RU2702061C2 - Stationary device for determining point of oil and oil products leakage at pipeline sections using metal probes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to devices for diagnostics of objects for transportation and storage of oil and oil products. Device includes probes, a switch, an ohmmeter and a personal computer. Three probes connected to terminals of electronic switches are laid under the pipeline. First and second probes are made from the same metal while the third probe is made from the other metal. First and second probes are connected to the ohmmeter through the switchboard, and the second and third probes are connected to the voltmeter via the other switchboard. Ohmmeter and the voltmeter are connected to a personal computer.

EFFECT: technical result consists in improvement of accuracy of determining leakage of oil and oil product and its place in water-moistened soil and in various earth rocks, prevention of leaks of fuel from pipeline, higher reliability of its operation.

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Description

The invention relates to devices for diagnosing objects of transportation and storage of oil and oil products and can be used in the petrochemical and oil production sectors of petroleum products.

The present invention is most applicable when transporting oil and petroleum products in underground process pipelines.

Pollution of the lithosphere and hydrosphere occur as a result of fuel leaks from pipelines and tanks and other reasons.

If a spill of fuel from an onshore pipeline can be detected visually, then a leak of oil and oil products from an underground pipeline can only be determined by complex diagnostic methods. These methods include: visual and measuring control, ultrasonic and acoustic emission control, magnetometric and capillary control and other types of diagnostics [ПБ 03-585-03. Rules for the design and safe operation of process pipelines].

Hydraulic and pneumatic tests for strength and density are also carried out.

Many of these methods are associated with the release of pipelines from fuel, with the opening and excavation of soil in separate areas, with subsequent removal of insulation, with the measurement of wall thickness, with the control of welded joints.

By the timing of the following types of diagnostics are established: primary, next and extraordinary. Initial diagnosis is carried out no later than 2 years after the commissioning of the pipeline. The next diagnosis is carried out with a frequency of not more than 1 time in 8 years. Extraordinary diagnostics are carried out in the event of an incident or accident, when commissioning an object that has not been in operation for more than 3 years, and also 30 years after the commissioning of technological pipelines [RD-23.040.00-KTN-387-07. Diagnostics of technological oil pipelines NPS].

During operation, the walls of the pipeline are subjected to various types of corrosion, which are associated with the presence of sulfur and other aggressive compounds in oil and oil products, as well as water in the pipeline and in the ground.

Combating fuel losses from leaks in pipelines is becoming an important environmental and economic problem. A known method for detecting leaks of oil or oil products from the pipeline [Sh.I. Razmatullin et al. Patent for invention No. 2008113927 dated August 27, 2010. Method for detecting leaks of oil and oil products from a pipeline].

This method of hydraulic location of fluid leaks from a linear section of a pipeline involves detecting fluid leaks from a pipeline — by changes in fluid flow and the hydraulic slope of the pipeline by graphical construction or analytical calculation. In this method, the controlled linear section of the pipeline, not equipped with a flowmeter system, is divided into two adjacent segments and using pressure sensors located at the ends of each of them, friction pressure losses are measured (hydraulic slopes of each segment), which determine the mass flow rate of the liquid on each segment G _1-2 (i _1-2 ), G _2-3 (i _2-3 ) and periodically control the value of the mass flow unbalance.

The unbalance threshold value is determined based on the use and analysis of a database characterizing the pumping parameters (pressure, temperature, density, fluid viscosity) during the period preceding an emergency (leakage), using a statistical methodology.

The disadvantages of this method when diagnosing pipelines are:

1. The low efficiency of the method with small leaks of fuel from the pipeline.

2. The complexity of the determination and the large time required for calculations.

3. Application of the method for sections of the pipeline of small length.

A device for detecting a leak of petroleum products in the pipeline [V.P. Dobrovolskov and others. Application for invention No. 95106872 of 04/20/1997, a device for detecting a leak of petroleum products in the pipeline].

The device is designed to detect the place of damage, accompanied by a leak of oil products. The invention solves the problem of simplifying the design, improving the reliability and fire and explosion safety of the device when it detects a leak of petroleum products from the pipeline. The invention consists in the following. The cable and conductor are made of fiber optic fibers laid outside the pipeline in two lines of the same length at a calculated distance from each other. The cable and conductor are connected at the end of the pipeline to the measuring unit of the leak. On both lines of the optical fibers, the polymer cladding is removed at certain distances, and the sections with the removed cladding are opposite each other in the housing with holes, while on one of the lines, the beginning of which is optically coupled to a radiation source electrically connected through the divider to the output of the launch unit , the sections of the fiber optic fiber with the removed sheath are covered with a polymer film, and the beginning of another line is optically coupled to a photodetector electrically connected to the measuring unit, Torah input coupled to one of the splitter outputs.

