Device for monitoring corrosion of oil and gas field gathering pipelines and corrosion inhibitor filling system

Abstract

The invention discloses a device for monitoring corrosion of oil and gas field gathering pipelines. The device comprises an MCU, a signal generator, a constant-potential circuit, a power amplifier, a corrosion monitoring probe low-pass filter and an A / D data acquisition unit. The MCU controller is used for transmitting waveform data to the signal generator to generate sine waves at certain frequency, loading the sine waves to the constant-potential circuit to form polarization current and outputting the polarization current to a corrosion monitoring probe through the power amplifier. Polarization potential and the polarization current of the corrosion monitoring probe are filtered through the low-pass filter and then transmitted to the A / D data acquisition unit to be acquired, the MCU is used for processing acquired potential and current data, dielectric resistance and polarization resistance of a working electrode can be obtained, the corrosion rate of the working electrode can be obtained, and then pipeline corrosion monitoring is achieved. The invention further discloses an intelligent corrosion inhibitor filling device. The filling concentration of corrosion inhibitor can be adaptively and dynamically adjusted according to the measured value of the pipeline corrosion rate and a fuzzy control algorithm, and therefore the pipeline corrosion control strategy is optimized accordingly, and scientific filling of the corrosion inhibitor is achieved.

Description

technical field [0001] The invention belongs to the technical field of anticorrosion of oilfield pipelines, and in particular relates to a corrosion monitoring system for gathering and transporting pipelines in oil and gas fields and a system for injecting corrosion inhibitors using the monitoring results of the above-mentioned device. Background technique [0002] The comprehensive water content of the produced fluid in the oil and gas field will increase year by year in the later stage of exploitation, and the highest may even exceed 90%. For example, it can be greater than 50°C) and other characteristics, plus H 2 S, CO 2 , SRB and other synergistic effects often cause severe corrosion and perforation of surface pipelines and downhole strings. Pipeline corrosion not only brings large economic losses, but also causes serious environmental pollution problems. In order to control the corrosion of the pipe network, it is necessary to continuously inject corrosion inhibitor...

AI Technical Summary

Problems solved by technology

However, the above scheme still has disadvantages such as inaccurate measurement results and the inability to measure multiple parameters at the same time. Moreover, due to the influence of various factors such as flow velocity in the pipe, corrosion inhibitor adsorption and desorption, and changes in the location of monitoring points, the corrosion rate and slowdown of the pipeline are different. There is a time difference in the injection concentration of the corrosion agent, resulting in the inability to accurately match the monitoring results with the added corrosion inhibitor due to dynamic changes

[0005] Moreover, the current method of adding corrosion inhibitors mainly uses manual adjustment of metering pumps. For example, Chinese patent CN203999516U uses solenoid valves and distribution boxes to realize automatic dosing of corrosion inhibitors in the oil refining process. The metering pumps are controlled by monitoring devices and PLC controllers. control, but this solution does not realize the automation of corrosion monitoring and feedback dosing control, the actual dosing amount still depends on manual adjustment

In this way, the injection concentration of corrosion inhibitor cannot be automatically adjusted to the best according to the change of the corrosion rate of the pipe network, which may easily lead to insufficient or excessive dosage, resulting in waste of chemicals

More importantly, the current pipeline network is complex, and considering the fluidity of reinjection water, the corrosion rate of a single monitoring point often cannot accurately reflect the corresponding corrosion situation, making the injection of corrosion inhibitors unable to effectively relieve the corrosion of the pipeline network. Corrosion

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