Multifunctional well pipe with pop-up electrode

Abstract

The present application belongs to the technical field of contaminated site soil remediation, and is a multifunctional well pipe with pop-up electrodes. The technical scheme is as follows: the multifunctional well pipe comprises a well shaft assembly, an extension assembly and an electrode assembly. The core innovation lies in the pop-up electrode driving mechanism, which is different from the conventional fixed well pipe. The device is designed with a delicate "longitudinal driving to transverse extension" structure: a force transmission sleeve is sleeved outside the positioning pipe and can slide axially along the positioning pipe; two roller combination bases are fixedly connected on the force transmission sleeve 204. The electrode assembly is radially installed on the side wall through a return spring and a guide shaft, and the upper and lower tail parts of the electrode seat are provided with inclined blocks. The device solves the problems of the existing indoor contaminated soil fracturing remediation test device, such as function dispersion, the limitation of resistivity tomography detection range caused by the close contact between the fixed electrode and the well pipe, and the difficulty in the collaborative implementation of fracturing injection, multiphase extraction and resistivity detection on the same well pipe.

Description

Technical Field

[0001] This invention belongs to the field of soil remediation technology for contaminated sites, and specifically relates to a multifunctional well pipe equipped with a pop-out electrode. Background Technology

[0002] Soil and groundwater pollution seriously threatens public health and environmental safety, making the development of efficient remediation technologies for contaminated sites and the treatment of contaminated sites a crucial issue in environmental geotechnical engineering. Many in-situ remediation sites have experienced a rebound in pollutant concentrations, sometimes reaching hundreds of times the initial level, especially in low-permeability contaminated sites, where difficulties in material transport and removal of residual pollutants easily arise, leading to poor remediation results. Fracturing and permeation enhancement technology is considered an effective method to increase the permeability of low-permeability contaminated sites and improve remediation effectiveness in conjunction with other remediation technologies. Based on the different media used to expand existing fractures or create new fractures, it can be broadly divided into hydraulic fracturing and pneumatic fracturing technologies. However, currently, there is a lack of methods to address the problems of seat failure and injection-extraction coordination during fracturing. Developing well casings with functions such as high-pressure seat, gas-liquid fracturing, multiphase extraction, and oxidation injection is one way to solve this problem. Currently, well casings that meet all these functions have not yet been developed. Therefore, developing multifunctional well casings that match the conditions for fracturing and permeation enhancement and multiphase extraction in contaminated soil under loading is of great significance.

[0003] Currently, fracturing and permeability enhancement technology is widely used in the remediation of low-permeability contaminated sites. Its core principle is to create fractures in the soil by injecting a high-pressure medium (such as water or gas), thereby increasing permeability and enhancing subsequent remediation effects. However, in indoor model tests of this technology, traditional resistivity tomography (ERT) electrodes are typically fixed to the outer wall of the well casing. Because the electrodes are close to the casing, the penetration depth of the current field in the soil is limited, making it difficult to accurately capture fracture propagation and contaminant transport characteristics in areas far from the well casing, resulting in insufficient depth measurement. Furthermore, existing testing equipment often separates fracturing injection, contaminant extraction, and monitoring functions, requiring frequent equipment changes during testing. This makes it difficult to achieve integrated "fracturing-monitoring-extraction" operations and is prone to sealing failure.

[0004] Therefore, this invention is mainly applied to indoor model test scenarios for the synergistic remediation of contaminated soil by fracturing and permeability enhancement. Addressing the aforementioned technical challenges, particularly the limited detection range of the ERT electrodes on the pipe wall, it is crucial to develop a well pipe device that can flexibly change the electrode position according to experimental needs and integrate injection and extraction functions. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a multifunctional well casing equipped with pop-out electrodes. This addresses the issues of existing indoor contaminated soil fracturing repair test devices having dispersed functions, fixed electrodes tightly attached to the well casing resulting in limited resistivity tomography detection range, and the difficulty in coordinating fracturing injection, multiphase extraction, and resistivity detection on the same well casing.

[0006] The technical solution of the invention is: a multi-functional well pipe equipped with a pop-out electrode, comprising: a well barrel assembly, a telescopic assembly and an electrode assembly.

