Scale removal and prevention device, equipment and method based on oilfield water injection system

Abstract

The invention provides a scale removal and prevention device, equipment and method based on an oil field water injection system. The device comprises a shell, a water inlet and a water outlet are formed in the outer side walls of the two sides of the shell respectively, a vacuum dosing port is further formed in the shell, and a drain outlet is formed in the bottom end of the shell; a partition plate, a plurality of first grids and a plurality of second grids are arranged in the shell; the first grids and the second grids are arranged on the two sides of the partition plate respectively. The grid size of the plurality of first grids is smaller than the grid size of the plurality of second grids. According to the device, scale removal and prevention can be dynamically carried out by increasing the flowing path and time of fluid, the scale removal and prevention procedures are reduced, manpower and cost are effectively reduced, and meanwhile the scale removal effect is improved.

Description

Technical Field

[0001] The present application relates to the technical field of oil production engineering, and in particular, to a scale removal and prevention device, equipment and method based on an oilfield water injection system. Background Art

[0002] With the development of oilfield water injection, the water injection demand increases, and it gradually changes from a single water injection source to multiple water sources for water injection. This leads to unstable mixed injection water, which is prone to scale formation, resulting in scale formation in surface pipelines, wellbores and formations, an increase in water injection pressure, and a decrease in the water absorption capacity of the formation, seriously affecting the water injection efficiency. Moreover, with the large-scale water injection development, the water cut of the oil reservoir increases significantly. From the formation to the surface, the pressure and temperature of the crude oil produced liquid change, which will also cause serious scale formation and affect normal production. Therefore, scale formation is a common phenomenon in oilfields, especially in high-mineralization oilfields, where the scale formation problem is particularly prominent, bringing great troubles to the oilfield water injection development.

[0003] Currently, the common method for treating scale in oilfields is to add scale inhibitors. Scale inhibitors can chelate with calcium and magnesium ions, thereby increasing the solubility of calcium and magnesium ions and preventing scale formation. However, due to the large volume of oilfield injection and production fluids, a large amount of scale inhibitor needs to be added in large quantities and multiple times during the scale removal process, and the scale deposits need to be filtered multiple times through filters with different pore sizes to achieve scale removal. The scale removal and prevention procedures are cumbersome. Moreover, on-site, poor scale prevention effects are caused by improper chemical agent quality and maintenance measures, etc., and the scaling ions are still in the solution and may re-scale with changes in the environment. Summary of the Invention

[0004] The present application provides a scale removal and prevention device, equipment and method based on an oilfield water injection system to solve the technical problems in the prior art that for the scale removal and prevention of an oilfield water injection system, the scale prevention effect is poor, the scale prevention procedures are complicated, and it is labor-consuming and costly.

[0005] In a first aspect, an embodiment of the present application provides a scale removal and prevention device based on an oilfield water injection system, including: a housing,

[0006] An inlet and an outlet are respectively arranged on the outer side walls of both sides of the housing, a vacuum chemical addition port is also arranged on the housing, and a sewage discharge port is arranged at the bottom end of the housing;

[0007] A partition board, a plurality of first grids and a plurality of second grids are arranged in the housing; the plurality of first grids and the plurality of second grids are respectively arranged on both sides of the partition board; the partition board is respectively arranged on the sewage discharge port, and the partition board divides the interior of the housing into a plurality of accommodation spaces, enabling the liquid to flow mutually between the plurality of accommodation spaces; the inlet is arranged on one side where the plurality of first grids are located, and the outlet is arranged on one side where the plurality of second grids are located;

[0008] The grid size on the plurality of first grids is smaller than the grid size on the plurality of second grids.

[0009] In a possible implementation manner, one end of the plurality of first grids is connected to the inner side wall of the housing, and the other end of the plurality of first grids is connected to one side of the partition board;

[0010] And / or, one end of the plurality of second grids is connected to the inner side wall of the housing, and the other end of the plurality of second grids is connected to the other side of the partition board.

[0011] In a possible implementation manner, a plurality of inclined plates are further arranged in the housing;

[0012] One end of the inclined plate is connected to the edge of the sewage outlet, and the other end of the inclined plate is connected to the inner side wall of the housing.

[0013] In a possible implementation manner, the height of the partition board is smaller than the height of the housing, so that the liquid located on one side of the partition board can flow over the partition board to the other side of the partition board.

[0014] In a second aspect, an anti-scaling and anti-fouling device based on an oilfield water injection system provided by an embodiment of the present application includes: the device in any one of the implementation manners of the first aspect of the present application, and a special metal anti-scaling short joint;

[0015] The special metal anti-scaling short joint is used to be arranged in a water injection well, and the special metal anti-scaling short joint is used to prevent scaling from forming in the water injection well;

[0016] A water distribution string is further connected to the special metal anti-scaling short joint.

[0017] In a possible implementation manner, the device further includes: a buffer tank and a plurality of filters;

[0018] The buffer tank is communicated with the water inlet of the device; one ends of the plurality of filters are communicated with the water outlet of the device, and the other ends of the plurality of filters are communicated with the water injection well;

[0019] The plurality of filters are selected from walnut shell filters or filter element filters.

[0020] In a possible implementation manner, the device further includes a plurality of lift pumps;

[0021] The plurality of lift pumps are respectively arranged between the buffer tank and the water inlet, and between the water outlet and the plurality of filters.

