Optimization design and application of PDC bit in horizontal well

Compared with conventional polycrystalline diamond compact (PDC) bits for vertical and directional drilling, the gauge is more easy to wear for horizontal PDC bit, which suffers more much impact load and requires better steer ability.According to the horizontal strata characteristics of Honghe oilfield in Ordos basin, the cutter size and back rake angle are optimized through indoor experiment.Based on the characteristics of horizontal well bit, the bit profile is designed to be of shallow inner cone, short external cone and big crown arc.The gauge is enhanced with "active gauge cutter and low friction gauge pad" and the hydraulic structure is enhanced with asymmetric and multinozzle arrangement.The field application shows that the footage of new drill bit is comparing to ordinary bit, the footage is increased by 193%comparing with that of ordinary bit, and the penetration rate is increased by 132%.