CN-121784842-B - Self-calibration real-time accurate detection method and system for multiphase flow medium in oil gas pipeline

CN121784842BCN 121784842 BCN121784842 BCN 121784842BCN-121784842-B

Abstract

The invention belongs to the technical field of oil-gas medium detection, and provides a self-calibration real-time accurate detection method and system for multiphase flow medium in an oil-gas pipeline. The method comprises the steps of immersing a detection transmission line and a T4R calibration piece in the same detection environment, inverting the dielectric constant of fluid to obtain an inversion result of the dielectric constant for component analysis, and accurately positioning foreign matters in a pipeline by utilizing an optimized frequency diversity sensing method. The system includes a calibration and sensing unit and a signal processing and control unit. According to the invention, the T4R calibration method is introduced to calibrate the measurement data of the detection transmission line and the offset reflection calibration piece, dielectric inversion is performed by using the measurement data calibrated by the detection transmission line and the offset reflection calibration piece, the component analysis precision and stability are better, the frequency diversity sensing method is improved by using the measurement data calibrated by the detection transmission line, dependence on priori information is eliminated, and the foreign matter positioning of a packaging scene is realized.

Inventors

Gao Muzhi
LV YANLIN
ZHU GAOYANG
WANG BIN
XING LANCHANG

Assignees

中国石油大学(华东)

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (7)

1. The self-calibration real-time accurate detection method of multiphase flow medium in oil gas pipeline is characterized by comprising the following steps: Firstly, immersing a detection transmission line and a T4R calibration piece in the same detection environment, and realizing online calibration of the detection transmission line and an offset reflection calibration piece in a detection process by a T4R calibration method; Then, inversion of the dielectric constant of the fluid is carried out for component analysis; finally, the optimized frequency diversity sensing method is utilized to realize the accurate positioning of the foreign matters in the pipeline; The two-port network parameters of the connection structures at the two sides of the detection transmission line are obtained by measuring the input reflection coefficient S 11 Offset of deflection n of each offset reflection calibration piece and the scattering parameter S Straight line of one straight-through calibration piece, and the two-port network parameters of the connection structures at the two sides of the detection transmission line are used for processing the measurement data of the detection transmission line and the offset reflection calibration pieces, wherein n in S 11 Offset of deflection n represents the number of the input reflection coefficients of the measured offset reflection calibration pieces and is determined by the number of the offset reflection calibration pieces; Directly using the no-load forward transmission coefficient S 21 Empty school data after the calibration of the detection transmission line to calculate the propagation constant gamma of the sensing area when the detection transmission line is in the working environment, constructing a measurement matrix H by using the calculated propagation constant gamma, when the foreign matter passes through the sensing area, changing the input reflection coefficient S 11 Inspection and detection of the detection transmission line, and using the input reflection coefficient S 11 Checking and correcting device after the calibration of the detection transmission line in the compressed sensing process to obtain the position of the foreign matter; the calculation formula of the propagation constant gamma is as follows: ; S 21 Empty school is the no-load forward transmission coefficient after the calibration of the detection transmission line, and l is the length of the detection transmission line sensing area; the formula for constructing the measurement matrix H is as follows: ; Wherein ω is angular frequency, i is index of spatial sampling point, γω represents propagation constant γ changing with ω, x i is spatial position coordinate; the formula of the compressed sensing process is: ; S 11 Checking and correcting device is the input reflection coefficient after the calibration of the detection transmission line, H is a measurement matrix, mu is a regularization parameter, rho is a local reflection coefficient estimated value, the detection transmission line is obtained by minimizing an objective function, and the position of the foreign matter is judged according to the value of rho.
2. The method for precisely detecting multiphase flow media in an oil and gas pipeline in real time according to claim 1 is characterized in that the fluid dielectric constant inversion is carried out, on one hand, the scattering parameter S Inspection and detection of a detection transmission line is processed by a T4R calibration method, the scattering parameter S Checking and correcting device of the detection transmission line after calibration is utilized, the dielectric constant inversion is carried out by an NRW algorithm, on the other hand, the input reflection coefficient S 11 Offset of deflection n of an offset reflection calibration piece is processed by the T4R calibration method, the input reflection coefficient S 11 Offset correction n of the offset reflection calibration piece is utilized, the dielectric constant is subjected to secondary inversion by a single-port multi-line reflection method, and the dielectric inversion result of the detection transmission line measurement data and the dielectric inversion result of the offset reflection calibration piece measurement data are averaged after abnormal values are removed, so that a final dielectric constant inversion result is obtained and is used for component analysis.
3. The method for self-calibrating real-time accurate detection of multiphase flow media in an oil and gas pipeline according to claim 2, wherein the single-port multi-line reflection method is characterized in that the single-port reflection method is used for processing the input reflection coefficient S 11 Offset correction n after the calibration of a plurality of offset reflection calibration pieces, and dielectric constant inversion is respectively carried out by combining the measurement data of each offset reflection calibration piece with the offset length of each offset reflection calibration piece.
4. The self-calibration real-time accurate detection method of multiphase flow media in an oil and gas pipeline according to claim 2, wherein the outlier is a dielectric constant inversion result with abnormally large numerical deviation compared with other measured values in the detection process.
5. A self-calibrating real-time accurate detection system for multiphase flow media in an oil gas pipeline, which is used for realizing the self-calibrating real-time accurate detection method for multiphase flow media in an oil gas pipeline according to any one of claims 1-4, and is characterized by comprising a calibration and sensing unit and a signal processing and control unit: The calibration and sensing unit comprises two detection transmission lines and a T4R calibration piece, and the T4R calibration piece and the detection transmission lines are arranged at the same position of the oil gas pipeline during measurement and used for measuring required calibration data and sensing data; the signal processing and controlling unit comprises a display screen, a control button and a processor, wherein the processor processes calibration data and sensing data through a T4R calibration method, an NRW inversion algorithm, a single-port multi-line reflection algorithm and a frequency diversity sensing algorithm to obtain a fluid component analysis result and a foreign matter positioning result, the fluid component analysis result and the foreign matter positioning result are realized on the display, and the measuring state is changed through the control button.
6. The self-calibrating real-time accurate detection system for multiphase flow media in an oil and gas pipeline according to claim 5, wherein the T4R calibration piece and the detection transmission line are fixed into the oil and gas pipeline through a connecting flange.
7. The self-calibrating real-time accurate detection system of multiphase flow media in an oil and gas pipeline according to claim 5, wherein the measuring state comprises: (1) Calibration setting, wherein the calibration is performed before ① detection, and the calibration is performed according to a set time interval during ② detection; (2) The component detection comprises ①, ② and ②, wherein the ① automatically selects which inversion result is acquired; (3) Foreign matter positioning, ① particle positioning, ② bubble positioning, ③ particle and bubble positioning.

