Filtering device for steam injection

Abstract

The utility model relates to the field of high-temperature steam injection wells, in particular to a filtering device for steam injection. The filtering device for steam injection comprises a vertically-arranged filtering cylinder, a steam inlet and a steam outlet are formed in the filtering cylinder, the steam inlet is located below the steam outlet, a filtering piece used for filtering steam is arranged between the steam inlet and the steam outlet, and a storage structure is formed in the position, below the steam inlet, of the filtering cylinder. The filtering piece is arranged between the steam inlet and the steam outlet, steam needing to enter the well is filtered, accumulated slag is prevented from entering the well, the accumulated slag such as welding slag and rust mixed in the steam can reach the filtering piece only by overcoming gravity, in other words, only part of the accumulated slag can reach the position of the filtering piece to be collected by the filtering piece, and the filtering effect is improved. And larger deposited slag can be deposited downwards in the storage structure, so that the problem that the overall structure of the filtering device is complicated as the deposited slag on the filtering piece is cleaned by arranging a turbine structure in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the field of high-temperature steam injection wells, in particular to a filtering device for steam injection. Background Technique

[0002] During the oilfield development process, relatively viscous oil layers will be encountered, and the resistance during oil pumping is relatively large. In order to better extract crude oil, high-temperature steam is usually injected into the oil layer, and production is carried out after soaking the well for a period of time. Injecting high-temperature steam to soak the well heats the crude oil on the one hand, reducing the viscosity of the crude oil, and on the other hand, the steam turns into water after cooling, diluting the crude oil. The high-temperature steam injected into the oil well is generated in the boiler room. The high-temperature steam generated in the boiler room is not only injected into one well, but generally into multiple nearby oil wells. In order to facilitate the boiler room to inject steam into multiple oil wells, the boiler room is usually arranged in the middle position of several oil wells, which will result in a certain distance between the boiler room and each oil well. Generally, the steam is transported between the boiler room and the oil well through metal pipes.

[0003] The long-distance metal pipes cannot be integrally processed and formed. Generally, multiple pipe segments are welded together. During the welding process, welding slag will inevitably be generated. When high-temperature steam is introduced, the welding slag may enter the interior of the oil well along with the high-temperature steam. At the same time, over time, rust may be generated inside the pipe, and the rust will also enter the interior of the oil well along with the high-temperature steam during the process of introducing high-temperature steam. After the well soaking is completed, oil is pumped from the oil well. During oil pumping, these accumulated slag such as welding slag and rust will enter the oil pump along with the oil liquid, easily causing the oil pump to get stuck or blocked, and then requiring maintenance, resulting in the interruption of the oil pumping operation, which not only increases the operation cost but also causes heat loss. Therefore, in the prior art, a filtering element is also provided at the end of the pipe before injecting steam into the oil well to filter the high-temperature steam to be injected into the oil well.

[0004] Steam injection often takes several days. During the long steam injection process, if there is a lot of slag in the pipeline, it may clog the filter element, causing the resistance of the filter element to increase and increasing the difficulty of steam injection. Therefore, there are technical solutions in the prior art to prevent slag from accumulating on the filter element. For example, the Chinese utility model patent with the authorization announcement date of April 13, 2021 and the authorization announcement number CN212942015U discloses a filtering device and a steam injection system. The filtering device includes a steam injection joint, a filter cartridge (i.e., a filter element) arranged at the outlet of the steam injection joint, the filter element is arranged horizontally, and filter holes are arranged on the outer peripheral surface of the filter element. A turbine structure is also arranged inside the filter element. The turbine structure contacts the inner wall of the filter element to form a scraper for cleaning the slag inside the filter element. The turbine structure rotates under the action of steam to clean the slag and avoid clogging the filter cartridge. A storage cylinder for collecting slag is also provided at the end of the filter element away from the steam injection joint. After the slag is cleaned from the filter element, it will move toward the storage cylinder under the action of steam and turbine structure, so that the slag is collected in the storage cylinder to avoid accumulation on the filter element.

[0005] However, the above technical solution also requires a turbine structure to clean the accumulated residue on the filter cartridge, and after the cleaning is completed, an additional storage cartridge needs to be provided, making the overall structure more complicated. Contents of utility model

[0006] The purpose of the utility model is to provide a filter device for steam injection, which is used to solve the problem in the prior art that the accumulated residue on the filter element is cleaned by setting a turbine structure, thereby causing the overall structure of the filter device to be complicated.

[0007] To achieve the above purpose, the steam injection filter device in the utility model adopts the following technical solutions:

[0008] A filtering device for steam injection, comprising a vertically arranged filter cartridge, a steam inlet and a steam outlet are arranged on the filter cartridge, the steam inlet is located below the steam outlet, a filter element for filtering steam is arranged between the steam inlet and the steam outlet, and a storage structure is formed below the steam inlet of the filter cartridge, so that when the steam moves from the steam inlet to the steam outlet, the accumulated slag falls into the storage structure under the action of gravity.

