A separation assembly and downhole multiphase integrated separation device employing the same

Abstract

The present disclosure relates to a kind of separation assembly and the downhole multiphase integrated separation device for applying it.The device includes gas separation module and multiple separation module;The gas phase in the gas oil water sand mixed liquid is separated in advance by using primary gas-liquid separator in gas separation module, a small amount of oil phase carried by gas phase enters gas-oil separation unit when gas phase is separated, and the oil phase after separation is re-discharged into oil-water sand mixed liquid from the small hole of gas-oil separation unit;Multiple separation module enters annular sand settling structure through lower liquid inlet, and sand phase is settled into sand settling chamber by gravity settling, and sand phase is discharged from sand settling chamber with gas after gas-oil separation structure separation;Oil and water two-phase after sand removal enter spiral flow channel through liquid inlet to form cyclone field and separate oil and water two-phase, and oil phase is discharged to upper oil pipe coupling, and water phase is gathered with gas phase and sand phase and is discharged into lower oil pipe coupling.The device can complete multistage separation of gas oil water sand four-phase in wellbore.

Description

Technical Field

[0001] This disclosure relates to a separation device used in the field of downhole oil-water separation, specifically, to a device capable of achieving multi-stage separation of four phases (gas, oil, water, and sand) within a confined downhole space. Background Technology

[0002] In many regions of my country, high sand content in oil wells leads to a series of operational problems, including damage to pumping equipment, subsidence of pump house foundations, and bending or even breakage of well casings. Some wells are scrapped after a very short service life, causing not only economic losses but also disrupting normal production and daily life. Some downhole wells use screen filters for sand removal, but over time, the screens become clogged with accumulated sand, hindering downhole sand removal. Furthermore, in the process of promoting the application of injection and production systems in the same well, the processing capacity of downhole oil-water separation equipment is insufficient for high-yield oil wells containing gas and sand, resulting in reduced separation efficiency and significant difficulties for oilfield development. The presence of gas and sand in the mixed liquid reduces the separation efficiency of the equipment and accelerates equipment wear; a single oil-water hydrocyclone is insufficient to meet the requirements. To address this issue, a multi-stage spiral combined multiphase integrated separation device for downhole applications was designed. This technology enables gas-liquid-sand mixtures to achieve gas-liquid, solid-liquid, and liquid-liquid separation downhole. The liquid phase is lifted to the surface, while the gas and sand phases are discharged into the tubing annulus, ensuring stable liquid flow, gas control, sand removal, and improved oil recovery. Furthermore, the device has a reasonable size and can be directly applied to downhole same-well injection and production technology, further expanding its application scope. A related patent, titled "An Oil-Water-Gas Three-Phase Separator Based on Electromagnetic Eddy Currents," patent application number CN202223137095.0, presents a solution that improves oil-water separation quality by setting up cyclone separation and adding electromagnetic coils. However, with this structure, when the inlet liquid velocity is low, the flow rate of the mixture will be too low during the gas-liquid separation to oil-water separation stage, reducing the oil-water separation efficiency. Moreover, electromagnetic coil separation is not as efficient as traditional oil-water cyclone separators, and the presence of sand in the mixture further affects the separation efficiency. When a hydrocyclone separator is running, the mixed liquid undergoes intense rotational motion. Under the severe scouring of sand particles, the wall surface and hydrocyclone tubes experience severe wear. This not only shortens the service life of the equipment but also affects the separation efficiency of the hydrocyclone due to changes in the dimensions of key components, thus degrading operational performance. While the applicant's earlier applications (CN116241229A and CN116427902A) for in-well injection-production oil and sand removal devices and in-well injection-production backwashing oil and sand removal devices can solve the above problems, the sand removal module and oil-water separation module are horizontally connected in series, resulting in a large lateral dimension of the device. This makes it unsuitable for downhole casing with small diameters. It also contains easily damaged parts such as springs, leading to a short service life. The device relies on the gravity of the sand phase to open the sand discharge port, which may cause blockages under certain operating conditions. Furthermore, this device is designed for the separation of oil, water, and sand phases and is not suitable for gas-containing conditions. Summary of the Invention

[0003] To address the technical problems existing in the background art, this disclosure proposes a separation component and a downhole multiphase integrated separation device using it. The purpose of the solution provided in this disclosure is to provide a downhole multi-stage spiral combined multiphase integrated separation device, which realizes multi-stage series connection, achieves multi-stage fine separation of swirling and settling in a narrow wellbore space, and enables the separated gas containing a small amount of oil phase to coalesce into oil phase through baffles to achieve the purpose of gas purification.

