A method and system for monitoring oil pipeline tapping

Abstract

The application provides a kind of oil pipeline punching oil theft monitoring method and monitoring system, each interval preset time obtains the energized potential and alternating voltage of each monitoring point position on the oil pipeline to be monitored.Based on the obtained energized potential, the amplitude value of the energized potential corresponding to each monitoring point is determined.Based on the obtained alternating voltage, the amplitude value of the alternating voltage corresponding to each monitoring point is determined.The first proportion value and the second proportion value corresponding to each monitoring point are obtained.The first proportion value is the ratio of the amplitude value of the energized potential corresponding to the monitoring point to the reference value of the energized potential corresponding to the monitoring point.The second proportion value is the ratio of the amplitude value of the alternating voltage corresponding to the monitoring point to the reference value of the alternating voltage corresponding to the monitoring point.Based on the first proportion value and the second proportion value corresponding to each monitoring point, the position of the punching oil theft event occurring on the oil pipeline to be monitored is determined, which can monitor the punching oil theft situation occurring on the oil pipeline in real time, and reduce the loss caused by the punching oil theft of the oil pipeline.

Description

Technical Field

[0001] This invention relates to the field of cathodic protection technology for oil pipelines, and in particular to a monitoring method and system for detecting oil theft through drilling in oil pipelines. Background Technology

[0002] Pipeline theft refers to the act of welding or installing oil-stealing valves or short sections into the pipe wall of an oil pipeline, and then drilling holes in the pipe wall to steal crude oil, refined oil products, etc. This not only causes serious economic losses to the transport company but also shortens the lifespan of the pipeline and causes environmental pollution.

[0003] Currently, a spherical internal detector equipped with a three-component magnetic sensor and an accelerometer can be used to inspect oil pipelines for instances of oil theft through perforation. The magnetic field signal recorded by the spherical internal detector is downloaded to a host computer, and the converted magnetic field is used to identify any abnormalities in pipeline bends, circumferential welds, stress concentrations, valve chambers, scratches, and perforated oil theft valves.

[0004] However, the above methods cannot achieve real-time monitoring of oil theft through drilling on oil pipelines. The detection results obtained by the spherical internal detector are delayed, making it difficult to promptly detect and prevent thieves from drilling holes in oil pipelines to steal oil. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a monitoring method and system for detecting oil and gas theft by drilling into oil and gas pipelines, which can monitor the oil theft by drilling into oil pipelines in real time, so as to reduce the losses caused by oil theft by drilling into oil pipelines.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] In a first aspect, the present invention provides a method for monitoring oil theft through perforation in oil pipelines, comprising: determining an oil pipeline to be monitored; the oil pipeline to be monitored includes at least one monitoring point. For any monitoring point, acquiring the electrical potential and AC voltage at the location of the monitoring point at preset time intervals. Based on the acquired electrical potential corresponding to the monitoring point, determining the amplitude value of the electrical potential corresponding to the monitoring point. Based on the acquired AC voltage corresponding to the monitoring point, determining the amplitude value of the AC voltage corresponding to the monitoring point. Acquiring a first proportional value and a second proportional value corresponding to the monitoring point; the first proportional value is the ratio of the amplitude value of the electrical potential corresponding to the monitoring point to a reference value of the electrical potential corresponding to the monitoring point; the second proportional value is the ratio of the amplitude value of the AC voltage corresponding to the monitoring point to a reference value of the AC voltage corresponding to the monitoring point. Based on the first proportional value and the second proportional value corresponding to each monitoring point included in the at least one monitoring point, determining the location of the oil theft through perforation event on the oil pipeline to be monitored.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the distance between any two adjacent monitoring points in the at least one monitoring point is a first preset distance.

[0010] Furthermore, based on a multimeter, a reference electrode, and a cathodic protection test post installed at any of the monitoring points, the energized potential and AC voltage at each monitoring point are acquired at preset time intervals. The multimeter includes a positive port and a negative port; the positive port is connected to the cathodic protection test post at each monitoring point, and the negative port is connected to the reference electrode.

[0011] Furthermore, assuming no oil theft incident has occurred in the monitored oil pipeline, the electrical potential and AC voltage at any monitoring point are acquired at preset time intervals. A reference value for the electrical potential and a reference value for the AC voltage corresponding to any monitoring point are determined. The reference value for the electrical potential at any monitoring point is the average value of the electrical potential at any monitoring point acquired under the assumption that no oil theft incident has occurred in the monitored oil pipeline. The reference value for the AC voltage at any monitoring point is the average value of the AC voltage at any monitoring point acquired under the assumption that no oil theft incident has occurred in the monitored oil pipeline.

[0012] Furthermore, based on the difference between the maximum and minimum values ​​of the energized potential corresponding to any monitoring point, the amplitude value of the energized potential corresponding to any monitoring point is determined.

[0013] Furthermore, based on the difference between the maximum and minimum values ​​of the AC voltage corresponding to any monitoring point, the amplitude value of the AC voltage corresponding to any monitoring point is determined.

