Applicable to multi-stage parallel device of downhole cyclone separator for injection and production in the same well of offshore oil field

Abstract

The present invention relates to a multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field. The device comprises a multi-stage cyclone separator, which is connected in sequence from top to bottom. Each stage of the cyclone separator has a combined sleeve structure. The multi-stage combined sleeve structure is connected in sequence to form an assembled shell. An oil-water mixed liquid inlet channel, an oil delivery channel, and a drainage channel are arranged in the assembled shell wall. The multi-stage cyclone separator is connected in parallel with the oil-water mixed liquid inlet channel through its oil-water mixed liquid inlet port. The parallel cyclones of each stage are fed with liquid at the same time, and oil-water separation work is performed at the same time, and the oil phase is lifted upward at the same time. The upper end of the upper sleeve of the first-stage cyclone is connected to the liquid inlet pipe through a bridge channel, and the liquid inlet pipe is connected to the oil-water mixed liquid inlet channel. The cyclone separator comprises an upper sleeve, a lower sleeve, a spiral flow channel, an oil-water separation cone, and a bridge channel. The present invention can improve the recovery rate of offshore oil fields and can continuously process large-volume offshore oil-water mixed liquid separation.

Description

Technical Field

[0001] The invention relates to a device capable of efficiently separating a large displacement oil-water mixture on an offshore platform, and in particular to a multi-stage parallel device for downhole cyclone separators suitable for the same well injection and production in an offshore oil field. Background Art

[0002] With the continuous development of my country's oil extraction technology, oil extraction has gradually entered the late stage of high water content or even ultra-high water content, resulting in increasingly complex extraction media. The situation of offshore platform extraction in my country is complicated. Faced with problems such as high water content in produced fluids and oil-water emulsification, it is difficult to meet the recovery standards by gravity sedimentation alone. In addition, the space and load-bearing capacity of offshore platforms are limited. It is urgent to install compact, lightweight and efficient separation equipment to reduce the occupied area and platform load.

[0003] In order to solve the problems of low efficiency and complex process flow of crude oil dehydration in offshore oil fields, technicians have proposed some solutions. Solution 1, as shown in Chinese patent document CN202111457180.2, the oilfield produced liquid is mixed with chemical agents, heated and then enters the primary electric field built-in enhanced demulsification type three-phase separator in turn, and the secondary electric field built-in enhanced demulsification type three-phase separator is demulsified and dehydrated. The crude oil after secondary dehydration is transported to the tubular electric field demulsification separator for further separation, and the separated qualified crude oil is transported out. However, under this solution, the heating temperature and the addition of chemicals will increase the operating cost. At the same time, the separated gas will carry a small amount of oil droplets. The use of chemical agents in the enhanced demulsification process will aggravate marine pollution. During the treatment of oily wastewater entering the hydrocyclone separator, the separated water phase will also contain a small amount of oil phase. Although the three-phase separation of oil, gas and water is achieved, under this solution, the separation efficiency of the oil and water phases is low, and the offshore processing volume is large, so it is difficult to achieve efficient separation. In addition, there is a device described in Chinese patent document CN201120515123.0 that uses a two-stage cyclone to separate multiple media, but the device occupies a large space, is complex, and is not easy to disassemble and repair. In addition, the device described in Chinese patent document CN202011504895.4 improves the separation of oil, gas and water by setting a three-stage columnar gas-liquid cyclone separator and a horizontal three-phase gravity separator in series. However, it is difficult to achieve effective separation of oil and water by gravity sedimentation alone. When the inlet liquid flow rate is low, when the mixed liquid is separated from the gas-liquid to the oil-water separation stage, the mixed liquid flow rate will be too small, thereby reducing the oil-water separation efficiency, and the processing volume is small. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field. The multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field is used to solve the problems of low efficiency of crude oil dehydration in offshore oil fields and complex process flow in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows: the multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field comprises a multi-stage cyclone separator, the multi-stage cyclone separators are connected in sequence from top to bottom, the cyclone separators at each stage have a combined sleeve structure, the multi-stage combined sleeve structures are connected in sequence to form an assembled shell, an oil-water mixed liquid inlet channel, an oil delivery channel, and a drainage channel are arranged in the wall of the assembled shell, the multi-stage cyclone separator is connected in parallel with the oil-water mixed liquid inlet channel through its oil-water mixed liquid inlet port, the parallel cyclones at each stage are fed with liquid at the same time, oil-water separation work is performed at the same time, and the oil phase is lifted upward at the same time; the upper port of the upper sleeve of the first-stage cyclone is connected to the liquid inlet pipe through a bridge channel, and the liquid inlet pipe is communicated with the oil-water mixed liquid inlet channel;