[0004] The gas separation assembly disclosed herein includes a gas-liquid separation structure, which includes an upper tubing coupling 101, an upper end cap 102, an upper outer shell 103, an inverted cone 104, and a gas-liquid separation chamber 105. The upper tubing coupling 101, the upper outer shell 103, the inverted cone 104, and the gas-liquid separation chamber 105 are all hollow structures. The upper tubing coupling 101 is used to connect the device and the pipeline. The upper end cap 102 is used to block the wellbore and the gas-liquid separation chamber. The mixed liquid enters the space formed by the upper outer shell 103 and the gas-liquid separation chamber 105 from the upper outer shell 103. The inverted cone 104 pushes the mixed liquid downward. After entering the gas-liquid separation chamber 105, the mixed liquid obtains a sufficiently large velocity to complete centrifugal separation.

[0005] The upper end of the upper end cap 102 is threaded to the upper oil pipe coupling 101, and the lower end has threads on both the inner and outer sides, which are threaded to the upper outer shell 103 and the gas-liquid separation chamber 105 respectively. The inverted cone 104 is threaded to the upper end cap 102. The gas-liquid separation chamber 105 has threaded structures at both the upper and lower ends. The upper end of the gas-liquid separation chamber 105 is threaded to the inner side of the lower end of the upper end cap 102, and the lower end of the gas-liquid separation chamber 105 is threaded to the upper end of the guide channel 107.

[0006] A tangential inlet 1051 is provided on the gas-liquid separation chamber 105. The mixed liquid enters the gas-liquid separation chamber 105 through the tangential inlet 1051 and obtains a sufficiently large velocity to complete the centrifugal separation.

[0007] Furthermore, the gas separation assembly also includes an oil removal structure;

[0008] The oil removal structure includes an oil filtration channel 106 using a sand removal filter screen. The oil filtration channel 106 has multiple layers of inclined baffles 1061 inside. The baffles 1061 are welded to the oil filtration channel 106. When the gas phase carries a small amount of oil phase through the baffles 1061, the baffles 1061 collect the oil phase on their surface. The channel has evenly distributed vent holes 1062 to ensure gas phase passage. The oil filtration channel 106 has oil leakage holes 1063 on its wall, at the same height as the baffles, used to discharge the oil phase on the baffles into the gas-liquid separation chamber 105 to mix with the liquid after gas phase removal. The lower part of the oil filtration channel 106 is threadedly connected to the interior of the guide channel 107. The lower side of the oil filtration channel 106 in the oil removal structure is threadedly connected to the upper side of the guide channel 107.

[0009] Furthermore, the gas separation assembly also includes a flow guiding structure:

[0010] The flow guiding structure includes a flow guiding channel 107 and a sleeve spacer 108. The upper end of the flow guiding channel 107 is threadedly connected to the oil filter channel 106, the upper end of the flow guiding channel 107 is threadedly connected to the gas-liquid separation chamber 105, and the lower end is threadedly connected to the sleeve spacer 108. A liquid inlet 1071 is provided on the flow guiding channel 107. The internal flow channel of the flow guiding channel 107 is sloped to ensure that the mixed liquid can flow along the internal flow channel. The mixed liquid enters the liquid inlet 1071 through the flow guiding channel 107. The gas-liquid separation structure and the flow guiding structure are placed from top to bottom in space. The inner and outer sides of the sleeve spacer 108 are threadedly connected to the upper outer shell 103 of the gas-liquid separation structure and the flow guiding channel 107 of the flow guiding structure, respectively.

[0011] Another aspect of this disclosure provides a downhole multiphase integrated separation device that utilizes the aforementioned gas separation components; its unique feature is that:

[0012] The device also includes a sand removal structure and an oil-water separation structure;

[0013] The sand removal structure includes a sand settling chamber 201, a lower outer shell 202, a vortex chamber 204, a sand removal filter screen 206, and a lower oil pipe coupling 205;

[0014] The filter screen portion of the sand removal filter 206 has a slope, which allows the sand-containing oil-water mixture to flow along the filter screen;

[0015] A sand discharge port 2011 is opened on the outside of the sand settling chamber 201. The sand phase deposited in the sand settling chamber 201 is discharged from the sand discharge port 2011. An air outlet 2012 is opened on the inner pipe wall. The gas phase enters the sand settling chamber 201 from the air outlet 2012 and carries the sand phase out from the sand discharge port 2011. Below is a sand settling chamber 2013. The hole 2014 has the same outer diameter as the overflow pipe 2031. The overflow pipe 2031 passes through the hole 2014. Below is a liquid inlet 2015. The mixed liquid enters the vortex chamber 204 through the liquid inlet 2015.

