Sterilization and scale removal device and oilfield reservoir water injection system

Abstract

The application discloses a sterilization and descaling device and an oilfield oil layer water injection system, and belongs to the technical field of oilfield water injection treatment devices. The sterilization and descaling device is installed between a water injection transportation pipe and a wellbore of a water injection well of an oilfield, and comprises a flow guide pipe, an electrolysis assembly and a radiation sterilization device. The sterilization and descaling device performs secondary sterilization and descaling treatment on water flowing out of the water injection transportation pipe through a physical mode of radiation and electrochemistry, avoids, to a certain extent, scaling and plugging and corrosion of the wellbore of the water injection well, prolongs the service life of the wellbore of the water injection well, and saves oil production cost. Meanwhile, the sterilization and descaling device does not add chemical agents, does not cause secondary corrosion of the wellbore of the water injection well due to agent residues, does not cause environmental pollution and compatibility problems of oilfield chemical agents, and has important significance for reducing microbial corrosion and scaling of the wellbore of the water injection well and realizing long-term green and efficient development of the oilfield.

Description

Technical Field

[0001] This application belongs to the technical field of oilfield water injection treatment equipment, and particularly relates to a sterilization and descaling device and an oilfield reservoir water injection system. Background Technology

[0002] As more and more oilfields enter the middle and late stages of development, the original formation pressure decays significantly. To achieve stable production, most oilfields choose water injection to maintain formation pressure. Water injection refers to injecting water into the oil-bearing reservoir through injection wells to replenish its energy. It is one of the important means to maintain reasonable reservoir pressure and improve oilfield recovery. Under normal circumstances, the water injection pressure does not exceed 15 MPa, and the water sources for the injection system are varied, including production wastewater, source water, and even river water.

[0003] In related technologies, water treatment plants are typically used to sterilize and descale the water flow to prevent blockage and corrosion of the injection well casing. However, even after treatment at the water treatment plant, blockage and corrosion can still sometimes occur in the injection well casing. Summary of the Invention

[0004] This application aims to at least partially solve the technical problems of wellbore blockage and corrosion in water injection wells in related technologies. To this end, this application provides a sterilization and descaling device and an oilfield reservoir water injection system.

[0005] In a first aspect, embodiments of this application provide a sterilization and descaling device installed between a water injection transport pipe and a water injection well in an oil field. The water injection transport pipe has a first outlet, and the water injection well has a second inlet. The device includes: a guide pipe with a third inlet and a third outlet, wherein the third inlet is connected to the first outlet, and the third outlet is connected to the second inlet; an electrolysis assembly including a cathode electrode, an anode electrode, and a power source, wherein both the cathode electrode and the anode electrode are electrically connected to the power source, and both the cathode electrode and the anode electrode are located inside the guide pipe; the electrolysis assembly is used to perform ion exchange, remove scale-forming ions from the guide pipe, and sterilize; and a radiation sterilization device located inside the guide pipe for generating radiation sterilization.

[0006] In some embodiments, a first flange for fixed connection with the first outlet side of the water injection transport pipe is fixedly provided on the third inlet side of the guide pipe, and a second flange for fixed connection with the second inlet side of the water injection well is fixedly provided on the third outlet side.

[0007] In some embodiments, the cathode electrode and the anode electrode are located on the third inlet side and the third outlet side, respectively, and the radiation sterilization device is located between the cathode electrode and the anode electrode.

[0008] In some embodiments, the sterilization and descaling device further includes a protective element located inside the flow guide tube, the protective element having a mounting cavity, and the radiation sterilization device located inside the mounting cavity.

[0009] In some embodiments, the protective member further has an installation port communicating with the mounting cavity, the protective member is partially located inside the guide tube, the installation port is located outside the guide tube, and the protective member and the guide tube are connected in a sealed manner; the radiation sterilization device is located inside the mounting cavity and inside the guide tube through the installation port.

[0010] In some embodiments, the guide pipe includes a first guide pipe, a second guide pipe, and a third guide pipe connected in sequence; the third inlet is disposed on the first guide pipe, the third outlet is disposed on the third guide pipe, and the axis of the second guide pipe is angularly disposed with respect to the axes of the first and third guide pipes; the mounting cavity is cylindrical and has two mounting ports, which are disposed at both ends of the length direction of the mounting cavity, the length direction of the mounting cavity being parallel to the axis of the second guide pipe, the protective member penetrating both sides of the length direction of the first guide pipe, and both mounting ports being located outside the second guide pipe.

[0011] In some embodiments, the protective element is located in the middle of the second guide tube.

[0012] In some embodiments, the radiation sterilization device is an ultraviolet lamp, the protective component is a quartz glass tube, and the length of the ultraviolet lamp tube is not less than the length of the second guide tube.

[0013] In some embodiments, the sterilization and descaling device further includes a cleaning component and a driving component. The cleaning component is sleeved outside the protective component and in contact with the protective component. The cleaning component is drively connected to the driving component. The driving component drives the cleaning component to reciprocate along the protective component to clean the outer surface of the protective component.

