LAUSR

In this study, drillable composite bridge plugs and specialized cylindrical cutter bits were considered as the research objects. Through elastic–plastic mechanical analysis of plugs during drilling, the relationship between single-cutter feeding force and drilling depth and that between cutting force and cuttings separation were deduced. By taking the influences of the bit geometrical structures and bridge plug material properties into consideration, the relationship between WOB, torque and footage were established and validated by finite element simulations. The ROP equation was constructed by comprehensively considering the drillability and drilling parameters of bridge plugs. Based on the field tests of composite bridge plug drilling, the calculation method of a structural influence factor in the ROP equation was decided in combination with the geometrical features of bridge plugs. The results of this study can provide theoretical calculation basis for the control of WOB and ROP, as well as the prediction of bridge plug drilling duration and depth, during the drilling processes of coiled tubing bridge plugs.