A water adsorption filtration device, methods of use and related applications
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2022-07-13
- Publication Date
- 2026-07-03
Smart Images
Figure CN117427438B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of petroleum development technology, and in particular to a water adsorption filtration device, its usage method, and related applications. Background Technology
[0002] Water-gas dispersion system oil displacement technology is an emerging oil displacement technology. This system disperses microbubbles in an aqueous phase to form a stable whole. The implementation process involves installing a water-gas dispersion system generator within a water injection process. The outside of the generator is a water flow space, while gas is injected inside. The gas forms microbubbles in a specific area of the generator and enters the water; currently, this specific area uses a porous material.
[0003] Water-gas dispersion system injection is a method of simultaneous water and gas injection. However, existing water and gas injection processes are not fully adapted to the requirements of water-gas dispersion system injection. Generally, before formal gas injection, high-pressure gas is used to purge solid particles such as rust, welding slag, and soil from the surface pipelines before injecting the gas into the reservoir. However, the gas injection pipelines inside the wellbore are usually not cleaned and purged, and during the process of lowering the injection string to the bottom of the well, operations such as connecting individual pipelines inevitably result in a small amount of soil entering. In the initial stage of the gas injection process, these solid particles enter the bottom of the wellbore along with the gas. During the gas injection phase, a small amount of tightly adsorbed rust, welding oxides, and other particles detach from the pipeline and enter the bottom of the well. Although the amount of these solid particles will not clog the formation near the bottom of the well, because the end of the injection string is a dispersion system generation device, such as... Figure 1 As shown, its wall surface is a microporous plate structure, which prevents solid particles and other impurities in the gas injection pipe from passing through. They will adhere to the inner wall or be deposited at the bottom of the dispersion device. Since the length of the tubing in the well is usually more than 1000m, the total amount of impurities inside is relatively large. Field tests have shown that microsolid particles can easily block the pore structure of the generation device. After blockage, the gas injection pressure increases, and bubbles cannot be generated in the water, which will cause the dispersion system device to fail.
[0004] Therefore, how to filter solid particles during the gas injection process of a dispersion system is an urgent technical problem that needs to be solved to ensure the effective application of the dispersion device. Existing technologies for filtering solid particles can be selected according to filtration requirements, such as... Figure 2 The uniform filter particles shown are used for coarse filtration or as... Figure 3 The multi-layered filter particles shown provide fine filtration, and this filtration method ensures water quality by periodically replacing the filter particles or filter cartridges. Summary of the Invention
[0005] The inventors have discovered that using traditional filtration methods in water-dispersed systems requires raising and lowering the tubing string when replacing the filter device. Furthermore, the presence of numerous contaminants within the wellbore necessitates frequent replacement of the filter device, making the operation difficult and costly.
[0006] In view of the above problems, the present invention is proposed to provide a water adsorption filtration device, its method of use, and related applications that overcome or at least partially solve the above problems.
[0007] In a first aspect, embodiments of the present invention provide a water adsorption filtration device, comprising: a top section, at least one middle section, and a bottom section;
[0008] The top section includes a top section outer cylinder, a sealing pipe and a top section embedded pipe disposed inside the top section outer cylinder, and a top section air intake pipe located in the top section annulus formed by the top section outer cylinder, the sealing pipe and the top section embedded pipe; the upper end of the top section air intake pipe is connected to the sealing pipe.
[0009] The middle section includes a middle section outer cylinder, a middle section embedded pipe disposed inside the middle section outer cylinder, and a middle section air intake pipe located in the middle section annulus formed by the middle section outer cylinder and the middle section embedded pipe;
[0010] The bottom section includes a bottom section outer cylinder and a bottom section embedded pipe disposed inside the bottom section outer cylinder. The bottom section embedded pipe includes a bottom section sealing plate that connects to the bottom section outer cylinder to form a bottom seal, and a bottom section air vent pipe located in the bottom section annulus formed by the bottom section outer cylinder and the bottom section embedded pipe.
[0011] The device is in the assembled state:
[0012] The top section, at least one middle section, and the bottom section are connected in sequence; the annular space of the top section, the annular space of the middle section, and the annular space of the bottom section are connected to form an annular cavity for injecting water for filtration; the air intake pipe of the top section, the air intake pipe of the middle section, and the air intake pipe of the bottom section are connected in sequence to form an air intake pipeline to guide gas into the water for filtration; the embedded pipe of the top section, the embedded pipe of the middle section, and the embedded pipe of the bottom section are connected in sequence to form an airflow channel, and the top of the airflow channel is connected to the annular cavity to deliver the filtered gas.
[0013] In some optional embodiments, the sealing tube includes a sealing tube body and a top sealing plate, the top sealing plate being connected to the top outer cylinder to form a top seal, and the sealing tube body being provided with an air venting pipe connection hole for connecting the top air venting pipe.
[0014] The top section embedded tube includes a top section embedded tube body and a top section perforated plate. The top section perforated plate is connected to the top section outer cylinder, and the top section air intake tube passes through the through hole of the top perforated plate.
[0015] In some optional embodiments, the mid-section embedded tube includes a first mid-section perforated plate, a mid-section embedded tube body, and a second mid-section perforated plate. The first mid-section perforated plate is connected to the upper end of the mid-section outer cylinder, and the second mid-section perforated plate is connected to the lower end of the mid-section outer cylinder. The mid-section air intake tube passes through the through holes of the first mid-section perforated plate and the second mid-section perforated plate.
