海洋天然气水合物分解抑制实验

Experimental Study on Inhibition to Marine Gas Hydrate Decomposing

在海洋含天然气水合物地层中钻进时,水合物的分解会导致井壁不稳定、钻井液性能降低和管道内生成水合物塞等一系列问题,对安全钻井作业造成了很大风险。采取适合于海洋天然气水合物地层钻井的钻井液,最大限度控制水合物的分解是解决天然气水合物安全钻井的关键。本文采用了课题组研制的一套天然气水合物钻井模拟实验系统,利用此实验系统在不同温度压力条件下人工合成水合物样品,然后加入配置的一种稀硅酸盐钻井液,考察了水合物样品在不同分解条件下(加热、降压)的分解情况进行了对比和分析研究,结果表明此钻井液配方具有良好的抑制水合物分解的能力,能够应用于海洋水合物地层钻井。

When drilling in marine hydrae-bearing formation,the decomposition of hydrate will lead to a series of problems,including instability of wellbore wall,degradation of drilling fluid performance,and hydrate blockage within pipeline.These problems bring great risks to safety of drilling operation.As a result,the application of properly designed drilling fluid which can minimize gas hydrate dissociation is crucial for the drilling in this type of formation.In this work,a set of gas hydrate stimulating experiment system was used to synthesize several kinds of gas hydrate samples in laboratory,and thin silicate drilling fluid was added to the system.The behavior of gas hydrate samples decomposing under different conditions（heating,depressurization）was studied.The results show that the drilling fluid can effectively inhibit gas hydrate decomposition and can be applied to drilling in oceanic gas hydrate formation.