Methanol. Methanol has a low viscosity, while ethylene glycol has a high viscosity. This means that methanol flows more easily during transportation and injection, which can improve the efficiency of operation. In addition, methanol is more soluble in water than ethylene glycol. This makes it easier for methanol to mix with water, so that it can penetrate into underground soil more easily and achieve a wider anti-freezing effect. So it is good to inject methanol into the wellhead.