[0014] In some embodiments, electrode mounting holes are respectively provided on the third inlet side and the third outlet side of the guide pipe. The cathode electrode and the anode electrode are located inside the guide pipe through the electrode mounting holes and are detachably and sealedly connected to the electrode mounting holes. A first connecting part for detachable connection with the pressure-controlled electrode switching device is provided on the side of the cathode electrode and the anode electrode facing out of the electrode mounting holes. A second connecting part for detachable connection with the pressure-controlled electrode switching device is also provided next to the electrode mounting holes and on the guide pipe.

[0015] Secondly, embodiments of this application provide an oilfield reservoir water injection system, comprising: a water treatment station, a water injection transport pipe, the sterilization and descaling device provided in the first aspect above, and a water injection well casing; the water injection transport pipe has a first inlet and a first outlet, the water injection well casing has a second inlet and a second outlet, the water injection transport pipe is connected to the water treatment station through the first inlet, the first outlet is connected to the third inlet of a guide pipe, the third outlet of the guide pipe is connected to the second inlet of the water injection well casing, and the second outlet of the water injection well casing is used to communicate with the oil reservoir.

[0016] The present invention has at least the following beneficial effects:

[0017] This application describes a sterilization and descaling device installed between the water injection pipeline and the injection wellbore in an oilfield. The device includes a guide pipe, an electrolysis assembly, and a radiation sterilization device. The electrolysis assembly comprises a cathode electrode, an anode electrode, and a power source. The cathode and anode electrodes are located inside the guide pipe and electrically connected to the power source. An electrolysis reaction occurs within the guide pipe, where scale-forming ions (such as calcium and magnesium ions) in the water undergo a reduction reaction at the cathode electrode, removing these ions and softening the water, thereby reducing the number of scale-forming ions flowing into the injection wellbore. An oxidation reaction occurs at the anode electrode, producing strong oxidizing substances such as OH, O3, and H2O2, which kill microorganisms in the water. Furthermore, the radiation sterilization device generates radiation that irradiates bacteria, viruses, and other microorganisms in the water flow within the guide pipe, disrupting their internal structure and causing them to die or lose their reproductive capacity, thus reducing the number of microorganisms flowing into the injection wellbore.

[0018] The sterilization and descaling device of this application, to a certain extent, avoids scaling, clogging, and corrosion of water injection well barrels, extends the service life of water injection well barrels, and saves oil production costs. At the same time, the sterilization and descaling device of this application has a simple structure, is easy to manufacture, and has low cost; it sterilizes and descals through physical methods of radiation and electrochemistry, without the addition of chemical agents, thus avoiding secondary corrosion of the water injection well barrel due to chemical residues, and preventing environmental pollution and compatibility issues with oilfield chemicals. It is of great significance for reducing microbial corrosion and scaling in water injection well barrels and achieving long-term green and efficient development of oilfields. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1A schematic diagram of the sterilization and descaling device in one or more embodiments of this application is shown.

[0021] Figure 2 It shows Figure 1 Enlarged view of a portion of point A in the middle.

[0022] Figure 3 It shows Figure 1 Enlarged view of section B in the middle.

[0023] Figure 4 A schematic diagram of the structure of an oilfield reservoir water injection system in one or more embodiments of this application is shown.

[0024] Reference numerals: 100-Water injection transport pipe, 110-Third flange, 100b-First outlet, 200-Water injection well shaft, 210-Fourth flange, 200a-Second inlet, 300-Sterilization and descaling device, 310-Guide pipe, 310a-Third inlet, 310b-Third outlet, 310c-Electrode mounting hole, 310d-Second connection, 311-First guide pipe, 312-Second guide pipe, 313-Third guide pipe. 314-First flange, 315-Second flange, 320-Electrolysis assembly, 320a-First connection part, 321-Cathode electrode, 322-Anode electrode, 323-Power supply, 330-Radiation sterilization device, 340-Protective component, 340a-Mounting cavity, 340b-Mounting port, 350-Cleaning component, 360-Drive component, 361-Motor, 362-Worm gear, 363-Turbine, 400-Pressurized pole changing device, 500-Water treatment station. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0029] As more and more oilfields enter the middle and late stages of development, the original formation pressure weakens significantly. To achieve stable production, most oilfields choose water injection to maintain formation pressure. Water injection refers to injecting water into the oil-bearing reservoir through injection wells to replenish its energy. It is one of the important means to maintain reasonable reservoir pressure and improve oilfield recovery. Under normal circumstances, the water injection pressure does not exceed 15 MPa. Water sources for water injection systems are varied, including production wastewater, source water, and even river water.

