海洋天然气水合物钻井的硅酸盐钻井液研究

在海洋含天然气水合物地层中钻进时，遇到的问题有水合物在井底的分解和管线内的再生成，以及井壁稳定和井涌的问题。配制合适的钻井液是解决上述问题的关键。通过大量实验，得到一种加入无机盐和动力学抑制剂的稀硅酸盐钻井液，并通过实验对其性能进行评价。结果表明:配制的硅酸盐钻井液不仅能满足常规钻井液携带岩屑和清洁井眼的要求，还能有效抑制井壁岩层的水化，抑制水合物地层的分解，以及控制水合物在管线内的再生成;因此可以满足深水含水合物地层钻进的要求，确保水合物地层钻探安全高效地进行。

Study on Silicate Drilling Fluid for Drilling in Marine Gas Hydrate Bearing Sediments

When drilling in the marine gas hydrate bearing sediment,the encountered problems include gas hydrate dissociation at the bottom of hole and reformation within the pipeline,as well as the instability of wellbore.A properly designed drilling fluid is a solution to these problems.After tremendous experiments,a formulation of silicate drilling fluid with the addition of inorganic salt and kinetic gas hydrate inhibitor was proposed,and its performance has been evaluated.Finally,it is suggested that the silicate drilling fluid can not only meet the requirements of transporting debris and cleaning hole,but also can effectively inhibit the hydration of wellbore formation and the dissociation of gas hydrate bearing sediments,and the reformation of gas hydrate as well,so the drilling fluid can ensure the safety and efficiency of drilling in marine gas hydrate bearing sediments.