[0007] The wellbore assembly includes an outer cylinder, a lower end cap, an upper end cap, a positioning tube, a guide sleeve, and a series of through holes. The lower end cap and the upper end cap are fixed to both ends of the outer cylinder, and the positioning tube is positioned at the central axis inside the outer cylinder, with its lower end fixed to the lower end cap by screws. The upper end passes vertically through the upper end cap. Four series of through holes are evenly distributed along the circumference of the outer cylinder. Each series of through holes consists of multiple through holes arranged vertically and evenly along the same generatrix of the outer cylinder. The through holes penetrate the outer cylinder wall laterally. A transverse guide sleeve is fixed on the outer cylinder. The guide sleeve is positioned above and below each series of through holes.

[0008] The electrode assembly includes: a multi-functional well electrode, an electrode holder, a PTFE nut, a return spring, a guide shaft, an upper inclined block, and a lower inclined block. The electrode holder is elongated, and multiple electrodes are fixed to the electrode holder by PTFE nuts and move with the electrode holder as a whole to detect the resistivity at a fixed point, thereby reflecting changes in contaminant concentration. Each electrode is inserted into the through hole of the outer cylinder. The upper and lower inclined blocks are respectively located at both axial ends of the electrode holder. The electrode is positioned between the upper and lower inclined blocks. The guide shaft is fixed to both axial ends of the electrode holder, respectively facing away from the upper and lower inclined blocks. The transverse axis of the guide shaft is parallel to the axis of the electrode. The guide shaft slides through the guide sleeve. The return spring is sleeved on the outer circumference of the corresponding guide shaft and horizontally engaged between the inner wall of the outer cylinder and the electrode holder.

[0009] The telescopic assembly includes a roller assembly base, a force transmission sleeve, and a force transmission nut.

[0010] The force-transmitting sleeve is fitted over the positioning tube and can move axially up and down along the positioning tube; the force-transmitting sleeve passes upward through the upper end cover. The force-transmitting nut is connected to the upper end of the force-transmitting sleeve.

[0011] The roller assembly base is cross-shaped with a hole in the middle for fixing it to the outside of the force transmission sleeve, allowing it to move up and down with the force transmission sleeve. Roller seats are located at the four ends of the roller assembly base, each with a U-shaped notch. Rollers are mounted in the U-shaped notches of the roller seats via pins, allowing the rollers to rotate freely around the pins. The outer circumference of the rollers makes rolling contact with the inclined surfaces of the upper and lower inclined blocks, respectively. There are two roller assembly bases, respectively positioned at corresponding horizontal positions on the upper and lower inclined blocks.

[0012] Based on the above technical features: an insulating sleeve made of polytetrafluoroethylene is fixedly installed in each of the through holes, and the electrode passes through the corresponding insulating sleeve.

[0013] Based on the above technical features: the entire outer cylinder includes an upper section without through holes and a lower working section; the four columns of through holes are all arranged within the working section.

[0014] Based on the above technical features: the force-transmitting nut is fixed to the upper end of the force-transmitting sleeve by a thread, and the external linear drive mechanism applies axial driving force to the force-transmitting sleeve through the force-transmitting nut; the positioning tube is fixed, and the force-transmitting sleeve can slide axially relative to the positioning tube.

[0015] Based on the above technical features: one end of the reset spring is fixed to the electrode seat, and the other end is embedded in the spring positioning groove correspondingly provided on the inner wall of the outer cylinder, and abuts against the bottom of the spring positioning groove.

[0016] Based on the above technical features: an injection assembly is integrated inside the side wall of the outer cylinder, the injection assembly includes several extraction tubes and several injection tubes, the extraction tubes and the injection tubes are vertically embedded in the side wall of the outer cylinder, avoiding the through hole; the extraction tubes are longitudinally connected to multiple extraction injection holes, and the injection tubes are longitudinally connected to multiple injection injection holes; the extraction injection holes and the injection injection holes are arranged vertically and uniformly along the same generatrix of the outer cylinder, avoiding the through hole.

[0017] Based on the above technical features: there are four extraction tubes, and the extraction orifices connected to the extraction tubes form four rows, forming a 45° angle with the adjacent rows of through holes in the circumferential direction; the height of a single extraction orifice in each row is at the same axial height as the adjacent through hole; there are four injection tubes, respectively disposed between the extraction tubes and the rows of through holes, and the injection orifices connected to the injection tubes are disposed between two adjacent upper and lower through holes.

