Soil pollution monitoring device and method for buried oil pipeline in oil depot

Abstract

The invention provides a device and a method for monitoring soil pollution of a buried oil pipeline in an oil depot, the monitoring device comprises a leakage monitoring device, the leakage monitoring device comprises a sleeve, a support and a leakage collector, and the sleeve is used for sleeving the oil pipeline; the support is used for being installed above a pipeline in a supporting mode. The leakage collector is used for collecting liquid leaked from the buried oil pipeline in the warehouse, further, the monitoring method of the monitoring device is provided, the sensing electrode is used for conducting the conductive channel after the leaked oil is soaked, the pipeline leakage is judged through the current change of the current sensor, and then the monitoring of the pipeline leakage is achieved. The oil depot monitoring device has the advantages of being easy to implement and high in monitoring reliability, through arrangement of the device, automatic monitoring of the interior of the oil depot is achieved, the monitoring speed is increased, and then the monitoring reliability is guaranteed.

Description

[Technical field]

[0001] The present invention relates to a monitoring device and method, and in particular to a soil pollution monitoring device and method for an underground oil pipeline in an oil depot. [Background Technology]

[0002] Oil pipelines in oil depots often need to be buried or crossed in important areas such as roads, railways, highways, and oil tank areas, oil pump rooms (sheds), automobile oil platforms, and railway trestles. Therefore, buried oil pipelines are one of the ways of transporting oil pipelines in finished oil depots and an important part of oil pipeline transportation. However, buried oil pipeline transportation is affected by engineering construction standards, engineering construction quality, soil burial concealment, long pipeline lines, complex operating conditions, and third parties. The probability of accidents is relatively high. Therefore, it is necessary to establish and improve the buried oil pipeline early warning system in the oil depot to protect the operating pipelines. According to the early warning principle, the buried oil pipeline early warning system is mainly divided into an evaluation and early warning method based on mathematical models and an evaluation and early warning method based on data-driven. Among them, the evaluation and early warning method based on data-driven requires a long time series of pipeline operation data for analysis. The early warning analysis of buried oil pipelines in oil depots needs to have high prediction accuracy and strong fault tolerance.

[0003] The buried oil pipeline in the oil depot is directly buried underground, so it is not easy to be discovered after a leak, and it is difficult to repair. It requires special operations such as groundbreaking, temporary electricity, and fire, which are prone to serious safety hazards. In the prior art, the soil near the oil depot is directly monitored, but its monitoring range is large, and the location of the leak cannot be determined. It is impossible to monitor the buried oil pipeline in the oil depot, and it is impossible to detect pipeline leaks in time, resulting in the inability to quickly repair the pipeline and deal with the leak, which is easy to cause sudden environmental incidents. The buried oil pipeline in the oil depot usually adopts the method of daily inspection by personnel, relying on personnel to check whether there are oil stains on the pipeline ground and whether there are oil spots in the drainage system to determine whether the buried oil pipeline is leaking. However, there are three problems with manual inspection: (1) High labor intensity: Since the buried oil pipeline is buried below the ground, once a suspected leakage is found, a large area of ​​the ground needs to be dug up for inspection one by one, which makes it impossible to accurately find the leakage point of the buried pipeline, and the labor intensity is high; (2) High missed detection rate: On the one hand, the manual inspection method is highly subjective and easily affected by responsibility, external environment, and weather. For example, when the weather is hot, the groundwater level is low, and there is no heavy rainfall, the oil leaked from the buried oil pipeline cannot float to the ground in time or cannot flow from the soil to the underground drainage system for discharge. On the other hand, it is impossible for manual inspection to be carried out on site at all times, so missed detection may occur. Moreover, due to the late discovery time, by the time oil stains, oil smell, oil spots, etc. are found on the ground or in the drainage system, the leakage has already formed a large scale; (3) The leakage has already formed a scale when it is discovered: Depending on the size of the leak point, some small leaks need to be discovered after the leakage forms a scale, and the buried oil pipeline leakage cannot be discovered in the first time.