[0006] The cyclone separator includes an upper sleeve, a lower sleeve, a spiral flow channel, an oil-water separation cone, and a bridge channel. The combined sleeve structure is composed of an upper sleeve connected to a lower sleeve through a connector, and the lower end of the lower sleeve is connected to a bridge channel. The outer walls of the upper sleeve, the connector and the lower sleeve are all provided with an oil-water mixture inlet channel, an oil delivery channel and a drainage channel; the bridge channel is a cylinder with an annular boss on the outer wall, and the bridge channel is provided with an oil delivery port and a drainage port. The oil-water mixture inlet channel, the oil delivery channel and the drainage channel are provided along the circumference of the annular boss. The oil delivery port is communicated with the oil delivery channel, and the drainage port is communicated with the drainage channel. The annular boss of the bridge channel is exactly matched with the outer wall of the lower sleeve; the first spiral flow channel is arranged below the second spiral flow channel An overflow pipe is arranged at the center of the first spiral flow channel, a combination plate is arranged on the outer wall of the upper port of the overflow flow pipe, the combination plate is threadedly connected to the upper end sleeve, the upper port of the overflow flow pipe is opposite to the inverted cone of the second spiral flow channel, the oil-water mixed liquid inlet of the oil-water mixed liquid inlet channel is arranged under the combination plate, an oil-water separation cone is arranged below the first spiral flow channel, the lower port of the oil-water separation cone is connected to the bottom flow port collecting pipe, and the bottom flow port collecting pipe is connected to the oil delivery port of the bridge channel; the second spiral flow channel is arranged on the upper part of the upper end sleeve, an overflow port is arranged at the spiral groove in the middle part of the second spiral flow channel, the overflow port is communicated with the overflow pipe arranged in the center of the second spiral flow channel, the overflow pipe extends into the oil delivery port of the bridge channel of the upper-stage cyclone separator, and an inverted cone is arranged in the center of the lower end of the second spiral flow channel.

[0007] In the above scheme, there are three levels of cyclone separators, namely, a primary cyclone separator, a secondary cyclone separator, and a tertiary cyclone separator; the upper end of the liquid inlet pipe is threadedly connected to the oil pipe coupling; the liquid inlet pipe is threadedly connected to the bridge channel thereunder, and the lower end of the bridge channel is threadedly connected to the upper sleeve.

[0008] In the above scheme, the lower end of the upper sleeve is threadedly connected to the connecting piece, the connecting piece is threadedly connected to the lower sleeve, the oil-water separation cone is threadedly connected to the lower sleeve; the lower sleeve is threadedly connected to the upper end of the bridge channel, and the bottom flow port oil phase collection pipe is threadedly connected to the oil delivery port of the bridge channel.

[0009] In the above scheme, the oil-water mixture liquid inlet channel of the upper sleeve, the oil-water mixture liquid inlet channel of the connecting piece, the oil-water mixture liquid inlet channel of the lower sleeve and the oil-water mixture liquid inlet channel of the bridge channel are connected in sequence from top to bottom to form a primary oil-water mixture liquid inlet channel, and the oil-water mixture liquid inlet channels of each level are connected in sequence from top to bottom to form an oil-water mixture liquid inlet channel in the outer wall of the combined sleeve structure. After the cyclones of each level in parallel separate oil and water at the same time, the oil phase is collected in the oil delivery channel, and the water phase is collected in the drainage channel.

[0010] In the above scheme, the oil delivery channel of the upper sleeve, the oil delivery channel of the connecting piece, the oil delivery channel of the lower sleeve and the oil delivery channel of the bridge channel are connected in sequence from top to bottom to form a primary oil delivery channel, and the oil delivery channels of each level are connected in sequence from top to bottom to form an oil delivery channel in the outer wall of the combined sleeve structure; the drainage channel of the upper sleeve, the drainage channel of the connecting piece, the drainage channel of the lower sleeve and the drainage channel of the bridge channel are connected in sequence from top to bottom to form a primary drainage channel, and the drainage channels of each level are connected in sequence from top to bottom to form a drainage channel in the outer wall of the combined sleeve structure.

[0011] When the cyclones of each level in the above scheme are working, the oil-water mixture is accelerated and centrifuged through the first spiral flow channel, and the primary gas-liquid separation is performed. The water phase is distributed on the outside, and the oil phase is concentrated in the middle. The overflow port of the first spiral flow channel lifts the oil phase upward to the second spiral flow channel through the overflow pipe; the water phase flows out from the oil-water separation cone, flows into the drainage channel from the drainage port of the bridge channel, and is collected below; the small amount of oil phase contained in the middle of the oil-water separation cone is collected by the oil phase collection pipe at the bottom flow port, flows into the oil delivery port of the bridge channel, and then flows into the oil delivery channel and is lifted to the ground;

[0012] The oil phase lifted to the second spiral flow channel is drained by the inverted cone and flows into the second spiral flow channel for further oil-water fine separation. After the second separation, the oil phase is concentrated in the center under the action of centrifugal force and flows into the overflow port of the second spiral flow channel. The overflow port lifts the oil phase upward through the overflow pipe to the oil delivery port of the upper-level bridge channel, and then flows into the oil delivery channel and is lifted to the ground; the water phase separated again is collected from the drainage port of the bridge channel to the drainage channel and then collected downward. Beneficial Effects

[0013] 1. The present invention allows the oil phase after oil-water separation to be finely separated again and the oil phase to be collected at the bottom flow port, which can improve the recovery rate of offshore oil fields and can continuously process the separation of large-volume offshore oil-water mixtures.