[0016] The upper side of the sedimentation chamber 201 is threaded to the lower end of the guide channel 107, the lower side is threaded to the upper end of the vortex chamber 204, and the interior is threaded to the sand removal filter screen 206; the upper side of the lower outer shell 202 is threaded to the sleeve spacer 108, and the lower side is threaded to the lower oil pipe coupling 205.

[0017] The lower outer shell 202, the swirling chamber 204, and the lower oil pipe coupling 205 adopt a hollow structure so that when the sand-containing mixture passes through the oil filter channel 106, the denser sand phase settles from the gaps in the filter screen into the sand settling chamber 201. The upper interior of the sand settling chamber 201 is connected to the oil filter channel 106 by a thread. The gas phase after deoiling enters the sand settling chamber through the oil filter channel and carries the settled sand phase out of the sand settling chamber 201 and out through the lower oil pipe coupling 205 into the space between the lower outer shell 202 and the swirling chamber 204. The lower part of the sand settling chamber is connected to the upper part of the swirling chamber 204 by a thread.

[0018] The oil-water separation structure includes a spiral flow channel 203 and a swirling cavity 204. The spiral flow channel 203 is a spiral channel that can provide sufficient centrifugal force to the oil-water mixture. The separated oil phase is lifted upward through the overflow pipe 2031 to the upper oil pipe coupling 101. The spiral flow channel 203 and the swirling cavity 204 are interference-fitted. The upper part of the swirling cavity 204 is connected to the sedimentation chamber 201 by a thread.

[0019] The upper end cover 102 has a connection hole 1021 in the middle, which is connected to the overflow pipe 2031. The separated oil phase enters the upper oil pipe coupling 101 through the connection hole. The upper outer shell has a liquid inlet hole 1031 on its surface. The mixed liquid enters the chamber formed by the upper outer shell 103 and the gas-liquid separation chamber 105 through the liquid inlet hole 1031.

[0020] The mixture flows into the inlet 1071 through the guide channel 107, and the sleeve interval 108 is used to isolate the gas-liquid separation component from the sand removal structure and the oil-water separation structure.

[0021] Furthermore, the vortex chamber 204 has a structure in which the upper part is a cylindrical pipe and the lower part is a conical pipe, and it is connected to the sedimentation chamber 201 by a thread at the top;

[0022] The sand removal filter (206) has a spiral structure that descends along the outer wall of the pipe, and the filter 270° surrounds the pipe wall. When the sand removal filter 206 is connected to the sand settling chamber 201, the empty part of the sand removal filter 206 is aligned vertically with the liquid inlet 2015 of the sand settling chamber 201.

[0023] The above-described at least one technical solution adopted in one or more embodiments of this specification can achieve the following beneficial effects:

[0024] First, the multiphase integrated separation device provided in this disclosure combines swirling, settling, gas separation, and sand removal structures, and has both sand removal and settling and gas and sand discharge devices, so that sand particles are separated from the mixed liquid and discharged by gas. It can achieve the simultaneous separation of four media in a small downhole space and can achieve multi-stage separation, thereby improving the separation effect of the device.

[0025] Secondly, the multiphase integrated separation device provided in this disclosure, after achieving primary gas separation, allows the gas carrying a small amount of oil droplets after initial separation by the gas separation component to pass through a baffle, causing the oil droplets to coalesce on the baffle and be discharged back into the liquid chamber, thereby improving the gas separation accuracy and achieving the purpose of gas purification.

[0026] In addition, the spiral flow channel in the device can accelerate the flow rate of the mixed liquid, solving the problem of the low flow rate of the mixed liquid after gas-liquid separation.

[0027] In summary, the downhole multi-stage spiral combined multiphase integrated separation device proposed in this invention can be applied to the complex situation of multi-media mixtures containing gas, oil, water and sand. It can also separate gas and oil, remove sand and discharge sand, and can be used for separation and purification under various working conditions.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0029] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0031] Figure 1 (a) is an overall appearance view of the downhole multiphase integrated separation device described in this disclosure.

[0032] Figure 1 (b) is a cross-sectional view of the downhole multiphase integrated separation device described in this disclosure.

[0033] Figure 2 This is an exploded view of the downhole multiphase integrated separation device described in this disclosure.

[0034] Figure 3 (a) is an appearance view of the gas separation component.

[0035] Figure 3 (b) is a cross-sectional view of the gas separation assembly.