[0004] The pipeline leakage monitoring device is used to warn the pressure and oil volume in the pipeline, but its warning point is inside the pipeline, and it cannot monitor the soil pollution caused by the rupture of the buried oil pipeline. Therefore, it is necessary to design a monitoring device that can directly monitor soil pollution and then monitor whether the buried oil pipeline is leaking. [Summary of the invention]

[0005] The technical problem to be solved by the present invention is to provide a soil pollution monitoring device and method for an underground oil pipeline in an oil depot in view of the deficiencies in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a soil pollution monitoring device for an underground oil pipeline in an oil depot, the monitoring device comprising a leakage monitoring device, the leakage monitoring device comprising a casing, a bracket and a leakage collector, the casing is used to be sleeved outside the oil pipeline; the bracket is used to support and install above the pipeline; the leakage collector is used to collect liquid leaked from the pipeline; the leakage collector comprises a shell, a liquid sensing chamber, a liquid guide hole, a drainage pipe, a sealing valve, a first contact head, a second contact head, a sensor, a first sensing electrode, a second sensing electrode, a grounding electrode and soil.

[0007] Furthermore, the shell is mounted on a bracket, the oil pipeline is located inside the shell, the liquid guide hole is arranged on a side wall of the shell, the oil pipeline is connected to the drainage pipe through the liquid guide hole, and the sensing chamber is arranged at the bottom of the shell.

[0008] Furthermore, one end of the drainage tube is connected to the liquid guide hole, and the other end is connected to the upper part of the sensing chamber, a sealing valve is provided at the upper part of the sensing chamber, and a sensing electrode 1 is provided at the bottom of the sensing chamber; the first contact head is located inside the sensing chamber, the second contact head is located outside the sensing chamber, the first contact head is connected to the sensing electrode 2, the sensing electrode 2 is connected to the sensing electrode 1 through a wire, the sensor is arranged outside the sensing chamber, the sensor is connected to the sensing electrode 1 through a wire, and the grounding electrode is arranged on the outer shell wall of the leakage collector and is in contact with the soil.

[0009] Furthermore, a drainage tube is provided on the inner wall of the shell, one end of which is connected to the sensing chamber, and the other end is connected to the liquid guide hole. A grounding electrode is provided on the outer wall of the sleeve, and the sleeve is connected to the shell of the leakage collector through a grounding wire, so that the sleeve, the leakage collector shell, the grounding wire, and the grounding electrode are connected to form an induction loop; when the pipeline leaks, the oil opens the drainage tube, and the leaked liquid enters the sensing chamber through the drainage tube, and connects the liquid conductive sensing electrode 1 and the sensing electrode 2 in the sensing chamber, and the leakage monitoring device detects the current and reports the pipeline fault point.

[0010] On the other hand, the present invention provides a method for monitoring soil pollution of an underground oil pipeline in an oil depot, and the specific steps are as follows: a. Setting a monitoring device: setting the monitoring device as described above, and sleeve the casing outside the oil pipeline for pipe laying; b. Measuring initial parameters: measuring the current and resistance value of the leakage monitoring device in the initial state by the monitoring device, and taking the resistance value as the initial resistance value; c. Monitoring the oil pipeline: when the oil pipeline leaks, the casing sleeved on the pipeline is grounded, the sensing electrode 1 is connected to the sensing electrode 2, and the data measured by the sensor is compared with the initial resistance value. When the resistance value changes within a range of 3%, it is determined that the oil pipeline is leaking, and the position is calibrated.