[0014] Furthermore, based on the fact that the first proportion value corresponding to any monitoring point is greater than the first threshold, and / or the second proportion value corresponding to any monitoring point is greater than the second threshold, it is determined that a drilling and oil theft event has occurred in the coverage area corresponding to any monitoring point. The maximum distance between the boundary of the coverage area corresponding to any monitoring point and any monitoring point is a second preset distance.

[0015] Further, at least one abnormal monitoring point is identified. The first proportion value corresponding to the abnormal monitoring point is greater than a first threshold, and / or, the second proportion value corresponding to the abnormal monitoring point is greater than a second threshold. For any one of the at least one abnormal monitoring points, a first difference and a second difference corresponding to that abnormal monitoring point are obtained. The first difference corresponding to any abnormal monitoring point is the difference between the first proportion value corresponding to that abnormal monitoring point and the first threshold, and the second difference corresponding to any abnormal monitoring point is the difference between the second proportion value corresponding to that abnormal monitoring point and the second threshold. Based on the first difference and the second difference corresponding to each of the at least one abnormal monitoring points, the location of the oil theft incident occurring on the monitored oil pipeline is determined.

[0016] The beneficial effects of this invention are:

[0017] This invention solves the problem of monitoring oil theft through drilling in oil pipelines. It does not require relying entirely on complex and cumbersome technical means such as oil pipeline leak detection systems, pipeline fiber optic early warning systems, pipeline internal detection technology and pipeline external detection technology. This invention can directly utilize existing equipment and technology of oil pipelines to monitor oil theft through drilling in oil pipelines.

[0018] This invention improves the monitoring accuracy of oil theft through pipeline drilling. While similar technologies rely on potentiostats within cathodic protection systems, these systems are often located far from the site of the theft, leading to attenuation of cathodic protection parameter changes along the pipeline. This invention, however, utilizes the pipeline's cathodic protection system while simultaneously monitoring changes in the energized potential and AC voltage of test piles, effectively confirming the location of oil theft through drilling and thus significantly improving monitoring accuracy.

[0019] The monitoring method provided by this invention has a wider range of applications compared to existing methods for monitoring oil theft through pipeline perforation. While similar technologies identify perforation-related oil theft events based on changes in pipe-to-ground potential measured by a potentiostat, the type of welding machine used by perforators is random. Therefore, this invention focuses on the changes in two cathodic protection parameters—current potential and AC voltage—and is applicable to the influence of different welding machines on changes in pipeline cathodic protection parameters, effectively expanding the applicability of this monitoring method.

[0020] Secondly, the present invention provides a monitoring system, comprising:

[0021] The target oil pipeline selection module is used to determine the oil pipeline to be monitored; the oil pipeline to be monitored includes at least one monitoring point.

[0022] A data acquisition module is used to acquire the electrical potential and AC voltage at any monitoring point at preset time intervals. A first calculation module is used to determine the amplitude value of the electrical potential corresponding to any monitoring point based on the acquired electrical potential. A second calculation module is used to determine the amplitude value of the AC voltage corresponding to any monitoring point based on the acquired AC voltage. A processing module is used to acquire a first ratio value and a second ratio value corresponding to any monitoring point. The first ratio value is the ratio of the amplitude value of the electrical potential corresponding to any monitoring point to a reference value of the electrical potential corresponding to any monitoring point; the second ratio value is the ratio of the amplitude value of the AC voltage corresponding to any monitoring point to a reference value of the AC voltage corresponding to any monitoring point. An analysis module is used to determine the location of the oil theft incident on the monitored oil pipeline based on the first ratio value and the second ratio value corresponding to each monitoring point, including the at least one monitoring point.

[0023] Based on the above technical solution, the present invention can be further improved as follows.

[0024] Furthermore, the data acquisition module is also used to acquire the energized potential and AC voltage at any monitoring point location based on a multimeter, a reference electrode, and a cathodic protection test pile set at any monitoring point location at preset time intervals; wherein, the multimeter includes a positive terminal and a negative terminal, the positive terminal is connected to the cathodic protection test pile set at any monitoring point location, and the negative terminal is connected to the reference electrode.

[0025] Thirdly, the present invention provides an electronic device, which includes a memory and one or more processors; the memory is coupled to the processors; wherein the memory stores computer program code, which includes computer instructions, and when the computer instructions are executed by the processor, the electronic device performs a method for monitoring oil theft by drilling holes in an oil pipeline as described in any implementation of the first aspect.

[0026] Fourthly, the present invention provides a computer-readable storage medium including computer instructions that, when executed on an electronic device, cause the electronic device to perform a method for monitoring oil theft by drilling holes in an oil pipeline as described in any implementation of the first aspect.

[0027] Fifthly, the present invention provides a computer program product that, when run on a computer, causes the computer to execute a method for monitoring oil theft through drilling in an oil pipeline, as described in any implementation of the first aspect.