[0016] In some optional embodiments, the bottom section embedded tube includes a bottom section perforated plate, a bottom section embedded tube body, and a bottom section sealing plate. The bottom section perforated plate is connected to the upper end of the bottom section outer cylinder, the bottom section sealing plate is connected to the lower end of the bottom section outer cylinder, and the bottom section air duct passes through the through hole of the bottom section perforated plate.
[0017] In some optional embodiments, the top section embedded tube includes an upper annular filter tube and a lower hollow tube. The annular filter tube includes a perforated tube and a pore tube connected in sequence, and at least one reinforcing strip is provided on the outer circumference of the pore tube and the perforated tube.
[0018] In some optional embodiments, the upper end of the middle section air intake tube and the upper end of the bottom section air intake tube are provided with connectors. The inner diameter of the connector on the middle section air intake tube is not less than the outer diameter of the upper section air intake tube, so that the lower end of the upper section air intake tube extends into the connector. The inner diameter of the connector on the bottom section air intake tube is not less than the outer diameter of the middle section air intake tube, so that the lower end of the middle section air intake tube extends into the connector.
[0019] In some alternative embodiments, the top segment further includes a pathway guide plug;
[0020] The upper end of the passage guide plug is connected to the sealing tube body, and the lower end extends into the top section and is embedded inside the tube body.
[0021] In some optional embodiments, adjacent sections of the top embedded tube, middle embedded tube, and bottom embedded tube are connected by a connecting tube.
[0022] The connecting tube has symmetrical tapered portions at both ends. The larger diameter end of the tapered portion is located away from the end face of the connecting tube, and the tapered portion mates with the tapered hole at one end of the connected embedded tube.
[0023] In some optional embodiments, a sealing element is provided at the connection between the connecting pipe and the top embedded pipe, the connection between the connecting pipe and the middle embedded pipe, and the connection between the connecting pipe and the bottom embedded pipe.
[0024] In some alternative embodiments, two adjacent segments of the top segment, at least one middle segment, and the bottom segment are connected by a bidirectional coupling;
[0025] The bidirectional coupling and the top section of the outer cylinder, at least one section of the middle section of the outer cylinder, and the bottom section of the outer cylinder are connected by threads.
[0026] In some optional embodiments, the upper end of the top section and the lower end of the bottom section are further provided with core tube interfaces for connection to the gas injection pipe.
[0027] Secondly, embodiments of the present invention provide a water adsorption filtration system, comprising: a casing, an oil pipe, an air injection pipe, a dispersion device, and any of the above-described water adsorption filtration devices;
[0028] The casing extends into the oil layer;
[0029] The oil pipe is disposed inside the casing;
[0030] The air injection pipe is installed inside the oil pipe, and the lower end of the air injection pipe is connected to the dispersion device;
[0031] The water adsorption filtration device is connected between the two gas injection pipes so that the gas injected from the gas injection pipes is filtered by the water adsorption filtration device before entering the dispersion device through the gas injection pipes.
[0032] Thirdly, embodiments of the present invention provide a water adsorption filtration method for filtering gas using the above-mentioned water adsorption filtration device.
[0033] Fourthly, embodiments of the present invention provide a method of using any of the above-described water adsorption filtration devices, comprising:
[0034] After water is injected into the annular cavity, gas is injected from the top sealing pipe and enters the water in the annular cavity through the gas venting pipe for filtration. The filtered gas enters the space above the annular cavity from the gas-water interface, enters the airflow channel from the space above, and enters the lower gas injection pipe through the airflow channel.
[0035] Fifthly, embodiments of the present invention provide an application of any of the above-described water adsorption filtration devices in the downhole injection process of a water dispersion system.
[0036] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:
[0037] The water adsorption filtration device provided in this embodiment of the invention comprises a top section, a middle section, and a bottom section connected and fixed in sequence. The annular space of the top section, the middle section, and the bottom section are interconnected to form an annular cavity for injecting water for filtration. The air intake pipe of the top section, the air intake pipe of the middle section, and the air intake pipe of the bottom section are connected in sequence to form an air intake pipeline to guide gas into the water in the annular cavity for filtration. The embedded pipe of the top section, the embedded pipe of the middle section, and the embedded pipe of the bottom section are connected in sequence to form an airflow channel. The top of the airflow channel is connected to the annular cavity to deliver the filtered gas into the lower dispersion device. When gas needs to be injected, the gas enters the pipeline from the inlet above the air intake pipeline and enters the annular cavity from the outlet below. The water in the cavity is filtered before entering the upper space of the annular cavity from the gas-water interface and then entering the dispersion device through the airflow channel. This achieves simultaneous gas injection and gas filtration. The filtration device has a simple structure, connecting the filtration device and the gas injection pipe. Gas filtration is completed during the gas injection process. At the same time, there is a certain distance between the bottom gas inlet pipe and the sealing plate of the filtration device, so the solid particles settled in the annular cavity will not affect the filtration of the newly injected gas. Therefore, it is not necessary to frequently raise and lower the tubing to replace the filtration device. Cleaning can be carried out during the tubing raising and lowering operation cycle without adding extra downhole operation time, thus saving operating costs.
[0038] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.