[0022] In a third aspect, an anti-scaling and anti-fouling method based on an oilfield water injection system provided by an embodiment of the present application includes: the method uses the device in any one of the implementation manners of the second aspect of the present application, and includes the following steps:

[0023] Detect the water quality of the water injection in the buffer tank to determine the type of scale formation. According to the type of scale formation, determine the addition of crystal seeds and / or soluble salts, and inject the water injection from the water inlet into the shell.

[0024] Add the crystal seeds and / or soluble salts into the shell from the vacuum chemical addition port, and control the water injection to flow through the multiple first grids and the multiple second grids, and flow out from the water outlet and inject into the injection well.

[0025] In a possible implementation manner, when the water injection flows out from the water outlet and injects into the injection well, it further includes:

[0026] The water injection flows out from the water outlet, passes through the multiple filters, and flows into the injection well.

[0027] In a possible implementation manner, the crystal seeds are selected from any one of dolomite, calcite or garnet;

[0028] And / or, the soluble salts are selected from any one of sodium chloride, calcium chloride, magnesium chloride, sodium sulfate, sodium bisulfate or magnesium sulfate.

[0029] An anti-scaling device, equipment and method based on an oilfield water injection system provided by the present application. Through a shell, a water inlet and a water outlet are respectively arranged on the outer side walls on both sides of the shell. A vacuum chemical addition port is also arranged on the shell, and a sewage outlet is arranged at the bottom end of the shell. A partition, multiple first grids and multiple second grids are arranged inside the shell; the multiple first grids and the multiple second grids are respectively arranged on both sides of the partition; the grid size on the multiple first grids is smaller than the grid size on the multiple second grids; in the specific implementation process, the fluid is injected into the interior of the shell from the water inlet, the fluid rises through the multiple first grids, blocks the scale deposits with smaller particle sizes, and deposits at the bottom of the shell. The fluid passes through the partition and the multiple second grids, slows down the fluid flow rate and the fluid direction, so that the scale deposits with larger particle sizes pass through the multiple second grids and sink to the bottom of the shell. The device of the present application, during the oilfield water injection process, by flowing the water quality through the device, scale deposit particles are formed in the device, and the scale deposits with different particle sizes are filtered, so that the water quality flowing out of the device is descaled. And the device can increase the flow path and time of the fluid, dynamically perform anti-scaling and descaling, reduce the anti-scaling and descaling procedures, effectively reduce the labor and cost, and improve the descaling effect at the same time. Description of the Drawings

[0030] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0031] Figure 1 Structural schematic of the scale removal and prevention device based on the oilfield water injection system provided by the embodiment of the present application Figure 1 ;

[0032] Figure 2 Structural schematic of the scale removal and prevention device based on the oilfield water injection system provided by the embodiment of the present application Figure 2 ;

[0033] Figure 3 Structural schematic of the scale removal and prevention device based on the oilfield water injection system provided by the embodiment of the present application Figure 3 ;

[0034] Figure 4 Structural schematic of the scale removal and prevention device based on the oilfield water injection system provided by the embodiment of the present application Figure 4 ;

[0035] Figure 5 Structural schematic diagram of the scale removal and prevention equipment based on the oilfield water injection system provided by the embodiment of the present application;

[0036] Figure 6 Process flow chart of the scale removal and prevention method based on the oilfield water injection system provided by the embodiment of the present application;

[0037] Figure 7 Variation law of calcium sulfate scaling index and scaling amount with the mixing ratio of MOD river water in the embodiment provided by the present application Figure 1 (T = 37°C);

[0038] Figure 8 Variation law of calcium sulfate scaling index and scaling amount with the mixing ratio of MOD river water in the embodiment provided by the present application Figure 2 (T = 90°C);

[0039] Figure 9 Variation law of strontium sulfate scaling index and scaling amount with the mixing ratio of MOD river water in the embodiment provided by the present application Figure 1 (T = 37°C);

[0040] Figure 10 Variation law of strontium sulfate scaling index and scaling amount with the mixing ratio of MOD river water in the embodiment provided by the present application Figure 2 (T = 90°C).

[0041] Explanation of reference numerals:

[0042] 100 ———— Scale removal and prevention device;

[0043] 110 ———— Housing;

[0044] 120 ———— Vacuum chemical addition port;

[0045] 130 ———— Inlet;

[0046] 140 ———— Outlet;

[0047] 150 ———— First grille;

[0048] 160 ———— Second grille;

[0049] 170 ———— Baffle;

[0050] 180 ———— Inclined plate;

[0051] 190 ———— Drain port;

[0052] 200 ———— Buffer tank;

[0053] 300 ———— Lift pump;

[0054] 400 ———— Filter;

[0055] 500 ———— Special metal scale prevention jumper;

[0056] 510 ———— Injection string;

[0057] 60 ———— Injection well.

[0058] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0059] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all the implementation manners consistent with the present application. On the contrary, they are merely examples of the devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0060] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "counterclockwise", "clockwise", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0061] With the development of oilfield water injection, the demand for water injection increases, and it gradually changes from a single water injection source to multiple water sources for injection. This leads to unstable mixed injection water, which is prone to scale formation, resulting in scale formation in surface pipelines, wellbores, and formations, an increase in injection pressure, and a decrease in the water absorption capacity of the formation, seriously affecting the water injection efficiency. Moreover, with the large-scale water injection development, the water cut of the oil reservoir increases significantly. From the formation to the surface, the produced crude oil liquid faces changes in pressure and temperature, which also leads to serious scale formation and affects normal production. Therefore, scale formation is a common phenomenon in oilfields, especially in high-mineralization oilfields, where the scale formation problem is particularly prominent, bringing great troubles to the oilfield water injection development.