[0036] Figure 4 This is an exploded view of the gas separation assembly.

[0037] Figure 5 (a) is an external view of the upper end of the flow channel.

[0038] Figure 5 (b) is an external view of the bottom of the flow channel.

[0039] Figure 5 (c) is a cross-sectional view of the flow channel.

[0040] Figure 6 (a) is a top view of the oil filter channel.

[0041] Figure 6 (b) is a cross-sectional view of the oil filter channel.

[0042] Figure 7 (a) is an appearance diagram of the multi-separated module.

[0043] Figure 7 (b) is a cross-sectional view of the multiple separation modules.

[0044] Figure 8 This is an exploded view of the multiple separate modules.

[0045] Figure 9 (a) is an appearance view of the upper part of the sand removal filter screen.

[0046] Figure 9 (b) is a view of the bottom of the sand removal filter.

[0047] Figure 10 (a) is an external view of the interior of the sedimentation chamber.

[0048] Figure 10 (b) is an external view of the bottom of the settling chamber.

[0049] Figure 10 (c) is a schematic diagram of the sand discharge port of the settling chamber.

[0050] Figure 11 Cross-sectional view of the settling chamber and settling filter assembly.

[0051] In the diagram, 101-upper oil pipe coupling, 102-upper end cap, 1021-connection hole, 103-upper outer shell, 1031-liquid inlet hole, 104-inverted cone, 105-gas-liquid separation chamber, 1051-tangential inlet, 106-oil filter channel, 1061-inclined baffle, 1062-vent hole, 1063-oil leakage hole, 107-guide channel, 1071-liquid inlet, 108-sleeve spacer, 201-sand settling chamber, 2011-sand discharge port, 2012-air outlet, 2013-sand settling chamber, 2014-hole, 2015-liquid inlet, 202-lower outer shell, 203-spiral flow channel, 2031-overflow pipe, 204-vortex chamber, 205-lower oil pipe coupling, 206-sand removal filter screen, 2061-air guide pipe. Detailed Implementation

[0052] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0053] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods and means well-known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0054] This disclosure first provides a separation component, with preferred embodiments including a gas-liquid separation structure, an oil removal structure, and a flow guiding structure;

[0055] The gas-liquid separation structure includes an upper tubing coupling 101, an upper end cap 102, an upper outer shell 103, an inverted cone 104, and a gas-liquid separation chamber 105. The upper tubing coupling 101, the upper outer shell 103, the inverted cone 104, and the gas-liquid separation chamber 105 are all hollow structures. The upper tubing coupling 101 is used to connect the device and the pipeline. The upper end cap 102 is used to isolate the wellbore and the gas-liquid separation chamber. The mixed liquid enters the space formed by the upper outer shell 103 and the gas-liquid separation chamber 105 from the upper outer shell 103. The inverted cone 104 pushes the mixed liquid downward. After entering the gas-liquid separation chamber 105, the mixed liquid obtains a sufficiently large velocity to complete centrifugal separation.

[0056] The upper end of the upper cover 102 is threaded to the upper oil pipe coupling 101, and the lower end has threads on both the inner and outer sides, which are threaded to the upper outer shell 103 and the gas-liquid separation chamber 105 respectively. The upper end cover has a connecting hole 1021 in the middle, which is connected to the overflow pipe 2031. The separated oil phase enters the upper oil pipe coupling 101 through the connecting hole. The inverted cone 104 is threaded to the upper end cover 102. The gas-liquid separation chamber 105 has threaded structures at both the upper and lower ends. The upper end of the gas-liquid separation chamber 105 is threaded to the inner side of the lower end of the upper end cover 102, and the lower end of the gas-liquid separation chamber 105 is threaded to the upper end of the guide channel 107.

[0057] The oil removal structure uses an oil filtration channel 106, which has multiple layers of inclined baffles 1061 inside. The baffles 1061 are connected to the oil filtration channel 106 by welding. When the gas phase carries a small amount of oil phase through the baffles 1061, the baffles 1061 collect the oil phase on the surface. The channel has evenly distributed vent holes 1062 to ensure the passage of the gas phase. The oil filtration channel 106 has oil leakage holes 1063 on its wall, which are at the same height as the baffles. The oil phase on the baffles is discharged into the gas-liquid separation chamber 105 and mixed with the mixture after the gas phase has been removed. In the oil removal structure, the lower side of the oil filtration channel 106 is internally connected to the upper side of the guide channel 107 by threads.