[0014] 2. The present invention can connect multiple cyclone separators in parallel according to the actual processing volume, thereby achieving high separation efficiency and rapid separation.

[0015] 3. After the primary cyclone separation of the present invention, the oil phase enters the secondary separation structure, and the oil phase after centrifugal acceleration separation enters the secondary oil phase re-separation device to complete the secondary oil-water separation, further improving the oil-water separation efficiency of the device.

[0016] 4. The present invention utilizes the centrifugal force to gather the oil phase in the middle of the bottom flow port, and an oil phase collecting device is arranged at the bottom flow port to separate the oil in the water phase, thereby improving the oil phase recovery rate.

[0017] 5. The present invention adds a slow-flow cone at the short-circuit flow generation position of the secondary oil-water separation device, and uses the slow-flow cone to change the internal flow field, thereby reducing the generation of short-circuit flow in the separation chamber and reducing the impact of short-circuit flow on separation efficiency.

[0018] 6. The present invention realizes multi-stage parallel connection of downhole cyclones and simultaneously connects secondary oil-water separation structures in series at the overflow ports of each stage of downhole cyclones to achieve fine oil-water separation.

[0019] 7. The present invention can realize that the cyclones at various levels are connected in parallel and simultaneously feed liquid and work at the same time. The secondary cyclone devices are connected in series inside the cyclones at various levels for fine separation. The oil phase collecting devices are arranged at the bottom flow ports of the cyclones at various levels. The cyclones at various levels are connected in parallel externally to increase the processing capacity, and are connected in series internally to increase the oil phase recovery rate. The practicality of the increased equipment can achieve maximum efficient separation in a limited space and improve the economic efficiency of oil field exploitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 and 2 are drawings of the present invention, wherein (a) is an overall appearance diagram of the present invention; and (b) is a cross-sectional view of the present invention.

[0021] Figure 2 Figure 2 is a diagram of a cyclone separator, where (a) is the appearance of a first-stage cyclone separator; (b) is the appearance of a second-stage cyclone separator; and (c) is the appearance of a third-stage cyclone separator.

[0022] Figure 3 This is a cross-sectional view of a first-stage cyclone separator.

[0023] Figure 4 This is an exploded view of the first-stage cyclone separator.

[0024] Figure 5 Figure 2 is a diagram of the liquid inlet pipe, where (a) is a half-section diagram of the liquid inlet pipe; (b) is an appearance diagram of the liquid inlet pipe; and (c) is a top view of the liquid inlet pipe.

[0025] Figure 6 Figure 2 is a diagram of an upper bridge type channel, wherein (a) is a cross-sectional view of the upper bridge type channel; and (b) is a top view of the upper bridge type channel.

[0026] Figure 7Figure 2 is a diagram of a first-stage upper sleeve, wherein (a) is a cross-sectional view of the first-stage upper sleeve; and (b) is a top view of the first-stage upper sleeve.

[0027] Figure 8 Figure 2 is a diagram of a first-level bridge channel, where (a) is a cross-sectional view of the first-level bridge channel; and (b) is a top view of the first-level bridge channel.

[0028] Fig. 9 This is a cross-sectional view of the first-stage second spiral flow channel.

[0029] Fig.10 This is a cross-sectional view of the secondary cyclone separator.

[0030] Fig.11 This is an exploded diagram of the secondary cyclone separator.

[0031] Fig.12 This is a cross-sectional view of a three-stage cyclone separator.

[0032] Fig.13 This is an exploded diagram of a three-stage cyclone separator.

[0033] Fig.14 Figure 1 is a drainage pipe diagram, where (a) is the appearance of the drainage pipe; (b) is the cross-sectional view of the drainage pipe.

[0034] In the figure: 101-upper oil pipe coupling, 102-liquid inlet pipe, 1021-total liquid inlet, 1022-total oil delivery port, 103-upper bridge channel, 1031-upper oil delivery port, 1032-upper drainage port, 1033-upper oil-water mixed liquid inlet channel, 1304-upper drainage channel, 1035-upper oil delivery channel, 104-first-level upper sleeve, 1041-first-level upper sleeve oil-water mixed liquid inlet, 1042-first-level upper sleeve oil-water mixed liquid inlet channel, 1043-first-level upper sleeve drainage channel, 1044-first-level upper sleeve oil delivery channel, 105-first-level connector, 106-first-level lower sleeve, 1061-first-level lower sleeve oil delivery port, 1 062-first-level lower sleeve oil-water mixture inlet channel, 1063-first-level lower sleeve drainage channel, 107-first-level second spiral flow channel, 1071-second overflow port, 108-first-level inverted cone, 109-first-level combination plate, 110-first-level first spiral flow channel, 1101-first overflow port, 111-oil-water separation cone, 1111-bottom flow port, 112-first-level bridge channel, 1121-first-level bridge channel oil delivery port, 1122-first-level bridge channel drainage port, 1123-first-level bridge channel drainage pipeline, 1124-first-level bridge channel oil-water mixture inlet channel, 1125-first-level bridge channel oil delivery pipeline, 113-first-level bottom flow port oil phase collecting pipe;

