天然气水合物地层钻井时水基钻井液性能实验研究

文章在分析天然气水合物地层钻井特性的基础上，提出了在进行天然气水合物地层钻井液体系设计时除考虑其对天然气水合物抑制性外，还要重点关注钻井液的相对密度、护壁性和流变性等对井壁稳定和井内安全起关键作用的性能指标。据此，通过实验分析了不同类型处理剂对以盐/聚乙二醇为抑制剂的水基钻井液的上述几个性能改善情况，并在此基础上探讨了盐、聚乙二醇和固相含量对钻井液相对密度、护壁性和流变性的影响。目的是为今后天然气水合物地层钻井液体系设计提供理论依据。

EXPERIMENTAL STUDY ON PERFORMANCE OF WATER-BASED DRILLING FLUID USED TO DRILL FORMATIONS WITH GAS HYDRATE

Based on the drilling features of the formations with gas hydrate, the performance indexes of drilling fluids such as the relative density, encasing and rheological properties that play the great role in stabilizing the borehole and making the down-hole safe should be paid more attention to besides considering the hydrate inhibition of the drilling fluids while making the design of drilling fluids used to drill formations with gas hydrate. With experiments, the improvements of the above-mentioned performance indexes by different additives are analyzed for water-based drilling fluids taking salt/polyethylene glycol as inhibitor. Then, the influence of the contents of salt, polyethylene glycol and solid phase on the relative density, encasing and rheological properties is discussed in order to provide the theoretical basis for the design of drilling fluids used to drill formations with gas hydrate in the future.