Study On Fluid Movement Law Of Throttling Bubble Exhaust Well

Foam drainage gas recovery technology is an efficient technology suitable for early water recovery of gas wells.It has the characteristics of low cost,good use effect,convenient operation and wide application range.It is an effective technical means to improve gas field development and gas well production efficiency and is widely used in the field.However,some gas wells in gas fields are equipped with throttles.The existence of throttles makes the movement law of foam fluid in the wellbore vague,and the calculation of critical bubble carrying flow and pressure drop is inaccurate,which makes serious liquid accumulation still exist in the wellbore,which seriously affects the production capacity of gas wells and even stops production.For this reason,this paper has carried out in-depth research on the fluid movement law of vertical well throttling bubble exhaust well,and established critical bubble carrying and throttling critical bubble carrying models with different foam concentrations,foam pipe flow pressure drop model and throttling bubble discharge prediction model.The main work is as follows:In order to study the fluid movement law of the throttling bubble exhaust well,a physical simulation experimental device was built.The total installation height of the device was 13m,the inner diameter of the tube was 60mm,the orifice plate could be installed 3 m away from the inlet,and the main supporting equipment was equipped,which provided the simulation experimental conditions for this study.The critical bubble carrying capacity of LAO lauramidepropyl amine oxide foaming agent under the working conditions of foam concentration of 0.1,0.2,0.3,0.4and 0.5%and the throttling critical bubble carrying capacity of 10,12,14 and 16mm throttles with the same concentration were tested experimentally.Firstly,the influence law of foam concentration on critical bubble-carrying velocity is compared and analyzed,and the relationship between critical bubble-carrying coefficient and foam concentration is regressed,and the calculation model of critical bubble-carrying velocity suitable for different foam concentrations is obtained.Then,the influence of foam concentration and orifice diameter on the critical bubble-carrying velocity is compared and analyzed,and the relationship between critical bubble-carrying coefficient and foam concentration and orifice diameter is regressed,and the calculation model of critical bubble-carrying velocity is established.The pressure drop experiment of foam pipe under the working conditions of LAO lauramide propyl amine oxide foaming agent 0.1,0.3 and 0.5%foam concentration,gas flow rate 10～80m~3/h and liquid flow rate 0.1 m~3/h was tested.The influence law of different foam concentrations on the pressure drop of pipe flow is compared and analyzed.The relationship between friction coefficient and Reynolds number is modified through experimental data,and the pressure drop model of foam pipe flow is put forward.Experiments were carried out to test the pressure drop of throttling bubble discharge under the working conditions of LAO lauramidopropyl amine oxide foam discharge agent 0.1,0.3 and 0.5%foam concentration,gas flow rate 2～10m~3/h and liquid flow rate 0.1～0.4m~3/h.The variation law of gas-liquid ratio in front of nozzle pressure under different foam concentrations was compared and analyzed,and the relationship of slippage factor was regressed by gas mass holdup,foam concentration and orifice diameter of throttle.Considering the influence of slippage phenomenon,a prediction model of throttling bubble discharge was put forward.By using the established calculation models of critical bubbling velocity,throttling critical bubbling velocity,foam pipe flow pressure drop model and throttling bubble row prediction model,the field data are calculated and verified,and the calculation results improve the gas well development efficiency to some extent.