对双壁钻杆低压钻井过程中双壁钻杆的最大下入深度和井底压力的计算方法进行了研究,使用马古3井的有关数据进行了实例计算。结果表明,双壁钻杆的最大下入深度与地面注气增压设备的出口压力、泥浆泵的泵压、地面管汇、钻杆内外压耗以及钻头水力参数等因素有关,使用双壁钻杆钻井可有效地降低井底压力,是一种较有应用前景的低压钻井工作方式。 The calculation method of maximum penetration depth and bottom hole pressure of double-wall drill pipe during the low-pressure drilling process of double-wall drill pipe was studied, and the relevant data of Magu-3 well were calculated. The results show that the maximum penetration depth of double-walled drill pipe is related to the outlet pressure of injection equipment, pump pressure of pump, ground manifold, internal and external pressure loss of drill pipe and bit hydraulic parameters. Rod drilling can effectively reduce the bottom hole pressure, which is a promising method of low pressure drilling.