[0011] Furthermore, the oil leakage detection process in step c is as follows: 1) When the internal pressure of the oil pipeline changes, the contact resistance between the ground electrode and the soil changes, and the resistance of the leakage monitoring device in the initial state is measured by a sensor. When the resistance value is 0.5-1.0MΩ, the resistance value is collected by a testing device as the initial resistance value; 2) When the oil pipeline leaks, the leaked liquid enters the soil layer between the oil pipeline and the casing, and gradually flows upward, and contacts and forms a liquid channel between the sensing electrode 1 and the sensing electrode 2; 3) When the liquid channel is connected, the sensing electrode 1 and the sensing electrode 2 are connected through the liquid, and then the current is transferred from the sensing electrode 1 to the sensing electrode 2; 4) When the current measured by the sensor is 10-40mA, it is judged that the pipeline has a leak and an alarm is issued; 5) The leakage collection device is dug up, and it is determined that the actual location of the pipeline is consistent with the alarm location, and the pipeline is repaired; if it is inconsistent, the alarm is continued until the location is consistent.

[0012] Further, the step b specifically includes the following steps: S1, digging the soil layer between the sensing electrode 1 and the sensing electrode 2, taking out the sensing electrode 1 and the sensing electrode 2, washing them with pure water, and wrapping them with waterproof insulating tape, each circle is 0.5 cm apart, ensuring that the waterproof insulating tape is in contact with the grounding electrode; S2, inserting one end of the sensing electrode 24, connecting it with the wire, and checking whether it is closed, and installing the sensing electrode 2 into the shell, and ensuring that the bottom of the sensing electrode 2 is located 2-5 cm above the sensing electrode 1; S3, closing the sensing chamber, wrapping it with waterproof insulating tape 2-3 times, each circle is 0.5 cm apart, ensuring that the waterproof insulating tape is in contact with the grounding electrode, and sealing it through the sealing valve; S4, installing the shell on the bracket, and checking whether the sealing valve is closed; S5, moving the bracket to the position 25-4m away from the next bracket, and repeating the above steps S2-S4; S6, digging the lower end of the casing, taking out the grounding electrode, and connecting it through the grounding wire; S7, burying the soil so that the casing, the bracket and the leakage collector are buried at a depth of 2m.

[0013] Further, the step c specifically includes the following steps: SS1, measuring the above step b for each oil pipeline in the oil depot in turn, and recording the resistance values ​​of all pipelines as the initial resistance value; SS2, recording the resistance value every 3 months; SS3, taking the resistance value as the current change rate and recording it, when the current change rate exceeds 12%, an alarm is sounded, and the soil between the sensing electrode 1 and the sensing electrode 2 is dug to check whether the pipeline is damaged; SS4, if the pipeline is not damaged, continue to monitor and re-landfill; SS5, if the pipeline is damaged, determine the damaged position by the casing position, and repair it at the position; in the step SS2, recording the resistance value every 6 months; taking the resistance value as the current change rate and recording it, when the current change rate exceeds 13%, an alarm is sounded, and the soil between the sensing electrode 1 and the sensing electrode 2 is dug to check whether the pipeline is damaged; SS3, if the pipeline is not damaged, continue to monitor and re-landfill; SS4, if the pipeline is damaged, determine the damaged position by the casing position, and repair it at the position.

[0014] Compared with the prior art, the specific technical effects of the present invention are as follows:

[0015] The soil pollution monitoring device for an underground oil pipeline in an oil depot of the present invention uses an induction electrode to conduct a conductive channel after being soaked in leaking oil, and judges pipeline leakage through the current change of a current sensor, thereby realizing monitoring of pipeline leakage. It has the characteristics of simple implementation and high monitoring reliability. Through the setting of the device, automatic monitoring of the oil depot is realized, the monitoring speed is improved, and the reliability of supervision is guaranteed. [Drawings]

[0016] Figure 1 It is a schematic diagram of a soil pollution monitoring device for an underground oil pipeline in an oil depot according to an embodiment of the present invention.

[0017] Figure 2 It is a schematic cross-sectional view of a soil pollution monitoring device for an underground oil pipeline in an oil depot according to an embodiment of the present invention.

[0018] Figure 3 This is a flow chart of a method for monitoring soil pollution in an underground oil pipeline in an oil depot according to an embodiment of the present invention.