The disadvantages of this device are:

1. The presence in the design of a large number of additional buildings with holes located over small distances, which significantly increases the cost and metal consumption of the device.

2. Insufficient accuracy of determining the place of leakage from the pipeline. The resolution is determined by the frequency of location of the sections with the remote shell located in the housing with holes.

3. The technical complexity of determining the location of the leak. The device consists of complex and expensive elements.

Also known stationary device for diagnosing and detecting the leakage of oil and oil products in the pipeline [Matveev Yu.A. et al. Utility Model Patent No. 136527 of January 10, 2014. A stationary device for diagnosing and detecting a leak of oil and oil products in a pipeline].

Under the proposed pipeline, which has welds, a fuel meter, pressure gauge, gate valve, insulation, in a layer of ground soil, conductors with insulators are laid in parallel in two lines. The conductors are connected by communication lines to ohmmeters, which are also connected to a personal computer by communication lines. Conductors are made of nickel plated copper. Insulators are PVC coated.

The fuel meter, an ohmmeter and a valve are located in the technological well.

The invention works as follows. Oil is pumped through the pipeline.

In order to constantly diagnose the presence of leaks under the pipeline using communication lines, ohmmeters, resistance measurements are made between conductors with insulators of various lines that are output to a computer. At the same time, the resistance of the “dry” line is measured, which in the presence of leaks will decrease, and the value of the resistance during leakage will determine the place of leakage from the pipeline.

In the event of an oil product leakage from the pipeline, the values of the measured resistances begin to decrease and go beyond the established interval.

Assessment of the resistance values between the conductors located in the ground parallel to each other using ohmmeters and a computer allows us to determine not only the presence of oil and oil products from the pipeline, but also to identify the specific location of the leak in order to effectively repair the pipeline.

The disadvantages of this device are:

1. The presence in the design of two lines of conductors, which increases the cost and metal consumption of the device.

2. Insufficient accuracy of determining the place of leakage from the pipeline, since the lines of conductors are long and pass through the soils of various soils and rocks with different resistance.

3. The technical complexity of determining the location of the leak.

Closest to the indicated problem is a stationary device for diagnosing and detecting the place of leakage of oil and oil products in certain sections of the pipeline [Matveev Yu.A. et al. Utility Model Patent No. 151156 of March 20, 2015. A stationary device for determining the place of leakage of oil and oil products in certain sections of the pipeline].

Under the proposed pipeline, having welds, a fuel meter, pressure gauge, gate valve, insulation, in a layer of ground soil, a conductor with insulators is laid in one line. The conductor is connected to an ohmmeter by a communication line. The conductor is made of aluminum. Insulators are PVC coated.

The fuel meter, an ohmmeter and a valve are located in the technological well.

Aluminum probes are installed at a distance of 5-10 cm above the conductor. Aluminum probes are connected by communication lines to the terminals of the electronic switch and an ohmmeter.

An ohmmeter is connected to a personal computer by a communication line.

The utility model works as follows. Oil is pumped through the pipeline.

In order to continuously detect leaks under the pipeline using communication lines, an ohmmeter, soil resistance is measured between the conductor line and aluminum probes. The probes through the electronic switch are alternately connected to the ohmmeter and the soil resistance values are displayed on the computer. In this case, at the initial moment, the resistance of soil not moistened with oil and oil products is measured. In the presence of leaks of oil and oil products, the soil resistance between the conductor line and the aluminum probe will increase significantly, which will determine the place of leakage from the pipeline.

In the event of an oil product leakage from the pipeline, the values of the measured resistances begin to increase and go beyond the established interval along the pipeline sections.

The disadvantages of this device are:

1 Insufficient accuracy of determining the place of leakage from the pipeline in wet soil, since the resistance of wet soil moistened with oil will increase slightly.

2. Insufficient accuracy of determining the place of leakage from the pipeline, since the line of the conductor with insulators has a large length and passes through the soils of various soils and rocks with different resistance.

The objective of the present invention is to increase the accuracy of determining the leakage of oil and oil in water-moistened soil and in various rocks, preventing leakage of fuel from the pipeline, increasing the reliability of its operation.

The technical result is achieved by measuring the resistance of the soil between probes of the same metal, measuring the voltage of the soil between the probes of different metals, followed by an assessment of the values, which allows you to determine not only the presence of leakage of oil and oil products from the pipeline, but also to identify its specific place.

