Compared with the traditional method of hydrate prevention and control in the field of multiphase gathering and transportation in deep water, the method of adding low-dose hydrate inhibitor has significant advantages. It is favored in academic and industrial fields at home and abroad. Anti-Agglomerant (AA) is one type of the low-dose hydrate inhibitors that can still have good performance under more severe high undercooling conditions, which can ensure that the generated hydrate in multiphase flows can mix with the transport fluid as slurry. In this work, the indexes for evaluating the performance of anti-agglomerants and the key influence factors are summarized. The macro and micro characteristics of hydrate formation and the flow features of hydrate slurry in the presence of anti-agglomerants in the system are reviewed. In general, the performance of AA is affected by its dosage, water cut, mineralization degree and pH of the fluid, the emulsification state and subcooling degree under the application conditions. The more stable and moderate the hydrate formation amount is, the better is the fluidity of the hydrate slurry with AA addition and the lower the risk of hydrate blockage occurring in the multiphase flow with higher reliability of ensuring its flow safety. Based on all the research, the mechanisms of AA are summarized. Finally, suggestions for further research on anti-agglomerants in the future are given.

A hydrocarbon gas drive production method is used in an oil field in Changqing. The use of this method may lead to a high gas-oil ratio (30~100 m³/t) of well flow. This study carried out relevant experimental research into hydrate prevention and control problems that are common in the process of the hydrocarbon gas drive method. Compared with the prevention and control scheme of adding a traditional thermodynamic inhibitor(THI), a kinetic inhibitor(KHI) has attracted more and more attention for its advantages of low dosage, high efficiency and environmental protection. However, according to a large number of field examples and experimental research results, it can be found that the effect of a single inhibitor is not ideal, and the inhibition effect of traditional KHI is greatly affected by temperature. Under high undercooling, its suppression may fail. Adding synergists to the kinetic inhibitor system enhances the inhibition effect. This has become an important research topic Two kinetic inhibitors of PVP(polyvinylpyrrolidone) and PVCap(polyvinylcaprolactam) and their synergistic inhibitors combined with mono-ethylene glycol (MEG) were experimentally studied in a 500 mL autoclave. In the process of hydrate formation, the inhibition effect of compound inhibitors on hydrate formation was studied. The inhibition performance of the two kinetic inhibitors was tested from the perspectives of inhibitor concentration, maximum allowable undercooling and the effect of combination with MEG. A total of 42 groups of experiments were carried out in this study. The experimental results show that the inhibition ability of kinetic inhibitor PVCap is better than that of kinetic inhibitor PVP at the same mass concentration. PVCap still showed good inhibition ability at nearly 20 ℃ undercooling. In the synergistic experiment of PVCap and PVP combined with MEG, it can be found that they all showed a certain degree of synergistic inhibition. The synergistic effect of PVCap and MEG is more obvious. The synergistic inhibitor combination of 3 wt%PVCap and 5 wt%MEG can prolong the induction period of natural gas hydrate to more than 9 h under high undercooling (22 ℃), which shows that a reasonable and effective synergistic inhibition scheme can effectively improve the inhibition performance of KHI, help to promote the application of KHI in the field of oil and gas resources under a domestic high undercooling environment, and provide technical support for efficiently solving the problem of hydrate prevention and control in oil and gas production under high undercooling conditions.