[0030] Water sources typically contain microorganisms such as sulfate-reducing bacteria (SRB), saprophytic bacteria (TGB), and iron bacteria (FB). The products of these microorganisms can accumulate and clog water injection pipelines, wellbore, and formations. When sulfate-reducing bacteria (SRB) multiply in water, they produce large amounts of sulfides, which can lead to corrosion and scaling of water injection pipelines and wellbore, affecting normal water injection operations. When sulfate-reducing bacteria (SRB) enter the production formation with the injected water, they can react with organic matter to produce H2S. As the H2S content in the production formation increases, the reservoir can change from a non-acidic oil and gas reservoir without H2S to an acidic oil and gas reservoir containing H2S. Oil well pipes and downhole tools will need to undergo desulfurization treatment, which will cause corrosion of the produced wellbore and a significant increase in oilfield development costs. At the same time, if there are many scale-forming ions in the water source, they can easily react with other ions to form deposits, exacerbating the clogging phenomenon.

[0031] Therefore, in order to avoid water source blockage and corrosion of water injection and transportation pipelines and water injection wells, water sources such as production wastewater, aquifer water or river water will first be treated by a water treatment plant to remove bacteria and impurities.

[0032] In practice, the applicant of this application discovered that a certain oil field it developed was supplied with water by Water Treatment Plant A. After Water Treatment Plant A carried out sterilization and impurity removal treatment on the water source, the well casings of the oil field's water injection wells still showed signs of scaling, blockage, and corrosion. As a result, the oil field had to invest a large amount of money every year to repair and replace the well casings of the water injection wells.

[0033] The applicant of this application sampled and tested the soil around the injection well, analyzing information such as soil pH, moisture, and composition. A third-party testing agency was commissioned to conduct quality compliance testing on the injection well shaft. The composition of the water source was tested, and the effluent quality of Water Treatment Plant A was also tested. Ultimately, the cause of the blockage and corrosion of the injection well shaft was not identified. Fe at the outlet of Water Treatment Plant A... 2+ / Fe 3+ The concentration of sulfate-reducing bacteria (SRB) was 0.03 mg / L, which meets the recommended value of no more than 0.2 mg / L. The outlet water source of Water Treatment Plant A does not contain sulfate-reducing bacteria (SRB), and the water quality is good. All its indicators meet the requirements of oilfield water supply.

[0034] Ultimately, the applicant of this application sampled and tested the water entering the injection well (i.e., the water discharged from the injection transport pipeline) and found that the water injected into the injection well contained Fe. 2+ / Fe 3+ The concentration of sulfur dioxide was 2.66 mg / L, and the concentration of sulfate-reducing bacteria (SRB) was 20 CFU / mL, with many indicators far exceeding the recommended values ​​for oilfield water supply. Therefore, the applicant of this application concluded that the cause of the blockage and corrosion in the injection well was: the oilfield's water injection pipeline is relatively long (water from the oilfield's water treatment plant is pressurized and transported to the injection well via a 20km subsea water injection pipeline). The inner wall of the water injection pipeline is covered with microorganisms such as sulfate-reducing bacteria (SRB), saprophytic bacteria (TGB), and iron bacteria (FB). These microorganisms multiply rapidly on the inner wall of the water injection pipeline. The long time the water spends passing through the water injection pipeline causes the water, which was originally compliant with standards at the water treatment plant, to become contaminated after passing through the water injection pipeline, leading to water quality deterioration and consequently, corrosion and scaling in the injection well.

[0035] To address this technical problem, the applicant of this application analyzed the situation and found that if a water treatment plant were to be built at the end of the water injection pipeline to perform secondary sterilization and descaling treatment on the water flowing out of the pipeline, it would be difficult to find a suitable location at the oilfield site, and the construction period for the water treatment plant would be long and costly. Furthermore, if secondary treatment is achieved by adding bactericides and scale inhibitors, it is highly likely that microorganisms will develop drug resistance, impacting the environment. Additionally, the added bactericides and scale inhibitors are incompatible with other chemical agents (corrosion inhibitors, defoamers, oxygen scavengers, etc.), affecting the effectiveness of other chemical agents, and some residual agents may cause secondary corrosion to the oil casing, water injection wellbore, etc.

[0036] In summary, related technologies suffer from the technical problems of blockage and corrosion in water injection well casings. This application provides a sterilization and descaling device and an oilfield reservoir water injection system, which can at least partially solve the technical problems of blockage and corrosion in water injection well casings.

[0037] Based on the discovery of the aforementioned problems and the analysis of their causes, the applicant of this application has designed the sterilization and descaling device and the oilfield reservoir water injection system of this application. The application is described below with reference to the accompanying drawings and specific embodiments:

[0038] like Figure 1 As shown in the figure, this application embodiment provides a sterilization and descaling device 300. The sterilization and descaling device 300 provided in this application embodiment can perform secondary sterilization and impurity removal treatment on the water entering the water injection well barrel 200, which to a certain extent avoids corrosion and blockage of the water injection well barrel 200.