[0028] Understandably, the beneficial effects achieved by the processor chip of the second aspect, the electronic device of the third aspect, the computer-readable storage medium of the fourth aspect, and the computer program product of the fifth aspect provided above can be referred to in light of the beneficial effects of the first aspect and any of its possible design embodiments, which will not be repeated here. Attached Figure Description

[0029] Figure 1 A schematic diagram of a monitoring method for oil theft through drilling in oil pipelines provided by the present invention;

[0030] Figure 2 A graph showing the variation of cathodic protection parameters for the K409 test pile provided by this invention;

[0031] Figure 3 This is a graph showing the data variation of the cathodic protection parameters of the K371 test pile of this invention;

[0032] Figure 4 This is a graph showing the data variation of the cathodic protection parameters of the K372 test pile of this invention;

[0033] Figure 5 This is a graph showing the data variation of the cathodic protection parameters of the K373 test pile of this invention;

[0034] Figure 6 This is a graph showing the data variation of the cathodic protection parameters of the K374 test pile of this invention;

[0035] Figure 7 This is a graph showing the data variation of the cathodic protection parameters of the K375 test pile of this invention;

[0036] Figure 8A trend diagram of the variation of the average energized potential and the average AC voltage provided for this invention;

[0037] Figure 9 The AC voltage amplitude variation trend diagram provided by this invention;

[0038] Figure 10 This is a schematic diagram of a monitoring system provided by the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes.

[0040] Pipeline theft refers to the act of welding or installing oil-stealing valves or short sections into the pipe wall of an oil pipeline, and then drilling holes in the pipe wall to steal crude oil, refined oil products, etc. This not only causes serious economic losses to the transport company but also shortens the lifespan of the pipeline and causes environmental pollution.

[0041] In the first existing technology, a spherical internal detector equipped with a three-component magnetic sensor and an accelerometer can be used to inspect oil pipelines. The magnetic field signal recorded by the spherical internal detector is downloaded to a host computer, and the converted magnetic field is used to identify abnormalities in pipelines such as bends, circumferential welds, stress concentrations, valve chambers, scratches, and perforated oil theft valves.

[0042] However, this method cannot achieve real-time online monitoring of abnormal oil theft events caused by drilling, as there is a lag between the monitoring method and the occurrence of such events. Furthermore, it requires the addition of a spherical internal detector, increasing the pipeline's operation and management costs.

[0043] In the second existing technology, LBS data from telecommunications service operators can be accessed and big data analysis can be performed. A comprehensive rating system is established to assess the likelihood of oil theft through boreholes by individuals operating along the pipeline area and along its route. Suspicion levels are assigned to different areas within the pipeline and to individuals operating along its route, enabling 24-hour analysis and monitoring of oil theft through boreholes along the pipeline.

[0044] However, this method relies on the location services provided by telecommunications service providers, detached from the parameter changes inherent in the operation of the oil pipeline itself. It can only provide suspected areas and individuals involved in tapping for oil theft, but cannot determine whether tapping for oil theft has actually occurred on the pipeline.

[0045] In the third existing technology, the pipeline-to-ground potential shift can be monitored, and based on the characteristics of the monitored pipeline-to-ground potential shift, the corresponding monitoring section can be identified as a suspected section for drilling and stealing oil and gas. All suspected sections for drilling and stealing oil and gas are investigated to determine the actual sections for drilling and stealing oil and gas.

[0046] However, this method is beneficial for monitoring the tube-to-ground potential in cathodic protection systems. In reality, the changes on this potentiostat are very small during operation, and the tube-to-ground potential changes gradually decrease as the distance between the state point and the potentiostat increases.

[0047] In the fourth existing technology, pressure signals can be monitored on the pressurized oil pipeline, and the drilling and oil theft points can be initially located based on the time difference of the pressure signals, thus determining the mileage range. Weak magnetic field detection is then performed on the pipeline within the mileage range to identify areas with abnormal weak magnetic signals, allowing for precise location of the drilling and oil theft points.

[0048] However, this method uses pressurization to increase the pressure of the oil pipeline and detects the pressure at both ends of the pipeline; at the same time, it also uses weak magnetic signal analysis technology to monitor anomalies along the pipeline. Although the combination of the two monitoring and analysis methods can improve the accuracy of detecting and locating oil theft by drilling, the cost-effectiveness of this technology is not high. The combination of multiple technologies will not only increase the operating cost of the oil pipeline, but also bring operational risks to the oil pipeline.

[0049] To address the aforementioned problems, this invention provides a method and system for monitoring oil and gas theft through perforations in oil and gas pipelines. This system enables real-time monitoring of oil theft through perforations in pipelines, thereby reducing losses caused by such activities. Furthermore, this invention improves the accuracy and applicability of the monitoring method for oil theft through perforations in oil pipelines.

[0050] See Figure 1 The method for monitoring oil theft through perforated pipelines provided by the present invention includes steps S101-S106:

[0051] S101: Identify the oil pipeline to be monitored.

[0052] The oil pipeline to be monitored includes at least one monitoring point.

[0053] In some embodiments, the distance between any two adjacent monitoring points is a first preset distance.

[0054] It should be noted that those skilled in the art can set the value of the first preset distance based on the actual scenario. For example, the first distance can be set to 1km. The embodiments of this application do not limit the value of the first preset distance.

[0055] S102: For any monitoring point, acquire the energized potential and AC voltage at any monitoring point location at preset time intervals.