[0039] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0040] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:
[0041] Figure 1 This is a schematic diagram of the clogging of the dispersion device in the dispersion system according to an embodiment of the present invention;
[0042] Figure 2 This is a schematic diagram of uniform filtration in an embodiment of the present invention;
[0043] Figure 3 This is a schematic diagram of multi-layer filtering in an embodiment of the present invention;
[0044] Figure 4 This is a schematic diagram illustrating the principle of water adsorption filtration in an embodiment of the present invention;
[0045] Figure 5 This is a schematic diagram of the water adsorption filtration device in an embodiment of the present invention;
[0046] Figure 6 This is a schematic diagram of the top section of the water adsorption filtration device in an embodiment of the present invention;
[0047] Figure 7 This is a schematic diagram of the perforated tube in an embodiment of the present invention;
[0048] Figure 8 This is a schematic diagram of the pore tube in an embodiment of the present invention;
[0049] Figure 9 This is a schematic diagram of the middle section of the water adsorption filtration device in an embodiment of the present invention;
[0050] Figure 10 This is a schematic diagram of the bottom section of the water adsorption filtration device in an embodiment of the present invention;
[0051] Figure 11 This is a schematic diagram of the connecting pipe in an embodiment of the present invention;
[0052] Figure 12 This is a schematic diagram of the gas flow direction of the water adsorption filtration device in an embodiment of the present invention;
[0053] Figure 13 This is a schematic diagram of the water adsorption filtration system in an embodiment of the present invention.
[0054] Explanation of reference numerals in the attached figures:
[0055] 1-Top section, 2-Middle section, 3-Bottom section, 4-Two-way coupling, 5-Connecting pipe, 6-Joint, 7-Casing, 8-Oil pipe, 9-Gas injection pipe, 10-Water adsorption filtration device, 11-Dispersion device, 12-Oil layer;
[0056] 101-Top section outer cylinder, 102-Top section sealing plate, 103-Sealing pipe body, 104-Top section embedded pipe body, 105-Top section air venting pipe, 106-Top perforated plate, 107-Passage guide plug, 108-Core tube interface, 109-Hole tube, 110-Porous tube, 111-Hole, 112-Hole coupling, 113-Reinforcing strip, 114-Porous coupling;
[0057] 21-Middle section outer cylinder, 22-Middle section air intake pipe, 23-Middle section embedded pipe body, 24-First middle section perforated plate, 25-Second middle section perforated plate;
[0058] 31-Bottom section outer cylinder, 32-Bottom section air intake pipe, 33-Bottom section perforated plate, 34-Bottom section embedded pipe body, 35-Bottom section sealing plate, 36-Core tube interface;
[0059] 51-Seal, 52-Cone portion. Detailed Implementation
[0060] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0061] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "top section," "middle section," and "bottom section" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0062] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0063] To address the high operating costs associated with frequent tubing runs and runs for filter replacements in traditional dispersion systems, this invention provides a water adsorption filter. The filter is connected between two gas injection pipes, allowing solid particles to be filtered during gas injection. The cleaned gas then re-enters the dispersion system through the injection pipes. This filter has a simple structure and can be cleaned during tubing runs, without increasing downhole operation time and reducing operating costs.
[0064] During downhole gas injection, the solid particles carried in the gas are typically a mixture of silt and iron oxide powder, with a particle density ranging from 3.0 to 8.0 g / cm³. 3 During this process, solid particles can settle under the adsorption of water. To ensure that the solid particles in the gas are wetted by water and to reduce water flow disturbance, a relatively long pipeline is designed to achieve the filtration function. The working principle of the water adsorption filtration device provided in this embodiment of the invention is as follows: Figure 4As shown: Gas carrying tiny solid particles is injected into the water at the lower end of a long tube. The gas exists as bubbles in the water. Due to the high velocity during injection, the fluid within the annulus is in a turbulent state, ideal for sufficient gas-water contact. The gas, after entering the water, travels a relatively long distance H... tu After passing through a water body, solid particles become wetted, detach from the gas, and tend to aggregate to form larger particles, increasing their resistance to carrying and enhancing sedimentation. ga Settling begins within a certain distance range, with a reserved solid particle deposition height of H within the device. de At the distance H where settlement begins ga The foundation is reserved for the solid particle settling height H. cl To ensure sufficient sedimentation of solid particles; the gas rise height after filtration is set to H. g This process then completes the filtration of the gas.
[0065] The water adsorption filtration device provided in this embodiment of the invention filters particulate matter in gas based on the above-mentioned principle of water adsorption filtration, such as... Figure 5 As shown, it includes: top segment 1, at least one middle segment 2, and bottom segment 3;
[0066] The top section 1 includes a top section outer cylinder 101, a sealing pipe and a top section embedded pipe disposed inside the top section outer cylinder 101, and a top section air intake pipe 105 located in the top section annulus formed by the top section outer cylinder 101, the sealing pipe and the top section embedded pipe; the upper end of the top section air intake pipe 105 is connected to the sealing pipe.
[0067] The middle section 2 includes a middle section outer cylinder 21, a middle section embedded pipe disposed within the middle section outer cylinder 21, and a middle section air intake pipe 22 located in the middle section annulus formed by the middle section outer cylinder 21 and the middle section embedded pipe;
[0068] The bottom section 3 includes a bottom section outer cylinder 31 and a bottom section embedded pipe disposed inside the bottom section outer cylinder 31. The bottom section embedded pipe includes a bottom section sealing plate 35 connected to the bottom section outer cylinder 31 to form a bottom seal, and a bottom section air venting pipe 32 located in the bottom section annulus formed by the bottom section outer cylinder 31 and the bottom section embedded pipe.
[0069] The water adsorption filtration device in its assembled state:
[0070] The top section 1, at least one middle section 2, and the bottom section 3 are connected in sequence; the top annulus, the middle annulus, and the bottom annulus are connected to form an annular cavity for injecting water for filtration; the top air intake pipe 105, the middle air intake pipe 22, and the bottom air intake pipe 32 are connected in sequence to form an air intake pipeline to guide gas into the water for filtration; the top embedded pipe, the middle embedded pipe, and the bottom embedded pipe are connected in sequence to form an airflow channel, and the top of the airflow channel is connected to the annular cavity to deliver the filtered gas.
