The Study on Magnetization Effect of Crude Oil by Terahertz Spectroscopy

Author:Jiang Chen

Supervisor:zhao kun


Degree Year:2018





There are many transportation methods in the process of storage and transportation of oil and gas resources,but the most effective and common method is still pipeline transportation.Oil viscosity during the pipeline transportation of crude oil directly affects the transportation efficiency.The magnetic processing is simple and easy to implement,the cost is relatively low,and the working environment is less demanding.It has quickly become a method with great potential for development in crude oil viscosity reduction.Terahertz spectroscopy is an emerging non-destructive coherent far-infrared detection technology in recent decades.Its unique frequency range is sensitive to weak intermolecular interactions.Terahertz spectroscopy can monitors the composition,component aggregation,and distillation of crude oil,which has a huge potential for application in the oil industry.In this work,the terahertz time-domain spectroscopy technique is used to perform a comprehensive and systematic analysis of the magnetization effects of crude oil.In the analysis process,electron microscopy and optical microscopy are combined to observe the morphology of the particle in the samples.A two-dimensional correlation analysis method is used to the analysis of terahertz spectral date,and an empirical formula is used to calculate the attenuated signal to quantitatively analyze the order of the particle in samples.The investigation of crystallization and crystal morphology is carried out for the sample under magnetic field,and also aggregation state of particle in crude oil of various magnetic field has been characterized.The main research results are listed as follows:1.Several different paraffin components are analyzed by spectral characteristics in the terahertz band.The surface morphology of these solid alkanes with different carbon number are observed by electron microscopy.Terahertz absorption spectrum is used to find out the common absorption peak of several alkanes in terahertz band,which provides a theoretical basis for the subsequent analysis of magnetization effect of crude oil.2.Terahertz spectroscopy has been used to monitor the natural condensation phase transitions of ten different alkanes in situ,and an empirical formulae is used to process the terahertz signal to obtain the corresponding attenuation signal.The attenuation signal is used to quantitatively analyze the order of particles in sample.The results have potential the terahertz technology has higher accuracy in determining the phase transition temperature of alkane sample,and can respond to the appearance of fine crystal grains inside the alkane sample.3.The magnetization and natural condensation transitions of different alkanes under the same magnetic field has been compared and analyzed.The magnetization effect on the relative order of the samples is quantitatively analyzed based on the signal attenuation curve.The magnetization effect on the ten groups of samples could slightly advance the phase transition point of the seven groups of alkane,but effectively reduce the phase transition point of hexacosane,octacosane and dodecane.At the same time,it has been found that although the phase transition point of nonadecane and triacontane don’t decrease under magnetization,the magnetization effect retarded the phase transition of the two alkanes.The degree of order of the sample increased and decreased in the opposite direction.4.The real crude oil has been monitored in situ by terahertz spectroscopy under different magnetic field intensity.Finally,the absorption spectra and extinction spectra of crude oil under several magnetic field is obtained through date processing.Combining with theoretical analysis,it is concluded that the diameter of aggregate in crude oil decreases with the increase of magnetic field intensity.The experiment of magnetization effect of model crude oil found that the magnetization effect on particles in oil is not completely consistent,the same magnetic field intensity shows different effects on model crude oil with different paraffin content.The specific effects of magnetization on wax crystals and wax crystals original state has an important relationship.