Sterilizing and descaling device and oil field oil layer water injection system

Abstract

The invention discloses a sterilizing and descaling device and an oil field oil layer water injection system, and belongs to the technical field of oil field water injection treatment devices. The sterilization and descaling device is installed between a water injection conveying pipe and a water injection well shaft of an oil field and comprises a flow guide pipe, an electrolysis assembly and a radiation sterilization device. Water flowing out of the water injection conveying pipe is subjected to secondary sterilization and descaling treatment in a radiation and electrochemical physical mode, the water injection well shaft is prevented from scaling, blocking and corrosion to a certain degree, the service life of the water injection well shaft is prolonged, and the oil extraction cost is saved. Meanwhile, no chemical agent is added into the sterilization and descaling device, secondary corrosion to the water injection well shaft due to agent residues is avoided, environmental pollution and the compatibility problem of oil field chemical agents are avoided, and the sterilization and descaling device has great significance in reducing microbial corrosion and scaling of the water injection well shaft and achieving long-term green and efficient development of an oil field.

Description

Technical Field

[0001] The present application belongs to the technical field of oilfield water injection treatment devices, and in particular, relates to a sterilization and descaling device and an oilfield oil layer water injection system. Background Art

[0002] As more and more oilfields enter the middle and late stages of development, the original formation pressure is seriously attenuated. In order to achieve stable production, most oilfields choose to inject water to maintain the formation pressure. Water injection refers to injecting water into the oil layer through injection wells to replenish the energy of the oil layer. It is one of the important means to maintain a reasonable reservoir pressure and improve the recovery rate of the oil field. Under normal circumstances, the water injection pressure does not exceed 15MPa, and there are many types of water sources in the water injection system, including production wastewater, water from the water source layer and even river water.

[0003] In the related art, water flow is usually sterilized and descaled through a water treatment station to avoid blockage and corrosion of the injection well shaft. However, after being treated by the water treatment station, the injection well shaft sometimes still becomes blocked and corroded. Summary of the invention

[0004] The present application aims to solve the technical problems of wellbore blockage and corrosion of water injection wells in the related art to a certain extent. To this end, the present application provides a sterilization and descaling device and an oilfield oil layer water injection system.

[0005] In the first aspect, an embodiment of the present application provides a sterilization and descaling device, which is installed between an injection and transport pipe of an oil field and a wellbore of an injection well, wherein the injection and transport pipe has a first water outlet, and the wellbore of the injection well has a second water inlet, and comprises: a guide pipe, provided with a third water inlet and a third water outlet, wherein the third water inlet is used to communicate with the first water outlet, and the third water outlet is used to communicate with the second water inlet; an electrolytic component, comprising a cathode electrode, an anode electrode and a power supply, wherein the cathode electrode and the anode electrode are both electrically connected to the power supply, and the cathode electrode and the anode electrode are both located in the guide pipe, and the electrolytic component is used to perform ion exchange, remove scale-forming ions in the guide pipe and sterilize; a radiation sterilization device, located in the guide pipe, for generating radiation for sterilization.

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

[0007] In some embodiments, the cathode electrode and the anode electrode are located on the third water inlet side and the third water 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 comprises a protective member, the protective member is located in the flow guide tube, the protective member has an installation cavity, and the radiation sterilization device is located in the installation cavity.

[0009] In some embodiments, the protective member also has an installation port connected to the installation cavity, the protective member is partially located in the guide tube, the installation port is located outside the guide tube, and the protective member and the guide tube are airtightly connected; the radiation sterilization device is located in the installation cavity and in the guide tube through the installation port.

[0010] In some embodiments, the flow guide pipe includes a first flow guide pipe, a second flow guide pipe and a third flow guide pipe which are connected in sequence; the third water inlet is arranged on the first flow guide pipe, the third water outlet is arranged on the third flow guide pipe, and the axis of the second flow guide pipe is arranged at an angle to the axis of the first flow guide pipe and the axis of the third flow guide pipe; the installation cavity is columnar and has two installation ports, and the two installation ports are arranged at both ends of the length direction of the installation cavity, and the length direction of the installation cavity is parallel to the axis of the second flow guide pipe, the protective member passes through both sides of the length direction of the first flow guide pipe, and the two installation ports are located outside the second flow guide pipe.

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

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

[0013] In some embodiments, the sterilization and descaling device also includes a cleaning member and a driving member. The cleaning member is mounted outside the protective member and contacts the protective member. The cleaning member is transmission-connected to the driving member. The driving member drives the cleaning member to reciprocate along the protective member to clean the outer surface of the protective member.

