Investigation of amine-based surfactants for foamed acid stimulation at high temperature, pressure, and salinity

This research investigated the rheology of foamed acid using different amine-based surfactants including Duomeen TTM (TTM), Ethoduomeen T/13 (T/13), Ethomeen C/12 (C/12), and Armogel O at 150 °C and 1000 psi using a modified (high pressure-high temperature) HPHT foam rheometer. The study was conducted in high-salinity water as a replacement for freshwater to promote sustainability. Foam properties such as foam stability, foamability, foam structure, bubble count, and size were investigated through a novel HPHT foam analyzer under different conditions; (23 °C, 14.7 psi) and (120 °C, 1000 psi). The obtained results showed that Duomeen TTM exhibited the highest foam viscosity as a result of the generation of stable wormlike micelles at 150 °C and 1000 psi. Additionally, both Duomeen and Ethoduomeen T/13 displayed stable foam viscosity at a steady shear rate of 500 1/s for 8 h. The temperature has a major impact on foam viscosity; as the temperature raised from 100 °C to 150 °C, the apparent foam viscosity dropped by 36.9% at 500 1/s and at least by 26.5% at 2000 1/s. The outcomes of the HPHT foam analyzer showed that the surfactants, except for Ethomeen C/12, showed poor foamability under ambient conditions. However, at HPHT, high bubbles count was generated with a uniformly fine texture. For Duomeen TTM, the initial bubble count increased, almost by 76.7%, indicating better foamability at HPHT. Additionally, the foam half-life time of all surfactants except for Duomeen TTM decreased sharply once pressure and temperature increased. The stability decreased by 9.7% for Duomeen TTM, 57.7% for Armogel O, 69.1% for Ethoduomeen T/13, and 85.7% for Ethomeen C/12 as compared to ambient conditions. This paper offers a wide-ranging understanding of amine-based surfactants on stimulating foam viscosity and stability at HPHT.