[0056] It should be noted that those skilled in the art can set the value of the preset time based on the actual scenario. For example, the preset time can be set to 10 minutes, that is, the energized potential and AC voltage at each monitoring point are acquired every 10 minutes. The embodiments of this application do not limit the value of the preset time.

[0057] In some embodiments, a cathodic protection test post is provided at any monitoring point location. Based on a multimeter, a reference electrode, and the cathodic protection test post provided at any monitoring point location, the energized potential and AC voltage at any monitoring point location can be obtained at preset time intervals.

[0058] The multimeter includes a positive terminal and a negative terminal. The positive terminal is connected to a cathodic protection test post set at any monitoring point, and the negative terminal is connected to a reference electrode.

[0059] The following is a detailed introduction to the multimeter, reference electrode, and cathodic protection test post.

[0060] Multimeter: A digital multimeter with a DC voltage range of 0.1mV-1000V, an AC voltage range of 0.1mV-1000V, a frequency range of 0.5Hz-200kHz, and a temperature measurement range of -200℃-1090℃.

[0061] Reference electrode: A copper-saturated copper sulfate electrode (also referred to as a copper sulfate electrode, or CSE for short) is used as the reference electrode. The electrode potential error should not be greater than 5mV. The materials used and the use of the electrode should meet the following requirements: (1) The copper electrode is made of copper wire or rod with a purity of not less than 99.7%; (2) The copper sulfate is chemically pure and a saturated copper sulfate solution is prepared with distilled water or purified water; (3) The permeation membrane is made of microporous material with high permeability and the outer shell should be made of insulating material; (4) The allowable current density flowing through the copper sulfate electrode is not greater than 5uA / cm2.

[0062] Cathodic protection test posts: including terminal blocks, copper lugs, VV-0.6 / 1kV 1x10mm2 cables, test posts, and aluminothermic welding electrodes.

[0063] S103: Based on the acquired energized potential at any monitoring point, determine the amplitude value of the energized potential at any monitoring point.

[0064] In some embodiments, the amplitude value of the energized potential corresponding to any monitoring point can be determined based on the difference between the maximum and minimum values ​​of the energized potential corresponding to any monitoring point.

[0065] For example, if the energized potentials corresponding to the target monitoring points are -1.5V, -1.45V, -1.56V, -1.53V, and -1.49V respectively, where the maximum value of the energized potential corresponding to the target monitoring point is -1.45V and the minimum value is -1.56V, then the amplitude of the energized potential corresponding to the target monitoring point is [(-1.45V) - (-1.56V)], that is, the amplitude of the energized potential corresponding to the target monitoring point is 0.11V.

[0066] S104: Based on the AC voltage corresponding to any monitoring point, determine the amplitude value of the AC voltage corresponding to any monitoring point.

[0067] In some embodiments, the amplitude value of the AC voltage corresponding to any monitoring point can be determined based on the difference between the maximum and minimum values ​​of the AC voltage corresponding to any monitoring point.

[0068] For example, if the AC voltages corresponding to the target monitoring points are 0.154V, 0.167V, 0.149V, 0.165V, and 0.150V respectively, where the maximum AC voltage corresponding to the target monitoring point is 0.167V and the minimum AC voltage corresponding to the target monitoring point is 0.149V, then the amplitude of the AC voltage corresponding to the target monitoring point is (0.167V-0.149V), that is, the amplitude of the AC voltage corresponding to the target monitoring point is 0.018V.

[0069] S105: Obtain the first and second proportional values ​​corresponding to any monitoring point.

[0070] The first ratio is the ratio of the amplitude of the energized potential at any monitoring point to the reference value of the energized potential at any monitoring point. The second ratio is the ratio of the amplitude of the AC voltage at any monitoring point to the reference value of the AC voltage at any monitoring point.

[0071] For example, if the amplitude of the energized potential corresponding to the target monitoring point is 0.11V and the reference value of the energized potential corresponding to the target monitoring point is 0.1V, then the first ratio is 0.11 / 0.1, that is, the first ratio is 110%.

[0072] If the amplitude of the AC voltage corresponding to the target monitoring point is 0.018V and the reference value of the AC voltage corresponding to the target monitoring point is 0.129V, then the first proportional value is 13.9%.

[0073] In some embodiments, if it is determined that no oil theft incident has occurred in the monitored oil pipeline, the energized potential and AC voltage at any monitoring point can be acquired at preset time intervals. Then, a reference value for the energized potential and a reference value for the AC voltage corresponding to any monitoring point are determined.

[0074] The reference value for the energized potential at any monitoring point is the average value of the energized potential at any monitoring point location, obtained under the premise that no oil theft incident has occurred in the monitored oil pipeline. The reference value for the AC voltage at any monitoring point is the average value of the AC voltage at any monitoring point location, obtained under the premise that no oil theft incident has occurred in the monitored oil pipeline.

[0075] S106: Based on the first and second proportional values ​​corresponding to each monitoring point, including at least one monitoring point, determine the location of the oil theft incident that occurred on the oil pipeline to be monitored.

[0076] In some embodiments, an oil theft incident can be determined to have occurred in the coverage area corresponding to any monitoring point based on a first proportion value corresponding to any monitoring point being greater than a first threshold, and / or a second proportion value corresponding to any monitoring point being greater than a second threshold.

