Combined Effects of Hydrate Kinetic Inhibitors and Antiagglomerants

Kinetic hydrate inhibitors (KHIs) and antiagglomerants (AAs) are important agents for preventing and controlling hydrate plugging in oil and gas development, but there are hardly any studies on their combined effect to date. In this study, experiments were carried out in a high-pressure stirred autoclave experimental system to evaluate the effects of different KHIs, AAs, and their mixtures. With the formation induction time, formation rate, and conversion ratio of hydrate as the main evaluation indexes, the evaluation results show that PVP-K88 and PEG-20000 have better performance among the kinetic inhibitors, and among the AAs, DDBAB, CDEA, and AEO-9 have optimal concentrations of 0.2, 0.5, and 0.1 wt %, respectively. The compound system of DDBAB + PEG-20000 works better than the compound system of DDBAB + PVP-K88 in preventing hydrate formation, while the combined effect of CDEA and KHIs is not satisfactory. The combination of AEO-9 and PVP-K88 has the best effect; specifically, it can significantly shorten the time for hydrate slurry to enter a stable flow state without increasing the feedback torque and has feedback torque significantly lower than other systems. The results of this study can provide a valuable reference for the future combination of different hydrate inhibitors.