Novel foam-draining and anti-polymerization integrated agent for gas well application

In this article, surfactants such as cetyl trimethyl ammonium chloride (CTAC) and coconut oil amide propyl betaine (CAB) were compounded (TCJ) and used as a double function with foam drainage and hydrate anti-polymerization. According to the result it was found that 0.05% of CTAC and 0.7% of CAB exhibited both excellent foam property and hydrate anti-polymerization property. For further clarifying the stability characteristic of foam, the foam half-life, drainage process, microcosmic liquid film structure, and stability mechanism were investigated in this article. The high initial foam volume of 415 mL with relatively long half-life time of 5.5 min under high-speed agitation at 50°C after 25 min indicated a good temperature resistance. The excellent foam properties still remained even amount of methanol and NaCl was added, which indicated its well stability and salt resistance. Furthermore, it was found that TCJ exhibited high liquid carrying rate of 62.5% at 65°C and good compatibility with poly vinyl pyrrolidone (PVP), which played great potential to the application in oil field. By the results of DSC curves, it can be found that the phase transformation point of hydrate decreases after addition of TCJ, which indicates the inhibition to the formation of hydrate as thermodynamic inhibitors.