天然气水合物浆液黏度的实验研究

随着海洋天然气开发深度的增加，混输管线的天然气水合物堵塞问题越来越受到重视。传统的水合物防止技术，如保温、注入甲醇等方法，因应用条件苛刻和高成本等原因而很难应用于深海油气田的开发。新的替代技术之一就是把天然气水合物以固体颗粒的形式分散在多相流中形成浆液进行输送。为此，应用高压落球式黏度计测试了合成天然气在柴油和凝析油中形成的水合物浆液黏度。实验结果表明，浆液的相对黏度随水合物分率的增加而增加，并且当天然气水合物分率大于某个临界值时，相对黏度增加的幅度增大。初始乳状液黏度对浆液黏度影响很大。甚至当初始乳状液的黏度较大时，低天然气水合物分率浆液黏度会大于高水合物分率浆液黏度。

EXPERIMENTAL RESEARCHES ON VISCOSITY OF GAS HYDRATE SLURRY

Natural gas hydrate plugging which takes place in the multiphase pipeline has attracted wide attentions as the rapid development for natural gas in the sea. The traditional hydrate prevention technologies, like thermal insulation and methanol injection, can be hardly applied to the development of deep sea oil and gas fields for the stern application condition and high cost, etc. One of the substitute technologies is to disperse the gas hydrate in solid grain form into the multiple phase flow to prepare for slurry and then transport it. The viscosities of the synthetic gas hydrate slurries which separately produced in diesel oil and condensate oil were measured by the high pressure drop ball viscometer. The experiment result showed that the relative viscosity of the slurry will be raised as the increase of the hydrate fraction. Moreover, when the gas hydrate fraction exceeds a certain critical value, the growth of the relative viscosity will be enhanced. The viscosity of the initial emulsion has great influences on the viscosity of the slurry. Even when the viscosity of the initial emulsion is high, the viscosity of the slurry with low gas hydrate fraction will be higher than that of the slurry with high gas hydrate fraction.