[0035] 201-secondary upper sleeve, 202-secondary connecting piece, 203-secondary lower sleeve, 204-secondary second spiral flow channel, 205-secondary inverted cone, 206-secondary second spiral flow channel combination plate, 207-secondary first spiral flow channel, 208-secondary oil-water separation cone, 209-secondary bridge channel, 210-secondary bottom flow outlet oil phase collection pipe;

[0036] 301-third-level upper sleeve, 302-third-level connecting piece, 303-third-level lower sleeve, 304-third-level second spiral flow channel, 305-third-level inverted cone, 306-third-level combination plate, 307-third-level first spiral flow channel, 308-third-level oil-water separation cone, 309-third-level bridge channel, 310-plug, 311-drain pipe, 3111-drain outlet, 312-lower oil pipe coupling. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings:

[0038] See also Figure 1-Figure 14 The multi-stage parallel device of downhole cyclone separators suitable for injection and production in the same well of offshore oil fields includes a multi-stage cyclone separator, which is connected in sequence from top to bottom, and each stage of the cyclone separator has a combined sleeve structure. The multi-stage combined sleeve structure is connected in sequence to form an assembled shell, and an oil-water mixed liquid inlet channel, an oil delivery channel, and a drainage channel are arranged in the wall of the assembled shell. The multi-stage cyclone separator is connected in parallel with the oil-water mixed liquid inlet channel through its oil-water mixed liquid inlet port. The parallel cyclones of each stage are fed with liquid at the same time and perform oil-water separation work at the same time. Multiple cyclone separators can be connected in parallel according to the actual processing volume. This embodiment connects three cyclone separators in parallel, including a first-stage cyclone separator containing an oil-water separation structure and a bottom flow port oil phase collection structure and an oil phase re-separation structure, a second-stage cyclone separator, and a third-stage cyclone separator.

[0039] Each level of cyclone separator contains an oil-water separation structure, an underflow oil phase collection structure and an overflow oil phase re-separation structure. The three cyclone separators perform the following work simultaneously: the oil-water mixture enters the oil-water separation structure of the three cyclone separators respectively through the inlet of the oil-water mixture inlet channel, and after the spiral centrifugal acceleration of the first spiral flow channel, the oil phase and the water phase complete cyclone separation, and the oil pipe on the oil phase is lifted to the overflow oil phase re-separation device. After de-oiling, the water phase still contains a small amount of oil phase, which is collected by the underflow oil phase collection pipe and flows into the bridge channel and then lifted to the ground; the overflow oil phase re-separation device cyclones the oil phase of the overflow again, and the separated oil phase gathers in the middle and is lifted from the inlet of the cyclone separation chamber column section through the bridge channel to merge with the underflow oil phase. The three cyclone separators work simultaneously, and the oil phases separated by the three cyclone separators are lifted upward at the same time, thereby improving the processing capacity.

[0040] Each cyclone separator includes an oil-water separation device and an overflow oil phase re-separation device. The oil-water separation device includes an upper oil pipe coupling, a liquid inlet pipe, an upper sleeve, a lower sleeve, a first spiral flow channel, an oil-water separation cone, a connector, a bridge channel and an underflow collection pipe; the upper sleeve is connected to the lower sleeve through a connector, and the lower end of the lower sleeve is connected to the bridge channel. The outer walls of the upper sleeve, the connector and the lower sleeve are all provided with an oil-water mixture liquid inlet channel, an oil delivery channel and a drainage channel; the bridge channel is a cylinder with an annular boss on the outer wall, and the bridge channel is provided with an oil delivery port and a drainage port. The oil-water mixture liquid inlet channel, an oil delivery channel and a drainage port are provided along the circumference of the annular boss, and the oil delivery port and the oil delivery channel are connected to each other. The channels are connected, the drain outlet is connected to the drain channel, the annular boss of the bridge channel just matches with the outer wall of the lower end sleeve; the first spiral channel is arranged below the second spiral channel, an overflow pipe is arranged at the center of the first spiral channel, a combination plate is arranged on the outer wall of the upper port of the overflow pipe, the combination plate is threadedly connected in the upper end sleeve, the upper port of the overflow pipe is facing the inverted cone of the second spiral channel, the oil-water mixed liquid inlet of the oil-water mixed liquid inlet channel is arranged under the combination plate, an oil-water separation cone is arranged below the first spiral channel, the lower port of the oil-water separation cone is connected to the bottom flow port collecting pipe, and the bottom flow port collecting pipe is connected to the oil delivery port of the bridge channel. The overflow port oil phase re-separation device includes an inverted cone, a second spiral flow channel, an oil-water separation chamber, a bridge channel and a sleeve; the second spiral flow channel is arranged on the upper part of the upper sleeve, and an overflow port is arranged at the spiral groove in the middle of the second spiral flow channel. The overflow port is communicated with an overflow pipe arranged in the center of the second spiral flow channel, and the overflow pipe extends into the oil delivery port of the bridge channel of the upper-level cyclone separator. An inverted cone is arranged in the center of the lower end of the second spiral flow channel. The oil-water separation structure allows the oil-water mixture to enter the second spiral flow channel through the liquid inlet. After spiral centrifugal acceleration, the oil phase and the water phase complete cyclone separation, and the oil pipe on the oil phase is lifted to the overflow port oil phase re-separation device. After de-oiling, the water phase still contains a small amount of oil phase, which is collected by the bottom flow oil phase collection pipe and flows into the bridge channel and then lifted to the ground; the overflow port oil phase re-separation device cyclones the oil phase of the overflow port again, and the separated oil phase gathers in the middle and is lifted from the overflow port of the second spiral flow channel column section through the bridge channel to merge with the bottom flow port oil phase; the present invention adopts a multi-stage parallel method to handle large-displacement oil-water separation in a short time and separate the oil phase more finely.

