湘西北复杂构造区破碎地层绳索取心钻进技术难点及优化

以湘西北复杂构造区湘慈地1井为例，针对钻进过程中遇到的岩心采取率低以及卡钻埋钻等钻进难点，通过采用无泵反循环超前侧喷绳索取心钻具以及优化钻井液体系的方法，有效地提高了该钻井工程中的岩心采取率；该新型钻具能够在孔底形成局部反循环，并且结合钻具内部防堵锥网以及超前侧喷钻头的设计能够有效地提高破碎地层中的岩心采取率；通过在钻井实践中应用，该钻具在岩心破碎井段的采取率达到了94.4%，取得了良好的应用效果。

Difficulties and optimization of wire-line core drilling technology for broken formation in complex structure area of northwest Hunan

Taking Xiangcidi 1 Well in the complex structural area of northwest Hunan as an example, in view of the common drilling difficulties encountered during the drilling process such as low core adoption rate and stuck-drilling buried drilling, we adopted the self-developed pumpless reverse circulation advanced side spray line and optimized the drilling fluid system to effectively improve the core drilling rate of the drilling project. The new type of drilling tool can form a local reverse circulation at the bottom of the hole, and combined with the internal anti-clogging cone net of the drilling tool and the design of the advanced side jet bit can effectively improve the drilling core rate in broken formations. By applying the drilling tool in practice, the drilling core rate in the core broken formation reached 94.4%, so it has achieved good application effects.