[0039] like Figure 4 As shown, the sterilization and descaling device 300 of this application is installed between the water injection transport pipe 100 and the water injection well shaft 200 in an oil field. The water injection transport pipe 100 has a first water outlet 100b, and the water injection well shaft 200 has a second water inlet 200a. Figure 1 As shown, the sterilization and descaling device 300 of this application includes a guide pipe 310, an electrolysis component 320, and a radiation sterilization device 330. The guide pipe 310 is provided with a third inlet 310a and a third outlet 310b. The third inlet 310a of the guide pipe 310 is connected to the first outlet 100b of the water injection transport pipe 100, and the third outlet 310b of the guide pipe 310 is connected to the second inlet 200a of the water injection well shaft 200. The electrolysis component 320 is used to perform ion exchange, remove scale-forming ions in the guide pipe 310, and sterilize. The electrolysis component 320 includes a cathode electrode 321, an anode electrode 322, and a power supply 323. The cathode electrode 321 and the anode electrode 322 are both electrically connected to the power supply 323, and both the cathode electrode 321 and the anode electrode 322 are located inside the guide pipe 310. The radiation sterilization device 330 is located inside the guide pipe 310 and is used to generate radiation sterilization.

[0040] With this design, the water treated by the water treatment plant 500 is transported through the oilfield's water injection pipeline 100 to the sterilization and descaling device 300 of this application for secondary sterilization and descaling treatment, and then flows into the injection well shaft 200. Both the cathode electrode 321 and the anode electrode 322 are electrically connected to the power supply 323, and both are located within the guide pipe 310. When water flows into the guide pipe 310, scale-forming ions (such as calcium ions, magnesium ions, etc.) in the water will undergo a reduction reaction at the cathode electrode 321, removing the scale-forming ions from the water. At the anode, an oxidation reaction will occur, producing strong oxidizing substances such as OH, O3, and H2O2. These strong oxidizing substances destroy the structure of the microbial membrane through oxidation, thereby achieving sterilization and killing microorganisms in the water. The radiation sterilization device 330 generates radiation that irradiates bacteria, viruses, and other microorganisms in the water flow through the radiant guide pipe 310, disrupting the structure of these microbial communities, causing them to die or lose their reproductive capacity. This reduces the number of microorganisms and scale-forming ions flowing into the injection well casing 200, thus preventing scaling, clogging, and corrosion of the injection well casing 200 to a certain extent. This makes the injection well casing 200 less prone to corrosion and extends its service life, saving oil production costs. Furthermore, the sterilization and descaling device 300 has a simple structure, low manufacturing difficulty, and low cost. The sterilization and descaling device 300 uses physical methods of radiation and electrochemistry for sterilization and descaling, without the addition of chemical agents. This avoids secondary corrosion of the injection well casing 200 due to chemical residues, and does not cause environmental pollution or compatibility issues with oilfield chemicals. It is of great significance for reducing microbial corrosion and scaling in the injection well casing 200 and achieving long-term green and efficient development of the oilfield.

[0041] The third inlet 310a of the guide pipe 310 can be welded or bonded to the first outlet 100b of the water injection transport pipe 100 to achieve communication between the third inlet 310a and the first outlet 100b. The third outlet 310b of the guide pipe 310 can be welded or bonded to the second inlet 200a of the water injection well shaft 200 to achieve communication between the third outlet 310b and the second inlet 200a.

[0042] In some embodiments, such as Figure 1 and Figure 2As shown, a first flange 314 is fixedly installed on the third inlet 310a side of the guide pipe 310 for fixed connection with the first outlet 100b side of the water injection transport pipe 100, and a second flange 315 is fixedly installed on the third outlet 310b side for fixed connection with the second inlet 200a side of the water injection well shaft 200. In these embodiments, a third flange 110 is also fixedly installed on the first outlet 100b side of the water injection transport pipe 100, and a fourth flange 210 is fixedly installed on the second inlet 200a side of the water injection well shaft 200. The first flange 314 and the third flange 110 are fixedly connected by bolts so that the third inlet 310a is aligned and connected with the first outlet 100b; the second flange 315 and the fourth flange 210 are fixedly connected by bolts so that the third outlet 310b is aligned and connected with the second inlet 200a. The arrangement of the first flange 314 and the second flange 315 facilitates the disassembly and installation of the sterilization and descaling device of this application.

[0043] The number of pairs of anode electrodes 322 and cathode electrodes 321 in the electrode assembly is not limited in this application; it can be one pair, two pairs, three pairs, etc. When multiple pairs of electrodes are provided, they are connected in parallel. The electrical connection relationship between the cathode electrode 321 and anode electrode 322 and the power supply 323, the selection of the power supply 323, and the materials of the cathode electrode 321 and anode electrode 322 are known to those skilled in the art and will not be described in detail here.

[0044] The radiation sterilization device 330 sterilizes by generating radiation, which can be ultraviolet light, ionizing radiation (such as X-rays and gamma rays), microwaves, etc. The type of radiation is not limited in this application. Excessive ionizing radiation can harm the environment and human body; therefore, the radiation dose must be strictly controlled when using ionizing radiation. The structure of the radiation-generating device is known to those skilled in the art and will not be described in detail here.