[0041] In the first-stage cyclone separator, the oil-water separation and bottom flow oil phase collection module includes an inlet pipe 102, an upper bridge channel 103, a first-stage upper sleeve 104, a first-stage connector 105, a first-stage lower sleeve 106, a first-stage combination plate 109, a first-stage first spiral flow channel 110, a first-stage oil-water separation cone 111, a first-stage bridge channel 112, a first-stage bottom flow oil phase collection pipe 113, the inlet pipe 102 has two total inlets 1021, a total oil delivery port 1022, the lower end of the inlet pipe 102 is threadedly connected to the upper end of the upper bridge channel 103, the upper end of the first-stage upper sleeve 104 is threadedly connected to the lower end of the upper bridge channel 103, and the first-stage upper sleeve includes a first-stage upper sleeve oil-water mixed liquid inlet 1041, two first-stage upper sleeves An oil-water mixture liquid inlet channel 1042, a first-level upper sleeve oil delivery channel 1043, and a first-level upper sleeve drainage channel 1044, a first-level combination plate 109 is fixed in the first-level upper sleeve 104 by threaded connection, a first-level first spiral flow channel 110 is welded on the first-level combination plate 109, the first-level upper sleeve 104 and the first-level lower sleeve 106 are threadedly connected to the upper and lower ends of the first-level connecting piece 105, the first-level lower sleeve includes two first-level lower sleeve oil-water mixture liquid inlet channels 1062, a first-level lower sleeve oil delivery channel 1061, and a first-level lower sleeve drainage channel 1063, and the first-level connecting piece includes two first-level connecting piece liquid inlet channels, a first-level connecting piece oil delivery channel, and a first-level connecting piece drainage channel. The oil-water mixture enters from the main liquid inlet 1021, flows through the upper bridge channel oil-water mixture liquid inlet channel 1033, the first-stage upper sleeve oil-water mixture liquid inlet channel 1042, and then enters the cyclone separation chamber for oil-water separation. Under the action of centrifugal force, the oil phase is concentrated in the center, flows out from the first-stage first spiral flow channel overflow port 1101 and enters the secondary oil-water separation device, and the water phase is discharged from the first-stage oil-water separation cone bottom flow port 1111, and the oil phase discharged from the bottom flow port is collected by the first-stage bottom flow oil port phase collection pipe 113.

[0042] In the primary cyclone separator, the secondary oil-water separation module includes a primary bridge channel 112, a primary upper sleeve 104, a primary second spiral flow channel 107, and a primary inverted cone 108. The upper end of the primary second spiral flow channel 107 is threadedly connected to the upper bridge channel 103, and the primary inverted cone 108 is threadedly connected to the lower end of the primary second spiral flow channel 107. The oil phase separated from the primary oil and water is lifted from the overflow port 1101 of the primary first spiral flow channel to the secondary oil-water separation chamber, and the primary inverted cone 108 is drained. After the secondary separation of the primary second spiral flow channel 107, the oil phase flows from the second overflow port 1071 into the upper oil delivery port 1031 of the upper bridge channel, and is collected from the bottom flow port through the upper oil delivery channel 1035.

[0043] like Figure 1As shown, the present invention is vertically placed in a downhole pipeline. When working, the oil-water mixture enters the oil-water mixture channel from the total liquid inlet 1021, flows through the upper bridge channel liquid inlet channel 1033, the first-level upper sleeve oil-water mixture liquid inlet channel 1042, and then enters the cyclone separation chamber for oil-water separation. After the mixed liquid is centrifugally accelerated through the first-level first spiral flow channel 110, the oil phase is distributed in the middle and flows out from the overflow port 1101 into the secondary oil-water separation device, and the water phase is discharged from the first-level oil-water separation cone bottom flow port 1111, and the oil phase discharged from the first-level oil-water separation cone bottom flow port is collected by the first-level bottom flow port oil phase collection pipe 113. The oil phase separated from the primary oil-water separation is lifted from the overflow port 1101 of the first spiral flow channel to the secondary oil-water separation chamber, and is drained by the first inverted cone 108. After secondary separation in the first second spiral flow channel 107, the oil phase flows from the second overflow port 1071 into the upper bridge channel oil delivery port 1031, and is merged with the oil phase collected by the bottom flow port through the upper oil delivery channel 1035.

