hole 1073 in the middle for the transmission shaft 117 to pass through. The bottom has a bottom flow drainage hole 1074. The separated water phase eventually flows out from here and is pumped out and re-injected after passing through the bottom bridge channel 109 and the motor. In addition, the transmission shaft 117 also passes through here. The appearance and cross-sectional view of the oil-water cyclone separator are shown in the figure. Fig.10 As shown, the oil-water mixture enters the cyclone from the liquid inlet 1121, and undergoes a strong swirling motion after passing through the spiral flow channel 1124. The light oil phase gathers toward the axis and flows out from the overflow pipe 1125, while the heavy water phase flows toward the side wall and flows out from the bottom flow port 1122, completing the separation of the oil and water phases. In addition, a card bead 1123 is left on the outer wall of the cyclone to fix the cyclone in the chute 1 1153 and the chute 2 1163.

[0050] The overall structure of the present invention is simple, and it can realize the efficient separation of oil, gas and water three-phase media in a small space underground, and has a wide range of applications. The device utilizes the combination of gravity separation technology and cyclone technology to realize the efficient separation of multiphase media. The separation area is reasonably allocated through the innovative eccentric, single-stage parallel and multi-stage series structural layout, and the efficient parallel arrangement of cyclones is realized. It has extremely high applicability, greatly improves the recovery rate of the oil field, increases its processing capacity, enhances the economy of the production system, and reduces the operating pressure of subsequent separation equipment.

Claims

1. An eccentric over-axis multiphase medium high-efficiency separation device for an ultra-high liquid production oil well, characterized by: It includes an oil-gas-water separation module and a transmission shaft. The transmission shaft passes eccentrically through the oil-gas-water separation module. The two ends of the transmission shaft are respectively connected to the top and bottom centrifugal pumps, and the bottom centrifugal pump is connected to the motor; the oil-gas-water separation module includes a top bridge channel, an upper connector, a mask, a combined shell, a multi-stage separator, a bottom plugger and a bottom bridge channel. The upper end of the combined shell is connected to the upper connector, the upper connector is connected to the lower eccentric hole of the top bridge channel, the lower end of the combined shell is connected to the bottom plugger, the bottom plugger is connected to the upper eccentric hole of the bottom bridge channel, the multi-stage separator is connected in series in the combined shell from top to bottom, and an overflow channel and an underflow channel are arranged in the wall of the combined shell; the mask is arc-shaped, and the mask buckle is placed on the outer wall of the upper connector to form a gas-liquid separation chamber with an upper opening, and the liquid inlet holes of the upper connector are distributed at the bottom of the gas-liquid separation chamber. After gas-liquid separation, the gas is discharged from the upper opening of the gas-liquid separation chamber, and the oil-water mixture enters the liquid inlet channel from the liquid inlet hole; the upper connector has a liquid inlet cavity inside The cylinder, the liquid inlet cavity is connected with the liquid inlet hole, the upper end of the liquid inlet cavity is connected with the eccentric through-axis hole inside the upper connector, the bottom of the liquid inlet cavity is eccentrically contracted to form a liquid outlet hole, the groove surrounds the outside of the liquid outlet hole, the liquid outlet hole is connected with the lower threaded connection hole, the straight overflow channel runs through the upper connector, the eccentric overflow channel is formed by connecting the upper and lower ends of the inclined flow channel to the straight channel, the straight overflow channel and the eccentric overflow channel are respectively connected with the overflow channel in the combined shell, and the separated oil phase is collected to the top bridge channel through the straight overflow channel and the eccentric overflow channel and discharged; when the feed pipe is installed, it surrounds the outer side of the transmission shaft, leaving a flow gap in the middle, the upper end of the feed pipe is inserted into the upper connector and clamped in the groove, the annulus between the transmission shaft and the feed pipe is the liquid inlet channel, the oil-water mixture enters the multistage separator from the liquid inlet channel to separate oil and water, the multistage separator is connected with the overflow channel in the combined shell, and the multistage separator is also connected with the bottom flow channel, and the separated water phase is collected to the bottom bridge channel through the bottom flow channel and discharged; The multi-stage separator comprises a plurality of parallel oil-water cyclone separators, an upper combination plate and a lower combination plate. The upper combination plate and the lower combination plate are arranged at intervals and fixed in a combination shell. The upper combination plate is provided with an eccentric through-axis hole and a plurality of guide platforms. The center of each guide platform is provided with an overflow pipe hole. The lower combination plate is provided with an eccentric through-axis hole and a plurality of oil-water cyclone separators. A slide groove is provided in each cyclone fixing hole. The oil-water cyclone separator shell is integrally composed of a straight tube section, a primary cone section and a secondary cone section. A card bead is provided outside the straight tube section of the oil-water cyclone separator shell. The straight tube section is provided with a liquid inlet, and the liquid inlet is connected to the inlet. The feed hole of the material pipe corresponds to the feed hole of the material pipe. The oil-water cyclone separator is fixed in the cyclone fixing hole of the lower combined plate through a card bead and a slide groove. A spiral flow channel is arranged inside the oil-water cyclone separator. The spiral flow channel is located in the straight section. The lower opening of the secondary cone section of the oil-water cyclone separator shell is the bottom flow port of the oil-water cyclone separator. The overflow pipe passes through the spiral flow channel and extends from the oil-water cyclone separator shell. The upper end of the overflow pipe is inserted into an overflow pipe hole of a guide platform of the upper combined plate. The overflow pipe is communicated with the overflow channel in the combined shell to form an oil discharge channel. The bottom flow port of the oil-water cyclone separator is communicated with the bottom flow channel in the combined shell.