[0071] When gas needs to be injected, the gas enters the pipeline from the inlet above the gas venting pipe and enters the water in the annular cavity from the outlet below. After being filtered in the water, the gas enters the upper space of the annular cavity from the gas-water interface and enters the dispersion device through the airflow channel, thus achieving gas injection and filtration at the same time.
[0072] The top section 1 of the water adsorption filtration device provided in this invention is the pipeline section for gas injection and backflow into the middle section 2, and its structure is as follows: Figure 6 As shown, the sealing tube includes a sealing tube body 103 and a top sealing plate 102. The top sealing plate 102 is connected to the top outer cylinder 101 to form a top seal. The sealing tube body 103 is provided with an air inlet pipe connection hole for connecting the top air inlet pipe 105. The top air inlet pipe 105 and the sealing tube body 103 can be an integral design or a separate design. That is, the top air inlet pipe 105 can be installed in the air inlet pipe connection hole of the sealing tube body 103, or the top air inlet pipe 105 and the sealing tube body 103 can be integrally formed.
[0073] The top section embedded tube includes a top section embedded tube body 104 and a top section perforated plate 16. The top section perforated plate 16 is connected to the top section outer cylinder 101, and the top section air intake tube 105 passes through the through hole of the top perforated plate 106. The connection part between the top section embedded tube body 104 and the top section perforated plate 16 can be set as a tapered structure to facilitate the installation of the connecting pipe 5.
[0074] The top section embedded tube 104 includes an annular filter tube at the upper end and a hollow tube at the lower end. The annular filter tube includes a perforated tube 109 and a pore tube 110 connected in sequence. The structure of the perforated tube 109 is as follows: Figure 7 As shown, the perforated tube 109 is provided with perforations 111 and perforation couplings 112. The perforations 111 are distributed on the wall of the perforated tube 109, and the size, number, and shape of the perforations 111 can be selected according to the gas flow rate. The structure of the perforated tube 110 is as follows... Figure 8 As shown, the perforated tube 109 and the pore tube 110 are connected from top to bottom to the pore coupling 114 via the perforated coupling 112.
[0075] Optionally, at least one reinforcing strip 113 is provided on the outer circumference of the pore tube 110 and the perforated tube 109. Since the pore tube 110 and the perforated tube 109 have holes in their walls compared to the lower hollow tube, with the pore tube 110 having densely packed small holes, they can perform secondary filtration of tiny solid particles entrained in the filtered gas. The holes in the tube walls reduce the strength of the perforated tube 109 and the pore tube 110 compared to the lower hollow tube, resulting in poor load-bearing capacity of the pore tube 110 and the perforated tube 109 during connection. The reinforcing strip 113 provides a certain degree of reinforcement, and the specific number of reinforcing strips 113 can be selected as needed.
[0076] When the filtered gas flows to the upper end of the top section embedded tube 104, it preferentially enters the airflow channel through the pore tube 110 due to pressure. When the airflow is large, it enters the airflow channel through the perforated tube 109 or the opening at the upper end of the top section embedded tube 104. The perforated tube 109 is provided to prevent the pore tube 110 from generating excessive resistance, so as not to damage the structure of the pore tube 110. The lengths of the perforated tube 109 and the pore tube 110 can also be selected. Generally, the length of the perforated tube 109 can be selected from 1 to 5 m, and the length of the pore tube 110 can be selected from 5 to 20 m. This invention does not limit these lengths.
[0077] Optionally, the top section of the filter device also includes a passage guide plug 107, which is in the shape of an inverted frustum. The upper end of the passage guide plug 107 is connected to the sealing tube 103, and the lower end extends into the interior of the top section embedded tube 104. A certain gap is left between the top section embedded tube 104 and the inner wall of the top section embedded tube 104, so that the top section embedded tube 104 is centered and stable during installation, and prevents the top section embedded tube 104 from swaying left and right.
[0078] In this embodiment of the water adsorption filtration device, the upper end of the top section is also provided with a core tube interface 108. The top section 1 is connected to the air injection pipe through the core tube interface 108. The gas injected from the air injection pipe is sealed by the sealing tube body 103 and enters the interior of the top section air injection pipe 105 through the air injection pipe connection hole. The connection between the sealing tube body 103 and the top section sealing plate 102 can be designed as a conical structure, that is, the core tube interface 108 is a conical structure, to facilitate the connection of the air injection pipe.
[0079] The middle section 2 of the water adsorption filtration device provided in this embodiment of the invention is the part where the gas is wetted by water, gathers, and begins to settle. Its structure is as follows: Figure 9 As shown, the intermediate embedded tube includes a first intermediate perforated plate 24, an intermediate embedded tube body 23, and a second intermediate perforated plate 25. The first intermediate perforated plate 24 is connected to the upper end of the intermediate outer cylinder 21, and the second intermediate perforated plate 25 is connected to the lower end of the intermediate outer cylinder 21. The intermediate air intake tube 22 passes through the through holes of the first intermediate perforated plate 24 and the second intermediate perforated plate 25. The connection part between the intermediate embedded tube body 23 and the first intermediate perforated plate 24 can be set as a conical structure, and the connection part between the intermediate embedded tube body 23 and the second intermediate perforated plate 25 can also be set as a conical structure to facilitate the installation of the connecting tube 5.
