NUMERICAL ANALYSIS ON THE INFLUENCE OF JET-FLOW TYPES ON BOTTOMHOLE FLOWING FIELD OF ROTARY BIT

To study the influence of different types of jet flow on bottomhole flowing field of the rotary bit, numerical comparisons and simulations are conducted to the drilling bit with multiple nozzles, combining the arrangement of three-dimension, rotary and asymmetric geometry under different jet flow types. Simulating results show that the jet flow type has little influence on the thickness of cross flow, while it has remarkable effect on cuttings removing capability at the bottomhole. As compared with other jet flows, the dipping jet flow in the same angle results a more desirable bottle hole configuration.