[0014] In some embodiments, electrode mounting holes are respectively provided on the third water inlet side and the third water outlet side of the guide tube, and the cathode electrode and the anode electrode are located in the guide tube through the electrode mounting holes and are detachably and tightly connected at the electrode mounting holes; a first connecting portion for detachably connecting to a pressure-bearing pole-changing device is provided on the side of the cathode electrode and the anode electrode facing outside the electrode mounting hole, and a second connecting portion for detachably connecting to a pressure-bearing pole-changing device is also provided on the guide tube next to the electrode mounting hole.

[0015] In the second aspect, an embodiment of the present application provides an oilfield oil layer 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 shaft; the water injection transport pipe has a first water inlet and a first water outlet, the water injection well shaft has a second water inlet and a second water outlet, the water injection transport pipe is connected to the water treatment station through the first water inlet, the first water outlet is connected to the third water inlet of the guide pipe, the third water outlet of the guide pipe is connected to the second water inlet of the water injection well shaft, and the second water outlet of the water injection well shaft is used to connect to the oil layer.

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

[0017] The sterilization and descaling device of the present application is installed between the water injection transport pipe and the wellbore of the water injection well of the oil field, and the present application includes a guide pipe, an electrolytic component and a radiation sterilization device. The electrolytic component includes a cathode electrode, an anode electrode and a power supply, the cathode electrode and the anode electrode are located in the guide pipe and are electrically connected to the power supply, and the electrolytic component undergoes an electrolytic reaction in the guide pipe, and the scale-forming ions (such as calcium ions, magnesium ions, etc.) in the water will undergo a reduction reaction at the cathode electrode, and the scale-forming ions will be taken out of the water, softening the water quality, thereby reducing the number of scale-forming ions flowing into the wellbore of the water injection well. An oxidation reaction will occur at the anode electrode to produce strong oxidizing substances such as OH, O3, and H2O2 to kill microorganisms in the water, and radiation will be generated through the radiation sterilization device to radiate bacteria, viruses and other microorganisms in the water flow in the guide pipe, destroying the structure in the body of these microorganisms, causing them to die or lose their reproductive ability, thereby reducing the number of microorganisms flowing into the wellbore of the water injection well.

[0018] The sterilization and descaling device of the present application avoids the scaling blockage and corrosion of the wellbore of the water injection well to a certain extent, prolongs the service life of the wellbore of the water injection well, and saves the cost of oil production. At the same time, the sterilization and descaling device of the present application has a simple structure, low difficulty in processing and manufacturing, and low cost; it sterilizes and descales by physical means of radiation and electrochemistry, without adding chemical agents, and will not cause secondary corrosion to the wellbore of the water injection well due to residual agents, and will not cause environmental pollution and compatibility problems of oilfield chemicals. It is of great significance to reduce microbial corrosion and scaling of the wellbore of the water injection well and realize the long-term green and efficient development of the oil field. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0021] Figure 2 Shows Figure 1 A partial enlarged view of point A in the middle.

[0022] Figure 3 Shows Figure 1 Enlarged view of point B in the middle.

[0023] Figure 4 A schematic diagram of the structure of an oil field oil layer water injection system in one or more embodiments of the present application is shown.

[0024] Reference numerals: 100-water injection transport pipe, 110-third flange, 100b-first water outlet, 200-water injection well shaft, 210-fourth flange, 200a-second water inlet, 300-sterilization and descaling device, 310-flow guide pipe, 310a-third water inlet, 310b-third water outlet, 310c-electrode mounting hole, 310d-second connecting portion, 311-first flow guide pipe, 312-second flow guide pipe, 313-third flow guide pipe, 314-first flange, 315-second flange, 320-electrolytic assembly, 320a-, first connecting part, 321-cathode electrode, 322-anode electrode, 323-power supply, 330-radiation sterilization device, 340-protective part, 340a-installation cavity, 340b-installation port, 350-cleaning part, 360-driving part, 361-motor, 362-worm, 363-turbine, 400-pressure pole changing device, 500-water treatment station. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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 position relationship, movement status, etc. between various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] As more and more oilfields enter the middle and late stages of development, the original formation pressure is seriously attenuated. In order to achieve stable production, most oilfields choose to inject water to maintain the formation pressure. Water injection refers to injecting water into the oil layer through injection wells to replenish the energy of the oil layer. It is one of the important means to maintain a reasonable reservoir pressure and improve the recovery rate of the oil field. Under normal circumstances, the water injection pressure does not exceed 15MPa. There are many types of water sources for the water injection system, including production wastewater, water from the water source layer and even river water.