[0077] The maximum distance between the boundary of the coverage area corresponding to any monitoring point and any monitoring point is the second preset distance.

[0078] For example, if the first threshold is 100%, and the oil pipeline includes monitoring point 1, monitoring point 2, monitoring point 3, and monitoring point 4, where the first proportion value corresponding to monitoring point 1 is 62%, the first proportion value corresponding to monitoring point 2 is 110%, the first proportion value corresponding to monitoring point 3 is 132%, and the first proportion value corresponding to monitoring point 4 is 97%, then it can be determined that a drilling and oil theft event has occurred in the coverage area corresponding to monitoring point 2 and monitoring point 3.

[0079] For example, if the second threshold is 100%, and the oil pipeline includes monitoring point 1, monitoring point 2, monitoring point 3, and monitoring point 4, where the second proportion value corresponding to monitoring point 1 is 97%, the second proportion value corresponding to monitoring point 2 is 120%, the second proportion value corresponding to monitoring point 3 is 96%, and the second proportion value corresponding to monitoring point 4 is 65%, then it can be determined that a drilling and oil theft event has occurred in the coverage area corresponding to monitoring point 2 and monitoring point 3.

[0080] In some embodiments, at least one anomaly monitoring point can be determined. Wherein, a first proportion value corresponding to the anomaly monitoring point is greater than a first threshold, and / or, a second proportion value corresponding to the anomaly monitoring point is greater than a second threshold. A first difference and a second difference corresponding to any anomaly monitoring point are obtained.

[0081] Wherein, the first difference corresponding to any abnormal monitoring point is the difference between the first proportion value and the first threshold value corresponding to any abnormal monitoring point, and the second difference corresponding to any abnormal monitoring point is the difference between the second proportion value and the second threshold value corresponding to any abnormal monitoring point.

[0082] Because the cathodic protection parameters (current potential and AC voltage) attenuate as they are transmitted along the oil pipeline, the location of the oil theft incident on the monitored oil pipeline can be determined by analyzing the first and second differences corresponding to each abnormal monitoring point.

[0083] To verify the monitoring method for oil theft through pipeline perforation provided in this application, this application also provides a test method for oil theft through pipeline perforation. This test method for oil theft through pipeline perforation includes two parts: a test method and an analytical method. These two parts are described in detail below.

[0084] Test methods

[0085] First, long-distance oil pipelines equipped with cathodic protection test posts, potentiostats, and cathodic protection systems were selected. Cathodic protection test posts were then marked along the upstream and downstream sections of the pipeline along the proposed drilling and oil theft point. Based on the actual conditions of the pipeline, one cathodic protection test post was installed every 1 km, and continuous monitoring was conducted up to 5 km upstream and downstream of the proposed drilling and oil theft point.

[0086] Then, a hot work pit was constructed at the designated drilling point for oil theft, along with an escape route. Fiber bags filled with sand were stacked along the steps of the escape route. After the pit was excavated, personnel were assigned to monitor it 24 hours a day, observing the groundwater level and draining the water. After removing the anti-corrosion layer, the designated drilling point for oil theft was confirmed and measured to prepare for simulated hot work operations involving drilling, welding, and sealing of the oil theft valve.

[0087] Next, the cathodic protection parameters of the oil pipeline were tested according to GB / T21246-2020 "Measurement Method for Cathodic Protection Parameters of Buried Steel Pipelines". The testing equipment included a multimeter, a reference electrode, and cathodic protection test stakes.

[0088] Subsequently, professional testing personnel were deployed within a 5km radius upstream and downstream of the proposed oil theft site (one person per test pile). The testing personnel connected the negative terminal (black test probe) of a digital multimeter to the reference electrode and the positive terminal (red test probe) to the test pile. Before the welding operation at the proposed oil theft site began, the testing personnel tested the energized potential and AC voltage at 10-minute intervals, serving as a "baseline and blank control test group." After the welding operation at the proposed oil theft site began, the testing personnel tested the energized potential and AC voltage at 10-minute intervals.

[0089] Finally, the energized potential and AC voltage test values ​​of the upstream and downstream test piles of the proposed oil theft drilling point were collected, and the data were analyzed and charts were drawn.

[0090] Analytical methods

[0091] First, one hour before the planned drilling point for oil theft, the electrical potential and AC voltage of 10 test piles located 5 km upstream and downstream were tested at 10-minute intervals. The average value of the electrical potential and AC voltage measured at each test pile was used as the "baseline and blank control test group".

[0092] Then, after planning the welding operation for drilling and stealing oil, test data of energized potential and AC voltage were collected, and a "scatter plot with curve" was plotted to show the changes over time. The same Y-axis coordinate scale value was selected for the potential / voltage data of all test groups.

[0093] Subsequently, the maximum and minimum values ​​of the energizing potential and AC voltage during the planned oil theft welding operation were selected, and the amplitude between the maximum and minimum values ​​was calculated. The amplitude value was compared with the value of the "baseline". When the amplitude value was greater than 100% of the baseline value, it was determined that an oil theft welding operation had occurred in the oil pipeline section.