[0019] Among them, there are leakage collector 1, shell 10, oil pipeline 11, liquid sensing chamber 12, casing 13, liquid guide hole 14, drainage tube 15, sealing valve 16, grounding electrode 17, first contact head 18, second contact head 19, bracket 20, sensor 21, soil 22, sensing electrode 1 23, and sensing electrode 2 24. [Specific implementation method]

[0020] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element, or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element, or there can be one or more centered elements therebetween. The orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0022] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Example 1

[0024] A soil pollution monitoring device for an underground oil pipeline in an oil depot, the monitoring device comprising a leakage monitoring device, the leakage monitoring device comprising a sleeve 13, a bracket 20 and a leakage collector 1, the sleeve 13 is used to be sleeved outside the oil pipeline 11; the bracket 25 is used to support and install above the oil pipeline 11; the leakage collector is used to collect liquid leaked from the pipeline.

[0025] like Figure 2As shown, the leakage collector comprises a housing 10, a liquid sensing chamber 12, a liquid guide hole 14, a drainage pipe 15, a sealing valve 16, a grounding electrode 17, a first contact head 18, a second contact head 19, a bracket 20, a sensor 21, soil 22, a sensing electrode 1 23, and a sensing electrode 2 24. The sensing chamber 12 is used to collect leaked oil, the liquid guide hole 14 is used to guide the leaked oil into the drainage pipe 15, and the sealing valve 16 is normally open to control the flow of the liquid. At the same time, the sealing valve 16 has good sealing performance, can effectively prevent fluid leakage, and ensure the safe operation of the system. After the oil leakage is found, it needs to be closed to prevent excessive leakage from causing the oil to penetrate into the soil. The shell 10 is installed on a bracket, the oil pipeline 11 is located inside the shell 10, the liquid guide hole 14 is arranged on the side wall of the shell 10, the oil pipeline 11 is connected to the drainage pipe 15 through the liquid guide hole 14, the sensing chamber 12 is arranged at the bottom of the shell 10, one end of the drainage pipe 15 is connected to the liquid guide hole 14, and the other end is connected to the sensing chamber 12, a sealing valve 16 is arranged on the upper part of the sensing chamber 12, and a sensing electrode 1 23 is arranged at the bottom of the sensing chamber 12; the first contact head 18 is located inside the sensing chamber 12, the first contact head 18 is connected to the sensing electrode 2 24, the sensing electrode 24 is connected to the sensing electrode 1 23 through a wire, the sensor 21 is arranged on the outside of the sensing chamber 12 for transmission or alarm positioning, the sensor 21 is connected to the sensing electrode 1 23 through a wire, and the grounding electrode 17 is arranged on the wall of the shell 10 of the leakage collector and contacts the soil 22.

[0026] Preferably, the outer wall of the sleeve 13 is provided with a grounding electrode 17, and the sleeve 13 is connected to the outer shell of the leakage collector 1 through a grounding wire 26, so that the sleeve, the leakage collector outer shell 10, the grounding wire and the grounding electrode 17 are connected to form an induction loop.

[0027] Preferably, when the pipeline leaks, the oil opens the drainage tube 15, and the leaked liquid enters the sensing chamber 12 through the drainage tube 15, and connects the liquid conductive electrodes 1 23 and 2 24 of the sensing chamber 12. The leakage monitoring device detects the current and reports the pipeline fault point.

[0028] Example 2

[0029] A method for monitoring soil pollution of buried oil pipelines in oil depots, the specific steps are as follows: a. Setting a monitoring device: Setting a monitoring device as described in any of the above claims, and putting a casing outside the oil pipeline for pipe laying; b. Measuring initial parameters: Using the monitoring device to measure the current and resistance value of the leakage monitoring device in the initial state, and using the resistance value as the initial resistance value. c. Monitoring the oil pipeline: When the oil pipeline leaks, the casing on the pipeline is grounded, the induction electrode 1 23 is connected to the induction electrode 2 24, and the data measured by the sensor is compared with the initial resistance value. When the resistance value changes within a range of 3%, it is determined that the oil pipeline 11 is leaking, and the position is calibrated.