[0058] The specific structure of the flow guiding structure is a flow guiding channel 107 and a sleeve gap 108. The upper end of the flow guiding channel 107 is connected to the gas-liquid separation chamber 105 by a thread, and the lower end is connected to the sleeve gap 108 by a thread. There is a liquid inlet 1071 on the flow guiding channel 107. The internal flow channel of the flow guiding channel 107 has a certain slope to ensure that the mixed liquid flows along the flow channel. The mixed liquid flows into the liquid inlet 1071 through the structure of the flow guiding channel 107. The sleeve gap 108 is used to separate the gas-liquid separation module and the multiple separation module. The gas-liquid separation module refers to the separation component composed of the gas-liquid separation structure, the oil removal structure and the flow guiding structure.

[0059] The multiple separation module includes a sand removal structure and an oil-water separation structure. These are described in detail below: The sand removal structure includes a sand settling chamber 201, a lower outer shell 202, a vortex chamber 204, and a lower oil pipe coupling 205. The lower outer shell 202, vortex chamber 204, and lower oil pipe coupling 205 are hollow structures. A sand discharge port 2011 is opened on the outside of the sand settling chamber 201, through which the sand phase deposited in the sand settling chamber 201 is discharged. An air outlet 2012 is opened on the inner pipe wall, through which the gas phase enters the sand settling chamber 201 from the air outlet 2012, carrying the sand phase, and is discharged from the sand discharge port 2011. Below, there is a sand settling chamber 2013, with a hole 2014 having the same outer diameter as the overflow pipe 2031, through which the overflow pipe 2031 passes. Below, there is a liquid inlet 2015, through which the mixed liquid enters the vortex chamber 204. The upper side of the sedimentation chamber 201 is threaded to the lower end of the guide channel 107, and the lower side is threaded to the upper end of the vortex chamber 204. The interior is threaded to the sand removal filter screen 206. When the sand-containing mixture passes through the sand removal filter screen 106, the denser sand phase settles from the gaps in the filter screen into the sedimentation chamber 201. The upper interior of the sedimentation chamber 201 is threaded to the oil filter channel 106. The gas phase after oil removal enters the sedimentation chamber through the oil filter channel and carries the settled sand phase out of the sedimentation chamber 201 and out into the space between the lower outer shell 202 and the vortex chamber 204, and is discharged through the lower oil pipe coupling 205. The lower part of the sedimentation chamber is threaded to the upper part of the vortex chamber 204.

[0060] The oil-water separation structure includes a spiral flow channel 203 and a swirling cavity 204. The spiral flow channel 203 is a spiral channel that allows the passing oil-water mixture to obtain sufficient centrifugal force. The separated oil phase is lifted upward through the overflow pipe 2031 to the upper oil pipe coupling 101. The spiral flow channel 203 and the swirling cavity 204 are interference-fitted. The upper part of the swirling cavity 204 is connected to the sedimentation chamber 201 by a thread.

[0061] The overall appearance and cross-sectional view of this type of downhole multi-stage spiral combined multiphase integrated separation device are as follows: Figure 1As shown, the device is placed vertically downhole. During operation, the gas-containing oil-water-sand mixture enters the device through the inlet 1031, passes through the tangential inlet 1051, and enters the gas-liquid separation chamber 105. The tangential inlet 1051 accelerates the mixture, causing centrifugal separation. This separates the gas phase, carrying a small amount of oil, from the oil-water-sand mixture, causing it to concentrate towards the center. The gas phase, carrying a small amount of oil, approaches and enters the oil filter channel 106 to remove the oil carried by the gas phase. The de-oiled gas phase then enters the internal pipe of the desanding filter 206 and is discharged through the outlet 2012 into the sand settling chamber 2013, exiting through the sand discharge port 2011. The oil-water-sand mixture enters the sand settling chamber 201 through the inlet 1071. After desanding, the sand phase is discharged through the sand discharge port 2011 along with the gas phase entering the sand settling chamber. After sand removal, the oil-water mixture enters the vortex chamber 204. After passing through the spiral flow channel 203, a strong vortex field is formed. The oil phase, after vortex separation, enters the overflow pipe 2031 from the oil inlet 2032 and is then discharged into the upper oil pipe coupling 101, where it is finally lifted to the ground. The water phase is discharged from the bottom outlet 2041 and, together with the separated gas and sand, is discharged into the lower oil pipe coupling 205.

[0062] Exploded view of the underground multiphase integrated separation device as shown below Figure 2 As shown, it mainly consists of a gas separation module and a multi-separation module.