[0045] In some embodiments, the cathode electrode 321 and the anode electrode 322 are located on the third inlet 310a side and the third outlet 310b side of the guide pipe 310, respectively, and the radiation sterilization device 330 is located between the cathode electrode 321 and the anode electrode 322. Scale buildup on the surface of the radiation sterilization device 330 can affect the amount of radiation released into the water, thus affecting the sterilization efficiency. With this design, the radiation sterilization device 330 is located after the cathode along the water flow direction. When the cathode is activated, it adsorbs scale-forming ions in the water, thereby reducing the number of scale-forming ions flowing through the radiation sterilization device 330. This slows down the scaling rate of the radiation sterilization device 330, which to some extent helps to release radiation into the water and ensures the sterilization efficiency of the radiation sterilization device 330. After the water flows through the radiation sterilization device 330, most of the microorganisms in the water have been killed. The anode electrode 322 is located after the radiation sterilization device 330. The strong oxidizing substances such as OH, O3, and H2O2 generated by the oxidation reaction at the anode perform a secondary sterilization operation on the water flow that has undergone radiation sterilization, which helps to ensure that the microorganisms in the water flow entering the injection well shaft 200 are at a low level.

[0046] In some embodiments, to ensure the stable operation of the radiation sterilization device 330, the sterilization and descaling device 300 of this application further includes a protective component 340. The protective component 340 is located inside the guide pipe 310 and has a mounting cavity 340a, in which the radiation sterilization device 330 is located. With the protective component 340 in place, the radiation sterilization device 330 is located within the mounting cavity 340a, preventing direct contact with water flow and damage from immersion in water. Since the water pressure in the water supply pipe 100 is relatively high, installing the radiation sterilization device 330 within the mounting cavity 340a also prevents damage from pressure, extending the service life of the radiation sterilization device 330 and ensuring its continuous and stable operation. It should be understood that the water flow in the mounting cavity 340a and the guide pipe 310 is not connected; water from the guide pipe 310 cannot enter the mounting cavity 340a. The material and shape of the protective component 340 are diverse and are not limited in this application. The protective component 340 is located inside the guide pipe 310. The water pressure inside the guide pipe 310 is relatively high. The material and structure of the protective component 340 should be able to withstand a certain pressure. At the same time, the radiation sterilization device 330 is located inside the protective component 340. The material and structure of the protective component 340 should not affect the radiation penetration.

[0047] In some embodiments, the protective component 340 includes a body and a cover, which are detachably and sealingly connected, and together form an installation cavity 340a. When the cover is opened, the radiation sterilization device 330 can be installed in the installation cavity 340a. The radiation sterilization device 330 has its own power supply 323. After the cover is closed, the cover and the body are sealed together, preventing water from the guide pipe 310 from flowing into the installation cavity 340a. A fixing bracket or the like is provided inside the guide pipe 310 to fix the protective component 340. When installing the protective component 340 or repairing the radiation sterilization device 330, the water supply needs to be shut off, and the guide pipe 310 needs to be removed from the water injection transport pipe 100 and the water injection well shaft 200 of the oil field.

[0048] In some embodiments, to facilitate the installation and disassembly of the radiation sterilization device 330, the protective member 340 further has an installation port 340b communicating with the installation cavity 340a. The protective member 340 is partially located inside the guide tube 310, and the installation port 340b is located outside the guide tube 310. The protective member 340 and the guide tube 310 are connected in a sealed manner. The radiation sterilization device 330 is located inside the installation cavity 340a and inside the guide tube 310 through the installation port 340b. In other words, the protective component 340 has an installation port 340b for mounting the radiation sterilization device 330. An opening for mounting the protective component 340 is provided on the guide pipe 310. The protective component 340 extends into the guide pipe 310 through this opening, but the installation port 340b of the protective component 340 is located outside the guide pipe 310. Simultaneously, the outer wall of the protective component 340 and the opening on the guide pipe 310 are sealed together to prevent water from overflowing from the opening. The radiation sterilization device 330 can then extend into the guide pipe 310 through the installation port 340b of the protective component 340. This design makes the installation and removal of the radiation sterilization device 330 more convenient, as the water flow does not need to be shut off during installation and removal, which helps ensure the water injection efficiency of the oilfield reservoir. Meanwhile, the radiation sterilization device 330 does not come into contact with the water flow in the guide pipe 310, thus reducing the requirements for its sealing and pressure resistance performance, which helps to lower the manufacturing cost of the radiation sterilization device 330. Furthermore, this design allows the radiation sterilization device 330 to be connected to an external power supply 323 via an electrical wire, making its power supply more convenient.