[0030] Preferably, the oil leakage detection process in step c is as follows: 1) When the internal pressure of the oil pipeline 11 changes, the contact resistance between the ground electrode 17 and the soil 22 changes, and the resistance of the leakage monitoring device in the initial state is measured by the sensor 21. When the resistance value is 0.5-1.0MΩ, the resistance value is collected by the testing device as the initial resistance value; 2) When the oil pipeline 11 leaks, the leaked liquid enters the soil layer between the oil pipeline 11 and the casing 13, and gradually flows downward, and contacts and forms a liquid channel between the sensing electrode 1 23 and the sensing electrode 2 24; 3) When the liquid channel is connected, the sensing electrode 1 23 and the sensing electrode 2 24 are connected through the liquid, and then the current is transferred from the sensing electrode 1 23 to the sensing electrode 2 24; 4) When the current measured by the sensor 21 is 10-40mA, it is determined that the pipeline has a leak and an alarm is issued; 5) The leakage collection device is dug up, and it is determined that the actual location of the pipeline is consistent with the alarm location, and then the pipeline is repaired.

[0031] Example 3

[0032] A method for monitoring soil pollution in an underground oil pipeline in an oil depot, the specific steps are as follows: a. Setting a monitoring device: setting a monitoring device as described in any one of the above claims, and sleeve the casing outside the oil pipeline for pipe laying; b. Measuring initial parameters: measuring the current and resistance value of the leakage monitoring device in the initial state by the monitoring device, and taking the resistance value as the initial resistance value; specifically, the step b specifically includes the following steps: S1, digging up the soil layer between the sensing electrode 1 23 and the sensing electrode 2 24, taking out the sensing electrode 1 23 and the sensing electrode 2 24, washing them with pure water, and wrapping them with waterproof insulating tape, with each circle separated by 0.5 cm, to ensure that the waterproof insulating tape is in contact with the grounding electrode 17; S2, inserting one end of the sensing electrode 2 24 into the grounding electrode 17; , and connect it with the wire, and check whether it is closed, and install the sensing electrode 24 into the shell, and ensure that the bottom of the sensing electrode 24 is 2-5cm above the sensing electrode 1 23; S3, close the sensing chamber 12, wrap it with waterproof insulating tape 2-3 times, each circle is 0.5cm apart, ensure that the waterproof insulating tape is in contact with the grounding electrode 17, and seal it through the sealing valve; S4, install the shell 10 on the bracket 25, and check whether the sealing valve is closed; S5, move the bracket 25 to the position 25m away from the next bracket, and repeat the above steps S2-S4; S6, dig the lower end of the casing 13 to expose the grounding electrode 17, and connect it through the grounding wire; S7, bury the soil so that the casing 13, the bracket 25 and the leakage collector are buried at a depth of 2m.

[0033] c. Monitoring the oil pipeline: When the oil pipeline leaks, the casing on the pipeline is grounded, the sensing electrode 1 23 is connected to the sensing electrode 2 24, and the data measured by the sensor is compared with the initial resistance value. When the resistance value changes within 3%, it is determined that the oil pipeline 11 is leaking and the position is calibrated.

[0034] Preferably, the step c specifically includes the following steps: SS1, measuring the above step b on each oil pipeline in the oil depot in turn, and recording the resistance values ​​of all pipelines as initial resistance values; SS2, recording the resistance values ​​every three months; SS3, taking the resistance value as the current change rate and recording it. When the current change rate exceeds 12%, an alarm is sounded, and the soil between the sensing electrode 1 23 and the sensing electrode 2 24 is dug up to check whether the pipeline is damaged; SS4, if the pipeline is not damaged, continue monitoring and re-landfill; SS5, if the pipeline is damaged, determine the damaged position through the position of the casing 13, and repair it at that position.