[0018] Based on the above technical features: the air-mounted connector is installed on the upper end cover to collect the signal lines of the electrodes inside the cylinder, and the signal lines are soldered to the pins on the back of the air-mounted connector.

[0019] This invention fills the gap in well casings required for simulating fracturing and permeability enhancement, multiphase extraction, and other working conditions in contaminated soil under loading. It integrates functions such as gas-liquid fracturing, multiphase extraction, and oxygen injection. The injection pipe delivers fracturing gas, fracturing fluid, or remediation agents to the contaminated soil sample unit through an injection perforation connected to it, to form fractures or inject agents. When oxygen injection is required, the injection pipe connects to an external oxygen supply device, and oxygen enters the contaminated soil sample unit through the injection pipe and the injection perforation connected to it, providing an oxygen source for aerobic microorganisms in the soil to promote the biodegradation of pollutants. The extraction pipe extracts gaseous, liquid, and non-aqueous liquid pollutants from the soil through an extraction perforation connected to it under the action of an external negative pressure device. The electrode follows... The corresponding electrode holder extends out of the outer cylinder and enters the surrounding soil. An external resistivity tomography system is used to perform detection before, during, or after the test as needed, thus solving the problem of insufficient depth measurement in existing pipe wall resistivity tomography. This multifunctional well pipe can realize fracturing and permeation enhancement, multiphase extraction, and resistivity tomography detection of contaminated soil. It solves the problem of injection-extraction coordination during fracturing, enhances the treatment capacity of contaminated soil, and strongly promotes the research process of simulating working conditions such as fracturing and permeation enhancement and multiphase extraction of contaminated soil under loading.

[0020] To address the problem of insufficient depth measurement by fixed electrodes in existing technologies, this invention designs a "wedge-roller" mechanical linkage structure. Unlike conventional well casings that only serve as support structures, the well casing of this invention endows the electrode with the ability to dynamically extend and retract. By controlling the sliding of the force transmission sleeve on the positioning tube, the roller slides on the wedge, causing the upper and lower sets of rollers to act simultaneously on the wedges at both ends of the electrode seat axially, thereby controlling the ejection of the electrode. After ejection, the electrode can penetrate deep into the soil for in-situ monitoring, effectively solving the problem of insufficient depth measurement in conventional pipe wall resistivity tomography, and significantly improving data accuracy and effective detection range.

[0021] Meanwhile, this invention changes the traditional method of requiring multiple separate pipelines for testing. Within the limited wall thickness of the outer cylinder, it integrates extraction tubes, injection tubes, and multiple rows of retractable electrodes, achieving integrated functions of gas-liquid fracturing injection, multiphase contaminant extraction, and real-time resistivity tomography monitoring. This compact design avoids the cumbersome process of frequently changing pipelines and equipment in traditional experiments, meeting the requirements for high-pressure fracturing fluid injection and multiphase contaminant extraction while ensuring the online operation of real-time monitoring, greatly simplifying the experimental process.

[0022] To address the risks of electrical leakage and seepage in well casings with electrodes, this invention incorporates an insulating sleeve made of polytetrafluoroethylene (PTFE) at each through-hole. This ensures electrical insulation between the electrode and the metal outer cylinder, reducing the risk of electrode signals being interfered with by the metal cylinder or experiencing electrical leakage. It also ensures strict isolation between the internal circuitry and mechanical transmission areas of the well casing and the external soil fluid area under high-pressure injection conditions, guaranteeing the long-term operational stability of the equipment. Attached Figure Description

[0023] Figure 1 This is a three-dimensional cross-sectional structural diagram of the multifunctional well casing in this embodiment.

[0024] Figure 2 This is a schematic diagram of the multifunctional well casing structure in this embodiment.

[0025] Figure 3 This is a schematic diagram of the multi-functional well pipe telescopic structure in this embodiment.

[0026] Figure 4 This is a schematic diagram of the multifunctional well casing electrode structure in this embodiment.

[0027] Figure 5 This is a schematic diagram of the multifunctional well casing injection structure provided in this embodiment.

[0028] Figure 6 This is a schematic diagram showing the arrangement of the extraction tubes in the outer cylinder.

[0029] Figure 7 This is a schematic diagram showing the arrangement of the injection pipe in the outer cylinder.