[0030] Water sources usually contain microorganisms such as sulfate-reducing bacteria (SRB), saprophytic bacteria (TGB) and iron bacteria (FB). The deposition of these microbial reproduction products will block water injection transportation pipelines, water injection well bores and formations. When sulfate-reducing bacteria (SRB) reproduce in water, they will produce a large amount of sulfide, which will also cause corrosion and scaling of water injection transportation pipelines and water injection well bores, affecting normal water injection operations. Sulfate-reducing bacteria (SRB) will also react with organic matter to produce H2S when entering the production layer with injected water. As the H2S content in the production layer increases, the oil reservoir will change from a non-acidic oil and gas reservoir that does not contain H2S to an acidic oil and gas reservoir that contains H2S. Oil well pipes and downhole tools need to be desulfurized, which will cause wellbore corrosion of the production well and a significant increase in oilfield development costs. At the same time, if there are many scaling ions in the water source, they are easy to react with other ions to form sediments, aggravating the blockage phenomenon.

[0031] Therefore, in order to avoid water source blockage and corrosion of water injection transportation pipelines, water injection wells, etc., water sources such as production wastewater, aquifer water or river water will first be sterilized and removed by water treatment stations.

[0032] The applicant of this application discovered in practice that an oil field developed by it was supplied with water by Water Treatment Plant A. After Water Treatment Plant A sterilized and removed impurities from the water source, scaling, blockage and corrosion still occurred in the wellbore of the injection wells of the oil field, requiring the oil field to invest a large amount of cost every year to repair and replace the wellbore of the injection wells.

[0033] The applicant of this application sampled and tested the soil layer around the injection well shaft, analyzed the soil's pH, humidity, composition and other information, commissioned a third-party testing agency to conduct quality inspections on the injection well shaft, tested the composition of the water source, and tested the quality of the water discharged from the A water treatment plant, but ultimately failed to find the cause of the blockage and corrosion of the injection well shaft. 2+ / Fe 3+ The content is 0.03mg / L, which meets the recommended value of no more than 0.2mg / L. There is no sulfate-reducing bacteria (SRB) in the outlet water of Water Treatment Plant A, and the water quality is good. All its indicators meet the requirements of oilfield water supply.

[0034] Finally, the applicant of this application sampled and tested the water entering the wellbore of the water injection well (i.e., the water discharged from the water injection transportation pipeline) and found that Fe 2+ / Fe 3+ The content of is 2.66mg / L, and the content of sulfate-reducing bacteria (SRB) is 20 / mL, and many of its indicators are far higher than the range of recommended values ​​for oil field water supply. Therefore, the applicant of this application analyzed that the reasons for the blockage and corrosion of the water injection well shaft are: the water injection transportation pipeline of the oil field is relatively long (the water flowing out of the water treatment station of the oil field is pressurized and transported to the water injection well shaft through a submarine water injection transportation pipeline of about 20km), and the inner wall of the water injection transportation pipe is attached with microorganisms such as sulfate-reducing bacteria (SRB), saprophytic bacteria (TGB) and iron bacteria (FB). These microorganisms multiply in large numbers on the inner wall of the water injection transportation pipe, and the water flow passes through the water injection transportation pipeline for a long time, resulting in the water treatment plant The water that originally met the standards is polluted after passing through the water injection transportation pipe, resulting in deterioration of water quality, and then leading to corrosion and scaling of the water injection well shaft.

[0035] How to solve this technical problem? The applicant of this application analyzed and found that if a water treatment plant is built at the end of the water injection transport pipeline to perform secondary sterilization and descaling treatment on the water flowing out of the water injection transport pipeline, it is difficult to find a suitable construction location at the oil production site, and the construction period of the water treatment station is long and the cost investment is large. At the same time, if secondary treatment is performed by adding bactericides and scale inhibitors, it is very easy to cause microorganisms to develop drug resistance and affect the environment. At the same time, the addition of chemical agents such as bactericides and scale inhibitors is incompatible with chemical agents (corrosion inhibitors, defoamers, deoxidizers, etc.), affecting the effects of other chemical agents. Some residual agents will cause secondary corrosion to oil casing, water injection wells, etc.

[0036] In summary, in the related art, there are technical problems of blockage and corrosion in the wellbore of water injection wells. The embodiment of the present application provides a sterilization and descaling device and an oilfield oil layer water injection system, which can at least solve the technical problems of blockage and corrosion in the wellbore of water injection wells to a certain extent.