[0035] Preferably, in step SS2, the resistance value is recorded every 6 months; the resistance value is used as the current change rate and recorded, and when the current change rate exceeds 13%, an alarm is sounded, and the soil between the sensing electrode 1 23 and the sensing electrode 2 24 is dug up to check whether the pipeline is damaged; SS3, if the pipeline is not damaged, continue to monitor and re-landfill; SS4, if the pipeline is damaged, the damaged position is determined by the position of the casing 13, and repair is performed at that position.

[0036] The soil pollution monitoring device for buried oil pipelines in oil depots of the present invention wraps the pipeline with a casing, and buries the casing in the soil by grounding the casing to reduce the grounding resistance and the contact area of ​​the sensing electrode, thereby avoiding the disadvantage that the traditional monitoring device cannot detect the large grounding resistance by grounding and affects the monitoring accuracy. By arranging a bracket above the pipeline and then installing a leakage collector, the leakage collector is installed above the buried pipeline, and the pipeline is connected through a liquid guide hole, so that the sensing chamber is located directly below the pipeline after the leakage, thereby improving the monitoring accuracy. By installing a sensor on the outer shell, the current is monitored, and the accuracy of the alarm is guaranteed, thereby improving the monitoring accuracy.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soil pollution monitoring device for buried oil pipelines in oil depots, characterized in that: The monitoring device comprises a leakage monitoring device, which comprises a casing, a bracket and a leakage collector, wherein the casing is used to be sleeved outside the oil pipeline; the bracket is used to support and be installed above the pipeline; the leakage collector is used to collect liquid leaked from the buried oil pipeline in the reservoir; the leakage collector comprises an outer shell, a liquid sensing chamber, a liquid guide hole, a drainage pipe, a sealing valve, a first contact head, a second contact head, a sensor, a first sensing electrode, a second sensing electrode, a grounding electrode and soil.

2. The soil pollution monitoring device for buried oil pipelines in oil depots according to claim 1 is characterized in that: The shell is installed on the bracket, the oil pipeline is located inside the shell, the liquid guide hole is arranged on the side wall of the shell, the oil pipeline is connected to the drainage pipe through the liquid guide hole, and the sensing chamber is arranged at the bottom of the shell.

3. The soil pollution monitoring device for buried oil pipeline in oil depot according to claim 1 is characterized in that: One end of the drainage tube is connected to the liquid guide hole, and the other end is connected to the upper part of the sensing chamber. A sealing valve is arranged on the upper part of the sensing chamber, and a sensing electrode 1 is arranged on the bottom of the sensing chamber. The first contact head is located inside the sensing chamber, and the second contact head is located outside the sensing chamber. The first contact head is connected to the sensing electrode 2, and the sensing electrode 2 is connected to the sensing electrode 1 through a wire. The sensor is arranged outside the sensing chamber, and the sensor is connected to the sensing electrode 1 through a wire. The grounding electrode is arranged on the outer shell wall of the leakage collector and is in contact with the soil.

4. The soil pollution monitoring device for buried oil pipeline in oil depot according to claim 1 is characterized in that: The inner wall of the shell is provided with a drainage tube, one end of which is connected to the sensing chamber, and the other end is connected to the liquid guide hole. The outer wall of the sleeve is provided with a grounding electrode, and the sleeve is connected to the shell of the leakage collector through a grounding wire, so that the sleeve, the leakage collector shell, the grounding wire, and the grounding electrode are connected to form an induction loop; when the pipeline leaks, the oil opens the drainage tube, and the leaked liquid enters the sensing chamber through the drainage tube, and connects the liquid conductive sensing electrode 1 and the sensing electrode 2 in the sensing chamber, and the leakage monitoring device detects the current and reports the pipeline fault point.

