Carbon dioxide pipeline flow regulation and differential pressure flowmeter precision test and calibration system

Abstract

The invention provides a carbon dioxide pipeline flow regulation and differential pressure flowmeter precision test and calibration system which is applied to pipelines for conveying liquid, dense-phase and supercritical carbon dioxide. According to the carbon dioxide pipeline differential pressure flowmeter precision test and calibration system, a mass flow meter is used as a reference flow meter, and the precision and correction coefficients of the differential pressure flow meters in all branch pipelines of the carbon dioxide pipeline are tested and calculated in combination with a carbon dioxide density compensation method; according to carbon dioxide pipeline flow regulation system, the mass flow value of carbon dioxide in each branch pipeline is calculated according to differential pressure data monitored by differential pressure flow meters in each branch pipeline by applying the correction factor and combining the carbon dioxide density compensation method, and thus he openingdegree of the electric control valves in all the branch pipelines is controlled, and thus the flow of carbon dioxide in each branch pipeline can be accurately controlled. Therefore, the system has theadvantages of cost saving and accurate control.

Description

technical field [0001] The invention relates to the field of carbon dioxide flooding surface engineering in oilfields, in particular to a pipeline used in transporting liquid, dense phase and supercritical carbon dioxide to test the accuracy and correction coefficient of differential pressure flowmeters in each branch of the pipeline A carbon dioxide pipeline flow adjustment and differential pressure flowmeter accuracy test and calibration system that can accurately control the flow of carbon dioxide in each branch pipeline. Background technique [0002] The wellhead injection pipeline usually transports liquid carbon dioxide, and the accurate measurement of the flow of carbon dioxide is a crucial link in the injection process of carbon dioxide flooding ground engineering. However, due to the influence of temperature and pressure, the carbon dioxide in the pipeline is often in a dense phase, Supercritical state, and the density of carbon dioxide is a function of temperature ...

AI Technical Summary

Problems solved by technology

This characteristic of carbon dioxide is completely different from water, oil and other substances. Therefore, in commonly used pipelines, general flowmeters (such as differential pressure flowmeters, volumetric flowmeters, velocity flowmeters, etc.) measure water and oil. The flow accuracy is high, but the flow accuracy of measuring carbon dioxide is poor, and the accuracy error can reach 30% or even higher, which cannot be used to guide production

However, since the total flow of carbon dioxide to be transported is constant, the flow adjustment of each branch pipeline will inevitably interfere with each other, resulting in bias flow, and it is difficult to achieve the purpose of coordinating and automatically adjusting the carbon dioxide flow of each branch pipeline

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