PDC bit optimization scheme for tight oil reservoirs in the Jidong Oilfield based on rock anti-drilling characteristics

Abstract The tight oil reservoir rocks in the Jidong Oilfield are generally characterized by high hardness, strong abrasiveness, and extremely unevenness, which seriously reduce drilling efficiency. In view of this problem, mineral composition, plasticity coefficient, drillability were first determined. It was found that rock integrity, compactness hardness main factors leading to low breaking efficiency PDC bits. Then, combined with logging data, resistance profile whole well section established. According crushing mechanism under action a bit, mechanical model single composite plate conditions is established, influence back angle on cutting force analyzed. flow field distribution drill bit surface different nozzle combinations calculated finite element numerical simulation. Based experimental simulation results, optimal backward 15°, combination two 16-mm central nozzles five 14-mm peripheral nozzles. Finally, personalized design scheme for reservoirs proposed. includes following: (1) 5-blade straight-arc crown profiled; (2) anti-impact cylindrical components set; (3) hydraulic structure adopts bending type; (4) diameter-retaining teeth diversion grooves optimized. optimized reduces stick–slip, improves stability, has an obvious acceleration effect.