[0037] The applicant of the present application, based on the discovery of the above-mentioned problems and the analysis of the causes of the problems, has designed the sterilization and descaling device and the oil field oil layer water injection system of the present application. The present application is described below in conjunction with the accompanying drawings and with reference to specific embodiments:

[0038] like Figure 1 As shown, an embodiment of the present application provides a sterilization and descaling device 300. The sterilization and descaling device 300 provided in the embodiment of the present application can perform secondary sterilization and decontamination treatment on the water entering the water injection well shaft 200, thereby avoiding corrosion and blockage of the water injection well shaft 200 to a certain extent.

[0039] like Figure 4 As shown, the sterilization and descaling device 300 of the present application is installed between the water injection transport pipe 100 and the water injection well shaft 200 of the 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 the present application includes a flow guide tube 310, an electrolytic component 320 and a radiation sterilization device 330. The flow guide tube 310 is provided with a third water inlet 310a and a third water outlet 310b. The third water inlet 310a of the flow guide tube 310 is connected to the first water outlet 100b of the water injection transport pipe 100, and the third water outlet 310b of the flow guide tube 310 is connected to the second water inlet 200a of the water injection well 200. The electrolytic component 320 is used to perform ion exchange, remove scale ions in the flow guide tube 310 and sterilize. The electrolytic 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 the cathode electrode 321 and the anode electrode 322 are both located in the flow guide tube 310. The radiation sterilization device 330 is located in the flow guide tube 310 and is used to generate radiation for sterilization.

[0040] After the present application is designed in this way, the water treated by the water treatment station 500 is transported to the sterilization and descaling device 300 of the present application through the water injection transport pipe 100 of the oil field, and then flows into the water injection well shaft 200. 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 in the guide tube 310. When water flows into the guide tube 310, the scale ions (such as calcium ions, magnesium ions, etc.) in the water will undergo a reduction reaction at the cathode electrode 321, and the scale ions will be removed from the water. An oxidation reaction will occur at the anode to produce strong oxidizing substances such as OH, O3, and H2O2. The strong oxidizing substances destroy the structure of the microbial membrane through oxidation to achieve a sterilization effect and kill the microorganisms in the water. The radiation sterilization device 330 generates radiation, radiates bacteria, viruses and other microorganisms in the water flow of the diversion pipe 310, destroys the structure of these microorganisms, causes them to die or lose their reproductive ability, and then reduces the number of microorganisms and the number of scaling ions flowing into the water injection well shaft 200, avoids the scaling blockage and corrosion of the water injection well shaft 200 to a certain extent, makes the water injection well shaft 200 not easy to corrode and corrode, prolongs its service life, and saves oil production costs. At the same time, the structure of the sterilization and descaling device 300 of the present application is simple, and the processing and manufacturing difficulty and cost are low. The sterilization and descaling device 300 of the present application sterilizes and descales by radiation and electrochemical physical methods, without the addition of chemical agents, will not cause secondary corrosion to the water injection well shaft 200 due to residual agents, will not cause environmental pollution and compatibility problems of oil field chemicals, and is of great significance for reducing microbial corrosion and scaling of the water injection well shaft 200 and realizing long-term green and efficient development of oil fields.

[0041] The third water inlet 310a side of the flow guide pipe 310 can be welded or bonded to the first water outlet 100b side of the water injection transport pipe 100, so that the third water inlet 310a is connected to the first water outlet 100b. The third water outlet 310b side of the flow guide pipe 310 can be welded or bonded to the second water inlet 200a side of the water injection well 200, so that the third water outlet 310b is connected to the second water inlet 200a.

