Laboratory Study On Polymerizing Effective Gas Hydrate Inhibitor Used In Deepwater Drilling Fluid

In the exploration of deepwater oil and gas fields,it was facing many complex technique difficultys,Such as natural gas hydrate easily forming in water based drilling fluid.The most common method is addition of hydrate inhibitor to avoid interference caused by hydrate in deepwater drilling engineering.However,the traditional thermodynamics inhibitors can not meet the requirements of economy and environmental protection. Consequently, at the present time researches has turned to late-model kinetics inhibitor step by step both at home and abroad.Based on the investigating and surveying of sufficient interrelated literature,The functional group of the hydrate inhibitor was determined, the first-generation and the second generation hydrate kinetics inhibitors were synthesized respectively With N-vinyl caprolactam and N-vinyl pyrrole monomer, PVCL and VCL/VP binary copolymer. the effects of these two kinds of inhibitors were tested through the laboratory hydrate inhibitory evaluation device .In view of their insufficient inhibition effect, a new model of hydrate inhibitor was designed and synthesized, the influence factors were discussed in orthogonal experiments to explore the optimal synthetic conditions. the molecular structure is characterized by infrared radiation spectrogram analysis,characteristic viscosity and other methods.The compatibility of the new model of hydrate kinetics inhibitor,traditional thermodynamics inhibitors and other drilling fluid agents is tested.The treatment results show that this new inhibitor has a good compatibility with thermodynamic inhibitors NaCl,and other drilling fluid agents also do not affect its original inhibitive ability. The basic performance of hydrate inhibitory drilling fluid systems was investigated under normal and low temperature, the validity of delaying hydrate formation was tested in these systems in different subcooling conditions, the drilling fluid system with effectively inhibitive ability was optimizated used in deep-water drilling engineering.