[0094] Finally, the location of oil theft incidents can be marked by the changes in the energized potential and AC voltage of the test piles, enabling accurate monitoring within a 3.5km radius.

[0095] Based on the above experimental and analytical methods, the following experimental data can be obtained.

[0096] See Figure 2 Test pile K409 is located 27.89 km downstream of the welding ignition point. The average electrical potential at the point of contact with the weld was -1.615V, showing almost no change. The average AC voltage was 0.298V (the baseline value is 0.307V), with a maximum of 0.350V and a minimum of 0.240V, exhibiting an amplitude of 0.11V. This AC voltage amplitude is 35.81% of the baseline value. The welding had a minimal impact on the AC voltage variation at test pile K409. Therefore, it cannot be determined whether a drilling incident occurred in the oil pipeline to steal oil.

[0097] Test pile K399 is located 19.51 km downstream of the welding ignition point. The average electrical potential at the K399 test pile was -1.563V, showing almost no change. The average AC voltage was 0.297V (baseline value is 0.309V), with a maximum of 0.350V and a minimum of 0.240V, exhibiting an amplitude of 0.11V. This AC voltage amplitude is 36.65% of the baseline value. The welding had a minimal impact on the AC voltage variation at the K399 test pile location. Therefore, it cannot be determined whether a drilling incident occurred in the oil pipeline to steal oil.

[0098] See Figure 3 Test pile K371 is located 4.478 km upstream of the welding ignition point. The average electrical potential of the pile, -1.537V, remained almost unchanged. The average AC voltage was 0.113V (the baseline value is 0.132V), with a maximum of 0.171V and a minimum of 0.065V, exhibiting an amplitude of 0.106V. This AC voltage amplitude is 80.53% of the baseline value. Welding has a certain impact on the AC voltage variation at the K371 test pile location. Therefore, it cannot be determined whether an oil theft incident occurred during drilling into the pipeline.

[0099] See Figure 4 Test pile K372 is located 3.560 km upstream of the welding ignition point. The average electrical potential of the pile, -1.568V, remained almost unchanged. The average AC voltage was 0.1136V (the baseline value is 0.084V), with a maximum of 0.192V and a minimum of 0.0740V, exhibiting an amplitude of 0.1180V. This AC voltage amplitude is 140.00% of the baseline value. Welding has a certain impact on the AC voltage variation at the location of test pile K372. Therefore, it can be determined that an oil theft incident occurred during pipeline drilling, and the incident took place within a 3.5 km radius.

[0100] See Figure 5Test pile K373 is located 2.641 km upstream of the welding ignition point. The average electrical potential at the K373 test pile was -1.591V, showing almost no change. The average AC voltage was 0.137V (the baseline value is 0.138V), with a maximum of 0.247V and a minimum of 0.106V, exhibiting an amplitude of 0.141V. This AC voltage amplitude is 101.86% of the baseline value. Welding has a certain impact on the AC voltage variation at the K373 test pile location. Therefore, it can be determined that an oil theft incident occurred during pipeline drilling, and that the incident took place within a 2.5 km radius.

[0101] See Figure 6 Test pile K374 is located 1.429 km upstream of the welding ignition point. The average electrical potential at the K374 test pile was -1.578V, showing almost no change. The average AC voltage was 0.154V (the baseline value is 0.129V), with a maximum of 0.238V and a minimum of 0.108V, exhibiting an amplitude of 0.130V. This AC voltage amplitude is 101.11% of the baseline value. Welding significantly affected the AC voltage variation at the K374 test pile location. Therefore, it can be determined that an oil theft incident occurred during pipeline drilling, and that the incident took place within a 1.5 km radius.

[0102] See Figure 7 Test pile K375 is located 0.396 km upstream of the welding ignition point. The average electrical potential at the K375 test pile was -1.573V, showing almost no change. The average AC voltage was 0.158V (the baseline value is 0.111V), with a maximum of 0.399V and a minimum of 0.092V, exhibiting an amplitude of 0.307V. This AC voltage amplitude is 275.51% of the baseline value. Welding significantly affected the AC voltage variation at the K375 test pile location. Therefore, it can be determined that an oil theft incident occurred during pipeline drilling, and that the incident took place within a 0.5 km radius.

[0103] As can be seen, see Figure 8 Within a 5km radius of the ignition point, the tested cathodic protection test piles showed little change in the energized potential, but the AC voltage varied and was easily identifiable.

[0104] See Figure 9 As the distance between the test pile and the ignition point increased, the average energized potential remained basically unchanged, but the average AC voltage showed a decreasing trend, decreasing from 0.158V to 0.113V, a decrease of about 28.44%.

[0105] As the distance between the test pile and the hot work point increased, the AC voltage amplitude showed a decreasing trend, decreasing from 0.307V to 0.106V, a decrease of approximately 65.50%. Test pile K375 had the largest amplitude, reaching 0.307V during welding operations, which was 275.51% of the baseline value; test pile K371 had the smallest amplitude, reaching 0.106V during welding operations, which was 80.53% of the baseline value.