Description

Self-calibration real-time accurate detection method and system for multiphase flow medium in oil gas pipeline Technical Field The invention relates to a method and a system for detecting multiphase flow media in oil and gas (petroleum and natural gas) pipelines, belonging to the technical field of oil and gas media detection. Background In the pipeline transportation process of oil gas, the method has important significance for real-time accurate monitoring of the composition of multiphase flow media in the pipeline and the distribution conditions of foreign matters such as bubbles, rock particles and the like, ensuring the transportation safety, optimizing the process and controlling the transportation process. The microwave sensing technology is considered as an effective means for achieving the above-mentioned objects because of its advantages such as non-invasiveness, rapid response speed, high measurement sensitivity, etc. At present, the method for detecting multiphase flow media in an oil gas pipeline mainly performs dielectric constant inversion on fluid in the pipeline so as to analyze the composition components of the fluid. Under the working condition of complex field, the detection result is easily influenced by factors such as deterioration of the performance of the detection transmission line under extreme environment, medium change and the like, so that the dielectric constant inversion precision is low and the stability is poor. Meanwhile, the existing detection method is single in function and difficult to monitor the distribution of foreign matters in the fluid in real time. The T4R (through-four offset reflection) calibration method in the prior art implements the detection transmission line calibration using at least four sets of offset reflection calibration pieces and one through calibration piece, wherein the number of offset reflection calibration pieces is increased (i.e., greater than four sets), so that the calibration bandwidth and accuracy can be improved (4 in T4R becomes the same number as the number of sets). The "group" is referred to herein as four groups because when the connection structures on both sides of the detection transmission line (i.e., the portions on both sides of the sensing region of the detection transmission line for impedance matching with the connection cable, simply referred to as connection structures) are different, the offset reflection calibration pieces required for the two ports are different. The T4R calibration method can remove the response information of the connection structure of the calibrated device, avoid the influence of the response information of the DUT (the detection transmission line sensing area in the middle of the invention) and the offset reflection area of the offset reflection calibration piece on the sensing result, and achieve the aim of improving the accuracy of the sensing result. The T4R calibration method (see the literature in detail: A Multireflect-Thru Method of Vector Network Analyzer Calibration (the multi-reflection-through calibration method ）",[J].IEEE Transactions on Microwave Theory and Techniques, 2017, 65(3):905-915.DOI:10.1109/TMTT.2016.2627036.） of the vector network analyzer is an improvement on the TRL calibration method, the difference between the TRL calibration method and the T4R calibration method is that the design and calculation process of the calibration piece are different, but the purposes are the same, the two calibration methods are both to obtain two-port network parameters of the connection structure at two sides of the DUT (when the calibrated device is a single-port device, only two-port network parameters of the single-side connection structure are required to be obtained), the means for processing the measurement data of the calibrated device after obtaining the parameters are the same and general, the scattering parameters S dut of the DUT are obtained through the conversion relation between the scattering parameters S and the transmission matrix T and the cascade operation of the matrix, and the input reflection coefficients S 11dut of the DUT are obtained through the correction operation by using the single-port error model for the single-port device, and at the moment, the correction is carried out only by using the two-port network parameters of the single-side connection structure connected with the single-port device. Although the above-described T4R calibration method is prior art, it has not been used for hydrocarbon testing. In component measurement, the dielectric constant of the fluid is generally inverted by measuring and detecting the scattering parameter S Inspection and detection of the transmission line, so as to determine the component, and the current more general method is to use the NRW algorithm. According to the method, two detection transmission lines are immersed in a measured medium to measure scattering parameters S Inspection and detection , and the scatte