[0062] Currently, the common method for treating scale in oilfields is to add scale inhibitors. Scale inhibitors can chelate with calcium and magnesium ions, thereby increasing the solubility of calcium and magnesium ions and preventing scale formation. However, due to the large volume of oilfield injection and production fluids, a large amount of scale inhibitor needs to be added, and the scale inhibitor needs to be continuously added. On-site, poor anti-scale effects may be caused by improper chemical agent quality and maintenance measures. Moreover, the existing anti-scale methods are single, and the scaling ions still remain in the solution and may re-scale with changes in the environment. Ion removal technology can effectively remove scaling ions in the solution, but the cost is high and it cannot be popularized and applied in oilfields.

[0063] In order to improve the scale formation control effect in oilfields and reduce costs, the present invention proposes a comprehensive anti-scale treatment method of fixed-point rapid centralized scale formation on the ground and special metal anti-scale short joints in the wellbore. This method is to establish a vertical scale formation fluidized bed device on the ground and add a chemical agent system. This system can accelerate scale formation and shorten the scale formation time, enabling the injection water to quickly complete the scale formation process in the fluidized bed device, achieving ion balance, and thus avoiding the impact of scale formation on surface pipelines, wellbores, and formations. At the same time, special metal anti-scale short joints are installed on the stratified water injection string in the wellbore to prevent scale formation problems caused by temperature and pressure changes and flow pattern changes of the fluid in the wellbore, achieving the purpose of scale formation control in the oilfield water injection system.

[0064] An anti-scale and scale removal device, equipment, and method based on an oilfield water injection system provided by an embodiment of the present application aims to solve the technical problems of poor anti-scale effect, complicated anti-scale procedures, and high cost in the anti-scale and scale removal of the oilfield water injection system in the prior art.

[0065] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0066] Figure 1 A structural schematic diagram of an anti-scale and scale removal device based on an oilfield water injection system provided by an embodiment of the present application. As Figure 1As shown in the figure, the device includes: a housing 110, with a water inlet 130 and a water outlet 140 respectively provided on the outer side walls on both sides of the housing 110, a vacuum chemical addition port 120 is also provided on the housing 110, and a sewage outlet 190 is provided at the bottom end of the housing 110; a plurality of partitions 170, a plurality of first grids 150 and a plurality of second grids 160 are provided inside the housing 110; the plurality of partitions 170 are provided on the sewage outlet 190, and the plurality of partitions 170 divide the interior of the housing 110 into a plurality of accommodation spaces, enabling the liquid to flow between the plurality of accommodation spaces; the plurality of first grids 150 and the plurality of second grids 160 are respectively provided on both sides of the partition 170; the water inlet 130 is provided on one side where the plurality of first grids 150 are located, and the water outlet 140 is provided on one side where the plurality of second grids 160 are located; the grid size on the plurality of first grids 150 is smaller than the grid size on the plurality of second grids 160.

[0067] The housing 110 can be a barrel-shaped structure with a certain volume. Its outer shell not only has excellent high-temperature resistance and can maintain stability under extreme temperature conditions, but also has excellent corrosion resistance, can effectively resist the erosion of various chemical substances, and extend the service life. In addition, the interior of the housing 110 can also be specially treated to ensure that it can still maintain structural integrity and functional reliability when in contact with corrosive fluids or gases, making the housing 110 particularly suitable for harsh industrial environments, such as chemical plants, refineries or oil and gas extraction operations under high temperature and high pressure, providing safety and durability guarantees.

[0068] The water inlet 130 and the water outlet 140 are respectively provided on the outer side walls on both sides of the housing 110 and are directly connected to the interior space of the housing 110 to ensure that the fluid can flow in and out of the housing 110 smoothly. In order to achieve precise control of the fluid flow, valves can also be respectively provided on the water inlet 130 and the water outlet 140 to regulate the inflow and outflow of liquid or gas, or completely close to prevent any unnecessary leakage or backflow, ensuring the safety and efficiency of the device.

[0069] The vacuum chemical addition port 120 is provided on the housing 110, which provides convenience for adding various chemicals into the housing 110. Through the vacuum chemical addition port 120, various chemical agents such as inorganic salts and scale inhibitors can be injected into the housing interior. In the oilfield water injection system, the vacuum chemical addition port 120 not only simplifies the chemical addition process, but also effectively prevents air from entering the device interior through the vacuum environment. Preventing the entry of air can lead to an increase in dissolved oxygen in the water, and the presence of dissolved oxygen may weaken the effect of the scale inhibitor or even cause adverse reactions such as corrosion. Reference Figure 1, the vacuum chemical dosing port 120 can be arranged at the top end of the housing 110. Through the vacuum chemical dosing port 120 at the top end of the housing 110, the occurrence of the above problems can be effectively avoided, ensuring that the chemical agent plays a role under the best conditions, thereby improving the scale removal and anti-corrosion effects.