[0106] In summary, within 1 km of the hot work point, the impact of welding on AC voltage is relatively large and easily detected, with an amplitude change of up to 0.3070V; within 3 km of the hot work point, the impact of welding on AC voltage is noticeable and can be detected, with an amplitude of approximately 0.130V; within 5 km of the hot work point, the impact of welding on AC voltage is small and not significantly different from normal operation, with an amplitude of approximately 0.100V.

[0107] See Figure 10 The present invention also provides a monitoring system, comprising: a target oil pipeline selection module, a data acquisition module, a first calculation module, a second calculation module, a processing module, and an analysis module.

[0108] The target oil pipeline selection module is used to determine the oil pipeline to be monitored. The oil pipeline to be monitored includes at least one monitoring point.

[0109] The data acquisition module is used to acquire the electrical potential and AC voltage at any monitoring point at preset time intervals.

[0110] The first calculation module is used to determine the amplitude value of the energized potential corresponding to any monitoring point based on the acquired energized potential corresponding to any monitoring point.

[0111] The second calculation module is used to determine the amplitude value of the AC voltage corresponding to any monitoring point based on the AC voltage obtained at any monitoring point.

[0112] The processing module is used to obtain the first and second proportional values ​​corresponding to any monitoring point.

[0113] The descriptions of the first and second proportional values ​​can be found in the foregoing embodiments and will not be repeated here.

[0114] The analysis module is used to determine the location of the oil theft incident on the monitored oil pipeline based on the first and second proportional values ​​corresponding to each monitoring point, including at least one monitoring point.

[0115] As can be seen, this invention solves the problem of monitoring oil theft through drilling in oil pipelines. It does not require relying entirely on complex and cumbersome technical means such as oil pipeline leak detection systems, pipeline fiber optic early warning systems, pipeline internal detection technology and pipeline external detection technology. This invention can directly utilize existing equipment and technology of oil pipelines to monitor oil theft through drilling in oil pipelines.

[0116] This invention improves the monitoring accuracy of oil theft through pipeline drilling. While similar technologies rely on potentiostats within cathodic protection systems, these systems are often located far from the site of the theft, leading to attenuation of cathodic protection parameter changes along the pipeline. This invention, however, utilizes the pipeline's cathodic protection system while simultaneously monitoring changes in the energized potential and AC voltage of test piles, effectively confirming the location of oil theft through drilling and thus significantly improving monitoring accuracy.

[0117] The monitoring method provided by this invention has a wider range of applications compared to existing methods for monitoring oil theft through pipeline perforation. While similar technologies identify perforation-related oil theft events based on changes in pipe-to-ground potential measured by a potentiostat, the type of welding machine used by perforators is random. Therefore, this invention focuses on the changes in two cathodic protection parameters—current potential and AC voltage—and is applicable to the influence of different welding machines on changes in pipeline cathodic protection parameters, effectively expanding the applicability of this monitoring method.

[0118] In some solutions, multiple embodiments of this application can be combined, and the combined solution can be implemented. Optionally, some operations in the processes of each method embodiment may be combined, and / or the order of some operations may be changed. Furthermore, the execution order between the steps of each process is merely exemplary and does not constitute a limitation on the execution order between steps; other execution orders are also possible. It is not intended to indicate that the execution order is the only possible order in which these operations can be performed. Those skilled in the art will conceive of various ways to reorder the operations described herein. In addition, it should be noted that the process details involved in one embodiment of this document are similarly applicable to other embodiments, or different embodiments may be combined.

[0119] Furthermore, some steps in the method embodiments can be equivalently replaced with other possible steps. Alternatively, some steps in the method embodiments may be optional and can be deleted in certain use cases. Or, other possible steps may be added to the method embodiments. Moreover, the various method embodiments can be implemented individually or in combination.

[0120] Through the above description of the implementation methods, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0121] In the several embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or units may be electrical, mechanical, or other forms.

[0122] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0123] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, in essence, or the part that contributes, or all or part of the technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0124] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for monitoring oil theft through perforated oil pipelines, characterized in that, include: Identify the oil pipeline to be monitored; the oil pipeline to be monitored includes at least one monitoring point; For any monitoring point, the electrical potential and AC voltage at the location of any monitoring point are acquired at preset time intervals. Based on the acquired energized potential corresponding to any of the monitoring points, the amplitude value of the energized potential corresponding to any of the monitoring points is determined; Based on the AC voltage corresponding to any of the monitoring points, determine the amplitude value of the AC voltage corresponding to any of the monitoring points; Obtain a first proportional value and a second proportional value corresponding to any monitoring point; the first proportional value is the ratio of the amplitude value of the energized potential corresponding to any monitoring point to the reference value of the energized potential corresponding to any monitoring point. The second ratio is the ratio of the amplitude of the AC voltage corresponding to any monitoring point to the reference value of the AC voltage corresponding to any monitoring point. Based on the first and second proportion values ​​corresponding to each monitoring point, the location of the oil theft incident occurring on the oil pipeline to be monitored is determined. The method of determining the location of the oil theft incident on the monitored oil pipeline based on the first and second proportion values ​​corresponding to each monitoring point, including the at least one monitoring point, further includes: Based on the fact that the first proportion value corresponding to any monitoring point is greater than the first threshold, and the second proportion value corresponding to any monitoring point is greater than the second threshold, it is determined that a drilling and oil theft event has occurred in the coverage area corresponding to any monitoring point; the maximum distance between the boundary of the coverage area corresponding to any monitoring point and any monitoring point is the second preset distance; The method of determining the location of the oil theft incident on the monitored oil pipeline based on the first and second proportion values ​​corresponding to each monitoring point, including the at least one monitoring point, further includes: At least one abnormal monitoring point is identified; the first proportion value corresponding to the abnormal monitoring point is greater than a first threshold, and the second proportion value corresponding to the abnormal monitoring point is greater than a second threshold. For any one of the at least one abnormal monitoring points, obtain a first difference and a second difference corresponding to the abnormal monitoring point; the first difference corresponding to the abnormal monitoring point is the difference between the first ratio value corresponding to the abnormal monitoring point and the first threshold, and the second difference corresponding to the abnormal monitoring point is the difference between the second ratio value corresponding to the abnormal monitoring point and the second threshold. Based on the first difference and the second difference corresponding to each of the at least one abnormal monitoring point, the location of the oil theft incident occurring on the oil pipeline to be monitored is determined.

