Experimental Study Of Low Dosage Gas Hydrate Inhibitors

As the development of natural gas industry, the exploitation of oil and gas field confronts with an important problem. It is the prevention and curing of hydrate. The conventional injection of thermodynamic inhibitors runs with high cost and turns to be harmful to environment. Hence, there exists a trend in these years that low dosage hydrate inhibitors (LDHI) shall take the place of the thermodynamic inhibitors. And the experimental study of LDHI is the key point of the application of LDHI. This thesis aims to summarize the laboratory inhibiting methods of LDHI, and to grope the application range, affecting factors and mechanism of LDHI. It is in the high-pressure hydrate reaction device where hydrate forms and gets inhibited. Experiments were taken to study the performance of kinetic hydrate inhibitor (KHI), including the impact of subcooling, initial pressure, stirring speed on the inhibitor's performance. And kinetic hydrate inhibitor experimental evaluating method was established. The experimental evaluating method of anti-agglomerants was also studied. The effect of different oil water ratio and stirring speed is mainly researched. And resulting from the effect of quaternary ammonium as a type of anti-agglomerants, it is found that it accelerates the hydrate formation, and prevents the hydrate hunch conglomeration efficiently. To prepare for the application of KHI, some basic experiments were also taken, including the inhibite performance of PVCap, glycol and the cooperating usage of the two and we also studied the effect of corrosion and scale inhibitors on the perfpormence of PVCap. Thereby, we ground on that to independently to prepare the kinetic hydrate inhibitors based on PVCap. In the last part of this thesis, according to the theory of core formation and on the basis of the foregoing data, the inhibition mechanism of the thermodynamic and kinetic inhibitors is analyzed.