[0030] Figure 8 This is a partial cross-sectional view of the multifunctional well casing provided in this embodiment.

[0031] Figure 9 This is a schematic diagram illustrating the working principle of the telescopic component provided in this embodiment when it is in the retracted state.

[0032] Figure 10 This is a schematic diagram illustrating the working principle of the telescopic component provided in this embodiment when it is in the pop-up state.

[0033] Figure 11 This is a cross-sectional view of the upper cover plate provided in this embodiment.

[0034] Figure 12 This is a top view of the top cover plate provided in this embodiment.

[0035] Figure label: Wellbore assembly 1, outer cylinder 101, lower end cover 102, upper end cover 103, insulating sleeve 104, positioning tube 105, guide sleeve 106 and through hole 107; Telescopic component 2, roller 201, pin 202, roller seat 203, force transmission sleeve 204, force transmission nut 205; Electrode assembly 3, electrode 301, electrode seat 302, PTFE nut 303, return spring 304, guide shaft 305, upper inclined block 306, lower inclined block 307; The injection assembly 4 includes an extraction tube 108, an extraction perforation 1081, an injection tube 109, an injection perforation 1091, and a transition tube 1092. Aircraft insertion unit 5, contaminated soil sample unit 6, loading top plate 7. Detailed Implementation

[0036] Combination Figures 1 to 12 This invention provides a multifunctional well casing equipped with a pop-out electrode to address the problem of insufficient depth measurement in well casing resistivity tomography. Its core innovation lies in its pop-out electrode driving mechanism. Unlike conventional fixed well casings, this device features a sophisticated "longitudinal drive to lateral telescopic" structure: a force-transmitting sleeve 204 is fitted around the outside of the positioning tube 105 and can slide axially along the positioning tube 105; two roller combination bases are fixedly connected to the force-transmitting sleeve 204. The electrode assembly 3 is radially mounted on the side wall via a return spring 304 and a guide shaft 305, and the upper and lower tails of the electrode seat 302 are equipped with inclined blocks.

[0037] When the detection range needs to be expanded, the operator controls the external linear drive mechanism to push the force transmission sleeve 204 downward through the force transmission nut 205. At this time, the roller 201 acts as a force-applying component, moving axially and pressing the upper inclined block 306 and the lower inclined block 307. Utilizing the inclined plane transmission principle, the vertical driving force is converted into a lateral thrust, overcoming the resistance of the return spring 304 and forcing the electrode 301 to pop outward along the through hole 107 and penetrate deep into the surrounding soil. When the external linear drive mechanism is controlled to move the force transmission nut 205 in the opposite direction, causing the roller 201 to disengage from the upper inclined block 306 and the lower inclined block 307, the electrode 301 automatically retracts back into the through hole 107 under the restoring force of the return spring 304.

[0038] This design not only significantly expands the detection radius of resistivity tomography without compromising the overall sealing of the well casing, but also cleverly utilizes the internal space, avoiding redundancy in the external mechanical structure.

[0039] The technical solutions provided in this application will be further described below with reference to specific embodiments and accompanying drawings. The advantages and features of this application will become clearer from the following description.

[0040] Example: The multifunctional well casing with a pop-out electrode used in this embodiment to address the problem of insufficient depth measurement in tubing wall resistivity tomography includes the following structural components: like Figure 1 and Figure 12As shown, a multi-functional well casing equipped with a pop-out electrode includes a well casing assembly 1, a telescopic assembly 2, an electrode assembly 3, and an injection assembly 4 (see...). Figure 12 ) and Hangtuo 5 (see Figure 12 ).

[0041] like Figure 2 As shown, the wellbore assembly 1 includes an outer cylinder 101, a lower end cap 102, an upper end cap 103, an insulating sleeve 104, a positioning tube 105, a guide sleeve 106, and a through hole 107.

[0042] The lower end cap 102 and the upper end cap 103 are respectively fixed to both ends of the outer cylinder 101. The positioning tube 105 is positioned at the central axis inside the outer cylinder 101, with its lower end fixed to the lower end cap 102 by screws; its upper end passes vertically through the upper end cap 103; four through holes are evenly distributed along the circumference of the outer cylinder 101 (e.g., ...). Figure 5 (As shown); each longitudinal row of through holes consists of multiple through holes 107 arranged in a straight line and evenly distributed vertically along the same generatrix of the outer cylinder 101; the through holes 107 penetrate the cylinder wall of the outer cylinder 101 laterally, and the through holes 107 must be deburred.