The specified technical result is achieved by the fact that the stationary device for determining the place of leakage of oil and oil products in the pipeline using metal probes includes probes, a switch, an ohmmeter and a personal computer, while three probes are laid under the pipeline connected to the terminals of electronic switches, the first and second probes made of the same metal, and the third probe of another metal, in addition, the first and second probes are connected to an ohmmeter through the switch, the second and third probes are through second switch connected to a voltmeter, ohmmeter and a voltmeter connected to a personal computer.

The above analogs also previously used probes made of the same metal, which were connected to an ohmmeter through a switch to determine the soil resistance over sections of the pipeline. An ohmmeter was connected to a personal computer. The measured values of the resistance were used to determine the leakage of oil and oil products from the pipeline.

The invention is illustrated by drawings (Fig. 1, Fig. 2), which depict: a functional diagram of a device for detecting leaks and a frontal section of a pipeline with conductors.

Under the proposed pipeline 1 (Fig. 1), having welds 2, a metering device 3, a pressure gauge 4, a valve 5, insulation 6 (Fig. 2), in a layer of soil 7, are laid parallel to each other and at a given distance of the probes 8 , 9, 10. The probes 8, 9 are made of the same metal, for example, copper. Probe 10 of another metal, for example, steel. In the soil between the probes of different metals there is a voltage (potential difference). When the earth is wetted with oil (oil), the voltage of the soil between the probes of different metals varies significantly.

The probes 8, 9 are connected by a communication line 11 to the terminals 12 of the first electronic switch 13. The switch is connected to an ohmmeter 14, which is connected by a communication line 11 to a personal computer 15.

The fuel meter, an ohmmeter and a valve are located in the technological well 16.

The probes 8, 9, 10 are installed between each other at a distance of 5-10 cm. The steel probe 10 and the copper probe 9 are also connected via communication lines 11 to the terminals 12 of the second electronic switch 13, which is connected to the voltmeter 17. The voltmeter 17 is connected to the communication line 11 with a personal computer 15.

The invention works as follows. Oil product 18 is pumped through a pipeline 1.

In order to constantly detect leaks under the pipeline 1 using communication lines 11, ohmmeter 14, soil resistance is measured between the probes of the same metal 8, 9. The probes are connected through an electronic switch 13 to the ohmmeter 14 and the soil resistance values are displayed on the computer 15. In this case at the initial moment, the resistance of soil not moistened with oil and oil products is measured. In the presence of leaks of oil and oil products 19, the soil resistance between the probes 8 and 9 will increase significantly, which will determine the place of leakage from the pipeline.

Also, in order to more accurately determine leaks under the pipeline 1 using communication lines 11, voltmeter 17, soil voltages are measured between probes of different metals 9, 10. The probes are connected through an electronic switch 13 to the voltmeter 17 and the voltage values of the soil are displayed on a computer 15. Moreover, at the initial moment, the voltage of the soil not moistened with oil and oil products is measured. In the presence of leaks of oil and oil products 19, the soil stress between the probes 9 and 10 will be significantly reduced, which will determine the place of leakage from the pipeline.

In the event of leakage of the oil product 19 from the pipeline 1, the values of the measured resistances (stresses) begin to increase (decrease) and go beyond the established interval along the pipeline sections.

Assessment of the resistance (stress) values of the soil between the probes using an electronic switch, an ohmmeter, a voltmeter, and a computer allows us to determine not only the presence of oil and oil products from the pipeline, taking into account humidity and various types of soil, but also to identify a specific leak point in the most dangerous areas pipeline for the purpose of efficient repair.

With the simultaneous passage of several oil pipelines, the invention will determine the leakage of a particular oil product from the pipeline. This definition is based on different values of the resistances and stresses of the soil moistened with gasoline, diesel fuel or oil. The measured values of the resistance and stress of the soil are compared with the statistical indicators of the indicated values of the soil moistened with gasoline, diesel fuel or oil. After the analyzes and comparisons, a conclusion is drawn about the leakage of a specific oil product or oil from oil pipelines.

Claims (1)

A stationary device for determining the place of leakage of oil and oil products in the pipeline using metal probes, including probes, a switch, an ohmmeter, a personal computer, characterized in that under the pipeline are three probes connected to the terminals of electronic switches, the first and second probes are made of the same metal, and the third probe is from another metal, in addition, the first and second probes are connected to an ohmmeter through a switch, the second and third probes are connected to a voltmeter through another switch , and an ohmmeter and a voltmeter are connected to a personal computer.

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