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

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

[0044] The radiation sterilization device 330 sterilizes by generating radiation, and the radiation can be ultraviolet rays, ionizing radiation (X-rays and gamma rays, etc.), microwaves, etc. The type of radiation is not limited in this application. Excessive ionizing radiation will cause damage to the environment and the human body. When ionizing radiation is used, the radiation dose should be strictly controlled. The structure of the device that generates radiation 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 respectively located on the third water inlet 310a side and the third water outlet 310b side of the flow guide tube 310, and the radiation sterilization device 330 is located between the cathode electrode 321 and the anode electrode 322. Scaling on the surface of the radiation sterilization device 330 will affect the amount of radiation released into the water and affect the sterilization efficiency. After such a design, along the direction of water flow, the radiation sterilization device 330 is located after the cathode. When the cathode takes effect, it will adsorb scaling ions in the water, thereby reducing the number of scaling ions flowing through the radiation sterilization device 330, slowing down the scaling rate of the radiation sterilization device 330, and to a certain extent, helping to release radiation into the water, thereby ensuring 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 behind the radiation sterilization device 330. The strong oxidizing substances such as OH, O3, H2O2 produced by the oxidation reaction at the anode perform secondary sterilization operations on the water flow that has been sterilized by radiation, 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, in order to ensure the stable operation of the radiation sterilization device 330, the sterilization and descaling device 300 of the present application further includes a protective member 340, which is located in the guide tube 310, and the protective member 340 has an installation cavity 340a, and the radiation sterilization device 330 is located in the installation cavity 340a. After the protective member 340 is set, the radiation sterilization device 330 is located in the installation cavity 340a to avoid direct contact with the water flow and damage caused by immersion in water. The water pressure of the water flow in the water injection transport pipe 100 is relatively high. The radiation sterilization device 330 is installed in the installation cavity 340a, which can also avoid the radiation sterilization device 330 from being damaged by pressure, thereby extending the service life of the radiation sterilization device 330 and ensuring the continuous and stable operation of the radiation sterilization device 330 of the present application. It should be understood that the installation cavity 340a is not connected to the water flow in the guide tube 310, and the water flow in the guide tube 310 cannot enter the installation cavity 340a. The material and shape of the protective part 340 are various and are not limited in the present application. The protective part 340 is located in the guide tube 310. The water pressure in the guide tube 310 is relatively high. The material and structure of the protective part 340 should be able to withstand a certain pressure. At the same time, the radiation sterilization device 330 is located in the protective part 340. The material and structure of the protective part 340 cannot affect the radiation penetration.

[0047] In some embodiments, the protective member 340 includes a main body and a cover, the main body and the cover are detachably and hermetically connected, and the main body and the cover are enclosed to 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 main body are hermetically connected to prevent the water in the guide tube 310 from flowing into the installation cavity 340a. A fixing frame is provided inside the guide tube 310 to fix the protective member 340. When installing the protective member 340 or repairing the radiation sterilization device 330, it is necessary to shut off the water supply and remove the guide tube 310 from the water injection transport pipe 100 of the oil field and the water injection well shaft 200.

[0048] In some embodiments, in order to facilitate the installation and disassembly of the radiation sterilization device 330, the protective member 340 also has an installation port 340b connected to the installation cavity 340a, the protective member 340 is partially located in the guide tube 310, and the installation port 340b is located outside the guide tube 310, and the protective member 340 and the guide tube 310 are tightly connected; the radiation sterilization device 330 is located in the installation cavity 340a and in the guide tube 310 through the installation port 340b. That is, the protective member 340 has an installation opening 340b for installing the radiation sterilization device 330, and an opening for installing the protective member 340 is provided on the flow guide tube 310. The protective member 340 extends into the flow guide tube 310 through the opening on the flow guide tube 310, but the installation opening 340b of the protective member 340 is located outside the flow guide tube 310. At the same time, the outer wall of the protective member 340 and the opening on the flow guide tube 310 are tightly connected to prevent the water flow in the flow guide tube 310 from overflowing from the opening, and the radiation sterilization device 330 can extend into the flow guide tube 310 through the installation opening 340b on the protective member 340. With this design, the radiation sterilization device 330 extends into and out of the flow guide tube 310 through the installation opening 340b of the protective member 340, and the installation and removal of the radiation sterilization device 330 are more convenient. The water flow does not need to be closed during the installation and removal of the radiation sterilization device 330, which helps to ensure the water injection efficiency of the oil layer in the oil field. At the same time, the radiation sterilization device 330 will not contact the water flow in the guide tube 310, and the requirements for the sealing performance and pressure resistance of the radiation sterilization device 330 are low, which helps to reduce the manufacturing cost of the radiation sterilization device 330. At the same time, after such a design, the radiation sterilization device 330 can be connected to the external power supply 323 through wires, and its electricity use is more convenient.

[0049] In some embodiments, the flow guide pipe 310 includes a first flow guide pipe 311, a second flow guide pipe 312 and a third flow guide pipe 313 which are connected in sequence; the third water inlet 310a is arranged on the first flow guide pipe 311, and the third water outlet 310b is arranged on the third flow guide pipe 313, and the axis of the second flow guide pipe 312 is arranged at an angle to the axis of the first flow guide pipe 311 and the axis of the third flow guide pipe 313; the installation cavity 340a of the protective member 340 is columnar and has two installation ports 340b, and the two installation ports 340b are arranged at both ends of the installation cavity 340a in the length direction, and the length direction of the protective cavity is parallel to the axis of the second flow guide pipe 312, the protective member 340 passes through both sides of the length direction of the first flow guide pipe 311, and the two installation ports 340b are located outside the second flow guide pipe 312.