[0043] The entire outer cylinder 101 includes an upper section without through holes and a lower working section; four rows of through holes are all arranged in the working section.

[0044] The outer cylinder 101 has a guide sleeve 106 fixed at each end of the axial direction of the four longitudinal rows of through holes, for a total of eight guide sleeves 106. Each group of electrode assemblies 3 corresponds to two guide sleeves 106. The guide sleeves 106 are fixed to the outer cylinder 101. The guide shafts 305 are respectively inserted into the corresponding guide sleeves 106 and slide with them; when the electrode seat 302 moves radially, the guide shafts 305 slide synchronously in the corresponding guide sleeves 106 to guide and position the radial movement of the electrode seat 302 (e.g., ...). Figure 9 and Figure 10 (As shown).

[0045] An insulating sleeve 104 made of polytetrafluoroethylene is fixed at each through hole 107. The electrode 301 passes through the corresponding insulating sleeve 104 so that the electrode 301 is electrically insulated from the metal outer cylinder 101.

[0046] like Figure 3 , Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the telescopic assembly 2 includes a roller assembly base, a force transmission sleeve 204, and a force transmission nut 205.

[0047] The force transmission sleeve 204 is fitted outside the positioning tube 105 and can move axially up and down along the positioning tube 105; the force transmission sleeve 204 passes upward through the upper end cover 103.

[0048] The roller assembly base is cross-shaped with a hole in the middle, and is fixed to the outside of the force transmission sleeve 204, allowing it to move up and down with the force transmission sleeve 204. Roller seats 203 are provided at the four ends of the roller assembly base. The roller seats 203 have U-shaped notches, and the rollers 201 are installed in the U-shaped notches of the roller seats 203 through pins 202. The rollers 201 can rotate freely around the horizontal pins 202. The outer circle of the rollers 201 makes rolling contact with the inclined surfaces of the upper inclined block 306 and the lower inclined block 307, respectively. The extension and retraction of the electrode 301 is achieved by the sliding of the rollers 201 on the upper inclined block 306 and the lower inclined block 307.

[0049] There are two roller assembly bases, which are respectively set at the corresponding horizontal positions of the upper inclined block 306 and the lower inclined block 307.

[0050] like Figure 11 As shown, the force-transmitting nut 205 is threadedly fixed to the upper end of the force-transmitting sleeve 204, and there is no threaded connection between the force-transmitting nut 205 and the positioning tube 105. For ease of installation, the positioning tube 105 has a retractable cross-section at the top. When the external linear drive mechanism acts on the force-transmitting nut 205, the force-transmitting nut 205 drives the force-transmitting sleeve 204 to move axially relative to the positioning tube 105. An annular clearance step is provided around the center hole of the upper end cover 103. This annular clearance step is used to reserve assembly and axial movement space for the force-transmitting sleeve 204, avoiding interference between the force-transmitting sleeve 204 and the upper end cover 103 during movement. This annular clearance step does not form a threaded connection with the positioning tube 105 or the force-transmitting nut 205, nor does it bear any force transmission function.

[0051] like Figure 4 As shown, the electrode assembly 3 includes a multi-functional well electrode 301, an electrode holder 302, a PTFE nut 303, a return spring 304, a guide shaft 305, an upper inclined block 306, and a lower inclined block 307. The electrode holder 302 is elongated, and multiple electrodes 301 are fixed to the electrode holder 302 by the PTFE nut 303 and move as a whole with the electrode holder 302 to detect the resistivity at a fixed point, thereby reflecting the change in pollutant concentration. Each electrode 301 is inserted into the through hole 107 of the outer cylinder 101. The upper inclined block 306 and the lower inclined block 307 are respectively disposed at both axial ends of the electrode holder 302. The electrode 301 is disposed between the upper inclined block 306 and the lower inclined block 307. The guide shaft 305 is fixed to both axial ends of the electrode holder 302, respectively facing away from the upper inclined block 306 and the lower inclined block 307. The guide shaft 305 and the electrode 301 are both arranged radially along the outer cylinder 101. Figure 9 and Figure 10As shown, the guide shaft 305 slides within the guide sleeve 106 to constrain the sway, rotation, and axial and circumferential movement of the electrode seat 302, ensuring the electrode seat 302 maintains radial translation. Return springs 304 are respectively sleeved on the outer periphery of the corresponding guide shaft 305, positioned between the inner wall of the outer cylinder 101 and the electrode seat 302. Furthermore, one end of the return spring 304 is fixed to the electrode seat 302, and the other end is embedded in a corresponding spring positioning groove on the inner wall of the outer cylinder 101, abutting against the bottom of the groove. The function of the return spring 304 is to drive the electrode seat 302 and the entire electrode 301 to return radially inward when the force transmission sleeve 204 moves upward.