[0080] The bottom section 3 of the water adsorption filtration device provided in this embodiment of the invention is the part where solid particles are deposited, and its structure is as follows: Figure 10As shown, the bottom section embedded tube includes a bottom section perforated plate 33, a bottom section embedded tube body 34, and a bottom section sealing plate 35. The bottom section perforated plate 33 is connected to the upper end of the bottom section outer cylinder 31, and the bottom section sealing plate 35 is connected to the lower end of the bottom section outer cylinder 31 to form a bottom section seal, allowing the water to be sealed within the annular cavity. The bottom section air intake pipe 32 passes through the through hole of the bottom section perforated plate 33. A certain gap is left between the bottom section air intake pipe 32 and the bottom section sealing plate 35 to allow for a certain amount of solid phase accumulation. A core tube interface 36 is also provided at the lower end of the bottom section to connect with the lower end air injection pipe. The connection part between the bottom section embedded tube body 34 and the bottom section perforated plate 33 can be set as a conical structure to facilitate the installation of the connecting pipe 5. The connection part between the bottom section embedded tube body 34 and the bottom section sealing plate 35 can also be set as a conical structure to facilitate the connection of the air injection pipe.
[0081] Optionally, in this embodiment of the filter device, the upper end of the middle section air intake pipe 22 and the upper end of the bottom section air intake pipe 32 are provided with connectors 6. The inner diameter of the connector 6 on the middle section air intake pipe 22 is not less than the outer diameter of the upper section air intake pipe 15, so that the lower end of the upper section air intake pipe 15 extends into the connector 6. The inner diameter of the connector 6 on the bottom section air intake pipe 32 is not less than the outer diameter of the middle section air intake pipe 22, so that the lower end of the middle section air intake pipe 22 extends into the connector 6. Adjacent air intake pipes are connected by threads through connectors 6 to ensure the air intake pipe is sealed to the external annular cavity, allowing gas to flow in the air intake pipe. The connection between the two air intake pipes is a sealed connection, which can be a threaded connection or other methods can be used to connect the air injection pipe.
[0082] The top section embedded tube, the middle section embedded tube, and the bottom section embedded tube are connected to adjacent tubes by a connecting tube 5; the structure of the connecting tube 5 is as follows: Figure 11 As shown, the connecting pipe 5 has an internally hollow structure and symmetrical tapered portions 52 at both ends. The larger diameter end of the tapered portion 52 is located away from the end face of the connecting pipe 5. The tapered portion 52 engages with the tapered hole at one end of the connected embedded pipe to limit the connection pipe 5 and prevent it from slipping out of the embedded pipe. Sealing elements 51 are provided at the connections between the connecting pipe 5 and the top embedded pipe, the connecting pipe 5 and the middle embedded pipe, and the connecting pipe 5 and the bottom embedded pipe. This ensures the airflow channel is sealed to its external annular cavity, allowing the cleaned gas to enter the dispersion device at the lower end of the filter device along the airflow channel without diffusing into the external annular cavity.
[0083] Optionally, in the embodiment of the present invention, two adjacent sections of the top section, at least one middle section and bottom section of the filter device are connected by a bidirectional coupling 4; the bidirectional coupling 4 and the top section outer cylinder 101, at least one middle section outer cylinder 21 and the bottom section outer cylinder 31 are connected by threads.
[0084] During the connection of each section of the filter device, the external bidirectional coupling 4 mainly bears the tension of the tubing, while the internal connecting pipe 5 mainly connects each section and plays a sealing role, allowing the injected gas to flow along the airflow channel.
[0085] Optionally, the water adsorption filtration device provided in this embodiment of the invention can select the number of middle sections according to filtration needs. Each middle section is externally connected by a bidirectional coupling 4 and internally connected by a connecting pipe 5.
[0086] The water adsorption filtration device provided in this embodiment of the invention has perforated plates arranged on the outside of each embedded tube, which can fix the embedded tube. In general, the through holes of the perforated plates are large, which not only allows the air intake tube to pass through, but also provides a passage for the rise of the return gas through the gap between the through holes of the perforated plates and the air intake tube.
[0087] The present invention will describe the water injection and gas flow process of the water adsorption filtration device using downhole nitrogen injection as an example:
[0088] Assuming the injection well is 2000m deep, during normal water injection, the wellhead pressure does not exceed 12MPa, and the daily gas injection is 1000Nm³. 3 The injection pressure should not exceed 25 MPa. The design is based on an outer cylinder diameter of 60 mm and a wall thickness of 4 mm; each section of the embedded tube has an outer diameter of 30 mm and a wall thickness of 2 mm, with a total section length of approximately 40 m. This includes perforated tubes of 2 m in length and pore tubes of 8 m in length. The middle section is approximately 40 m long. The bottom section is approximately 20 m long. To ensure sufficient accumulation, the air intake tube may not enter the bottom section space.
[0089] (1) Water injection process of water adsorption filtration device
[0090] The water adsorption filtration device is connected one tube column at a time. During the water injection process, water can be injected into the annular cavity of the filtration device once the connecting tube column reaches the required water injection height. After water injection, other tube columns can be connected. Alternatively, water can be injected through the air intake pipe after all tube columns are connected. The water injection height should be a certain distance from the lower end of the pore tube to ensure that the height of the water after the gas rises in the annular cavity does not exceed the height of the lower end of the pore tube. The specific height can be selected as needed, and this embodiment of the invention does not limit it.
[0091] In this example, when the total water volume is 80L, the water volume in the annulus is about 60L, the water volume in the air intake pipe is about 20L, and the water-air interface is located in the middle of the middle section, about 40m away from the bottom of the overall device.
