Research On Low-temperature Demulsifier Optimization And Its Demulsification Mechanism Of Oil From A Block Of Jilin Oilfield

Aimed at the high cost due to high temperature and long time for demulsification of produced fluid in a block of Jilin oilfield,the effects of the types of demulsifier,demulsifier concentration and demulsification temperature on the dehydration rate of the emulsion were studied with simulated emulsion.The demulsification conditions were optimized as temperature 45?,demulsifier AR301 and concentration 100 mg/L.In this condition the dehydration rate can reach 96.77% in the two days.And the temperature can be reduced by 15? compared to the dehydration conditions in practice.The relationship between the dehydration rate coefficient and the effect of demulsification was studied via the first stage dynamic equation which simulates the demulsification process.The demulsification process of emulsion was analyzed by stability analyzer and optical microscope.The changes of the dynamic parameters such as precipitation thickness and particle migration rate with the demulsification process were explored.The stability of the emulsion system become lower after the demulsifier was added,and the droplet migration speed was accelerated,and the droplets were merged and settled,and the oil droplets were floating up,so the oil and water separated.The ability of natural interface active materials and demulsifier to reduce the viscoelasticity of interface films was analyzed by using interface rheometer.The change in the interfacial tension of the oil-water interface caused by the demulsifier on was measured by the interfacial tensionmeter.The relationship between the reduction of interface film strength and demulsification performance was explored by single-drop method.The result shows as followed,the increase of the content of the natural interface active substance leads to a higher viscoelasticity and interfacial film strength.The concentration of demulsification is positively related to the diffusion of demulsifier in the oil phase and adsorption rate.The faster the adsorption rate,the higher the demulsification rate,and the better the demulsification effect.The demulsifier can be adsorbed on the oil-water interface.The higher the ability to reduce the properties of the interfacial viscoelasticity,the interfacial shear viscosity and the interfacial film strength,the better the demulsification effect.The ability to reduce interfacial tension is not necessarily related to demulsification.The demulsification performance of demulsifier is related to the concentration of demulsifier and temperature.While the concentration and temperature increase,it takes shorter time for the interfacial tension and interfacial film viscoelasticity to reach equilibrium.The increase of the temperature lead to a lower the interfacial viscoelasticity,the interfacial shear viscosity and the interfacial film,thus,the demulsification effect is better.The interface property increases slightly with demulsifier concentration increases,and then decreases.