Flexible bit: A new antivibration PDC-bit concept

This paper introduces the novel concept of a flexible polycrystalline diamo nd compact (PDC) bit and demonstrates its capability to reduce detrimental vibration often associated with drag bits. The tilt flexibility, introduced at the bit, decouples the dynamic motion of the bottomhole assembly (BHA) from that of the bit, thus providing a dynamically more stable bit. The pap er describes the details of a prototype 81/2-in. flexible bit design, labor atory experiments, and field tests, which verify the concept.