Preparation and Foaming Properties of N-Alkyl-β Aminopropionic Acid

N-alkyl-β-aminopropionic acid (HA) was synthesized from acrylonitrile and aliphatic primary amine in a ratio of 1:1.1. The structure of HA was characterized by paragon-1000 infrared spectrometer. The foaming properties of HA, anionic foaming agent ABS, nonionic foaming agent AEO and cationic foaming agent CTAB were selected. HA with better foam paerformance was selected to evaluate the properties of temperature resistance, salt resistance, calcium resistance and stability. The experimental results show that the foaming power of HA is not obvious with temperature. At 25℃, the maximum half-life is 14 min, and the foam stability is the best. When pH<3 and pH>7, the foaming volume is larger than 540 mL, the half-life is greater than 5.5 min, the foam performance is much higher than pH=3-7, and the volume of foam changes near 720 mL with the increase of salinity. The half-life continued to extend to 10 min, and the salt resistance was good. With the increase of Ca²⁺ concentration, the volume of foam decreased from 700 mL to 380 mL, but the half-life increased from 7.5 min to 17 min, and the foam stability increased, which could meet the downhole operation of foam fluid.