Abstract: Hole Cleaning is very important in extended reach well drilling, and insufficient hole cleaning often leads to serious problem such as pipe sticking. The minimum cuttings rolling and suspension return velocity and the critical flow rate were designed for well QK17-2-P33, based on the consideration of such factors as drilling fluid properties, pipe rotation speed and penetration rate. Cuttings transportation when drilling of well QK17-2-P30 was investigated, and the reasons causing stuck pipe in QK-17-2-P31 were also analyzed in this paper.