A method for on-line monitoring and evaluation of cathodic protection

Abstract

The invention discloses a cathodic protection site online monitoring and evaluating method which is used for monitoring the state and evaluating the effect of a cathodic protection system of equipment such as buried pipelines in a high-risk oil and gas transmission station. The method comprises the following steps: 1) adopting a buried saturated copper sulfate reference electrode and a site buried pipeline as a cathodic protection potential monitor; 2) transmitting cathodic protection signals of the monitor to a receiver outside the station by using a data cable; 3) carrying out data transmission on cathodic protection potential signals with a computer through A / D (Analog to Digital) conversion via a communicator; 4) monitoring a cathodic protection potential value and a cathodic protection current value on line in real time; 5) setting a valid cathodic protection potential range; 6) judging the validity of the cathodic protection potential in real time and giving out an evaluating result; and 7) warning when the evaluating result is abnormal and giving out a treatment scheme aiming at common problems. The method has the advantages of good universality, high degree of automation, high monitoring precision and real-time warning.

Description

technical field [0001] The invention belongs to the technical field of corrosion and protection, and in particular relates to a method suitable for on-site on-line monitoring and evaluation of cathodic protection in high-risk natural gas transportation stations. Background technique [0002] In oil and natural gas storage and transportation, most of the equipment used, such as pipelines, are buried below the ground and are corroded by the soil medium; the bottom of the oil storage tank is also in contact with the soil medium and is corroded by the soil medium. The corrosion of steel pipes and storage tanks in the soil environment is very serious. Once perforation occurs due to corrosion, resulting in leakage accidents, it will cause huge economic losses. It is necessary to stop the transmission and repair and repair the equipment. The leakage of the transmission medium will also cause environmental damage. severely polluted. For example, in 2013, the Sinopec Qingdao "11·12"...

AI Technical Summary

Problems solved by technology

If the detection period is too long, it is difficult to ensure the effectiveness of cathodic protection; if the detection time is too short, the detection cost will increase sharply, which is uneconomical

For high-risk places such as natural gas transmission stations, frequent manual inspections bring certain unsafe factors to the stations and cannot meet the special safety requirements for natural gas transmission stations

[0006] With the extension of time, the water absorption, aging and damage of the coating of the buried pipeline will affect the cathodic protection potential, causing the cathodic protection potential to drop, so that some buried pipelines and other facilities will be insufficiently protected

At the same time, it may also cause interference between different buried pipelines, affecting the effectiveness of the cathodic protection system

Due to the narrow space of the natural gas transmission station, the maintenance of pipelines and valves, the construction of expansion and reconstruction projects will have a certain impact on the protection potential of the existing cathodic protection system, and it is necessary to detect the protection potential of buried pipelines in time , to find insufficient or over-protected cathodic protection, and manual detection is difficult to find these problems in time

[0007] The evaluation of manual detection results is often determined by experience, not very accurate, and difficult to reflect the specific situation of cathodic protection

The replacement of testing personnel often brings difficulties to the evaluation of testing results, and it is even more difficult to evaluate the historical results of cathodic protection

[0008] In order to solve the shortcomings of manual detection of cathodic protection status of buried pipelines in high-risk natural gas transmission stations, which are not timely, unsafe, and difficult to evaluate, the present invention specifically relates to a method for on-site cathodic protection on-site monitoring and evaluation, which is used for high-risk oil and gas transmission stations. Monitor and evaluate the status of the cathodic protection system to ensure the effectiveness of the cathodic protection system and the safety of the natural gas transmission station

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