【摘要】 钻井液充气通常采用寄生管、双层套管、钻柱内注气等。进行充气钻井各种注气方式有不同,且各有优缺点。文章提出采用穿孔钻杆来实现充气钻井的设想,并对其机理进行了研究;结合多相流的相关知识,建立气液两相的H-K物理数学模型,分流型进行液柱压力计算和摩擦力计算;考虑到充气钻井液岩屑运移条件,研究出新工艺流程中井口压力变化情况,并对穿孔钻具下深、注气量等关键参数进行了研究。更多还原

【Abstract】 Parasitic string,double-layer casing,and injection within drill string are commonly used for injecting gas in drilling fluid,each having advantages and its disadvantages. In this paper the concept of using perforated drill pipe for gas injection was proposed,its mechanism studied,and the H-K gas-fluid physical/mathematic model set up based on the multi-phase flow theory. Then the hydraulic pressure and friction in different flow patterns were calculated. And considering the situation of cuttings migration in aerated drilling fluid,the wellhead pressure variation rules during this new process was studied and the critical parameters like running depth and gas injection rate were analyzed.更多还原