[0070] Reference Figure 2 , the vacuum chemical dosing port 120 can also be arranged on any side of the housing 110 and on the same side as the water inlet 130. Among them, the vacuum chemical dosing port 120 is arranged above the water inlet 130. By adding the chemical agent from the vacuum chemical dosing port 120, the scale formation reaction of the sewage inside the housing 110 can be accelerated.

[0071] A sewage discharge port 190 is arranged at the bottom end of the housing 110, used to discharge the scale products generated inside the housing 110 from the sewage discharge port 190 to the inside of the housing 110. At the same time, it can keep the inside of the housing 110 clean and tidy, ensuring that the system will not be secondarily polluted by dirt during the entire scale prevention and removal process.

[0072] A plurality of partition plates 170 inside the housing 110 can be arranged above the sewage discharge port 190. The number of partition plates 170 can be 1, 2, 3... For example, 1 partition plate 170 is arranged above the sewage discharge port 190. The arrangement of the partition plate 170 divides the inside of the housing 110 into two accommodation spaces. One accommodation space is communicated with the water inlet 130, and the other accommodation space is communicated with the water outlet 140. At the same time, the fluid can also flow from one accommodation space to the other accommodation space. During the scale prevention and removal process, when the injected water quality flows from the water inlet 130 into one accommodation space and then from one accommodation space into the other accommodation space and flows out from the drain port 140, it can play a role in slowing down the water flow velocity. The fluid needs to pass over the partition plate 170 to reach the other accommodation space. Under the action of the chemical agent at this stage, some scale deposits will be generated in one accommodation space. Under the action of the gravity of the scale deposits, they will be deposited at the sewage discharge port 190, achieving an efficient scale removal effect.

[0073] A plurality of first grids 150 and a plurality of second grids 160 are respectively arranged between the inner side wall of the housing 110 and the partition plate 170, and the plurality of first grids 150 and the plurality of second grids 160 are respectively arranged on both sides of the partition plate 170. The plurality of first grids 150 and the plurality of second grids 160 are provided with grid holes of the same or different sizes. For example, two, three or four first grids 150 are arranged on one side of the partition plate 170. Similarly, two, three or four second grids 160 are arranged on the other side of the partition plate 170. The plurality of first grids 150 can play a role in preventing the scale deposits from passing through the grids driven by the fluid flow and depositing them at the sewage discharge port 190. The plurality of second grids 160 play a role in slowing down the fluid flow velocity and the flow direction, enabling the scale deposits in the other accommodation space to pass through the grid holes of the plurality of second grids 160 and sink to the sewage discharge port 190 at the bottom end of the housing 110.

[0074] In yet another embodiment, the grid size on the plurality of first grids 150 is smaller than the grid size on the plurality of second grids 160. When the fluid flows from a receiving space provided with the plurality of first grids 150 to another receiving space provided with the plurality of second grids 160, under the action of the medicament, when the fluid is in one receiving space, the particle size of its scale deposits is small. In order to prevent the scale deposit particles from flowing into the other receiving space, the aperture of the grid holes of the plurality of first grids 150 is set smaller. When the fluid is in the other receiving space, due to the longer action time of the medicament, the particle size of its scale deposits becomes larger. In order to prevent the scale deposit particles from failing to pass through the grid holes of the plurality of second grids 160 and settling to the bottom of the housing 110, the grid holes of the plurality of second grids 160 are set larger. At the same time, it can also prevent the scale deposit particles from clogging the plurality of second grids 160 and affecting the scale removal and prevention effect of the system. Of course, for the setting of the grid sizes of the plurality of first grids 150 and the plurality of second grids 160, those skilled in the art can adjust according to the actual situation.

[0075] Further, in yet another embodiment, referring to Figure 3 and Figure 4 , only the plurality of first grids 150 and the plurality of second grids 160 are provided in the scale removal and prevention device. Among them, the grids provided on the first grid 150 and the second grid 160 can be regularly arranged or irregularly arranged. Exemplarily, the grids in the first grid 150 and the second grid 160 are irregularly arranged, becoming sparser or having no grids closer to the side wall surface of the housing 110. Of course, for the setting of the housing 110, it can also be such that the volume of the upper end is large and the volume of the lower end is small, so that after the sewage flows to the top of the housing 110, a sufficient scale formation reaction can occur, and then scale removal is carried out through a series connection of multiple scale removal devices, achieving an excellent scale removal and prevention effect.

[0076] An anti-scaling and anti-fouling device based on an oilfield water injection system provided by an embodiment of the present application includes a housing. An inlet and an outlet are respectively arranged on the outer side walls of both sides of the housing. A vacuum chemical addition port is also arranged on the housing, and a sewage discharge port is arranged at the bottom end of the housing. A partition board, a plurality of first grids and a plurality of second grids are arranged inside the housing; the plurality of first grids and the plurality of second grids are respectively arranged on both sides of the partition board; the grid size on the plurality of first grids is smaller than the grid size on the plurality of second grids; in the specific implementation process, the fluid is injected into the interior of the housing from the inlet, and the fluid rises through the plurality of first grids, blocking the scale deposits with smaller particle sizes and depositing them at the bottom of the housing. The fluid passes through the partition board and the plurality of second grids, slowing down the fluid flow rate and the fluid direction, enabling the scale deposits with larger particle sizes to pass through the plurality of second grids and sink to the bottom of the housing. The device of the present application can increase the flow path and time of the fluid, dynamically remove and prevent scale, reduce the anti-scaling and anti-fouling procedures, effectively reduce labor and costs, and improve the scale removal effect at the same time.

