表面活性剂对天然气水合物合成影响的实验研究

Experimental Study of the Effect of Sodium Dodecyl Sulfate on Gas Hydrate Formation

为研究钻井液化学成分对天然气水合物的影响作用,利用天然气水合物人工合成实验系统进行了天然气水合物的人工合成实验。在天然气水合物的合成过程中,分别对天然气-水溶液体系中加入表面活性剂(Sodi-um Dodecyl Sulfate)与未加入表面活性剂时水合物的生成时间、生成温度、生成压力及表面活性剂的浓度等对生成过程的影响进行了实验。在加入表面活性剂的天然气-水溶液体系中,由于表面活性剂的存在加速了气体和水溶液体系的接触面,从而加速了水合物的生成、降低了水合物的生成压力、提高了相同条件下的生成温度,即表面活性剂的存在改变了天然气水合物的生成条件,而且增加了水合物中的含气率。因此,表面活性剂用于配置钻井液有利于保持天然气水合物井的井壁稳定。

In order to understand the effect of sodium dodecyl suIfate （SDS） on gas hydrate formation, the experiments of gas hydrate formation were conducted using the gas hydrate formation and dissociation system. The impacts of time of gas hydrate formation, temperature, pressure and concentration of SDS on the formation of methane hydrates were investigated for water system with and without SDS. The results show that SDS could accelerate the hydrate formation process and reduce the required pressure for hydrate forma tion. The presence of SDS changed the conditions for hydrate formation and increased the gas saturation in hydrate. Therefore, the drilling with SDS can maintain wellbore stability for wells in hydrate reservoirs.