[0063] The appearance and cross-sectional view of the gas separation module are as follows: Figure 3 As shown, the upper end of the upper cover 102 is threadedly connected to the upper oil pipe coupling 101, and the lower end is threadedly connected to the upper outer shell 103 and the gas-liquid separation chamber 105 on its inner and outer sides, respectively. The inverted cone 104 is threadedly connected to the upper end cover 102. The oil filter channel 106 is threadedly connected to the guide channel 107. The upper end of the guide channel 107 is threadedly connected to the gas-liquid separation chamber 105, and the lower end is threadedly connected to the sleeve spacer 108. The oil-water mixture containing gas and sand enters the space between the inner wall of the upper outer shell and the outer wall of the gas-liquid separation chamber through the liquid inlet 1031, and enters the gas-liquid separation chamber through the tangential inlet 1051. After being accelerated by the tangential inlet 1051, a swirling flow field is formed. Under the action of the swirling flow field, the light gas phase carrying a small amount of oil droplets moves towards the center, while the heavy oil-water-sand mixture is located in the outer region. A small amount of oil phase carried by the gas phase approaches and enters the oil filter channel 106. As it passes through the inclined baffle 1061 with vent holes 1062, the oil phase accumulates on the baffle and enters the gas-liquid separation chamber 105 through the oil leakage hole 1063, merging with the oil-water-sand mixture. After oil removal, the gas phase continues to be discharged downwards along the channel. The oil-water-sand mixture approaches the inner wall of the gas-liquid separation chamber 105 and flows downwards into the multi-stage separation module 2 through the inclined guide channel 107. An exploded view of the gas separation module is shown below. Figure 4As shown, it mainly consists of an upper oil pipe coupling 101, an upper end cap 102, an upper outer shell 103, an inverted cone 104, a gas-liquid separation chamber 105, an oil filter pipe 106, a flow guide channel 107, and a sleeve gap 108. The appearance of the flow guide channel is shown in the figure. Figure 5 As shown in Figures a, b, and c, which are external views and half-sectional views from different angles (top and bottom, respectively), the guide channel 107 has a liquid inlet 1071. The upper end of the guide channel 107 is threadedly connected to the gas-liquid separation chamber, and the interior is threadedly connected to the oil filter channel 106. The lower end is threadedly connected to the sand removal chamber 201 and the sleeve spacer 108 on the inner and outer sides, respectively. After gas-liquid separation, the sand-containing oil-water mixture is guided by the guide channel 107, allowing the liquid to enter the multi-stage separation module 2 through the liquid inlet 1071 for processing. The external view of the oil filter channel is shown below. Figure 6 As shown in Figures a and b, respectively, are the top view and cross-sectional view of the oil filter channel. The oil filter channel has multiple layers of inclined baffles 1061. The baffles 1061 are connected to the oil filter channel 106 by welding. The channel has evenly distributed vent holes 1062, and the oil filter channel 106 has oil leakage holes 1063 on its wall at the same height as the baffles. The gas phase carries a small amount of oil phase droplets into the oil filter channel 106. When passing through the inclined baffles 1061, the oil droplets gather on the surface of the inclined baffles 1061 and are discharged into the gas-liquid separation chamber through the oil leakage holes 1063, where they merge with the sand-containing oil-water mixture outside. The gas phase passes through the vent holes 1062 on the inclined baffles 1061 and moves downwards for further processing.

