A Study On Detection Method Of Low Speed And High Water Cut Crude Oil Based On NIR Technique

The water content of crude oil is an important technical indicator in oil production.After the oil field is in the high water cut stage,real-time detection of crude oil moisture content is of great significance in estimating crude oil production and evaluating the value of oil well exploitation.The existing moisture content test method has a large test error in high water content,and it is necessary to adopt a new test method to improve the test accuracy and ensure the practicability of the test data.In this paper,the near-infrared light is used to study the water content detection method of low-flow high-water crude oil,and the static oil-water spectrum is modeled and analyzed.The experimental device for real-time measurement of oil-water twophase flow at low flow rate is designed.Convective flow regime The analysis was carried out,and the BP neural network was used to identify the flow pattern to improve the detection accuracy.In this paper,the absorption characteristics of high water cut crude oil for near-infrared light are gradually discussed.Firstly,according to Lambert Beer's law,a static high water cut crude oil moisture content detecting device is designed.Through the experiment,the fullspectrum data of 900nm-1700 nm under the same thickness and different water content can be obtained.The static model of high water cut crude oil was established by Partial Least SquaresSuccessive Projection Algorithm method(SPA-PLS)and good precision was obtained.According to the experimental results and the requirements of the sensor,the Self-CrossCorrelation joint method(SCC)is proposed to mine the data of the complete absorption band.Using the autocorrelation and cross-correlation of oil and water,the appropriate wavelength band is selected as the detection wavelength.The method selects the experimental wavelength.In the design stage of dynamic high-water crude oil experimental device,the experimental device uses tungsten halogen lamp and color filter to extract specific wavelength,designed photoelectric conversion circuit,designed the upper computer software based on LabVIEW,realized real-time data acquisition and storage.The ideal effect was obtained in the dynamic moisture content test experiment.The oil-water mixed flow pattern characteristics of low-flow and high-water vertical rising pipelines are analyzed.The BPN is used to train the detection signals for flow patterns identification.Different water content calculation methods are adopted for different flow patterns to improve the measurement accuracy.Theoretical and experimental data support is provided for the development of near-infrared-based fiber-optic high-water crude oil moisture content sensors for downhole.