A method for rapidly detecting the corrosion rate of chelating acid

Abstract

A method for quickly detecting the corrosion rate of chelating acid. Putting the petroleum casing into the detection bottle, pouring the chelating acid to be detected into the detection bottle, and immersing the chelating acid to be detected into the petroleum casing; Add the corrosion inhibition performance detection solution into the solution, stir evenly, and after standing still, compare the steel sheet with the color comparison card to find the color closest to the steel sheet on the color comparison card, so as to determine the corrosion rate range and grade of the chelated acid. The invention can qualitatively and quickly measure the rate range of the chelating acid corroding the steel sheet, realize the monitoring of the quality of the chelating acid during the on-site construction process, have simple detection steps, and provide data basis and quality assurance for the on-site acidizing construction effect.

Description

technical field [0001] The invention belongs to the field of pressure reduction and injection enhancement of water injection wells, and in particular relates to a method for quickly detecting the corrosion rate of chelating acid. Background technique [0002] At present, the commonly used methods for measuring the corrosion rate of metals are gravimetric method, titration method, electrochemical method and polarization curve method. These methods have certain requirements for instruments and can only be measured indoors at present. The gravimetric method is a more classical method, and it is also one of the most reliable methods for measuring the corrosion rate of metals. However, it is necessary to determine the quality change of metal coupons, which makes the operation cumbersome and takes a long time (generally at least 4 hours), which is harmful to the operation. Standardization and accuracy requirements are high. [0003] Conventional acidizing is currently the main me...

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Problems solved by technology

Conventional acidizing is easy to corrode the pipe string due to the acid liquid, so that the on-site construction needs to take out the original pipe string, then run the acidizing pipe string, and replace the original pipe string after the construction is completed. Big

However, the chelating acid has a low corrosion rate, can realize non-stop well and non-moving pipe string construction, and greatly shortens the construction time. At present, it has been popularized and applied in more than 200 wells in Changqing Oilfield, and the production increase effect is remarkable. However, during on-site construction, Due to the lack of scientific and rapid detection methods, it is impossible to ensure that the corrosion rate of the acid solution in the original well pipe string can fully meet the standard. At the same time, the measurement of the acid solution corrosion rate can only be taken back to the laboratory for testing, and the overall cost is high.

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