[0052] like Figure 5 , Figure 6 , Figure 7 and Figure 12 As shown, an injection assembly 4 is integrated within the side wall of the outer cylinder 101. The injection assembly 4 includes several extraction tubes 108 and several injection tubes 109. The extraction tubes 108 and injection tubes 109 are vertically embedded within the side wall of the outer cylinder 101, avoiding the through hole 107. The extraction tubes 108 are longitudinally connected to multiple extraction injection holes 1081, and the injection tubes 109 are longitudinally connected to multiple injection injection holes 1091. The extraction injection holes 1081 and injection injection holes 1091 are arranged vertically and uniformly along the same generatrix of the outer cylinder 101, avoiding the through hole 107.

[0053] As an optimization, there are four extraction tubes 108, and four rows of extraction perforations 1081 connected to the extraction tubes 108, forming a 45° angle with the adjacent rows of through holes in the circumferential direction. The height of a single extraction perforation 1081 in each row is at the same axial height as the adjacent through hole 107. There are four injection tubes 109, which are respectively arranged between the extraction tubes 108 and the rows of through holes. The injection perforations 1091 connected to the injection tubes 109 are arranged between two adjacent upper and lower through holes 107, that is, in the generatrix direction of the rows of through holes, the injection perforations 1091 and the through holes 107 are arranged alternately. The advantage of this arrangement is mainly that it forms an alternating arrangement of injection and detection positions, which can reduce the direct impact of the injection structure on electrode installation and detection.

[0054] The injection pipe (109) is connected to the injection perforation (1091) through the transition pipe (1092), and the transition pipe (1092) is located inside the side wall of the outer cylinder (101).

[0055] The injection tube 109 is used to connect to an external gas or liquid delivery device to inject fracturing gas, fracturing fluid or repair agents and other gas-liquid media. The extraction tube 108 is used to connect to an external negative pressure device to extract gaseous pollutants, liquid pollutants and non-aqueous liquid pollutants from the contaminated soil sample through the extraction perforation.

[0056] like Figure 11 and Figure 12 As shown, the aerial plug 5 is located on the upper end cover 103 and is used to collect the signal lines of the electrodes 301 inside the cylinder. The signal lines are soldered to the pins on the back of the aerial plug 5. During the test, simply twist the matching cable of the external resistivity tomography data acquisition system onto the aerial plug 5 to achieve stable and interference-resistant transmission of multiple detection signals.

[0057] The workflow of a multi-functional well casing equipped with a pop-out electrode in this embodiment involves the following steps: Step 1: As Figure 8 As shown, the multi-functional well pipe is pre-placed at the center of the indoor test model box, and then contaminated soil is filled into the model box to create contaminated soil sample unit 6. By applying pressure to the top plate 7, the corresponding consolidation stress is applied to the contaminated soil sample unit 6.

[0058] Step 2: After the consolidation process is completed, a matching device that can deliver fracturing fluid, repair agents and other gas-liquid media under high pressure is connected to the nozzle of the injection pipe 109. This device will inject the gas-liquid media into the contaminated soil sample unit 6 through the injection hole 1091 reserved on the side wall of the outer cylinder 101 under the set pressure.