[0077] Further, on the basis of the above embodiment, as Figure 1 shown, a more detailed description and illustration of the anti-scaling and anti-fouling device are provided. One end of the plurality of first grids 150 is connected to the inner side wall of the housing 110, and the other end of the plurality of first grids 150 is connected to one side of the partition board 170; and / or, one end of the plurality of second grids 160 is connected to the inner side wall of the housing 110, and the other end of the plurality of second grids 160 is connected to the other side of the partition board 170.

[0078] The plurality of first grids 150 are arranged in the internal structure of the housing 110. One end of it can be connected to the inner side wall of the housing 110 through detachable connection methods such as pins and clamps, or through welding, bonding and other methods to ensure the stability and durability of the grid. The other end is connected to one side of the partition board 170, which not only enhances the overall rigidity of the structure, but also optimizes the fluid flow path, enabling the fluid to effectively perform preliminary particle filtration and sedimentation when passing through the first grids. Similarly, one end of the plurality of second grids 160 is fixed on the inner side wall of the housing 110 to provide support. The other end is connected to the other side of the partition board 170, which can further extend the fluid flow path and enhance the capture and sedimentation effect on larger particle scale deposits by changing the flow direction and speed. Through the cooperation of this dual-grid system, the device can achieve more efficient separation and deposition in the treatment of scale deposits with different particle sizes.

[0079] Further, continuing as Figure 1 shown, a plurality of inclined plates 180 are also arranged inside the housing 110; one end of the inclined plate 180 is connected to the edge of the sewage discharge port 190, the other end of the inclined plate 180 is connected to the inner side wall of the housing 110, and the inclined plate 180 is arranged below the inlet 130 or the outlet 140.

[0080] In the internal structure of the housing 110, a plurality of inclined plates 180 are provided. One end of each inclined plate 180 is connected to the edge of the sewage outlet 190 by welding, bonding or other means, and the other end of the inclined plate 180 is connected to the inner side wall of the housing 110, so that the inclined plate 180 has a certain inclination, ensuring that when the sediment falls on the inclined plate 180, it can be smoothly guided to the sewage outlet, realizing efficient discharge and cleaning. The angle of the inclined plate 180 can optimize the flow path of the fluid and the guiding direction of the sediment. By increasing the contact area of the fluid and extending the flow path, the inclined plate 180 effectively promotes the sedimentation of particulate matter, enabling smaller scale particles to gradually aggregate and slide down to the sewage outlet 190 during the flow process, improving the descaling efficiency and reducing the maintenance frequency and difficulty of the system.

[0081] Furthermore, as Figure 1 shown, the height of the partition plate 170 is less than the height of the housing 110, so that the liquid on one side of the partition plate 170 can flow over the partition plate 170 to the other side of the partition plate 170.

[0082] The height of the partition plate 170 can be less than the overall height of the housing 110, so that the partition plate 170 forms a liquid flow channel inside the housing 110. When the liquid is on one side of the partition plate 170, its liquid level can easily exceed the height of the partition plate, and thus naturally flow to the other side of the partition plate 170. In this way, not only is the smooth flow of the liquid promoted, but also the gravity and the natural flow characteristics of the liquid are effectively utilized, reducing the dependence on external power, ensuring the uniform distribution and full contact of the fluid inside the housing. In addition, the descaling and sedimentation efficiency of the device is enhanced. As the liquid flows through the partition plate, the change in flow rate and the extension of the flow path contribute to the sedimentation of particulate matter, making it easier for scale deposits to be captured and deposited at the bottom, not only improving the processing efficiency of the device, but also reducing the possible risk of blockage and extending the service life of the device.

[0083] This embodiment of the present application also provides an anti-scaling and anti-fouling device based on an oilfield water injection system. As Figure 5 shown, the device includes the anti-scaling and anti-fouling device 100 in any of the above embodiments, and a special metal anti-scaling short joint 500; the special metal anti-scaling short joint 500 is used to be arranged in the injection well 60, and the special metal anti-scaling short joint 500 is used to prevent scaling from forming in the injection well 60; a separate injection string 510 is also connected to the special metal anti-scaling short joint 500.

[0084] In addition to the scale prevention and removal device 100, a scale prevention and removal equipment can be formed with the special metal scale prevention short joint 500 to address the scale formation problem in the injection well 60. The special metal scale prevention short joint 500 is installed in the injection well 60 to exert its unique scale prevention function. Through the characteristics of its special metal materials, such as 304 stainless steel, copper alloy, zinc alloy, copper-zinc alloy, titanium and titanium alloys, nickel-based alloys, Hastelloy, Inconel, zirconium and zirconium alloys, etc., it can effectively inhibit the formation of scale deposits, ensuring the smooth and efficient operation of the injection well. For the selection of the special metal scale prevention short joint, any metal or alloy that can achieve the above effects can be used, and those skilled in the art can make a selection according to actual needs, which will not be elaborated here.

[0085] The special metal scale prevention short joint 500 not only functions independently but also is closely connected to the separate injection string 510 to form an integrated scale prevention and fluid management system. The connection of the separate injection string 510 enables the system to achieve layered water injection in multi-layer reservoirs, further optimizing the overall performance of the injection well. This allows the system to control the injection volume and direction of water flow at different layers, preventing scale formation caused by uneven water injection. In addition, flexible operation and maintenance solutions are provided. The connection between the special metal scale prevention short joint 500 and the separate injection string 510 not only simplifies the installation and operation process of the system but also improves the reliability and durability of the entire system, enabling the injection well 60 to maintain high efficiency and stability during long-term operation and reducing the maintenance frequency and related costs.