[0050] The axis of the second flow guiding tube 312 may be arranged at an obtuse angle, a right angle, or an acute angle to the axis of the first flow guiding tube 311 and the axis of the third flow guiding tube 313. In some embodiments of the present application, for example Figure 1 As shown, the second flow guide tube 312 is arranged at 90 degrees with the first flow guide tube 311 and the third flow guide tube 313. The first flow guide tube 311 and the second flow guide tube 312 are connected by welding, and the second flow guide tube 312 and the third flow guide tube 313 are also connected by welding. The axis of the first flow guide tube 311, the axis of the second flow guide tube 312 and the axis of the third flow guide tube 313 are not coaxial, so the protective member 340 can pass through both ends of the second flow guide tube 312 in the length direction, and the two installation ports 340b are both located outside the flow guide tube 310. The radiation sterilization device 330 can be installed in the installation cavity 340a from any installation port 340b, which makes the installation of the radiation sterilization device 330 more convenient. At the same time, the design of the two installation ports 340b also facilitates the cleaning of the installation cavity 340a. The installation cavity 340 a is columnar, and the length direction of the installation cavity 340 a is parallel to the axis of the second flow conduit 312 , which helps to ensure that the radiation sterilization device 330 can radiate a larger area in the second flow conduit 312 , and helps to ensure the sterilization effect of the radiation sterilization device 330 .

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

[0052] In some embodiments, the radiation sterilization device 330 is an ultraviolet lamp, the protective member 340 is a quartz glass tube, and the length of the lamp tube of the ultraviolet lamp is not less than the length of the second guide tube 312. The ultraviolet lamp has a simple structure, and the sterilization rate can exceed 99.99%, which helps to reduce the cost of the sterilization and descaling device 300 of the present application. The inner cavity of the quartz glass tube is the installation cavity 340a, and the openings at both ends of the quartz glass tube are the installation ports 340b. The quartz glass tube has good pressure bearing performance, excellent light transmittance, and little interference with ultraviolet rays. The length of the ultraviolet lamp tube is not less than the length of the second guide tube 312, so that ultraviolet rays can be applied to all parts of the length direction of the first guide tube 311 to achieve a better sterilization effect.

[0053] As the water flows in the guide tube 310, impurities and the like will adhere to the protective member 340. If the surface of the protective member 340 is not cleaned for a long time, the radiation generated by the radiation sterilization device 330 will have difficulty penetrating the protective member 340, resulting in a reduction in the sterilization performance of the sterilization and descaling device 300 of the present application. The oil field water injection system is huge. If the water injection system is stopped and the protective member 340 is taken out for cleaning, it will have a great impact on the water injection system and affect the water injection efficiency. For this reason, in some embodiments of the present application, such as Figure 2 As shown, the sterilization and descaling device 300 further includes a cleaning member 350 and a driving member 360. The cleaning member 350 is sleeved outside the protective member 340 and contacts the protective member 340. The cleaning member 350 is in transmission connection with the driving member 360. The driving member 360 drives the cleaning member 350 to reciprocate along the protective member 340 to clean the outer surface of the protective member 340. With such a design, the protective member 340 can be cleaned online when the oilfield water injection system is in working state, thereby ensuring the water injection efficiency of the oilfield water injection system while ensuring the sterilization performance of the present application.

[0054] The structure of the cleaning member 350 is various. In some embodiments, a flannel is provided on the side of the cleaning member 350 that contacts the protective member 340. In some embodiments, a brush is provided on the side of the cleaning member 350 that contacts the protective member 340 to remove the attachments on the outer surface of the protective member 340. The driving member 360 can be a motor, an electric telescopic rod, etc.

[0055] In some embodiments, Figure 2As shown, the driving member 360 includes a motor 361, a turbine 363 and a worm 362. The axis of the worm 362 is parallel to the length direction of the protective member 340. Both sides of the worm 362 extend out of the second flow guide tube 312 and are tightly connected to the second flow guide tube 312. The motor 361 is located outside the second flow guide tube 312, and the output shaft of the motor 361 is connected to the worm 362 in a transmission manner. The turbine 362 is sleeved on the outside of the cleaning member 350 and is fixedly connected to the cleaning member 350. The turbine 363 cooperates with the worm 352 to form a turbine-worm pair. The motor 361 drives the worm 362 to rotate, thereby driving the cleaning member 350 to slide along the axis direction of the worm 362, thereby cleaning the outer surface of the protective member 340.