[0049] In some embodiments, the guide pipe 310 includes a first guide pipe 311, a second guide pipe 312, and a third guide pipe 313 connected in sequence; a third inlet 310a is disposed on the first guide pipe 311, and a third outlet 310b is disposed on the third guide pipe 313; the axis of the second guide pipe 312 is angularly disposed with respect to the axes of the first guide pipe 311 and the third guide pipe 313; the mounting cavity 340a of the protective member 340 is cylindrical and has two mounting ports 340b, which are disposed at both ends of the length direction of the mounting cavity 340a; the length direction of the protective cavity is parallel to the axis of the second guide pipe 312; the protective member 340 penetrates both sides of the length direction of the first guide pipe 311; and the two mounting ports 340b are located outside the second guide pipe 312.

[0050] The axis of the second guide tube 312 can be set at an obtuse angle, a right angle, or an acute angle with the axis of the first guide tube 311 and the axis of the third guide tube 313, as described in some embodiments of this application. Figure 1 As shown, the second guide tube 312 is set at a 90° angle to the first guide tube 311 and the third guide tube 313. The first guide tube 311 and the second guide tube 312 are connected by welding, and the second guide tube 312 and the third guide tube 313 are also connected by welding. The axes of the first guide tube 311, the second guide tube 312, and the third guide tube 313 are not coaxial, so the protective member 340 can pass through both ends of the second guide tube 312 along its length, and both mounting ports 340b are located outside the guide tube 310. This allows the radiation sterilization device 330 to be installed into the mounting cavity 340a from either mounting port 340b, making the installation of the radiation sterilization device 330 more convenient. At the same time, the design of two mounting ports 340b also facilitates the cleaning of the mounting cavity 340a. The mounting cavity 340a is cylindrical, and its length is parallel to the axis of the second guide tube 312. This helps ensure that the radiation sterilization device 330 can radiate a larger area within the second guide tube 312, thus ensuring the sterilization effect of the radiation sterilization device 330.

[0051] In some embodiments, the protective element 340 is located in the middle of the second guide tube 312. With this design, the radiation sterilization device 330 is also located in the middle of the second guide tube 312 after installation. The radiation energy emitted by the radiation sterilization device 330 is evenly distributed throughout the second guide tube 312, sterilizing all parts of the second guide tube 312 and achieving a better sterilization effect.

[0052] In some embodiments, the radiation sterilization device 330 is an ultraviolet lamp, and the protective component 340 is a quartz glass tube. The length of the ultraviolet lamp tube is not less than the length of the second guide tube 312. The ultraviolet lamp has a simple structure and a sterilization rate exceeding 99.99%, which helps to reduce the cost of the sterilization and descaling device 300 of this application. The inner cavity of the quartz glass tube is the mounting cavity 340a, and the openings at both ends of the quartz glass tube are the mounting ports 340b. The quartz glass tube has good pressure resistance and excellent light transmittance, and minimal interference with ultraviolet light. The length of the ultraviolet lamp tube is not less than the length of the second guide tube 312 so that ultraviolet light acts at all points along the length of the first guide tube 311, thereby achieving a better sterilization effect.

[0053] As water flows through the guide pipe 310, impurities will adhere to the protective component 340. If the surface of the protective component 340 is not cleaned for a long time, the radiation generated by the radiation sterilization device 330 will have difficulty penetrating the protective component 340, resulting in a reduction in the sterilization performance of the sterilization and descaling device 300 of this application. Oilfield water injection systems are large; if the water injection system is stopped and the protective component 340 is removed for cleaning, it will have a significant impact on the water injection system, affecting water injection efficiency. Therefore, in some embodiments of this application, such as... Figure 2 As shown, the sterilization and descaling device 300 also includes a cleaning component 350 and a driving component 360. The cleaning component 350 is sleeved outside the protective component 340 and in contact with the protective component 340. The cleaning component 350 is connected to the driving component 360 for transmission. The driving component 360 drives the cleaning component 350 to reciprocate along the protective component 340 to clean the outer surface of the protective component 340. With this design, the protective component 340 can be cleaned online while the oilfield water injection system is in operation, ensuring both the sterilization performance of this application and the water injection efficiency of the oilfield water injection system.

[0054] The structure of the cleaning component 350 varies. In some embodiments, a soft cloth is provided on the side of the cleaning component 350 that contacts the protective component 340. In other embodiments, a brush is provided on the side of the cleaning component 350 that contacts the protective component 340, so that the adhering substances on the outer surface of the protective component 340 can be removed. The driving component 360 can be a motor, an electric telescopic rod, etc.

[0055] In some embodiments, such as Figure 2As shown, the driving component 360 includes a motor 361, a turbine 363, and a worm gear 362. The axis of the worm gear 362 is parallel to the length direction of the protective component 340. The worm gear 362 extends from both sides of the second guide tube 312 and is sealed to the second guide tube 312. The motor 361 is located outside the second guide tube 312, and its output shaft is drively connected to the worm gear 362. The turbine 362 is sleeved on the outside of the cleaning component 350 and fixedly connected to it. The turbine 363 and the worm gear 352 cooperate to form a turbine-worm pair. The motor 361 drives the worm gear 362 to rotate, thereby causing the cleaning component 350 to slide along the axis of the worm gear 362, thus cleaning the outer surface of the protective component 340.