[0086] After the equipment undergoes scale prevention and removal by the device 100, it further performs scale prevention and removal using the special metal scale prevention short joint 500, further enhancing its scale prevention and removal effect, saving procedures, and having a simple operation.

[0087] Furthermore, as Figure 5 shown, the equipment further includes: a buffer tank 200 and multiple filters 400; the buffer tank 200 is connected to the water inlet 130 of the device; one end of the multiple filters 400 is connected to the water outlet 140 of the device, and the other end of the multiple filters 400 is connected to the injection well 60; the multiple filters 400 are selected from walnut shell filters or cartridge filters.

[0088] The buffer tank 200 cooperates with multiple filters 400 to ensure that the fluid is fully processed and purified before entering the injection well 60. The buffer tank 200 can be directly connected to the water inlet 130. As the initial receiving and regulating device of the equipment, it is used to stabilize the fluid flow rate, absorb the fluid pressure fluctuations, and ensure the smooth progress of the subsequent treatment process. After the preliminary regulation of the fluid by the buffer tank 200, the fluid passes through the device 100 and then is guided to multiple filters 400 for further purification treatment. One end of each filter 400 is tightly connected to the water outlet 140 to ensure that the fluid can smoothly enter the filtration stage. The other end of the filter 400 is connected to the injection well 60, and the filtered clean fluid is safely injected into the well.

[0089] The filters 400 can be selected in different types according to specific requirements, such as walnut shell filters or cartridge filters. Walnut shell filters have excellent adsorption capacity and durability, and are suitable for treating oily sewage and removing suspended particles. While cartridge filters provide high-precision filtration effects, which can effectively remove fine particles and impurities to ensure the purity of the fluid. In this way, the equipment not only improves the quality of the fluid, but also extends the service life of the injection well, reduces the risk of scaling and blockage, and ensures the efficient operation of the oilfield water injection equipment and the sustainable utilization of resources.

[0090] Furthermore, as Figure 5 shown, the equipment further includes multiple lift pumps 300; multiple lift pumps 300 are respectively arranged between the buffer tank 200 and the water inlet 130, and between the water outlet 140 and multiple filters 400.

[0091] Multiple lift pumps 300 are used to ensure the smooth flow and efficient treatment of the fluid in the whole equipment. One or more lift pumps 300 are arranged between the buffer tank 200 and the water inlet 130, and their main function is to enhance the input pressure of the fluid to ensure that the fluid can quickly and stably enter the buffer tank 200, so as to realize the effective control and regulation of the flow rate. While some other lift pumps 300 are installed between the water outlet 140 and multiple filters 400, which are used to transport the fluid from the buffer tank 200 to the filters 400, providing the necessary pressure to overcome the resistance of the filter medium, ensuring that the fluid can smoothly pass through the filter for deep purification, not only improving the filtration efficiency, but also ensuring the best working state of the filter and extending its service life.

[0092] The embodiment of the present application also provides an anti-scaling method based on the oilfield water injection system. As Figure 6 shown, the method includes:

[0093] S601. Detect the water quality of the water injection in the buffer tank 200, determine the type of scale formation, and determine the addition of crystal seeds and / or soluble salts according to the type of scale formation, and inject the water injection from the water inlet 130 into the housing 110.

[0094] To ensure the quality and effectiveness of water injection, it is necessary to detect the water quality in the buffer tank 200. Through water quality detection technology, the components and types of substances in the water that may cause scaling can be accurately analyzed and determined, providing important data support for subsequent treatment steps. After determining the types of scaling, corresponding treatment strategies can be formulated according to the specific scaling characteristics. For example, adding specific crystal seeds and / or soluble salts to the water to inhibit the formation of scaling or promote the dissolution of existing scaling. The addition of crystal seeds can induce the deposition of scaling substances at specific locations, thus avoiding the formation of hard scale in key equipment or pipelines, while the use of soluble salts can change the chemical balance of the water and reduce the scaling tendency. After the water quality adjustment is completed, the treated water injection is introduced into the housing 110 through the water inlet 130, starting its circulation and further treatment in the device 100, which can not only effectively prevent the formation of scaling, but also improve the overall efficiency and effectiveness of water injection.

[0095] S602: Add crystal seeds and / or soluble salts into the housing 110 from the vacuum chemical addition port 120, and control the water injection to flow through multiple first grids 150 and multiple second grids 160, and flow out from the water outlet 140 and be injected into the injection well 60.

[0096] Based on the guidance of the previous water quality detection results, the vacuum chemical addition port 120 can accurately add specific crystal seeds and / or soluble salts into the housing 110 to optimize the chemical properties of the water to prevent the formation of scaling or promote the dissolution of existing scaling. After the crystal seeds and / or soluble salts are added to the housing 110, the treatment path of the water injection fluid begins: First, the fluid flows through multiple first grids 150, which can effectively capture and sediment smaller particulate matters, while ensuring the uniform distribution of crystal seeds in the fluid and playing its role in inducing deposition. Then, the fluid continues to flow through multiple second grids 160, further slowing down the flow rate of the fluid and changing its flow direction, so that larger particulate scaling substances can effectively sediment to the bottom, not only improving the removal efficiency of scaling substances, but also ensuring the full reaction of crystal seeds and soluble salts in the fluid. After multi-level treatment, the purified and adjusted fluid flows out from the water outlet 140 and is finally injected into the injection well 60 to ensure the efficient operation and long-term stability of the injection well.