[0056] The cathode electrode 321 and the anode electrode 322 will be worn out during use and need to be replaced after a period of time to ensure good electrolysis performance. In order to facilitate the replacement of electrodes, in some embodiments, such as Figure 3 and Figure 4 As shown, electrode mounting holes 310c are respectively provided on the third water inlet 310a side and the third water outlet 310b side of the flow guide tube 310, and the cathode motor and the anode electrode 322 are located in the flow guide tube 310 through the electrode mounting hole 310c, and are detachably and tightly connected to the electrode mounting hole 310c. The cathode electrode 321 and the anode electrode 322 are provided with a first connection part 320a for detachably connecting to the pressure pole changing device 400 on the side facing the outside of the electrode mounting hole 310c, and a second connection part 310d for detachably connecting to the pressure pole changing device 400 is also provided on the mounting port 340b. With such a design, when the cathode electrode 321 and the anode electrode 322 are replaced, the water injection system can be kept unchanged, and they can be replaced online through the pressure pole changing device 400. The first connection part 320a can be a clamping structure, a connection hole, etc., and the second connection part 310d can be a clamping structure or a flange, etc.

[0057] The structure and use of the voltage-operated pole-changing device 400 are well known to those skilled in the art and will not be described in detail here. The voltage-operated pole-changing device 400 is provided with a third connection portion that matches the second connection portion 310d. The third connection portion and the second connection portion 310d are connected to each other so that the electrode mounting hole 310c and the inner cavity of the voltage-operated pole-changing device 400 can be connected. The voltage-operated pole-changing device is provided with a pole-changing rod, which can be telescopically connected to the first connection portion 320a.

[0058] The working principle of the sterilization and descaling device 300 provided in the embodiment of the present application is as follows: when in use, the sterilization and descaling device 300 of the present application is installed between the water injection transport pipe 100 and the wellbore of the water well, and the third water inlet 310a is connected with the first water outlet 100b, and the third water outlet 310b is connected with the second water inlet 200a, and 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 the present application performs secondary sterilization and descaling treatment on the water flowing out of the water injection transport pipe 100 by radiation and electrochemical physical methods, which avoids the scaling, clogging and corrosion of the water injection well shaft 200 to a certain extent, prolongs the service life of the water injection well shaft 200, and saves oil production costs. At the same time, the sterilization and descaling device 300 of the present application does not have chemical agents added, and will not cause secondary corrosion to the water injection well shaft 200 due to the residual agents, and will not cause environmental pollution and compatibility problems of oilfield chemicals. It is of great significance to reduce the microbial corrosion and scaling of the water injection well shaft 200 and realize the long-term green and efficient development of the oil field. The sterilization and descaling device 300 of the present application sets the cathode electrode 321 before the radiation sterilization device 330, which helps to slow down the scaling rate of the radiation sterilization device 330, helps to release radiation into the water, and ensures the sterilization efficiency of the radiation sterilization device 330. Through the setting of the protective member 340, the radiation sterilization device 330 is protected, making it more convenient to install and disassemble. The arrangement of the cleaning member 350 and the driving member 360 enables the protective member 340 of the sterilization and descaling device 300 of the present application to be cleaned online without shutting down the water injection system, thereby ensuring the sterilization performance of the sterilization and descaling device 300 of the present application and the water injection efficiency of the oilfield water injection system.

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

[0061] The oilfield oil layer water injection system of the present application first sterilizes and descales the water flow through the water treatment station 500, and then enters the sterilization and descaling device 300 for secondary sterilization and descaling after the water flow is discharged from the water injection transport pipe 100, which greatly reduces the amount of microorganisms and impurities flowing into the water injection well shaft 200, and to a certain extent avoids the technical problems of blockage and corrosion of the water injection well shaft 200. Since the oilfield oil layer water injection system adopts the sterilization and descaling device 300 provided by the present application, it naturally has all the beneficial effects of the sterilization and descaling device 300 of the present application, which will not be repeated here.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0063] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

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

Claims

1. A sterilization and descaling device, characterized in that: Installed between a water injection transport pipe (100) and a water injection well shaft (200) in an oil field, the water injection transport pipe (100) having a first water outlet (100b), the water injection well shaft (200) having a second water inlet (200a), the sterilization and descaling device comprising: The flow guide pipe (310) is provided with a third water inlet (310a) and a third water outlet (310b), wherein the third water inlet (310a) is used to communicate with the first water outlet (100b), and the third water outlet (310b) is used to communicate with the second water inlet (200a); An electrolytic component (320) comprises a cathode electrode (321), an anode electrode (322) and a power source (323), wherein the cathode electrode (321) and the anode electrode (322) are both electrically connected to the power source (323), and the cathode electrode (321) and the anode electrode (322) are both located in the flow guide tube (310), and the electrolytic component (320) is used for ion exchange, removal of scaling ions in the flow guide tube (310) and sterilization; The radiation sterilization device (330) is located in the flow guide tube (310) and is used to generate radiation for sterilization.