[0044] At the same time, the oil-water mixture entering from the liquid inlet pipe 102 flows through the secondary cyclone separator at the same time, and the oil-water mixture enters the cyclone separation chamber. Under the action of centrifugal force, the oil phase is concentrated in the middle and increases continuously. The oil phase is discharged from the overflow port and enters the secondary oil-water separation device. After being drained by the secondary inverted cone 205 and diverted by oil and water again, the oil phase is discharged from the overflow port of the secondary second spiral flow channel 204, and is collected into the oil pipeline through the upper oil delivery port 1031 of the upper bridge channel. The bottom flow water phase is discharged from the spirally connected secondary bridge channel drain port. A small amount of oil phase is contained in the middle of the water phase, which is collected by the bottom flow oil phase collecting pipe and flows into the secondary bridge channel oil delivery port, and is collected in the oil pipeline and lifted upward to collect the oil phase collected after the secondary oil-water separation.

[0045] The oil-water mixture enters the three-stage cyclone separator at the oil-water mixture inlet of the three-stage upper sleeve. Under the centrifugal force of the three-stage first spiral flow channel 307, the oil phase is separated from the water phase, and the oil phase is lifted upward from the overflow port to the secondary oil-water separation device. After being separated again through the two-stage second spiral flow channel 304, the oil phase flows into the secondary bridge channel oil pipeline in the secondary cyclone separation device, and is merged with the oil phase collected by the secondary bottom flow oil phase collecting pipe 210. The oil phase at the bottom flow port of the three-stage cyclone separator is collected by the three-stage bottom flow oil phase collecting pipe 313 and is gathered in the three-stage bridge channel 309 oil phase collecting pipe. Finally, the oil phases of the first, second and third stage cyclone separators are all lifted to the ground through the oil pipeline, and the water phase flows into the underground through the drainage channel.

[0046] Figure 2 (a) is an appearance diagram of a primary cyclone separator, in which an upper oil pipe coupling 101 is threadedly connected to an upper end of a liquid inlet pipe 102 , and a lower end of the liquid inlet pipe 102 is threadedly connected to an upper end of an upper bridge channel 103 . Figure 2(b) is an appearance diagram of a secondary cyclone separator. The upper end of the secondary upper sleeve 201 is threadedly connected to the lower end of the primary bridge channel 112 in the primary cyclone separator, and the lower end is threadedly connected to the secondary connecting piece 202. The secondary upper sleeve 201 has two liquid inlet channels, one oil delivery channel, and one drainage channel. The connecting piece 202 has two liquid inlet channels, one oil delivery channel, and one drainage channel. The secondary lower sleeve 203 is threadedly connected to the secondary bridge channel 209. Figure 2 (c) is an appearance diagram of a three-stage cyclone separator, wherein the upper end of the third-stage upper sleeve 301 is threadedly connected to the secondary bridge channel 209 of the secondary cyclone separator, and the lower end is connected to the third-stage connecting piece 302, the lower end of the third-stage connecting piece 302 is threadedly connected to the third-stage lower sleeve 303, the third-stage lower sleeve 303 is threadedly connected to the third-stage bridge channel 309, the plug 310 is threadedly connected to the third-stage bridge channel 309, the drain pipe 311 is threadedly connected to the plug 310, and the lower oil pipe coupling 312 is threadedly connected to the drain pipe 311.

[0047] like Figure 5 As shown, the liquid inlet pipe 102 has two symmetrical total liquid inlets 1021 , a total oil delivery port 1022 , an internal thread connected to the upper bridge channel 103 , and an external thread connected to the upper oil pipe coupling 101 . Figure 6 An upper bridge channel structure is provided. Due to the centrifugal force of the oil-water mixture, the oil phase is distributed in the middle and the water phase is distributed on the periphery. Therefore, the upper oil delivery port 1031 is located in the middle and the upper drainage port 1032 is on the outside. Figure 7 A structure of a first-stage upper sleeve is provided, wherein the oil-water mixture flows through each stage of cyclone separation devices from the liquid inlet pipe outside the upper sleeve, and the oil-water mixture enters the cyclone chamber from the liquid inlet; the oil-water mixture liquid inlet of the upper sleeve is symmetrically distributed, and the first-stage upper sleeve drainage channel 1043 and the first-stage upper sleeve oil delivery channel 1044 are relatively distributed. Figure 8 A first-level bridge channel structure is provided, with a first-level bridge channel oil delivery port 1121 in the middle, the upper end is used to transport the oil phase collected by the bottom flow port, and the lower end is used to collect the oil phase collected by the secondary separation device. The first-level bridge channel drainage port 1122 is distributed on the periphery, and the water phase is discharged downward through the first-level bridge channel drainage pipe 1123, and the first-level bridge channel oil delivery channel 1125 lifts the oil phase upward. Fig. 9 It is a cross-sectional view of the first-stage second spiral flow channel. The first-stage second spiral flow channel 107 is connected to the upper bridge channel 103 through threads. The second overflow port 1071 is opened at two-thirds of the first-stage second spiral flow channel. The lower end is threadedly connected to the first-stage inverted cone 108 for drainage.