[0064] The appearance and cross-sectional view of the multi-separated module are as follows: Figure 7 As shown, the lower side of the settling chamber 201 is connected to the vortex chamber 204 by a thread, and the interior is connected to the sand removal filter screen 206 by a thread; the lower side of the lower outer shell 202 is connected to the lower oil pipe coupling 205 by a thread; the spiral flow channel 203 and the vortex chamber 204 are interference-fitted. After being separated by the gas separation module 1, the sand-containing oil-water mixture enters the settling chamber 201 and falls onto the sand removal filter screen 206. During the flow of the mixture, the sand phase falls into the settling chamber 2013 with the sand removal filter screen 206 due to gravity settling. The gas separated by the gas separation module 1 enters the air guide pipe 2061 inside the sand removal filter screen 206 and is then discharged into the settling chamber 2013 through the air outlet 2012. The sand particles are discharged from the sand discharge port 2011 into the space between the inner wall of the lower outer shell 202 and the outer wall of the settling chamber 201 and continue to be discharged downwards. After sand removal, the oil-water mixture enters the vortex chamber 204 through the inlet 2015. After passing through the spiral channel 203, a vortex field is formed, with the oil phase near the center of the spiral channel 203 and the water phase on the periphery. The oil phase enters the overflow pipe 2031 through the oil inlet 2032 and is discharged into the upper oil pipe coupling 101, ultimately being lifted to the ground. The water phase is discharged from the bottom outlet 2041 and, together with the separated gas and sand, is discharged into the lower oil pipe coupling 205. An exploded view of the multi-separation module is shown below. Figure 8As shown, it mainly consists of a sand settling chamber 201, a lower outer shell 202, a spiral flow channel 203, a vortex chamber 204, a lower oil pipe coupling 205, and a sand removal filter screen 206. The appearance of the sand removal filter screen is shown in the figure below. Figure 9 As shown, Figures a and b are the front view and the lower view, respectively. The filter screen of the sand removal filter 206 has a slope, which allows the sand-containing oil-water mixture to flow along the filter screen. During the flow, the sand phase density settles from the filter screen into the lower sand settling chamber 2013, while the gas after oil removal continues to move downward in the air guide pipe 2061. The appearance of the sand settling chamber is shown in the figure. Figure 10 As shown in Figures a, b, and c, which are top and bottom views and frontal views respectively, the sand settling chamber 201 has a sand discharge port 2011 on its outer side and an air outlet 2012 on its inner wall. Below, there is a sand settling chamber 2013. The orifice 2014 has the same outer diameter as the overflow pipe 2031, and a liquid inlet 2015 is located below it. Sand particles falling into the sand settling chamber 2013 are carried by the gas entering through the air outlet 2012 and discharged through the sand discharge port 2011. A cross-sectional view of the assembled sand settling chamber and sand filter screen is shown below. Figure 11 As shown, the sedimentation chamber 201 and the sedimentation filter screen 206 are connected by threads and aligned at the following angles. Figure 11 As shown.

[0065] This device features a compact design and reliable, stable operation. It can achieve degassing, sand removal, and water removal within a single unit. Through its internal structural design, it removes oil droplets carried in the gas, improving separation efficiency. Furthermore, its optimized structure ensures that the separated gas, sand particles, and water are collected and discharged together. This invention combines cyclone and sedimentation technologies to achieve multi-stage, fine separation of the four phases (gas, oil, water, and sand) within a confined space. It boasts high efficiency, excellent separation effect, and can be used in complex operating conditions.

