定量分析了气体钻井中气-固两相流对井筒的冲蚀作用。结果表明,冲蚀作用最大的点在井底,这有助于破岩;井口段套管和钻杆的冲蚀作用次之,这是有害的。提出了在环空井口加载回压来控制气体钻井过程中气固两相流对井筒冲蚀的方法,确定了加载合理回压值的准则,即:确保环空内流速介于最小携岩速度和冲蚀临界速度之间。 The gas-solid two-phase flow in gas drilling is quantitatively analyzed for the erosion of the wellbore. The results show that the point of maximum erosion is at the bottom of the well, which is helpful for rock breaking; the erosion of the casing and the drill pipe at the wellhead is second, which is detrimental. A method to control the wellbore erosion by gas-solid two-phase flow during the process of gas drilling was put forward by applying back-pressure in the annulus of well head, and the criterion of loading reasonable back pressure was established, namely, to ensure that the annular velocity is within the minimum carrying velocity And erosion threshold speed.