Research On Influencing Factors Of Crude Oil

The three-phase separation of oil well produced fluid should be carried out first in the transfer station or the combined station for separate measurement.Crude oil foaming makes oil and gas separation incomplete,increases instrument measurement error,and causes damage to equipment.Heavy oil is easy to produce foam due to its high viscosity and high asphaltene content,and the foam liquid film is strong and stable,which is easy to form stable foam crude oil,resulting in long natural defoaming time.This paper explores the factors affecting crude oil foaming through experiments,and provides a theoretical basis for subsequent avoiding foaming and targeted defoaming according to the influencing factors.In this paper,Shengli crude oil was taken as the research object,and the physicochemical properties and family composition of crude oil were analyzed.The oil recovery agents were analyzed by FT-IR,¹H-NMR and GPC,The foaming property of crude oil was evaluated by airflow method.The effects of temperature,water content of crude oil,crude oil composition,dissolved gas and the concentration of oil recovery agents（viscosity reducer and desulfurizer）on crude oil foaming were explored.The relationship between crude oil foaming,stability and crude oil composition was obtained through the corresponding relationship between crude oil foaming,defoaming time and viscosity.The variation law of crude oil viscosity after adding oil recovery agents and the corresponding relationship between crude oil viscosity and foam half-life were explored.The experimental results show that high temperature is not conducive to foaming in the studied temperature range,and the water content of 20%has the greatest impact on crude oil foaming.Crude oil A and crude oil C with low viscosity have fast foaming and easy foaming at the same temperature,while crude oil B with high viscosity has higher foaming height than the other two crude oils at the same temperature,and has strong foaming ability.When dissolved gas is CO₂,crude oil foams quickly and easily,resulting in strong foam stability.Dissolved gas produces more bubbles when simulating associated gas.The crude oil with low viscosity and viscosity reducer have little effect.When crude oil with high viscosity is added with viscosity reducer-1 containing polymer and alkylphenol polyoxyethylene ether,foams are more and more stable than those of viscosity reducer-2 containing polyoxyethylene substances.Compared with the effects of viscosity reducer and desulfurizer,the crude oil with low viscosity and viscosity reducer have a greater impact on foam stability.The viscosity reducer of crude oil with high viscosity has great influence on foaming performance.At low concentration,the viscosity enhancement of triazine desulfurizer has great influence on foam stability.At high concentration,the polymer and surface active substances in viscosity reducer make crude oil foam more stable.The study on the stability mechanism of oil-based foam found that the foaming and defoaming properties of crude oil were related to the composition of crude oil,and the foaming and defoaming time increased with the increase of viscosity.Recombination fraction in crude oil can increase foam stability.The higher the viscosity of crude oil,the more stable the foam.