Effects of salt content on secondary formation of hydrates in complex systems

Abstract The phenomenon of ‘memory effect’ exists in the secondary generation of natural gas hydrates, which is mainly manifested in the fact that the induction time required for the nucleation of hydrates in the secondary generation of hydrates is significantly shorter than that of the primary generation, thus accelerating the generation of hydrates. At present, the research on the memory effect phenomenon has been proven to exist, and its influencing factors have become a research hotspot. In order to study the influence of decomposition time and salt content on the memory effect, the hydrate was generated under the system of porous medium alumina complexed with surfactant SDS, and hydrate secondary generation experiments were carried out by adding different contents of NaCl according to four different decomposition times. The influence of four different decomposition times on the memory effect phenomenon in the secondary generation of hydrates and the influence of different salt contents on the memory effect phenomenon were analyzed by observing the pressure drop changes in the reactor during the hydrate generation process and calculating the methane gas consumption. The experimental results show that different decomposition times can affect the effect and time of the memory effect, and the effect of decomposition time on the memory effect does not show a linear relationship. The addition of salt may have an inhibitory effect on the memory effect.