Flow Field Analysis And Component Optimization Of Separator In Changning-Weiyuan Shale Gas Test Platform

Commercial exploitation of shale gas is one of the important ways to balance natural gas supply and reduce dependence on foreign energy in China.Corrugated plate gas-liquid separator is widely used in oil and gas field test platforms because of its compact structure and small area.In the process of design and use,the corrugated plate separator mainly relies on the experience of engineers.At present,there is no industry design standard for the corrugated plate gas-liquid separator.There are many types of corrugated plate and the movement of fluid in it is complex,so it is difficult to pre-judge its separation effect.Through investigation on the separator of Changning-Weiyuan shale gas field test platform,it is found that the temperature of the fluid produced at the wellhead during the test period is high,the highest in the initial stage is 102?,and the average temperature reaches 80.4?.After throttling the platform,the average temperature of the gas-liquid mixture entering the separation equipment is 60.34?.The saturated water content in the gas flow is large,reaching 3.20g/m3.After the separator,there is serious water accumulation in the pipeline.The water ion analysis confirms that the water accumulation in the pipeline originates from the water caused by the unsatisfactory separator effect and condensate water caused by the change of saturated water content.From the view of dynamics theory,the movement of liquid-carrying airflow in the flow channel of corrugated plate separator is analyzed,the trajectory of liquid droplets in the separation process is studied,and the theoretical calculation formula of the separation efficiency of corrugated plate gas-liquid separator of Changning-Weiyuan shale gas testing platform is deduced.Using FLUENT commercial software to simulate the platform separator,it was found that the separator of Changning-Weiyuan shale gas test platform could not separate droplets with less than 5?m,and the separation efficiency could reach more than 90%when the droplet size was greater than 50?m.By simulating the separation efficiency of the separator at different flow velocities and plate spacing,the variation rules and efficiency curves of the separator under different working conditions were obtained.Based on the experimental results of water ion analysis,field process analysis,theoretical formulas,as well as numerical simulation results,an optimization scheme of separator is proposed,which combines reducing the working temperature of separator with improving the structure of corrugated plate.The operating temperature of the optimized separator is reduced from 60.34? to 30?,and the saturated water content of condensation can be reduced by about 2.47g/m3.Taking the inlet f1ow rate of 4m/s and droplet size of 20?m as examples,the separation efficiency was increased from 28.9%to 76.5%by improving the structure of corrugated plate.Through the research of corrugated plate gas-liquid separator in this paper,it has important guiding significance for the design and type selection of separator of shale gas development and testing platform in the future,and provides reference and help for the development of corrugated plate separator.