[0092] (2) Flow process of injected gas
[0093] Gas is injected into the bottom of the filter device. During injection, due to the sealing tube, the gas flows downward along the gas inlet pipe, exits at the bottom of the pipe, and enters the water-filled annular cavity. Within the annular cavity, the gas flows upward due to pressure, passing through the cavity for filtration. The filtered gas then enters the airflow channel and moves downward. A schematic diagram of the gas flow is shown below. Figure 12 As shown.
[0094] The gas initially rises in the annular cavity as a slug flow, and is broken into bubbles by the perforated plate, which facilitates the adsorption of solid particles in the gas by water. The bubbles carry the microparticles to the surface until the particles are adsorbed by water, and the bubbles become clean gas. The solid particles settle in the water, and when the amount of solid particles is large enough, they can overcome the interference of the upward flow and settle into the bottom annular cavity.
[0095] As the bubbles continue to rise, they break through the water-air interface, forming a continuous gas stream. This gas then enters the airflow channel through the pore tubes and perforations at the top, and continues to flow downwards into the dispersion device at the bottom. During the bubble's ascent, the water surface rises as a whole. A space is left above the water-air interface to accommodate this upward movement, preventing water from entering the internal airflow channel.
[0096] Optionally, a simulation device for the above-mentioned water adsorption filtration device was fabricated using organic tubes according to an embodiment of the present invention to test the fluid morphology within the annular cavity of the water adsorption filtration device, the bottom section reserved distance, the filtration capacity, and the liquid loss, and the following conclusions were obtained:
[0097] (1) Fluid morphology within the annular cavity
[0098] After exiting the gas intake pipe, the gas enters the annular cavity. In the initial stage, the gas slug shape is obvious, and its length is the longest. It is biased at the top of the water, but the largest cross-section does not completely occupy the annulus. The water is still a continuous phase, and the water level rises. As gas is continuously injected, the rising water flows down the inner wall of the outer cylinder of the filter device, disturbing the gas. The gas is no longer in a slug shape and is mainly composed of bubbles of different sizes.
[0099] The fluid morphology within the annulus shows that the gas moves mainly in the form of bubbles within this narrow annulus, with a large contact area with water, which is conducive to the adsorption of water by solid particles in the gas.
[0100] (2) Reservation distance at the bottom section
[0101] During the gas injection process, observation of the bottom section of the gas inlet pipe revealed a short gas injection distance, approximately 1 cm under a pressure difference of 0.1 MPa. Since the actual pressure difference on site did not exceed 1 MPa, a 30 cm allowance for the bottom gas injection distance was sufficient.
[0102] Because the amount of solid particles in the gas was too small, a mixture of solid particles was injected into the simulation device to replace the solid particles in the gas. 50g of 200-mesh (70μm) sand and 30g of kaolin with a mesh size of 2000-mesh (5μm or larger) were injected. Observation of the bottom of the simulation device revealed that the sand and kaolin were basically deposited at the bottom in a static state. After the gas was injected, the bottom sediments were disturbed; the sand was disturbed over a shorter distance, while the kaolin was carried into the overall water column.
[0103] Therefore, to minimize disturbance to the sediment, the lower end of the bottom air intake pipe of the filter device in this embodiment of the invention should be at least 300 cm away from the sediment. Considering the operation process, pipe wall residue, and particulate content in the air, it is optimal to leave a length of oil pipe (approximately 9 m) at the bottom of the filter device. This ensures that the solid particles have sufficient accumulation space, while the gas ejected from the bottom air intake pipe will not disturb the accumulated solid particles.
[0104] (3) Filtration capacity
[0105] The experiment lasted for one week, with a total gas volume of 100 Nm³. 3 Observing the upper part of the water column in the simulation device, it was found that the suspended solid particles in the water exhibited significant light scattering, while the gas remained clear, with no obvious particle-carrying phenomenon observed. The exhaust water remained clear, indicating that the solid particles were not carried out by the gas, demonstrating good filtration performance.
[0106] (4) Liquid loss
[0107] The experiment observed changes in liquid level and estimated the amount of water evaporated by the gas under closed conditions, which provided a basis for the amount of water added to the annulus. Under the condition of 5 days of experiment, the maximum water loss in the water column was 1 mm / d. Calculated over a year, the loss was less than 400 mm.
[0108] Based on the above simulation experiments, it can be seen that the water adsorption filtration device provided in this embodiment of the invention can effectively filter solid particles carried in the gas.
[0109] Optionally, in the design of the filter device length, since the downhole tubing is usually 10m long, the length of each section of the filter device can be designed as a multiple of the tubing length.
[0110] Based on the same inventive concept, such as Figure 13 As shown, an embodiment of the present invention provides a water adsorption filtration system, characterized in that it includes: a sleeve 7, an oil pipe 8, an air injection pipe 9, a dispersion device 11, and the aforementioned water adsorption filtration device 10;
[0111] The casing 7 extends into the oil layer 12;
[0112] Oil pipe 8 is installed inside casing 7;
[0113] Air injection pipe 9 is installed inside oil pipe 8, and the lower end of air injection pipe 9 is connected to dispersion device 11;
[0114] The water adsorption filter 10 is connected between the two gas injection pipes 9 so that the gas injected from the gas injection pipe 9 is filtered by the water adsorption filter 10 and then enters the dispersion device 11 through the gas injection pipe 9.