[0097] Furthermore, when the water injection flows out from the water outlet 140 and is injected into the injection well 60, it further includes:

[0098] The water injection flows out from the water outlet 140, passes through multiple filters 400, and then flows into the injection well 60.

[0099] Multiple filters 400 can be selected according to specific requirements, including various types such as walnut shell filters and filter element filters. Walnut shell filters are known for their excellent adsorption capacity and durability, and can effectively remove oil stains and suspended particles in fluids. Filter element filters, on the other hand, provide high-precision filtration effects to ensure that fine particles and impurities are completely removed.

[0100] Furthermore, the seed crystal is selected from any one of dolomite, calcite or garnet; and / or, the soluble salt is selected from any one of sodium chloride, calcium chloride, magnesium chloride, sodium sulfate, sodium bisulfate or magnesium sulfate.

[0101] The particle size range of the seed crystal includes but is not limited to 10 - 30 mesh, 30 - 50 mesh, 50 - 80 mesh, 80 - 100 mesh, etc.

[0102] Specifically, the following example is carried out using the above method. A certain oilfield uses water injection development, and the water injection source is the mixed water of produced water and river water. The produced water has a high salinity, with a total salinity of 282,000 ppm, of which the chloride ion content is 172,000 ppm, the calcium ion content is 13,700 ppm, and the sulfate ion content is 494 ppm. The total salinity of the river water is 54,000 ppm, of which the calcium ion content is 901 ppm and the sulfate ion concentration is 7,570 ppm. The two are mixed in different proportions and injected into the wellbore, with a daily water injection volume of 38,955 tons.

[0103] Table 1. Full composition analysis of injected water

[0104]

[0105]

[0106] Note: Sodium (Na + ), Potassium (K + ), Magnesium (Mg 2+ ), Calcium (Ca 2+ ), Strontium (Sr 2+ ), Barium (Ba 2+ ), Total Iron (Fe 2+ ), Chloride (Cl - ), Sulfate (SO 4 2- ), Bicarbonate (HCO 3 - ), Percentage of carbon dioxide in gas Total dissolved solids (TDS), pH value.

[0107] First, through the OLI software, the scaling tendency and scaling amount of the injected water are predicted. The results show that a large amount of sulfate scale will be generated when the two waters are mixed, and the scaling tendency and scaling amount are as Figures 7 to 10 shown.

[0108] Figures 7 - 10 It is a trend chart of the scaling index and scaling amount of two kinds of injection water in a certain oilfield under different mixing ratios and different temperature conditions. Figure 7 It is the calcium sulfate scaling index and scaling amount at 37°C (simulating the surface temperature) under different mixing ratios of MOD river water. The results show that as the proportion of MOD river water increases, the calcium sulfate scaling index and scaling amount first increase and then decrease. When the mixing ratio of MOD river water increases to 60%, the scaling amount reaches as high as 2250 mg / l. The colors in the figure represent the severity of scaling, and the darker the color, the more serious the scaling. Figure 8 It shows the calcium sulfate scaling index and scaling amount at 90°C (simulating the formation temperature) under different mixing ratios of MOD river water. The results show that as the proportion of MOD river water increases, the calcium sulfate scaling index and scaling amount first increase and then decrease. When the mixing ratio of MOD river water increases to 60%, the decoupling improvement is the largest, up to 4100 mg / l. Figure 9 and Figure 10 It shows the strontium sulfate scaling index and scaling amount of two kinds of mixed water under surface and formation temperature conditions.

[0109] In the laboratory, produced water and river water were respectively configured. According to 4:6, produced water and river water were taken respectively. After mixing, a scale promoter was added, and the scaling amount and scaling time within different time were tested until the scaling amount was stable, and it was determined that the scaling reaction ended. Through experiments, garnet and sodium sulfate, which are suitable for this system, were screened out. The addition concentration is 1 - 2 g / L garnet + 0.01 - 0.05 mg / l sodium sulfate. The scaling time tested in the laboratory is 15 - 30 min. It is added to the fixed-point scaling device through the vacuum chemical injection port. The scaling products are calcium sulfate and strontium sulfate, and the particle size of the inorganic scale is 1 - 10 um. Therefore, two-stage filters, walnut shell filter and cartridge filter, are adopted. Due to the high salinity of the injection water, large scaling amount, large daily treatment volume, and short surface treatment time, it is very difficult to ensure the complete scaling reaction of high-salinity water. Moreover, in the wellbore, the temperature and pressure increase, and the scaling amount of calcium sulfate scale increases, especially at the water nozzle position of the diverter in the separate injection string. Therefore, a special metal anti-scaling stub is installed above the separate injection string to effectively prevent the separate injection string from scaling and ensure the injection volume.

[0110] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be carried out in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0111] In the present specification, the embodiments or implementation manners are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0112] It should be noted that phrases such as "in specific implementation", "in some embodiments", "in this embodiment", "exemplarily", etc. mentioned in the specification indicate that the described embodiments may include specific features, structures or characteristics, but not necessarily every embodiment includes such specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. Moreover, when combining specific features, structures or characteristics with an embodiment, it is within the knowledge scope of those skilled in the art to implement such features, structures or characteristics in combination with other embodiments, whether explicitly or implicitly described.

