Mechanism Research On Functional Polyether Material Applied To Crude Oil

Crude oils usually have been extracted from underground in the form of stable emulsions.However,the rapid development of petroleum industry and obvious progress of mining technology make crude oil emulsion becomes more stable,which results in a series of new problems.Therefore it's necessary to deeply study the demulsification mechanism responsible for the stability of crude oil emulsion and the influence factors,and constantly develop new demulsifiers.Polyether is widely applied in oilfield as demulsifier.However,the structure-property relationship of polyether as demulsifier has not been evaluated.Therefore,the effective treatment of crude oil produced fluids by new methods of enhanced oil recovery is still in lack.In this paper,combining the surface and interfacial dilational rheology measurements,and establishing periodic oscillation method and interfacial tension relaxation experiments,air-water and oil-water interfacial rheological studies on different structures of polyether demulsifiers PE600,PE1800 and PE10000 have been conducted.Interfacial Zeta potential has been obtained by using Zeta potential analyzer for systems with demulsifiers.On the other hand,the comprehensive data on the stability of the simulated emulsion have also been obtained added TA01 and PAB03 by emulsion stability analyzer based on near infrared transmission and scattering light and then analyze the mechanism.Firstly,the surface parameters of different structure of demulsifier have been measured by using the surface tension meter.The effects of oscillation frequency,demulsifier concentration and structure of demulsifier on the surface properties have been investigated by surface dilational rheology.It indicates that for the different demulsifier concentrations,the dilational modulus and dilatational elasticity show little change with increasing frequency.This may be because the experimental frequency range deviates from the main characteristic frequency of relaxation process.In addition,improving the demulsifier concentration,dilational modulus dilational elasticity both appear a maximum.Secondly,surface tension relaxation method was used to study the surface microscopic relaxation process of demulsifier.At low concentration,surface film forms strong elastic surface film,and molecular reorientation process determines the nature of the surface membrane.With increasing bulk concentration the study shows the diffusion becomes more important.Thirdly,kerosene-water interface with relatively simple structure is formed.Interfacial tension,Zeta potential and the influence of concentration,structure on interfacial dilational properties were studied.The researches show that the increasing concentration contributes to the adsorption of demulsifier molecular,so the interfacial adsorption quantity increases,resulting in lower interfacial tension.The absolute value of Zeta potential reduces with the increase of demulsifier concentration.Different conditions can all affect the structure of interfacial adsorption and then change the interfacial viscoelasticity.The relaxation method in the paper is in good accordance with oscillating barriers method.Finally,emulsion stability analyzer based on near infrared transmission and scattering light can provide comprehensive data on the stability of the emulsion after adding polyether demulsifier.The research shows that polyether demulsifier can obviously increase the integral transmittance,and achieve the effect of demulsification.The Integral transmittance reaches a maximum value with the increase of demulsifier concentration.Therefore,during the process of demulsification,demulsifier dosage is not the larger the better.