[0115] Compare Figure 1 and Figure 13 It can be seen that when a water adsorption filtration device is used, the solid particles that were originally accumulated on the wall of the dispersion device are settled in the water adsorption filtration device, and the clean gas enters the dispersion device, thus avoiding the clogging of the dispersion device.
[0116] This invention also provides a method for filtering gas using the above-described water adsorption filtration device.
[0117] This invention also provides a method of using the above-described water adsorption filtration device, including:
[0118] After water is injected into the annular cavity, gas is injected from the top sealing pipe and enters the water in the annular cavity through the gas venting pipe for filtration. The filtered gas enters the space above the annular cavity from the gas-water interface, enters the airflow channel from the space above, and enters the lower gas injection pipe through the airflow channel.
[0119] This invention also provides the application of the above-mentioned water adsorption filtration device in the downhole injection process of a water dispersion system.
[0120] The water adsorption filtration device provided in this embodiment of the invention is connected to the gas injection pipes of the water dispersion system at both ends. Gas carrying solid particles is injected from the upper end of the filtration device into the annular cavity inside the filtration device for filtration. The filtered gas then enters the dispersion device through the lower gas injection pipe for operation. Compared with traditional filtration methods, the filtration method of this embodiment of the invention installs a three-section long pipe at the top of the dispersion device, embedding it inside the tubing, thus solving the problem of difficult filtration inside the wellbore. Moreover, the filtration device has a simple structure and easy connection. There is gas pressure inside the embedded pipe and water pressure outside the embedded pipe, resulting in a very small pressure difference between the inside and outside of the pipe, which meets the conditions for high-pressure downhole operations. Furthermore, the filtration method of this embodiment of the invention completes the gas filtration during downhole gas injection, simplifying operation. Sufficient distance is left between the bottom gas inlet pipe and the bottom sealing pipe of the filtration device for the accumulation of solid particles. During filtration, the water loss in the annular cavity is minimal, eliminating the need for frequent raising and lowering of the filtration device to clean solid particles or injecting water into the annular cavity, thus saving operating costs.
[0121] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.
[0122] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.
[0123] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."
Claims
1. A water adsorption filtration implementation system, characterized in that, include: Casing, tubing, gas injection pipe, dispersion device and water adsorption filtration device; The water adsorption filtration device includes: a top section, at least one middle section, and a bottom section; The top section includes a top section outer cylinder, a sealing pipe and a top section embedded pipe disposed inside the top section outer cylinder, and a top section air intake pipe located in the top section annulus formed by the top section outer cylinder, the sealing pipe and the top section embedded pipe; the upper end of the top section air intake pipe is connected to the sealing pipe. The middle section includes a middle section outer cylinder, a middle section embedded pipe disposed inside the middle section outer cylinder, and a middle section air intake pipe located in the middle section annulus formed by the middle section outer cylinder and the middle section embedded pipe; The bottom section includes a bottom section outer cylinder and a bottom section embedded pipe disposed inside the bottom section outer cylinder. The bottom section embedded pipe includes a bottom section sealing plate that connects to the bottom section outer cylinder to form a bottom seal, and a bottom section air vent pipe located in the bottom section annulus formed by the bottom section outer cylinder and the bottom section embedded pipe. The device is in the assembled state: The top section, at least one middle section, and the bottom section are connected in sequence; the annular space of the top section, the annular space of the middle section, and the annular space of the bottom section are connected to form an annular cavity for injecting water for filtration; the air intake pipe of the top section, the air intake pipe of the middle section, and the air intake pipe of the bottom section are connected in sequence to form an air intake pipeline to guide gas into the water for filtration; the embedded pipe of the top section, the embedded pipe of the middle section, and the embedded pipe of the bottom section are connected in sequence to form an airflow channel, and the top of the airflow channel is connected to the annular cavity to deliver the filtered gas; The casing extends into the oil layer; The oil pipe is disposed inside the casing; The air injection pipe is installed inside the oil pipe, and the lower end of the air injection pipe is connected to the dispersion device; The water adsorption filtration device is connected between the two gas injection pipes so that the gas injected from the gas injection pipes is filtered by the water adsorption filtration device before entering the dispersion device through the gas injection pipes.
2. The water adsorption filtration implementation system of claim 1, wherein, The sealing tube includes a sealing tube body and a top sealing plate. The top sealing plate is connected to the top outer cylinder to form a top seal. The sealing tube body is provided with an air venting pipe connection hole for connecting the top air venting pipe. The top section embedded tube includes a top section embedded tube body and a top section perforated plate. The top section perforated plate is connected to the top section outer cylinder, and the top section air intake tube passes through the through hole of the top perforated plate.
3. The water adsorption filter implementation system of claim 1, wherein, The middle section embedded tube includes a first middle section perforated plate, a middle section embedded tube body, and a second middle section perforated plate. The first middle section perforated plate is connected to the upper end of the middle section outer cylinder, and the second middle section perforated plate is connected to the lower end of the middle section outer cylinder. The middle section air intake tube passes through the through holes of the first middle section perforated plate and the second middle section perforated plate.
4. The water adsorption filter implementation system of claim 1, wherein, The bottom section embedded tube includes a bottom section perforated plate, a bottom section embedded tube body, and a bottom section sealing plate. The bottom section perforated plate is connected to the upper end of the bottom section outer cylinder, and the bottom section sealing plate is connected to the lower end of the bottom section outer cylinder. The bottom section air intake tube passes through the through hole of the bottom section perforated plate.
5. The water adsorption filter implementation system of claim 2, wherein, The top section embedded tube includes an annular filter tube at the upper end and a hollow tube at the lower end. The annular filter tube includes a perforated tube and a pore tube connected in sequence. At least one reinforcing strip is provided on the outer circumference of the pore tube and the perforated tube.