[0009] Furthermore, a steam inlet pipe is provided at the steam inlet of the filter cartridge, and the axis of the steam inlet pipe is perpendicular to the axis of the filter cartridge.

[0010] Furthermore, the filter cartridge comprises an upper filter cartridge and a lower filter cartridge which are threadedly assembled together, the steam inlet is arranged on the lower filter cartridge, the steam outlet is arranged on the upper filter cartridge, and the filter element is arranged between the upper filter cartridge and the lower filter cartridge.

[0011] Furthermore, the filter element is fixedly arranged on the lower filter cylinder.

[0012] Further, the upper filter cartridge is provided with an upper threaded section, and the lower filter cartridge is provided with a lower threaded section that is in threaded cooperation with the upper threaded section. One of the upper threaded section and the lower threaded section is a male thread, and the other is a female thread. A stepped surface is provided on the filter cartridge where the female thread is located to stop the filter element.

[0013] Further, a slag cleaning port is provided at the bottom of the storage structure, and a plugging member is hermetically assembled to the slag cleaning port.

[0014] Further, a lower end cover is fixedly provided at the bottom of the filter cartridge. A through hole is provided on the lower end cover. A plugging joint is provided on the outer side of the lower end cover facing the filter cartridge. The plugging joint is a hollow columnar structure. The inner cavity of the plugging joint communicates with the through hole on the lower end cover and forms the slag cleaning port, and the plugging member is provided on the plugging joint.

[0015] Further, a threaded hole is formed on the inner wall of the plugging joint, and the plugging member is threadedly assembled on the plugging joint.

[0016] Further, the diameter of the filter cartridge is larger than the diameter of the steam inlet.

[0017] Further, the steam outlet is provided on the top end cover of the filter cartridge.

[0018] The beneficial effects of the present utility model are as follows: The present utility model pioneerly proposes a filtering device for steam injection. By arranging the filter cartridge vertically, it is convenient for the filter cartridge to extend along the height direction. The steam outlet and the steam inlet are respectively arranged on the filter cartridge from high to low, so that the steam can only move from bottom to top when passing through the device. By arranging a filter element between the steam inlet and the steam outlet, all the steam that needs to enter the well is filtered to prevent accumulated slag from entering the well, and the accumulated slag such as welding slag and rust mixed in the steam needs to overcome gravity to reach the filter element. Since a storage structure is formed below the steam inlet of the filter cartridge, under the action of gravity, part of the accumulated slag will move downward and be stored in the storage structure. That is to say, only a part of the accumulated slag will reach the filter element and be collected by the filter element, while the larger accumulated slag will settle downward in the storage structure, reducing the filtering burden of the filter element, and separating according to gravity without the need to additionally set other structures, with a simple structure, thereby solving the problem in the prior art that the overall structure of the filtering device is complicated by setting a turbine structure to clean the accumulated slag on the filter element. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the filtering device for steam injection in the present utility model.

[0020] In the figure: 1. Steam outlet pipe; 2. Upper end cover; 3. Upper filter cartridge; 4. Filter screen; 5. Lower filter cartridge; 6. Lower end cover; 7. Sealing joint; 8. Plug; 9. Steam inlet pipe; 10. Steam inlet; 11. Steam outlet. Detailed implementation mode

[0021] The features and performance of the present utility model will be further described in detail below in conjunction with the embodiments.

[0022] In the present utility model, the steam inlet is arranged below the steam outlet, and a filter element is also provided between the steam inlet and the steam outlet so that the steam can only move upward. During the upward movement, some accumulated slag will deposit downward, avoiding a large accumulation of slag on the filter element.

[0023] In Embodiment 1 of the steam injection filtering device of the present utility model:

[0024] As Figure 1 shown, the filtering device in this embodiment includes a filter cartridge. The filter cartridge is arranged vertically, and a steam inlet 10 and a steam outlet 11 are provided on the filter cartridge. The steam outlet 11 is located above the steam inlet 10, and a filter element for filtering steam is also provided between the steam inlet 10 and the steam outlet 11.

[0025] Specifically, the filter cartridge is of a split structure and includes an upper filter cartridge 3 and a lower filter cartridge 5. The upper filter cartridge 3 and the lower filter cartridge 5 are assembled together by threads, and the filter element is arranged between the upper filter cartridge 3 and the lower filter cartridge 5, thereby facilitating disassembly and installation. After one steam injection, the filter cartridge can also be unscrewed to facilitate cleaning of the filter element. The filter cartridge is generally in the shape of a hollow cylinder, and a cavity is formed inside the filter cartridge. This cavity can not only accommodate steam, but also accumulated slag can deposit in this cavity. Therefore, a storage structure for accommodating accumulated slag is formed at the bottom of the filter cartridge where the steam inlet 10 is located. Of course, in other implementation modes, the filter cartridge can also be integrally provided. At this time, the filter screen cannot be cleaned, and when cleaning is required, the filtering device is directly replaced. Or, in other implementation modes, the filter cartridge may no longer be cylindrical, but in the form of a hexahedron or other prisms.