Claims

1. A downhole multiphase integrated separation device, comprising an oil-water separation structure, characterized in that: The separation device also includes a gas-liquid separation structure, an oil removal structure, a flow guiding structure, and a sand removal structure; The gas-liquid separation structure includes an upper tubing coupling (101), an upper end cap (102), an upper outer shell (103), an inverted cone (104), and a gas-liquid separation chamber (105); wherein the upper tubing coupling (101), the upper outer shell (103), the inverted cone (104), and the gas-liquid separation chamber (105) are all hollow structures. The upper tubing coupling (101) is used to connect the device and the pipeline. The upper end cap (102) is used to block the wellbore and the gas-liquid separation chamber. The mixed liquid enters the space formed by the upper outer shell (103) and the gas-liquid separation chamber (105) from the upper outer shell (103). The inverted cone (104) pushes the mixed liquid downward. After entering the gas-liquid separation chamber (105), the mixed liquid gains velocity to complete centrifugal separation. The upper end of the upper cover (102) is connected to the upper oil pipe coupling (101) by a thread, and the lower end has threads on both the inner and outer sides, which are connected to the upper outer shell (103) and the gas-liquid separation chamber (105) by a thread respectively. The inverted cone (104) is connected to the upper end cover (102) by a thread. The upper and lower ends of the gas-liquid separation chamber (105) have threaded structures. The upper end of the gas-liquid separation chamber (105) is connected to the inner side of the lower end of the upper end cover (102) by a thread, and the lower end of the gas-liquid separation chamber (105) is used to connect to the upper end of the guide channel (107) by a thread. A tangential inlet (1051) is provided on the gas-liquid separation chamber (105). The mixed liquid enters the gas-liquid separation chamber (105) through the tangential inlet (1051) and gains velocity to complete centrifugal separation. The oil removal structure includes an oil filter channel (106) with a sand removal filter screen. The oil filter channel (106) has multiple layers of inclined baffles (1061) inside. The baffles (1061) are connected to the oil filter channel (106) by welding. When the gas phase carries a small amount of oil phase through the baffles (1061), the baffles (1061) collect the oil phase on the surface. The oil filter channel has evenly distributed vent holes (1062) to ensure the passage of the gas phase. The oil filter channel (106) has oil leakage holes (1063) on the wall and is at the same height as the baffles. These holes are used to discharge the oil phase on the baffles into the gas-liquid separation chamber (105) and mix it with the mixed liquid after the gas phase is removed. The bottom of the oil filter channel (106) is used to connect with the inside of the guide channel (107) by threads. The lower side of the oil filter channel (106) is connected to the upper side of the guide channel (107) by a thread; The flow guiding structure includes a flow guiding channel (107) and a sleeve interval (108). The upper end of the flow guiding channel (107) is connected to the gas-liquid separation chamber (105) by a thread, and the lower end is connected to the sleeve interval (108) by a thread. An inlet (1071) is provided on the flow guiding channel (107). The flow channel (107) has a slope in the internal flow channel to ensure that the mixed liquid can flow along the internal flow channel. The mixed liquid enters the inlet (1071) through the flow guiding channel (107). The gas-liquid separation structure and the flow guiding structure are placed from top to bottom in space. The inner and outer sides of the sleeve interval (108) are respectively connected to the upper shell (103) in the gas-liquid separation structure and the flow guiding channel (107) in the flow guiding structure by threads. The sand removal structure includes a sand settling chamber (201), a lower outer shell (202), a vortex chamber (204), a sand removal filter (206), and a lower oil pipe coupling (205); The sand removal filter screen (206) has a slope, which allows the sand-containing oil-water mixture to flow along the filter screen; A sand discharge port (2011) is opened on the outside of the sand settling chamber (201). The sand phase deposited in the sand settling chamber (201) is discharged from the sand discharge port (2011). An air outlet (2012) is opened on the inner pipe wall. The gas phase enters the sand settling chamber (201) from the air outlet (2012) and carries the sand phase out from the sand discharge port (2011). There is a sand settling chamber (2013) below the sand settling chamber (2011). The hole (2014) has the same outer diameter as the overflow pipe (2031). The overflow pipe (2031) passes through the hole (2014). The mixed liquid enters the vortex chamber (204) through the liquid inlet (2015). The upper side of the sand settling chamber (201) is connected to the lower end of the guide channel (107) by a thread, the lower side is connected to the upper end of the vortex chamber (204) by a thread, and the interior is connected to the sand removal filter screen (206) by a thread; the upper side of the lower outer shell (202) is connected to the sleeve gap (108) by a thread, and the lower side is connected to the lower oil pipe coupling (205) by a thread; The lower outer shell (202), the swirling chamber (204), and the lower oil pipe coupling (205) adopt a hollow structure so that when the sand-containing mixture passes through the oil filter channel (106), the denser sand phase settles from the gap of the filter screen into the sand settling chamber (201). The upper interior of the sand settling chamber (201) is connected to the oil filter channel (106) by a thread. The gas phase after deoiling enters the sand settling chamber through the oil filter channel and carries the settled sand phase out of the sand settling chamber (201) and out of the space between the lower outer shell (202) and the swirling chamber (204) through the lower oil pipe coupling (205). The lower part of the sand settling chamber is connected to the upper part of the swirling chamber (204) by a thread. The oil-water separation structure includes a spiral flow channel (203) and a swirling cavity (204). The spiral flow channel (203) is a spiral channel that can provide sufficient centrifugal force to the passing oil-water mixture. The separated oil phase is lifted upward through the overflow pipe (2031) to the upper oil pipe coupling (101). The spiral flow channel (203) and the swirling cavity (204) are interference-fitted. The upper part of the swirling cavity (204) is connected to the sedimentation chamber (201) by a thread. The upper end cap (102) has a connecting hole (1021) in the middle to connect with the overflow pipe (2031). The separated oil phase enters the upper oil pipe coupling (101) through the connecting hole. The upper outer shell has a liquid inlet hole (1031) on its surface. The mixed liquid enters the chamber formed by the upper outer shell (103) and the gas-liquid separation chamber (105) through the liquid inlet hole (1031). The mixture flows into the inlet (1071) through the guide channel (107), and the sleeve interval (108) is used to isolate the gas-liquid separation structure, the guide structure, the oil removal structure, the sand removal structure, and the oil-water separation structure.

2. The downhole multiphase integrated separation device according to claim 1, characterized in that: The vortex chamber (204) adopts a structure in which the upper part is a cylindrical pipe and the lower part is a conical pipe, and is connected to the sedimentation chamber (201) by a thread at the top; The sand removal filter (206) has a spiral structure that descends along the outer wall of the pipe, and the filter is wrapped around the pipe wall at 270°. When the sand removal filter (206) is connected to the sand settling chamber (201), the empty part of the sand removal filter (206) is aligned vertically with the liquid inlet (2015) of the sand settling chamber (201).

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