Abstract:
When drilling into hard formations with a PDC bit, problems such as stick-slip vibration, bit bouncing and whirling of drilling string occur frequently, which causes the drill bit to collapse and the drilling string to twist and deform, hence compromising the drilling efficiency and the service life of the bit and the drill string. For this reason, based on the development of hydraulic torsional impactor and hydraulic booster as well as the combined application, a drilling acceleration technology was developed by jointly using hydraulic torsional impactor and hydraulic booster. The results of indoor performance test showed that the hydraulic torsional impactor could generate high-frequency impact torque, and the impact torque, impact frequency and choking pressure would increase with the flowrate. The hydraulic booster coudd effectively reduce the severe vibration in the drill bit, so as to achieve the purpose of improving ROP and protecting the drill bit. This technology was field tested in 3 wells. Compared with the adjacent wells, the ROPs were increased by 50%, 33% and 68%, respectively, and the footage of single bit was increased significantly. The research showed that the drilling speed-up technology of combining hydraulic torsional impactor with hydraulic booster could greatly increase ROP and solve the problem of WOB stacking in the directional drilling of this oilfield, which provided a technical measure to achieve an efficient development of reservoirs.