Study on rock breaking law of ring groove PDC bit mixed PDC cutter and field test

• Aiming at the problem of low rock breaking efficiency in the annular groove area, the proposed mixed PDC cutter can significantly improve the rock breaking efficiency and cutting stability of the cutting tool. • Using the finite element numerical simulation method, the rock breaking law of Non-planar PDC cutter and Planar PDC cutter in the annular groove region is studied. • The PDC ring-groove bit is developed by mixing Tri-ridged PDC cutter and Planar PDC cutter. The results of field test show that the penetration rate and service life of this bit are significantly higher than those of the same layer bit in adjacent wells. In order to solve the problems of low rock-breaking efficiency and poor bit stability of existing PDC bits in hard formation, a kind of annular PDC bit is proposed. The annular PDC bit can obviously improve rock-breaking efficiency and bit stability in hard formation. The cutting tool in the annular groove area formed at the bottom hole of annular groove bit have low rock breaking efficiency, The author uses finite element numerical simulation method to study the effect of Planar PDC cutter mixed with Ridged PDC cutter, Tri-ridged PDC cutter and Stinger PDC cutter on rock breaking efficiency in annular groove area. The results show: Compared with single Planar PDC cutter cutting 2.5mm, the overall rock breaking efficiency of Ridged PDC cutter, Tri-ridged PDC cutter and Stinger PDC cutter cutting 0.5mm and Planar PDC cutter cutting 2mm mixed double tool in annular groove area is increased by 6.68%, 7.71% and 6.75% respectively, and the cutting stability of Planar PDC cutter is increased by 47.22%, 24.42% and 43.9% respectively; Compared with single Planar PDC cutter cutting 3mm, the total rock breaking efficiency of Ridged PDC cutter, Tri-ridged PDC cutter and Stinger PDC cutter cutting 1mm and 2mm mixed double tool in annular groove area increased by 9.52%, 4.2% and 7.79% respectively, and the cutting stability of Planar PDC cutter increased by 40.73%, 17.86% and 36.09% respectively; Comprehensive study results show that Ridged PDC cutter and Planar PDC cutter or Stinger PDC cutter and Planar PDC cutter should be selected when cutting ring groove area with double tool mixed with Non-planar PDC cutter and Planar PDC cutter; Finally, through field test, CAS 6164HC type 12.25 inch double row tool annular PDC bit was used in Yun 'an 010-X1 well. Compared with adjacent wells in the same layer, the average penetration rate increased by 26.9%, and the newness of annular bit reached 80% after drilling. The research results provide a corresponding optimum scheme for improving the rock breaking law of annular PDC bit and selecting different PDC mixed tool arrangement.