[0026] The steam inlet 10 is arranged on the lower filter cartridge 5. Specifically, the steam inlet 10 is arranged on the side wall of the lower filter cartridge 5. An inlet steam pipe 9 is also arranged at the steam inlet 10. The axis of the inlet steam pipe 9 is arranged perpendicular to the axis of the filter cartridge, so that the steam entering from the inlet steam pipe 9 first blows on the side wall opposite to the steam inlet 10, reducing the flow rate of the steam and the speed of the slag carried in the steam, thus facilitating the settlement of the slag. At the same time, in order to further slow down the flow rate of the steam and reduce the speed of the slag in the steam, the diameter of the filter cartridge is larger than the diameter of the inlet steam pipe 9, so that the speed of the steam entering from the inlet steam pipe 9 is further reduced. Of course, in other embodiments, the axis of the inlet steam pipe 9 can also form a certain angle with the axis of the filter cartridge. For example, the axis of the inlet steam pipe 9 is inclined upward, and it can still blow to the wall of the filter cartridge. Or, in other embodiments, the diameter of the filter cartridge can also be equal to the diameter of the inlet steam pipe 9, and the slag is screened out by increasing the height of the filter cartridge.

[0027] The steam outlet 11 is arranged on the upper filter cartridge 3. The upper filter cartridge 3 includes an upper end cap 2 at the top. A perforation is arranged on the upper end cap 2, and the perforation forms the steam outlet 11. An outlet steam pipe 1 is also arranged at the position of the steam outlet 11 on the upper end cap 2. The upper end cap 2 is welded to the side wall of the upper cylinder body, and the outlet steam pipe 1 is welded to the upper end cap 2. Of course, in other embodiments, the outlet steam pipe 1 can also not be arranged, but only the steam outlet 11 is arranged. When in use, the outlet steam pipe 1 is installed at the steam outlet 11, and corresponding internal threads can be preset at the steam outlet 11. Or, in other embodiments, the upper end cap 2 and the outlet steam pipe 1 can also not be welded, but integrally cast.

[0028] The filter element is a filter screen 4, and the filter screen 4 is fixedly arranged at the end of the lower filter cylinder 5, thereby avoiding the filter element being blown and deformed by high-temperature steam, resulting in a reduction or even loss of the filtering function. Specifically, an upper thread section formed by female threads is arranged on the upper filter cylinder 3, and a stepped surface is formed between the side wall of the upper filter cylinder 3 and the upper thread section. Correspondingly, a lower thread section formed by male threads is arranged on the lower filter cylinder 5, and the lower thread section cooperates with the upper thread section to complete the installation between the upper filter cylinder 3 and the lower filter cylinder 5. At this time, the edge of the filter screen 4 abuts against the stepped surface of the upper filter cylinder 3, playing a supporting role for the filter screen 4 and preventing it from coming out under the action of steam. Of course, in other embodiments, the lower thread section can also be set as a female thread, and the upper thread section can be set as a male thread. At this time, the filter screen 4 is fixedly arranged at the lower end of the upper filter cylinder 3. Or, in other embodiments, the filter element can also be set as a rigid filter plate, and the filter plate abuts against the stepped surface where the female thread is located. At this time, the filter plate is not fixedly arranged on the upper filter cylinder 3 or the lower filter cylinder 5, but is clamped between the upper filter cylinder 3 and the lower filter cylinder 5. It should be noted that the upper filter cylinder 3 and the lower filter cylinder 5 can be sealed by screw assembly. Of course, in other embodiments, the upper filter cylinder 3 and the lower filter cylinder 5 can also be connected by a buckle, and a heat-resistant sealing ring is arranged between the upper filter cylinder 3 and the lower filter cylinder 5.

