关键词:

缓蚀剂, 预膜, 气井, 欧拉壁膜, 数值模拟

Abstract:

Sour gas wells are often associated with the corrosion of metal materials caused by CO₂ and H₂S. The prefilm anticorrosion technology by water-based corrosion inhibitor injection is relatively advanced and low-cost. However，no systematic research has been carried out on the prefilm time，thickness and distribution of liquid film and corrosion inhibitor spray cycle. Based on RNG k- ε model，the multiphase flow theory and the EWF model were coupled to simulate the formation and flow of the water-based corrosion inhibitor liquid film，and the flow law of corrosion inhibitors subjected gas stream flushing after injection was analyzed. The results showed that the gas stream in the sour gas well can entrain water-based corrosion inhibitors and form a liquid film with a thickness of about 2 mm on the pipe wall under production conditions，and the prefilm performance is better in the pipe section between the 20~60 m positions. After the injection of water-based corrosion inhibitor is stopped，the liquid film of corrosion inhibitors on the pipe wall is gradually destroyed and thinned due to the flushing of gas streams. Therefore，it is recommended to install a corrosion inhibitor injection nozzle at an interval of 60 m along the pipe and place the corrosion inhibitor nozzles along the wellbore in a spiral manner.

Key words:

corrosion inhibitor, prefilm, gas well, Eulerian wall film, numerical simulation