[0113] Generally speaking, terms should be understood at least in part based on their use in the context. For example, at least in part according to the context, the term "one or more" used in the text can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, at least in part according to the context, terms such as "a" or "the" can also be understood as conveying a singular usage or a plural usage.

[0114] It should be easily understood that the terms "on...", "above...", and "over..." in the present disclosure should be interpreted in the broadest manner, so that "on..." not only means "directly on something", but also includes the meaning of "on something" with intermediate features or layers therebetween, and "above..." or "over..." not only includes the meaning of "above or over something", but may also include the meaning of "above or over something" with no intermediate features or layers therebetween (i.e., directly on something).

[0115] In addition, for the convenience of description, spatial relative terms can be used in the text. Spatial relative terms are intended to include different orientations of the device in use or operation other than the orientation shown in the drawings. The device can have other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used in the text can be interpreted accordingly. In the above embodiments, the descriptions of the respective embodiments have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0116] Furthermore, in the description of the present invention, it should also be noted that the orientation or positional relationship indicated by terms such as "front" and "back" is based on the orientation or positional relationship, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention. In addition, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0117] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common general knowledge or conventional technical means in the technical field not disclosed in the present application.

[0118] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A scale removal and prevention device based on an oilfield water injection system, characterized in that: include: a housing (110), The outer walls on both sides of the shell (110) are respectively provided with a water inlet (130) and a water outlet (140), the shell (110) is also provided with a vacuum dosing port (120), and the bottom end of the shell (110) is provided with a sewage outlet (190); A partition (170), a plurality of first grids (150) and a plurality of second grids (160) are arranged in the shell (110); the partition (170) is arranged on the sewage outlet (190), and the partition (170) divides the interior of the shell (110) into a plurality of accommodation spaces, so that liquid can flow between the plurality of accommodation spaces; the plurality of first grids (150) and the plurality of second grids (160) are arranged on both sides of the partition (170), respectively; the water inlet (130) is arranged on one side of the plurality of first grids (150), and the water outlet (140) is arranged on one side of the plurality of second grids (160); The mesh size on the plurality of first grids (150) is smaller than the mesh size on the plurality of second grids (160).

2. The device according to claim 1, characterized in that One end of the plurality of first grids (150) is connected to the inner side wall of the shell (110), and the other end of the plurality of first grids (150) is connected to one side of the partition (170); And / or, one end of the plurality of second grids (160) is connected to the inner wall of the shell (110), and the other end of the plurality of second grids (160) is connected to the other side of the partition (170).

3. The device according to claim 2, characterized in that A plurality of inclined plates (180) are also arranged in the housing (110); One end of the inclined plate (180) is connected to the edge of the sewage outlet (190), the other end of the inclined plate (180) is connected to the inner wall of the shell (110), and the inclined plate (180) is arranged at the lower end of the water inlet (130) or the water outlet (140).

4. The device according to claim 2, characterized in that The height of the partition (170) is smaller than the height of the shell (110), so that the liquid on one side of the partition (170) can flow over the partition (170) to the other side of the partition (170).

5. A scale removal and prevention device based on an oilfield water injection system, characterized in that: include: The device according to any one of claims 1 to 4, and a special metal anti-scaling short circuit (500); The special metal anti-scaling short circuit (500) is used to be arranged in a water injection well (60), and the special metal anti-scaling short circuit (500) is used to prevent scaling from forming in the water injection well (60); The special metal anti-scaling short circuit (500) is also connected to a dispensing pipe column (510).

6. The device according to claim 5, characterized in that Also includes: A buffer tank (200) and a plurality of filters (400); The buffer tank (200) is in communication with the water inlet (130) of the device; one end of the multiple filters (400) is in communication with the water outlet (140) of the device, and the other end of the multiple filters (400) is in communication with the water injection well (60).

7. The device according to claim 6, characterized in that Also included are a plurality of lift pumps (300); The plurality of lift pumps (300) are respectively arranged between the buffer tank (200) and the water inlet (130), and between the water outlet (140) and the plurality of filters (400).

8. A method for descaling and preventing scale based on an oilfield water injection system, the method using the device according to any one of claims 5 to 7, characterized in that: The steps include: Testing the water quality of the injection water in the buffer tank (200) to determine the type of scaling, determining to add seed crystals and / or soluble salts according to the type of scaling, and injecting the injection water into the shell (110) from the water inlet (130); The seed crystals and / or soluble salts are added into the shell (110) from the vacuum dosing port (120), and the injection water is controlled to flow through the plurality of first grids (150), the plurality of second grids (160), and out of the water outlet (140) to be injected into the water injection well (60).

9. The method according to claim 8, characterized in that The injection water flows out from the water outlet (140) and is injected into the water injection well (60), and further comprises: The injection water flows out from the water outlet (140), passes through the multiple filters (400), and flows into the water injection well (60).

10. The method according to claim 8, characterized in that The seed crystal is selected from any one of dolomite, calcite or garnet; And / or, the soluble salt is selected from any one of sodium chloride, calcium chloride, magnesium chloride, sodium sulfate, sodium bisulfate or magnesium sulfate.

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