[0048] Figure 10-11A structure of a secondary cyclone separator is provided, wherein the lower end of the secondary upper sleeve 204 is threadedly connected to the upper end of the secondary connecting piece 202, the lower end of the secondary connecting piece 202 is threadedly connected to the secondary lower sleeve 203, the secondary first spiral flow channel 207 is welded to the secondary combination plate 206, the secondary combination plate 206 is threadedly connected to the inner wall of the secondary upper sleeve 201, the secondary oil-water separation cone 208 is threadedly connected to the inner wall of the secondary lower sleeve 203, the secondary bottom flow port oil phase collection pipe 210 is threadedly connected to the middle of the secondary bridge channel 209, and the secondary bridge channel 209 is threadedly connected to the secondary lower sleeve 203. The oil-water mixture enters the cyclone separation chamber from the oil-water mixture inlet of the secondary upper sleeve. Under the centrifugal force of the spiral flow channel, the oil phase is lifted upward from the overflow port, and the water phase is discharged from the oil-water separation cone outlet and flows into the drain port of the secondary bridge channel 209. The upwardly lifted oil phase enters the secondary oil-water separation device, is drained by the secondary inverted cone 205, and enters the secondary second spiral flow channel 204 for further separation. The separated oil phase is lifted upward from the overflow port, and the water phase is discharged from the drain port of the secondary bridge channel.

[0049] Figure 12-13 A structure of a three-stage cyclone separator is provided, wherein the lower end of the third-stage upper sleeve 301 is threadedly connected to the upper end of the third-stage connecting piece 302, the lower end of the third-stage connecting piece 302 is threadedly connected to the third-stage lower sleeve 303, the third-stage first spiral flow channel 307 is welded on the third-stage combination plate 306, the third-stage combination plate 306 is threadedly connected to the inner wall of the third-stage upper sleeve 301, the third-stage oil-water separation cone 308 is threadedly connected to the inner wall of the third-stage lower sleeve 303, the third-stage bottom flow oil phase collection pipe 313 is threadedly connected to the middle of the third-stage bridge channel 309, and the third-stage bridge channel 309 is threadedly connected to the third-stage lower sleeve 303. The oil-water mixture enters the cyclone separation chamber from the oil-water mixture inlet of the third-stage upper sleeve. Under the centrifugal force of the spiral flow channel, the oil phase is lifted upward from the overflow port, and the water phase is discharged from the third-stage oil-water separation cone outlet and flows into the third-stage bridge channel 309 drain port. The upwardly lifted oil phase enters the secondary oil-water separation device, is drained by the third-stage inverted cone 305, and enters the third-stage second spiral flow channel 304 for separation again. The separated oil phase is lifted upward from the overflow port, and the water phase is discharged from the secondary bridge channel drain port. Fig.14 A drainage pipe structure is provided, and an array of three drainage holes 3111 are opened inside the drainage pipe 311 for drainage.

[0050] In the present invention, the structures of the upper sleeves at each level are the same, and the structures of the connecting parts at each level, the lower sleeves at each level, the first spiral flow channels at each level, the second spiral flow channels at each level, and the oil-water separation cones at each level are also the same.

[0051] The overall structure of the device of the present invention is simple, and it can realize efficient separation of large-displacement oil and water on offshore platforms and has a wide range of applications. The device utilizes cyclone technology and multi-stage parallel connection to realize efficient separation of multiphase media. Through innovative structural layout, it rationally handles various media after separation and has extremely high applicability. It greatly improves the recovery rate of the oil field, enhances the economy of the production system, and reduces the operating pressure of subsequent separation equipment.