[0059] Step 3: Before the remediation experiment begins, the force transmission sleeve 204 in the telescopic assembly 2 is pushed downwards by the external linear drive mechanism. Using the inclined plane transmission, the electrode 301 for the multi-functional well is laterally ejected and inserted into the soil to measure the concentration of pollutants in the contaminated soil sample unit. Before the extraction test begins, the force transmission sleeve 204 is pulled in the opposite direction, causing the electrode 301 to retract back into the outer cylinder 101 for protection under the restoring force of the return spring 304. Subsequently, a device providing vacuum negative pressure is connected to the nozzle of the extraction tube 108. This device extracts gaseous, liquid, and non-aqueous liquid pollutants from the contaminated soil sample unit according to a pre-set negative pressure. Further purification is then performed using subsequent gas-liquid separation devices and exhaust gas / liquid post-treatment purification devices.

[0060] Step 4: After the extraction test is completed, connect a matching device that can deliver the agent under high pressure to the nozzle of the injection pipe 109. This device will inject the agent into the contaminated soil sample unit through the injection hole 1091 under a predetermined pressure to carry out the oxidation degradation test of the remaining multiphase pollutants.

[0061] Step 5: After the repair test is completed, the electrode 301 is popped out by controlling the movement of the telescopic component 2 in the cylinder. The concentration of pollutants after treatment is detected by measuring the resistivity at the fixed point of the electrode 301, and the repair effect is evaluated.

[0062] When the system does not receive an action command, the mechanism is in the normal retracted position, such as... Figure 9As shown, in this initial state, the force transmission sleeve 204 is in an undriven position, the external driving source does not apply force to the force transmission sleeve 204, the roller 201 has not yet contacted the lower inclined surface or only maintains slight contact, and does not apply effective squeezing force to the upper inclined block 306 and the lower inclined block 307; under the action of the return spring 304, the upper inclined block 306 and the lower inclined block 307 are pressed to the outermost limit position, so that the electrode (301) retracts to the predetermined position relative to the pop-up state; at this time, the main body of the electrode (301) is located inside the outer cylinder (101), but the electrode tip still extends a certain distance out of the outer cylinder (101) through the through hole (107), and the electrode (301) is in the retracted state.

[0063] When testing is required, the mechanism performs a pop-up action, such as... Figure 10 As shown, the external drive source drives the force transmission nut 205 and drives the force transmission sleeve 204 to move axially along the positioning tube 105. The roller 201 then engages with the inclined surfaces of the upper inclined block 306 and the lower inclined block 307. Utilizing the force decomposition and guiding principle of the inclined surface mechanism, the vertically downward driving force is converted into a horizontal rightward lateral thrust, which pushes the electrode 301 to extend outward along the guide shaft 305 and pass through the through hole 107 into the surrounding soil.

[0064] After the drive is released, the electrode 301 retracts into the outer cylinder 101 under the action of the reset spring 304.

[0065] Figure 9 and Figure 10 The diagram shows the motion of the upper roller assembly base. The lower roller assembly base operates on the same principle as the upper one, so it is not shown separately.

[0066] To clearly illustrate the specific location of guide shaft 305, Figure 9 The diagram of the external return spring 304 is omitted on the right side.