[0056] The cathode electrode 321 and anode electrode 322 will wear down continuously during use and need to be replaced after a period of time to ensure good electrolysis performance. To facilitate electrode replacement, in some embodiments, such as... Figure 3 and Figure 4 As shown, electrode mounting holes 310c are respectively provided on the third inlet 310a side and the third outlet 310b side of the guide pipe 310. The cathode motor and anode electrode 322 are located inside the guide pipe 310 through the electrode mounting holes 310c and are detachably and sealedly connected to the electrode mounting holes 310c. The cathode electrode 321 and anode electrode 322 are provided with a first connecting part 320a for detachable connection with the pressurized electrode switching device 400 on the side facing out of the electrode mounting holes 310c. A second connecting part 310d for detachable connection with the pressurized electrode switching device 400 is also provided on the mounting port 340b. With this design, when the cathode electrode 321 and anode electrode 322 are replaced, the water injection system can be kept open, and the replacement can be performed online through the pressurized electrode switching device 400. The first connecting part 320a can be a snap-fit ​​structure, a connecting hole, etc., and the second connecting part 310d can be a snap-fit ​​structure or a flange, etc.

[0057] The structure and usage of the live electrode switching device 400 are known to those skilled in the art and will not be described in detail here. The live electrode switching device 400 is provided with a third connecting part that matches the second connecting part 310d. By aligning the third connecting part with the second connecting part 310d, the electrode mounting hole 310c and the inner cavity of the live electrode switching device 400 can be connected. The live electrode switching device is provided with a switching rod, which can extend and retract to connect with the first connecting part 320a.

[0058] The working principle of the sterilization and descaling device 300 provided in this application embodiment is as follows: When in use, the sterilization and descaling device 300 is installed between the water injection transport pipe 100 and the well shaft, and the third water inlet 310a and the first water outlet 100b are connected, and the third water outlet 310b and the second water inlet 200a are connected. Then, the water injection system of the oil field is turned on, the cathode electrode 321, the anode motor and the power supply 323 are connected, and the radiation sterilization device 330 is turned on.

[0059] In summary, the sterilization and descaling device 300 of this application performs secondary sterilization and descaling treatment on the water flowing out of the water injection transport pipe 100 through physical methods of radiation and electrochemistry. This effectively prevents scaling, clogging, and corrosion of the water injection well casing 200, extending its service life and saving oil production costs. Furthermore, the sterilization and descaling device 300 does not add any chemical agents, preventing secondary corrosion of the water injection well casing 200 due to chemical residues. It also avoids environmental pollution and compatibility issues with oilfield chemicals, making it significant for reducing microbial corrosion and scaling in the water injection well casing 200 and achieving long-term green and efficient development of the oilfield. The sterilization and descaling device 300 places the cathode electrode 321 before the radiation sterilization device 330, which helps slow down the scaling rate of the radiation sterilization device 330, facilitates radiation release into the water, and ensures the sterilization efficiency of the radiation sterilization device 330. The protective component 340 protects the radiation sterilization device 330, making its installation and disassembly more convenient. The arrangement of the cleaning component 350 and the driving component 360 enables the protective component 340 of the sterilization and descaling device 300 of this application to achieve online cleaning without shutting down the water injection system, thus ensuring the sterilization performance of the sterilization and descaling device 300 of this application while ensuring the water injection efficiency of the oilfield water injection system.

[0060] Based on the same inventive concept, this application also provides an oilfield reservoir water injection system, including a water treatment station 500, a water injection transport pipe 100, the sterilization and descaling device 300 provided above in this application, and a water injection well shaft 200; the water injection transport pipe 100 has a first inlet and a first outlet 100b, the water injection well shaft 200 has a second inlet 200a and a second outlet, the water injection transport pipe 100 is connected to the water treatment station 500 through the first inlet, the first outlet 100b is connected to the third inlet 310a of the guide pipe 310, the third outlet 310b of the guide pipe 310 is connected to the second inlet 200a of the water injection well shaft 200, and the second outlet of the water injection well shaft 200 is used to communicate with the oil reservoir.

[0061] The oilfield reservoir water injection system of this application first performs initial sterilization and descaling treatment on the water flow through the water treatment station 500. After being discharged from the water injection transport pipe 100, the water then enters the sterilization and descaling device 300 for secondary sterilization and descaling treatment. This greatly reduces the amount of microorganisms and impurities flowing into the injection well barrel 200, and to a certain extent avoids the technical problems of blockage and corrosion of the injection well barrel 200. Since this oilfield reservoir water injection system uses the sterilization and descaling device 300 provided in this application, it naturally possesses all the beneficial effects of the sterilization and descaling device 300 of this application, which will not be elaborated here.