2. The downhole eccentric over-axis multiphase medium efficient separation device for ultra-high liquid production oil wells according to claim 1 is characterized by: The multi-stage separator has two stages, namely a primary separator and a secondary separator. Both the primary separator and the secondary separator have three parallel-connected oil-water cyclone separators.

3. The downhole eccentric over-axis multiphase medium efficient separation device for ultra-high liquid production oil wells according to claim 2 is characterized by: The combined shell is composed of a primary shell upper half, a primary shell lower half, a secondary shell upper half, and a secondary shell lower half connected in sequence; The upper half of the first-stage shell is a cylinder with an open lower end, the top of the cylinder is provided with a connector, the cylinder wall is provided with an overflow channel, the connector is a solid cylinder, the connector is provided with an eccentric through-axis hole, and the connector is threadedly connected to the lower threaded connection hole of the upper connector; the outer wall of the lower half of the first-stage shell is provided with an overflow channel, the upper half of the first-stage shell and the lower half of the first-stage shell constitute a first-stage shell, and the three first-stage oil-water cyclone separators of the first-stage separator are located in the first-stage shell; The upper half of the secondary shell is a cylinder with an open lower end, and the top of the cylinder is provided with a connector. An internal thread is arranged in the cylinder, and the internal thread is used to threadably connect the upper combined plate and the lower combined plate. An oil overflow chamber is provided between the upper combined plate and the top of the cylinder, and an overflow channel is provided in the cylinder wall above the upper combined plate and communicated with the oil overflow chamber; there is also an underflow channel in the cylinder wall, and an eccentric through-axis hole is provided in the connector, and the eccentric through-axis hole is provided close to the outer edge of the connector, and the space outside the eccentric through-axis hole where the connector is located forms a tapered arc groove downwardly, and an inclined underflow channel is provided at the bottom of the arc groove, and the inclined underflow channel is communicated with the underflow channel in the cylinder wall; the connector is threadedly connected to the lower port of the lower half of the primary shell, and the underflow port of the primary oil-water cyclone separator is provided above the inclined underflow channel; the outer wall of the lower half of the secondary shell is provided with an underflow channel, and the upper half of the secondary shell and the lower half of the secondary shell constitute the secondary shell, and the three secondary oil-water cyclone separators of the secondary separator are located in the secondary shell.

4. The downhole eccentric over-axis multiphase medium efficient separation device for ultra-high liquid production oil wells according to claim 3 is characterized by: The bottom end plugger is a variable diameter cylinder with a drainage cavity inside, an outer step is formed between the column head and the column body, and a bottom flow channel is arranged at the outer step, the bottom flow channel connects the bottom flow channel in the lower half of the secondary shell with the drainage cavity, and the bottom of the drainage cavity is eccentrically contracted to form a bottom flow drainage hole; an eccentric through-axis hole is arranged in the column head, the eccentric through-axis hole is arranged close to the outer edge of the column head, the column head is located in the space outside the eccentric through-axis hole to form a gradually shrinking arc groove downward, a bottom flow channel is arranged at the bottom of the arc groove, the bottom flow channel is communicated with the drainage cavity, and the bottom flow port of the first-level oil-water cyclone separator is arranged above the bottom flow channel at the bottom of the arc groove.

5. The downhole eccentric over-axis multiphase medium efficient separation device for ultra-high liquid production oil wells according to claim 4 is characterized in that: A one-way check valve is arranged in the overflow channel in the wall of the combined shell, and a one-way check valve is arranged in the bottom flow channel arranged in the wall of the combined shell.

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