Construction And Performance Evaluation Of Nano-particle Stable Foaming Agent System

The bottom-hole fluid accumulation of water-bearing gas wells will cause the productivity of the gas well to drop significantly,and have a great negative impact on the exploitation of the gas field and the production of the gas well.Therefore,it should be discharged in time and effectively to eliminate this impact.Foam drainage gas recovery technology has become an important measure to solve the problem of liquid accumulation at the bottom of production gas wells at home and abroad in recent years due to its simple operation,low cost,and quick effect.In this paper,a high-efficiency foaming agent that can withstand temperature of 70°C,30%condensate oil and 30%methanol is developed for gas wells with medium and deep water content.First of all,this article uses the shaking method to screen different foaming agent single agents,and selects four foaming agent single agents with good foaming performance to be compounded with fatty alcohol polyoxyethylene ethers with different EO numbers.Comparing the foaming volume and foam half-life,it is determined that the compound type is 2A1+AEO-9,the compounding ratio is 20:1,and the optimal concentration of foaming agent is 0.5%.Then add nanoparticles as a solid foam stabilizer and organic acid as an anti-oil additive to construct a nanoparticle stable foam discharge agent system.The formula of the foam discharge agent is determined to be:2A1+AEO-9+Si O₂+organic acid.Secondly,according to the foaming volume,foam half-life and liquid carrying rate of the foaming agent under different conditions,this article evaluates the temperature resistance,salt resistance,oil resistance,acid resistance and methanol resistance of the foaming agent.The results show that the foaming agent has good performance at a temperature of 90℃;it can withstand 100 g/L salinity and 30%methanol;and has good acid resistance,with an anti-condensate oil capacity of 30%,and condensate oil When the content is 40%,the performance of the foaming agent is greatly reduced.Finally,this paper discusses the influence of nanoparticles on the surface tension of foaming agent solution,the diffusion coefficient of surfactants and the adsorption mechanism of surfactants,and the effect of nanoparticles on the expansion modulus of the system surface is experimentally analyzed.Obtained:The mechanism of surfactant adsorption to the surface is hybrid controlled adsorption;Si O₂ nanoparticles can increase the surface expansion modulus of the system,and by increasing the surface expansion modulus of the foam discharging agent system,the foam caused by the drainage of the liquid film is inhibited.The particle size is smaller and uniform,and slows down the diffusion of gas through the liquid film.