[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0063] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0064] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A sterilization and descaling device, characterized in that, The water injection transport pipe (100) is installed between the water injection well casing (200) and the oilfield, wherein the water injection transport pipe (100) has a first outlet (100b) and the water injection well casing (200) has a second inlet (200a), and the sterilization and descaling device includes: The guide pipe (310) is provided with a third inlet (310a) and a third outlet (310b). The third inlet (310a) is used to communicate with the first outlet (100b), and the third outlet (310b) is used to communicate with the second inlet (200a). The guide tube (310) includes a first guide tube (311), a second guide tube (312) and a third guide tube (313) connected in sequence. The third inlet (310a) is located on the first guide pipe (311), and the third outlet (310b) is located on the third guide pipe (313). The axis of the second guide pipe (312) is set at an angle to the axis of the first guide pipe (311) and the axis of the third guide pipe (313). An electrolysis assembly (320) includes a cathode electrode (321), an anode electrode (322), and a power supply (323). The cathode electrode (321) and the anode electrode (322) are both electrically connected to the power supply (323), and the cathode electrode (321) and the anode electrode (322) are both located inside the flow guide tube (310). The electrolysis assembly (320) is used to remove scale-forming ions and sterilize the flow guide tube (310). A radiation sterilization device (330) is located inside the guide tube (310) and is used to generate radiation sterilization; The cathode electrode (321) and the anode electrode (322) are located on the side of the third inlet (310a) and the side of the third outlet (310b), respectively, and the radiation sterilization device (330) is located between the cathode electrode (321) and the anode electrode (322). The protective element (340) is located inside the guide tube (310) and has a mounting cavity (340a). The protective component (340) also has a mounting port (340b) communicating with the mounting cavity (340a). The protective component (340) is partially located inside the guide tube (310), and the mounting port (340b) is located outside the guide tube (310). The protective component (340) and the guide tube (310) are connected in a sealed manner. The radiation sterilization device (330) is located inside the mounting cavity (340a) through the mounting port (340b) and inside the guide tube (310). The mounting cavity (340a) is cylindrical and has two mounting ports (340b). The two mounting ports (340b) are located at both ends of the mounting cavity (340a) along its length. The length of the mounting cavity (340a) is parallel to the axis of the second guide tube (312). The protective member (340) penetrates both sides of the first guide tube (311) along its length. Both mounting ports (340b) are located outside the second guide tube (312).

2. The sterilization and descaling device according to claim 1, characterized in that, A first flange (314) for fixed connection with the first outlet (100b) of the water injection transport pipe (100) is fixedly installed on the third inlet (310a) side of the guide pipe (310), and a second flange (315) for fixed connection with the second inlet (200a) side of the water injection well barrel (200) is fixedly installed on the third outlet (310b) side.

3. The sterilization and descaling device according to claim 1, characterized in that, The protective element (340) is located in the middle of the second guide tube (312).

4. The sterilization and descaling device according to claim 3, characterized in that, The radiation sterilization device (330) is an ultraviolet lamp, the protective component (340) is a quartz glass tube, and the length of the ultraviolet lamp tube is not less than the length of the second guide tube (312).

5. The sterilization and descaling device according to claim 3 or 4, characterized in that, The sterilization and descaling device further includes a cleaning component (350) and a driving component (360). The cleaning component (350) is sleeved on the outside of the protective component (340) and in contact with the protective component (340). The cleaning component (350) is connected to the driving component (360) in a transmission manner. The driving component (360) drives the cleaning component (350) to reciprocate along the protective component (340) to clean the outer surface of the protective component (340).

6. The sterilization and descaling device according to any one of claims 1-4, characterized in that, Electrode mounting holes (310c) are respectively provided on the third inlet (310a) side and the third outlet (310b) side of the guide pipe (310). The cathode electrode (321) and the anode electrode (322) are located inside the guide pipe (310) through the electrode mounting holes (310c) and are detachably and sealedly connected to the electrode mounting holes (310c). The cathode electrode (321) and the anode electrode (322) are provided with a first connecting part (320a) for detachable connection with the pressure-controlled electrode switching device (400) on the side facing out of the electrode mounting hole (310c). A second connecting part (310d) for detachable connection with the pressure-controlled electrode switching device (400) is also provided next to the electrode mounting hole (310c) and on the guide tube (310).

7. An oilfield reservoir water injection system, characterized in that, include: The sterilization and descaling device (300), water treatment station (500), water injection and transport pipe (100), and water injection well shaft (200) as described in any one of claims 1-6; The water injection transport pipe (100) has a first inlet (100a) and a first outlet (100b), and the water injection well shaft (200) has a second inlet (200a) and a second outlet (200b). The water injection transport pipe (100) is connected to the water treatment station (500) through the first inlet (100a), and the first outlet (100b) is connected to the third inlet (310a) of the guide pipe (310). The third outlet (310b) of the guide pipe (310) is connected to the second inlet (200a) of the water injection well shaft (200), and the second outlet (200b) of the water injection well shaft (200) is used to connect with the oil layer.

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