Claims

1. A multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field, characterized in that: The multi-stage parallel device for downhole cyclone separators for injection and production in the same well of an offshore oil field comprises a multi-stage cyclone separator, which is connected in sequence from top to bottom, and each stage of the cyclone separator has a combined sleeve structure, which is connected in sequence to form an assembled shell, and an oil-water mixed liquid inlet channel, an oil delivery channel, and a drainage channel are arranged in the wall of the assembled shell. The multi-stage cyclone separator is connected in parallel with the oil-water mixed liquid inlet channel through its oil-water mixed liquid inlet port, and the parallel cyclones of each stage are fed with liquid at the same time, and oil-water separation work is performed at the same time, and the oil phase is lifted upward at the same time; the upper port of the upper sleeve of the first-stage cyclone is connected to the liquid inlet pipe through a bridge channel, and the liquid inlet pipe is communicated with the oil-water mixed liquid inlet channel; The cyclone separator includes an upper sleeve, a lower sleeve, a spiral flow channel, an oil-water separation cone, and a bridge channel. The combined sleeve structure is composed of an upper sleeve connected to a lower sleeve through a connector, and the lower end of the lower sleeve is connected to a bridge channel. The outer walls of the upper sleeve, the connector and the lower sleeve are all provided with an oil-water mixture inlet channel, an oil delivery channel and a drainage channel; the bridge channel is a cylinder with an annular boss on the outer wall, and the bridge channel is provided with an oil delivery port and a drainage port. The oil-water mixture inlet channel, the oil delivery channel and the drainage channel are provided along the circumference of the annular boss. The oil delivery port is communicated with the oil delivery channel, and the drainage port is communicated with the drainage channel. The annular boss of the bridge channel is exactly matched with the outer wall of the lower sleeve; the first spiral flow channel is arranged below the second spiral flow channel An overflow pipe is arranged at the center of the first spiral flow channel, a combination plate is arranged on the outer wall of the upper port of the overflow flow pipe, the combination plate is threadedly connected to the upper end sleeve, the upper port of the overflow flow pipe is facing the inverted cone of the second spiral flow channel, the oil-water mixed liquid inlet of the oil-water mixed liquid inlet channel is arranged under the combination plate, an oil-water separation cone is arranged below the first spiral flow channel, the lower port of the oil-water separation cone is connected to the bottom flow port collecting pipe, and the bottom flow port collecting pipe is connected to the oil delivery port of the bridge channel; the second spiral flow channel is arranged at the upper part of the upper end sleeve, an overflow port is arranged at the spiral groove in the middle part of the second spiral flow channel, the overflow port is communicated with the overflow pipe arranged at the center of the second spiral flow channel, the overflow pipe extends into the oil delivery port of the bridge channel of the upper-stage cyclone separator, and an inverted cone is arranged in the center of the lower end of the second spiral flow channel; When the cyclones of each level are working, the oil-water mixture is accelerated and centrifuged through the first spiral flow channel, and the primary gas-liquid separation is performed. The water phase is distributed on the outside, and the oil phase is concentrated in the middle. The overflow port of the first spiral flow channel lifts the oil phase upward to the second spiral flow channel through the overflow pipe; the water phase flows out from the oil-water separation cone, flows into the drainage channel from the drainage port of the bridge channel, and is collected below; the small amount of oil phase contained in the middle of the oil-water separation cone is collected by the oil phase collecting pipe at the bottom flow port, flows into the oil delivery port of the bridge channel, and then flows into the oil delivery channel and is lifted to the ground; The oil phase lifted to the second spiral flow channel is drained by the inverted cone and flows into the second spiral flow channel for further oil-water fine separation. After the second separation, the oil phase is concentrated in the center under the action of centrifugal force and flows into the overflow port of the second spiral flow channel. The overflow port lifts the oil phase upward through the overflow pipe to the oil delivery port of the upper bridge channel, and then flows into the oil delivery channel and is lifted to the ground; The water phase separated again is collected from the drainage port of the bridge channel to the drainage channel and then collected downward.

2. The multi-stage parallel device for downhole cyclone separators suitable for injection and production in the same well of offshore oil fields according to claim 1 is characterized in that: The cyclone separator has three stages, namely, a primary cyclone separator, a secondary cyclone separator, and a tertiary cyclone separator; the upper end of the liquid inlet pipe is threadedly connected to the oil pipe coupling; the liquid inlet pipe is threadedly connected to the bridge channel below it, and the lower end of the bridge channel is threadedly connected to the upper sleeve.

3. The multi-stage parallel device for downhole cyclone separators suitable for injection and production in the same well of offshore oil fields according to claim 2 is characterized in that: The lower end of the upper sleeve is threadedly connected to the connecting piece, the connecting piece is threadedly connected to the lower sleeve, the oil-water separation cone is threadedly connected to the lower sleeve; the lower sleeve is threadedly connected to the upper end of the bridge channel, and the bottom flow oil phase collection pipe is threadedly connected to the oil delivery port of the bridge channel.

4. The multi-stage parallel device for downhole cyclone separators suitable for injection and production in the same well of offshore oil fields according to claim 3 is characterized in that: The oil-water mixture liquid inlet channel of the upper sleeve, the oil-water mixture liquid inlet channel of the connecting piece, the oil-water mixture liquid inlet channel of the lower sleeve and the oil-water mixture liquid inlet channel of the bridge channel are connected in sequence from top to bottom to form a primary oil-water mixture liquid inlet channel, and the oil-water mixture liquid inlet channels of each level are connected in sequence from top to bottom to form an oil-water mixture liquid inlet channel in the outer wall of the combined sleeve structure. After the cyclones of each level connected in parallel separate oil and water at the same time, the oil phase is collected in the oil delivery channel, and the water phase is collected in the drainage channel.

5. The multi-stage parallel device for downhole cyclone separators suitable for injection and production in the same well of offshore oil fields according to claim 4 is characterized in that: The oil delivery channel of the upper sleeve, the oil delivery channel of the connecting piece, the oil delivery channel of the lower sleeve and the oil delivery channel of the bridge channel are connected in sequence from top to bottom to form a primary oil delivery channel, and the oil delivery channels of each level are connected in sequence from top to bottom to form an oil delivery channel in the outer wall of the combined sleeve structure; the drainage channel of the upper sleeve, the drainage channel of the connecting piece, the drainage channel of the lower sleeve and the drainage channel of the bridge channel are connected in sequence from top to bottom to form a primary drainage channel, and the drainage channels of each level are connected in sequence from top to bottom to form a drainage channel in the outer wall of the combined sleeve structure.

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