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

3. The sterilization and descaling device according to claim 1, characterized in that: The cathode electrode (321) and the anode electrode (322) are respectively located on the third water inlet (310a) side and the third water outlet (310b) side, and the radiation sterilization device (330) is located between the cathode electrode (321) and the anode electrode (322).

4. The sterilization and descaling device according to claim 1, characterized in that: The sterilization and descaling device further comprises a protective member (340), wherein the protective member (340) is located in the flow guide tube (310), the protective member (340) has an installation cavity (340a), and the radiation sterilization device (330) is located in the installation cavity (340a).

5. The sterilization and descaling device according to claim 4, characterized in that: The protective member (340) also has an installation opening (340b) connected to the installation cavity (340a); the protective member (340) is partially located in the flow guide tube (310); the installation opening (340b) is located outside the flow guide tube (310); the protective member (340) and the flow guide tube (310) are hermetically connected; the radiation sterilization device (330) is located in the installation cavity (340a) and in the flow guide tube (310) through the installation opening (340b).

6. The sterilization and descaling device according to claim 5, characterized in that: The flow guide pipe (310) comprises a first flow guide pipe (311), a second flow guide pipe (312) and a third flow guide pipe (313) which are connected in sequence; The third water inlet (310a) is arranged on the first flow guide pipe (311), the third water outlet (310b) is arranged on the third flow guide pipe (313), and the axis of the second flow guide pipe (312) is arranged at an angle to the axis of the first flow guide pipe (311) and the axis of the third flow guide pipe (313); The installation cavity (340a) is columnar and has two installation openings (340b). The two installation openings (340b) are arranged at two ends of the length direction of the installation cavity (340a). The length direction of the installation cavity (340a) is parallel to the axis of the second flow guide tube (312). The protective component (340) passes through both sides of the length direction of the first flow guide tube (311). The two installation openings (340b) are both located outside the second flow guide tube (312).

7. The sterilization and descaling device according to claim 6, characterized in that: The protective member (340) is located in the middle of the second flow guide pipe (312).

8. The sterilization and descaling device according to claim 7, characterized in that: The radiation sterilization device (330) is an ultraviolet lamp, the protective member (340) is a quartz glass tube, and the length of the lamp tube of the ultraviolet lamp is not less than the length of the second flow guide tube (312).

9. The sterilization and descaling device according to any one of claims 4 to 8, characterized in that: The sterilization and descaling device further comprises a cleaning member (350) and a driving member (360); the cleaning member (350) is sleeved outside the protective member (340) and contacts the protective member (340); the cleaning member (350) is transmission-connected to the driving member (360); the driving member (360) drives the cleaning member (350) to reciprocate along the protective member (340) so as to clean the outer surface of the protective member (340).

10. The sterilization and descaling device according to any one of claims 1 to 8, characterized in that: Electrode mounting holes (310c) are respectively provided on the third water inlet (310a) side and the third water outlet (310b) side of the flow guide tube (310); the cathode electrode (321) and the anode electrode (322) are located in the flow guide tube (310) through the electrode mounting holes (310c) and are detachably and hermetically connected to the electrode mounting holes (310c); A first connection portion (320a) for detachably connecting to a voltage-carrying pole-changing device (400) is provided on one side of the cathode electrode (321) and the anode electrode (322) facing outside the electrode mounting hole (310c), and a second connection portion (310d) for detachably connecting to a voltage-carrying pole-changing device (400) is also provided on the flow guide tube (310) next to the electrode mounting hole (310c).

11. An oilfield oil layer water injection system, characterized in that: include: The sterilization and descaling device (300), water treatment station (500), water injection transport pipe (100) and water injection well shaft (200) according to any one of claims 1 to 10; The water injection transport pipe (100) has a first water inlet (100a) and a first water outlet (100b), and the water injection well shaft (200) has a second water inlet (200a) and a second water outlet (200b). The water injection transport pipe (100) is connected to the water treatment station (500) via the first water inlet (100a), the first water outlet (100b) is connected to the third water inlet (310a) of the guide pipe (310), the third water outlet (310b) of the guide pipe (310) is connected to the second water inlet (200a) of the water injection well shaft (200), and the second water outlet (200b) of the water injection well shaft (200) is used to communicate with the oil layer.

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