Study On The Law Of Medium Flow And Heat Transfer In Four-in-one Separator In Oil Field

The four-in-one separator is the core equipment responsible for oil-gas-water separation,heating,sedimentation and buffer treatment in oil field production in recent years,and its internal medium flow,heat transfer and phase distribution are the key factors affecting its working efficiency.The study on the law of medium flow and heat transfer in a four-in-one separator is helpful to reveal the law of flow and heat transfer in the separator,to obtain the effect of various structural components on the flow field and temperature field,and to identify the bottleneck factors that restrict the improvement of unsteady flow and efficiency in the separator.it is of great significance to improve the working efficiency of the four-in-one separator.The following research work has been carried out:First,on the basis of considering the actual working characteristics of the four-in-one separator in the oil field,taking the single-phase water as the working medium and the whole flow field in the full three-dimensional space of the separator as the research object,the physical and mathematical models are constructed,and the numerical solution method is established.The overall flow law in the separator is obtained by simulation,and the flow characteristics and interrelations in different working regions of the separator are identified.It is found that the medium flow in the area below the inlet pipeline A of the heating chamber is weak,and the medium circulation is slow.After the action of the rectifier plate,the flow rate of the medium is relatively gentle.Taking the average velocity and variance as evaluation indexes,the flow field results under different inlet velocities are quantitatively analyzed.When the liquid inlet velocity is below 0.2m/s,the average velocity and variance are smaller and the flow field is more stable,which is conducive to the heating and separation of the medium and provides a theoretical basis for the optimization of the working parameters of the separator in actual operation.Secondly,taking the settling chamber and oil chamber in the separator(the main area of multiphase separation)as the research object,the mathematical model and solution method for controlling the separation behavior of multiphase media are constructed.The settlement and separation process of three-phase medium is numerically simulated by VOF model,the dynamic separation process is described,and the time-space evolution law of flow field and concentration field is revealed.On this basis,the steady-state simulation of oil-water separation process is carried out by using MIXTURE model to quantitatively explore the effects of various factors on the flow and separation characteristics of oil-water two-phase medium.it is found that the oil content at the outlet increases with the decrease of inlet velocity,the increase of oil droplet size,the decrease of oil phase density and the increase of inlet oil content.Identifying the inlet velocity is the core factor affecting oil-water separation.When the inlet velocity is reduced by 0.35m/s,the oil content of the outlet can be increased by 37.77%,which is 2.5 times of the increase of the oil content of the outlet caused by the oil phase density(15.20%).Finally,taking the heating chamber and water chamber(the main area of heat transfer)as the research object,the heating process in the separator is numerically simulated,and the law of medium flow and heat transfer in the process is revealed.The effects of fire tube diameter,fire tube temperature and smoke tube arrangement on the heat transfer process are quantitatively investigated.it is found that the temperature in the area where the pyrotechnic tube is located and the area above the pyrotechnic tube in the heating chamber is relatively high,and the temperature in the lower area of the inlet tube of the heating chamber is lower.The heating effect is quantitatively evaluated by taking the average temperature,outlet temperature and variance as characteristic parameters.It is found that in the range of parameters studied,increasing heating temperature has the best effect on increasing the overall average temperature and outlet temperature.Changing the arrangement of smoke pipes has the best effect on improving the uniformity of temperature distribution in the heating chamber.Thus,it provides a reference basis for the optimal design of the structure and working parameters of the heater.Generally speaking,this study is helpful to reveal the flow,heat transfer and phase separation characteristics of complex multiphase media,enrich the basic theory and engineering application of multiphase flow,and reveal the key factors affecting the working efficiency of the separator.it also has important practical engineering significance to improve the working efficiency of the separator and optimize its structural design.