Study On The Influence Of Methane And Ethane On The Compression Coefficient Of Waxy Crude Oil Based On Ultrasonic Detection

In the process of crude oil production and transportation,the light component is often accompanied by the precipitation and dissolution of light components,and the existence of light components will improve the fluidity of crude oil.At present,the focus of the research on the influence of dissolved light components on the physical properties of crude oil is mainly focused on "rheology",but the impact of light components on the volume compressibility of crude oil is not concerned.However,the compressibility of crude oil is related to the measurement and shutdown restart process.Therefore,the research on the influence of dissolution and precipitation of light components in crude oil on the compressibility of crude oil is carried out,and the compressibility of oil in the reservoir at present stage is studied The design of waxy crude oil pipeline,pipeline transportation of waxy crude oil and the design of the restart scheme of waxy crude oil pipeline will be of great significance.In this paper,the ultrasonic wave velocity,density and compression coefficient of dissolved gas crude oil are studied by using the ultrasonic testing device and the density solubility measurement system of dissolved gas crude oil.Firstly,the ultrasonic wave velocity,density and compression coefficient of high temperature degassing crude oil and gelling degassing crude oil are measured.Through the research and analysis,it is found that the ultrasonic velocity and density of waxy crude oil are negatively correlated with the temperature,but the slope of the gelled degassing crude oil is larger;the compression coefficient increases with the decrease of temperature.Then,the influence of temperature,pressure,methane and ethane dissolved gas on the solubility,density,ultrasonic velocity and compression coefficient of saturated gas crude oil under different conditions are analyzed according to the measured experimental data.The results show that when the pressure is constant,the solubility of different dissolved gases in the high temperature degassing crude oil decreases with the increase of temperature.The solubility in gelled degassing crude oil decreases with the decrease of temperature.The ultrasonic velocity and density of saturated gas crude oil under any state decrease with the increase of temperature,and the pressure of the crude oil decreases with the increase of temperature The shrinkage coefficient increases with the increase of temperature;when the temperature is constant,the solubility of different dissolved gas in degassing crude oil increases with the increase of pressure,and the ultrasonic velocity and density of each saturated gas-soluble oil decrease with the increase of pressure,and the compression coefficient of each saturated gas crude oil increases with the increase of pressure;through comparative analysis,when the temperature and the pressure increase When the pressure is constant,the solubility of ethane in crude oil is much greater than that of methane.The ultrasonic velocity and density of ethane saturated gas-soluble crude oil are lower than that of methane saturated gas soluble crude oil,and the compression coefficient is greater than that of methane saturated gas soluble crude oil.The physical properties of ethane saturated gas-soluble crude oil are more sensitive to the change of pressure.