2. The method according to claim 1, characterized in that, The distance between any two adjacent monitoring points in the at least one monitoring point is a first preset distance.

3. The method according to claim 2, characterized in that, A cathodic protection test pile is installed at any of the monitoring points; the acquisition of the energized potential and AC voltage at any of the monitoring points at preset time intervals includes: Based on a multimeter, a reference electrode, and a cathodic protection test post set at any of the monitoring points, the energized potential and AC voltage at any of the monitoring points are acquired at preset time intervals; wherein, the multimeter includes a positive terminal and a negative terminal, the positive terminal is connected to the cathodic protection test post set at any of the monitoring points, and the negative terminal is connected to the reference electrode.

4. The method according to claim 3, characterized in that, Before obtaining the first proportional value and the second proportional value corresponding to any monitoring point, the method further includes: If it is determined that no oil theft incident has occurred in the oil pipeline to be monitored, the energizing potential and AC voltage at any monitoring point are acquired at preset time intervals. A reference value for the energized potential corresponding to any monitoring point and a reference value for the AC voltage corresponding to any monitoring point are determined; wherein, the reference value for the energized potential corresponding to any monitoring point is the average value of the energized potential at the location of any monitoring point obtained under the condition that no oil theft incident has occurred in the oil pipeline to be monitored; the reference value for the AC voltage corresponding to any monitoring point is the average value of the AC voltage at the location of any monitoring point obtained under the condition that no oil theft incident has occurred in the oil pipeline to be monitored.

5. The method according to claim 4, characterized in that, The step of determining the amplitude value of the energized potential corresponding to any monitoring point based on the acquired energized potential of any monitoring point includes: Based on the difference between the maximum and minimum values ​​of the energized potential corresponding to any monitoring point, the amplitude value of the energized potential corresponding to any monitoring point is determined.

6. The method according to claim 5, characterized in that, The step of determining the amplitude value of the AC voltage corresponding to any monitoring point based on the acquired AC voltage at any monitoring point includes: Based on the difference between the maximum and minimum values ​​of the AC voltage corresponding to any monitoring point, the amplitude value of the AC voltage corresponding to any monitoring point is determined.

7. A monitoring system, characterized in that, The method applied to any one of claims 1-6 includes: The target oil pipeline selection module is used to determine the oil pipeline to be monitored; the oil pipeline to be monitored includes at least one monitoring point; The data acquisition module is used to acquire the electrical potential and AC voltage at any monitoring point at preset time intervals. The first calculation module is used to determine the amplitude value of the energized potential corresponding to any monitoring point based on the acquired energized potential corresponding to any monitoring point. The second calculation module is used to determine the amplitude value of the AC voltage corresponding to any monitoring point based on the AC voltage obtained at any monitoring point. The processing module is used to obtain a first ratio value and a second ratio value corresponding to any monitoring point; the first ratio value is the ratio of the amplitude value of the energized potential corresponding to any monitoring point to the reference value of the energized potential corresponding to any monitoring point; the second ratio value is the ratio of the amplitude value of the AC voltage corresponding to any monitoring point to the reference value of the AC voltage corresponding to any monitoring point. The analysis module is used to determine the location of the oil theft incident on the oil pipeline to be monitored based on the first and second proportion values ​​corresponding to each monitoring point, including the at least one monitoring point.

8. The system according to claim 7, characterized in that, A cathodic protection test stake is installed at each of the monitoring points; the data acquisition module is used to acquire the energized potential and AC voltage at each of the monitoring points at preset time intervals, including: The data acquisition module is also used to acquire the energized potential and AC voltage at any monitoring point location based on a multimeter, a reference electrode, and a cathodic protection test pile set at any monitoring point location at preset time intervals; wherein, the multimeter includes a positive terminal and a negative terminal, the positive terminal is connected to the cathodic protection test pile set at any monitoring point location, and the negative terminal is connected to the reference electrode.

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