5. A method for monitoring soil pollution of buried oil pipelines in oil depots, characterized in that: The specific steps are as follows: a. Setting a monitoring device: Setting a monitoring device as described in any one of claims 1 to 4, and putting a casing outside the oil pipeline for pipe laying; b. Measuring initial parameters: Using the monitoring device to measure the current and resistance value of the leakage monitoring device in the initial state, and using the resistance value as the initial resistance value; c. Monitoring the oil pipeline: When the oil pipeline leaks, the casing on the pipeline is grounded, the sensing electrode 1 is connected to the sensing electrode 2, and the data measured by the sensor is compared with the initial resistance value. When the resistance value changes within a range of 3%, it is determined that the oil pipeline is leaking, and the position is calibrated.

6. A method for monitoring soil pollution of an underground oil pipeline in an oil depot according to claim 5, characterized in that: The process of detecting oil leakage in step c is as follows: 1) When the internal pressure of the oil pipeline changes, the contact resistance between the ground electrode and the soil changes. The resistance of the leakage monitoring device in the initial state is measured by a sensor. When the resistance value is 0.5-1.0MΩ, the resistance value is collected by a testing device as the initial resistance value; 2) When the oil pipeline leaks, the leaked liquid enters the soil layer between the oil pipeline and the casing, and gradually flows upward, and contacts and forms a liquid channel between the sensing electrode 1 and the sensing electrode 2; 3) When the liquid channel is connected, the sensing electrode 1 and the sensing electrode 2 are connected through the liquid, and then the current is transferred from the sensing electrode 1 to the sensing electrode 2; 4) When the current measured by the sensor is 10-40mA, it is judged that the pipeline has a leak and an alarm is sounded; 5) The leakage collection device is dug up, and it is determined that the actual location of the pipeline is consistent with the alarm location, and the pipeline is repaired; if it is inconsistent, the alarm is continued until the location is consistent.

7. The method for monitoring soil pollution of buried oil pipelines in oil depots according to claim 5 is characterized in that: The step b specifically includes the following steps: S1, digging the soil layer between the sensing electrode 1 and the sensing electrode 2, taking out the sensing electrode 1 and the sensing electrode 2, washing them with pure water, and wrapping them with waterproof insulating tape, each circle is 0.5 cm apart, ensuring that the waterproof insulating tape is in contact with the grounding electrode; S2, inserting one end of the sensing electrode 24, connecting it with the wire, and checking whether it is closed, and installing the sensing electrode 2 in the shell, and ensuring that the bottom of the sensing electrode 2 is 2-5 cm above the sensing electrode 1; S3, closing the sensing chamber, wrapping it with waterproof insulating tape 2-3 circles, each circle is 0.5 cm apart, ensuring that the waterproof insulating tape is in contact with the grounding electrode, and sealing it through the sealing valve; S4, installing the shell on the bracket, and checking whether the sealing valve is closed; S5, moving the bracket to the position 25-4m away from the next bracket, and repeating the above steps S2-S4; S6, digging the lower end of the casing, taking out the grounding electrode, and connecting it through the grounding wire; S7, burying the soil so that the casing, the bracket and the leakage collector are buried at a depth of 2m.

8. The method for monitoring soil pollution of an underground oil pipeline in an oil depot according to claim 5 is characterized in that: The step c specifically includes the following steps: SS1, measuring each oil pipeline in the oil depot in the step b in turn, and recording the resistance values ​​of all pipelines as the initial resistance value; SS2, recording the resistance value every 3 months; SS3, taking the resistance value as the current change rate and recording it. When the current change rate exceeds 12%, an alarm is sounded, and the soil between the sensing electrode 1 and the sensing electrode 2 is dug to check whether the pipeline is damaged; SS4, if the pipeline is not damaged, continue to monitor and re-landfill; SS5, if the pipeline is damaged, determine the damaged position by the casing position, and repair it at the position; in the step SS2, recording the resistance value every 6 months; taking the resistance value as the current change rate and recording it. When the current change rate exceeds 13%, an alarm is sounded, and the soil between the sensing electrode 1 and the sensing electrode 2 is dug to check whether the pipeline is damaged; SS3, if the pipeline is not damaged, continue to monitor and re-landfill; SS4, if the pipeline is damaged, determine the damaged position by the casing position, and repair it at the position.

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