Development and application of V-shaped cuttings removal tool for horizontal wells

Abstract:

The accumulation of cuttings bed in the wellbore is one of the main factors restricting the safe and efficient drilling of horizontal wells. Research has shown that the spiral flow of drilling fluid in the annulus can effectively improve the efficiency of cutting removal. For this purpose， a rock debris removal tool capable of generating annular spiral flow was designed using CFD numerical simulation and experimental methods， and on-site application was also carried out. The results showed that the promoting effect of the V-shaped blade on cutting transport and disturbance ability on the cutting bed is stronger than that of the spiral and straight edged blades， making it the preferred structural form for generating annular spiral flow. There is an optimal range for the length of V-shaped blades， and the higher the blade height， the better the effect， while the number of blades has a weaker impact. The on-site application shows that the cutting removal tool meets the requirements of shale gas horizontal well operation in terms of strength， hardness， and blade wear resistance. The tool can destroy and remove the cutting bed while drilling. Combined with reaming operations on key sections where the cutting bed accumulates during the tripping process， it can effectively remove the stubborn large particle cuttings and improve the borehole cleaning effect.