[0067] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can make various modifications and variations to these embodiments, and can apply the general principles set forth herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the principles of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A multifunctional well casing equipped with a pop-out electrode, characterized in that: The multi-functional well casing includes a well casing assembly (1), a telescopic assembly (2), and an electrode assembly (3). The wellbore assembly (1) includes an outer cylinder (101), a lower end cap (102), an upper end cap (103), a positioning tube (105), a guide sleeve (106), and a series of through holes; the lower end cap (102) and the upper end cap (103) are respectively fixed to the two ends of the outer cylinder (101), and the positioning tube (105) is positioned at the central axis inside the outer cylinder (101), with its lower end fixed to the lower end cap (102) by screws; the upper end passes vertically through the upper end cap (103). 03); Four rows of through holes are evenly distributed along the circumference of the outer cylinder (101); each row of through holes consists of multiple through holes (107) arranged vertically and evenly along the same generatrix of the outer cylinder (101); the through holes (107) penetrate the cylinder wall of the outer cylinder (101) laterally; a transverse guide sleeve (106) is fixed on the outer cylinder (101); the guide sleeve (106) is set above and below each row of through holes; The electrode assembly (3) includes: a multi-functional well electrode (301), an electrode holder (302), a PTFE nut (303), a return spring (304), a guide shaft (305), an upper inclined block (306), and a lower inclined block (307); the electrode holder (302) is elongated, and multiple electrodes (301) are fixed on the electrode holder (302) by PTFE nuts (303) and move as a whole with the electrode holder (302) to detect the resistivity at a fixed point, thereby reflecting the change in pollutant concentration; each electrode (301) is inserted into the through hole (107) of the outer cylinder (101); the upper inclined block (306) and the lower inclined block (307) are respectively provided with The electrode (301) is placed at both ends of the electrode base (302); the electrode (301) is disposed between the upper inclined block (306) and the lower inclined block (307); the guide shaft (305) is fixed at both ends of the electrode base (302), respectively facing away from the upper inclined block (306) and the lower inclined block (307); the transverse axis of the guide shaft (305) is parallel to the axis of the electrode (301); the guide shaft (305) is slidably fitted inside the guide sleeve (106); the return spring (304) is respectively sleeved on the outer periphery of the corresponding guide shaft (305), and is disposed radially along the outer cylinder (101) between the inner wall of the outer cylinder (101) and the electrode base (302); The telescopic assembly (2) includes a roller assembly base, a force transmission sleeve (204), and a force transmission nut (205). The force transmission sleeve (204) is sleeved outside the positioning tube (105) and can move axially up and down along the positioning tube (105); the force transmission sleeve (204) passes upward through the upper end cover (103); the force transmission nut (205) is connected to the upper end of the force transmission sleeve (204); The roller assembly base is cross-shaped, with a hole in the middle for fixing it to the outside of the force transmission sleeve (204), and can move up and down with the force transmission sleeve (204); roller seats (203) are provided at the four ends of the roller assembly base, and the roller seats (203) have U-shaped notches. The rollers (201) are installed in the U-shaped notches of the roller seats (203) through pins (202), and the rollers (201) can rotate freely around the pins (202); the outer circle of the rollers (201) makes rolling contact with the inclined surfaces of the upper inclined block (306) and the lower inclined block (307) respectively; there are two roller assembly bases, which are respectively set at the corresponding horizontal positions of the upper inclined block (306) and the lower inclined block (307).

2. The multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: An insulating sleeve (104) made of polytetrafluoroethylene is fixedly installed in each of the through holes (107), and the electrode (301) passes through the corresponding insulating sleeve (104).

3. The multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: The entire outer cylinder (101) includes an upper section without through holes and a lower working section; the four columns of through holes are all arranged in the working section.

4. A multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: The force-transmitting nut (205) is fixed to the upper end of the force-transmitting sleeve (204) by threads. The external linear drive mechanism applies axial driving force to the force-transmitting sleeve (204) through the force-transmitting nut (205). The positioning tube (105) is fixed, and the force-transmitting sleeve (204) can slide axially relative to the positioning tube (105).

5. A multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: One end of the reset spring (304) is fixed to the electrode seat (302), and the other end is embedded in the spring positioning groove correspondingly provided on the inner wall of the outer cylinder (101) and abuts against the bottom of the spring positioning groove.

6. A multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: The outer cylinder (101) integrates an injection assembly (4) within its side wall. The injection assembly (4) includes several extraction tubes (108) and several injection tubes (109). The extraction tubes (108) and the injection tubes (109) are vertically embedded within the side wall of the outer cylinder (101), avoiding the through hole (107). The extraction tubes (108) are longitudinally connected to multiple extraction injection holes (1081), and the injection tubes (109) are longitudinally connected to multiple injection injection holes (1091). The extraction injection holes (1081) and the injection injection holes (1091) are arranged vertically and uniformly along the same generatrix of the outer cylinder (101), avoiding the through hole (107).

7. A multifunctional well casing with a pop-out electrode according to claim 6, characterized in that: There are four extraction tubes (108), and the extraction nozzles (1081) connected to the extraction tubes (108) form four rows, which are at a 45° angle to the adjacent rows of through holes in the circumferential direction; the height of a single extraction nozzle (1081) in each row is at the same axial height as the adjacent through hole (107); there are four injection tubes (109), which are respectively arranged between the extraction tubes (108) and the rows of through holes, and the injection nozzles (1091) connected to the injection tubes (109) are arranged between two adjacent upper and lower through holes (107).

8. A multifunctional well casing with a pop-out electrode according to claim 1, characterized in that: The connector (5) is located on the upper end cover (103) and is used to collect the signal lines of the electrode (301) inside the cylinder. The signal lines are soldered to the pins on the back of the connector (5).

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