Bit optimization method for rotary impact drilling based on specific energy model

Abstract

In the field application of oil and gas well drilling, it is found that the previous mechanical specific energy (MSE) model cannot well monitor the data of rotary impact drilling, and there are great errors. The main reason is that these MSE models focus on the correction of hydraulic and rate of penetration (ROP), ignoring the impact energy generated by hydraulic impactor, thereby reducing drilling efficiency (DE). Therefore, this paper improves weight-on-bit (WOB) and hydraulic parameter displacement Q to establish the rotary hydraulic impact specific energy model (RHISE) of polycrystalline diamond compact (PDC) and roller cone bits, and establishes the corresponding bit optimization model (BO) considering drilling cost (CT), RHISE, wear evaluation index (WI) and ROP. Applying this model to four wells in Shunbei, results show that the ROP of roller cone bits increases by about 10% and the DE increases by about 8% compared with the PDC bit. Compared with the combination of staggered PDC and roller cone bits (RCB) with hydraulic impactor, DE increased by 16% and BO increased by 4%. Therefore, the comprehensive efficiency of RCB combined with hydraulic impactor is better than that of PDC bit combined with hydraulic impactor.