6. The water adsorption filtration system as described in claim 1, characterized in that, The upper end of the middle section air intake pipe and the upper end of the bottom section air intake pipe are provided with joints. The inner diameter of the joint on the middle section air intake pipe is not less than the outer diameter of the upper section air intake pipe, so that the lower end of the upper section air intake pipe extends into the joint. The inner diameter of the joint on the bottom section air intake pipe is not less than the outer diameter of the middle section air intake pipe, so that the lower end of the middle section air intake pipe extends into the joint.
7. The water adsorption filtration system as described in claim 2, characterized in that, The top section also includes a pathway guide plug; The upper end of the passage guide plug is connected to the sealing tube body, and the lower end extends into the top section and is embedded inside the tube body.
8. The water adsorption filtration system as described in claim 1, characterized in that, The top section embedded tube, the middle section embedded tube, and the bottom section embedded tube are connected to adjacent tubes by connecting tubes; The connecting tube has symmetrical tapered portions at both ends. The larger diameter end of the tapered portion is located away from the end face of the connecting tube, and the tapered portion mates with the tapered hole at one end of the connected embedded tube.
9. The water adsorption filtration system as described in claim 8, characterized in that, Sealing elements are provided at the connection points of the connecting pipe and the top embedded pipe, the connecting pipe and the middle embedded pipe, and the connecting pipe and the bottom embedded pipe.
10. The water adsorption filtration system as described in claim 1, characterized in that, The top segment, at least one middle segment, and bottom segment are connected by a bidirectional coupling between adjacent segments; The bidirectional coupling and the top section of the outer cylinder, at least one section of the middle section of the outer cylinder, and the bottom section of the outer cylinder are connected by threads.
11. The water adsorption filtration system as described in any one of claims 1-10, characterized in that, The upper end of the top section and the lower end of the bottom section are also provided with core tube interfaces for connection to the gas injection pipe.
12. A method of using a water adsorption filtration device, characterized in that, The water adsorption filtration device includes: a top section, at least one middle section, and a bottom section; The top section includes a top section outer cylinder, a sealing pipe and a top section embedded pipe disposed inside the top section outer cylinder, and a top section air intake pipe located in the top section annulus formed by the top section outer cylinder, the sealing pipe and the top section embedded pipe; the upper end of the top section air intake pipe is connected to the sealing pipe. The middle section includes a middle section outer cylinder, a middle section embedded pipe disposed inside the middle section outer cylinder, and a middle section air intake pipe located in the middle section annulus formed by the middle section outer cylinder and the middle section embedded pipe; The bottom section includes a bottom section outer cylinder and a bottom section embedded pipe disposed inside the bottom section outer cylinder. The bottom section embedded pipe includes a bottom section sealing plate that connects to the bottom section outer cylinder to form a bottom seal, and a bottom section air vent pipe located in the bottom section annulus formed by the bottom section outer cylinder and the bottom section embedded pipe. The device is in the assembled state: The top section, at least one middle section, and the bottom section are connected in sequence; the annular space of the top section, the annular space of the middle section, and the annular space of the bottom section are connected to form an annular cavity for injecting water for filtration; the air intake pipe of the top section, the air intake pipe of the middle section, and the air intake pipe of the bottom section are connected in sequence to form an air intake pipeline to guide gas into the water for filtration; the embedded pipe of the top section, the embedded pipe of the middle section, and the embedded pipe of the bottom section are connected in sequence to form an airflow channel, and the top of the airflow channel is connected to the annular cavity to deliver the filtered gas; The method includes: after water is injected into the annular cavity, gas is injected from the top sealing pipe and filtered into the water in the annular cavity through the gas venting pipe. The filtered gas enters the space above the annular cavity from the gas-water interface, enters the airflow channel from the space above, and enters the lower gas injection pipe through the airflow channel.
13. The application of a water adsorption filtration device in the downhole injection process of a water dispersion system, characterized in that, The water adsorption filtration device includes: a top section, at least one middle section, and a bottom section; The top section includes a top section outer cylinder, a sealing pipe and a top section embedded pipe disposed inside the top section outer cylinder, and a top section air intake pipe located in the top section annulus formed by the top section outer cylinder, the sealing pipe and the top section embedded pipe; the upper end of the top section air intake pipe is connected to the sealing pipe. The middle section includes a middle section outer cylinder, a middle section embedded pipe disposed inside the middle section outer cylinder, and a middle section air intake pipe located in the middle section annulus formed by the middle section outer cylinder and the middle section embedded pipe; The bottom section includes a bottom section outer cylinder and a bottom section embedded pipe disposed inside the bottom section outer cylinder. The bottom section embedded pipe includes a bottom section sealing plate that connects to the bottom section outer cylinder to form a bottom seal, and a bottom section air vent pipe located in the bottom section annulus formed by the bottom section outer cylinder and the bottom section embedded pipe. The device is in the assembled state: The top section, at least one middle section, and the bottom section are connected in sequence; the annular space of the top section, the annular space of the middle section, and the annular space of the bottom section are connected to form an annular cavity for injecting water for filtration; the air intake pipe of the top section, the air intake pipe of the middle section, and the air intake pipe of the bottom section are connected in sequence to form an air intake pipeline to guide gas into the water for filtration; the embedded pipe of the top section, the embedded pipe of the middle section, and the embedded pipe of the bottom section are connected in sequence to form an airflow channel, and the top of the airflow channel is connected to the annular cavity to deliver the filtered gas.