[0029] As the steam injection progresses, the accumulated slag will settle in the storage space of the lower filter cylinder 5. To improve the service life and avoid the filter device becoming unusable due to the accumulation of slag, a slag cleaning port is also arranged at the bottom of the lower filter cylinder 5. Specifically, the lower filter cylinder 5 includes a lower end cover 6, and the lower end cover 6 is welded to the bottom of the lower cylinder body. A perforation is arranged on the lower end cover 6, and a plugging joint 7 is also arranged on the side of the lower end cover 6 away from the filter cylinder. The plugging joint 7 is a hollow columnar structure. The perforation on the lower end cover 6 and the inner cavity of the plugging joint 7 together form the slag cleaning port. A threaded hole is arranged in the plugging joint 7, and a plugging member is hermetically assembled at the slag cleaning port. In this embodiment, the plugging member is a plug 8 threadedly assembled in the plugging joint 7. Of course, in other embodiments, the lower end cover 6 can no longer be arranged on the filter cylinder, and an internal threaded hole is formed on the side wall of the lower filter cylinder 5, and the plug 8 is directly installed on the side wall of the filter cylinder. Or, in other embodiments, the plugging joint 7 no longer has a threaded hole, but is set as a snap structure similar to the lid of a water cup. Or, in other embodiments, when the filter element is separately manufactured from the lower filter cylinder 5, the slag cleaning port can also no longer be arranged. When slag cleaning is required, the lower filter cylinder 5 is directly unscrewed, and the accumulated slag is poured out from the upper part.

[0030] When high-temperature steam needs to be injected into the well, the filtering device is connected to the end of the pipeline, so that the steam inlet pipe 9 is connected to the pipeline for transporting steam, and the steam outlet pipe 1 is connected to the steam injection inlet of the steam injection well, and then high-temperature steam is introduced. After the steam first enters from the steam inlet 10, it directly blows on the side wall of the filter cartridge, impacting the side wall of the cartridge, thereby changing the flow direction of the sediment in the steam. During the process of changing the direction, its kinetic energy decreases, which is convenient for sedimentation. Then the steam moves upward, and part of the sediment settles downward under the action of gravity, settling at the bottom of the lower filter cartridge 5, that is, depositing in the storage structure. Part of the smaller sediment moves upward with the steam until it contacts the filter screen 4. Under the separation action of the filter screen 4, the steam continues to move upward until it flows out through the steam outlet 11 and the steam outlet pipe 1. The sediment in the steam is blocked by the filter screen 4 and remains in the lower cylinder body or on the filter screen 4.

[0031] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. All equivalent structural changes made by using the description and drawings of the present invention should be included in the protection scope of the present invention by the same token.

Claims

1. A steam injection filtering device, characterized in that: The invention comprises a vertically arranged filter cartridge, which is provided with a steam inlet and a steam outlet, wherein the steam inlet is located below the steam outlet, and a filter element for filtering steam is arranged between the steam inlet and the steam outlet, and a storage structure is formed below the steam inlet of the filter cartridge so that when the steam moves from the steam inlet to the steam outlet, the accumulated slag falls into the storage structure under the action of gravity.

2. The steam injection filtering device according to claim 1, characterized in that: A steam inlet pipe is arranged at the steam inlet of the filter cartridge, and the axis of the steam inlet pipe is perpendicular to the axis of the filter cartridge.

3. The steam injection filtering device according to claim 1 or 2, characterized in that: The filter cartridge comprises an upper filter cartridge and a lower filter cartridge which are threadedly assembled together, the steam inlet is arranged on the lower filter cartridge, the steam outlet is arranged on the upper filter cartridge, and the filter element is arranged between the upper filter cartridge and the lower filter cartridge.

4. The steam injection filtering device according to claim 3, characterized in that: The filter element is fixedly arranged on the lower filter cylinder.

5. The steam injection filtering device according to claim 3, characterized in that: The upper filter cartridge is provided with an upper threaded section, and the lower filter cartridge is provided with a lower threaded section that is threadably matched with the upper threaded section. One of the upper threaded section and the lower threaded section is a male thread, and the other is a female thread. A step surface is provided on the filter cartridge where the female thread is located to stop the filter element.

6. The steam injection filtering device according to claim 1 or 2, characterized in that: A slag cleaning port is provided at the bottom of the storage structure, and the slag cleaning port is sealed with a blocking piece.

7. The steam injection filtering device according to claim 6, characterized in that: A lower end cover is fixedly arranged at the bottom of the filter cartridge, and a through hole is arranged on the lower end cover. A sealing joint is arranged on the lower end cover toward the outside of the filter cartridge, and the sealing joint is a hollow cylindrical structure. The inner cavity of the sealing joint is connected with the through hole on the lower end cover and constitutes the slag cleaning port, and the sealing part is arranged on the sealing joint.

8. The steam injection filtering device according to claim 7, characterized in that: The inner wall of the plugging joint is formed with a threaded hole, and the plugging piece is threadedly assembled on the plugging joint.

9. The steam injection filtering device according to claim 1 or 2, characterized in that: The diameter of the filter cartridge is greater than the diameter of the steam inlet.

10. The steam injection filtering device according to claim 1 or 2, characterized in that: An upper end cover is arranged on the top of the filter cartridge, and a steam outlet is arranged on the end cover.

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