WAYS TO IMPROVE THE DESIGN OF DRILL BITS EQUIPPED WITH PDC CUTTERS

The study discusses approaches to solving the problem with the «hanging» of the rock cutting tool and, as a result, improving the mechanical speed of drilling by increasing the efficiency of PDC drill bits and extending the life of their cutters. According to the results of the analysis of the destruction of PDC cutters to increase the duration of the cutters, it was revealed that most of the cutting edge of the PDC bits limits the contact of the cutter with the rock and more than half of the circumference of the cutting edge of the cutter remains unused in the process of bottomhole destruction. Two approaches to solving the problem are proposed: - the use of cone-shaped cutters in the central part of the bit or a crown-shaped design of the bit, which allows, by crushing the central part of the bit with a cone-shaped cutter, to solve the problem of “hanging” of the central part of the rock; - use of rotating PDC cutters or uniform rectangular cutters, which provide optimal location in areas of the greatest wear of the cutting structure of the bit. Here, the entire length of the cutting edge is used to cut the rock. Based on the results of the research, a PDC bit with an annular rock destruction pilot was developed (RK patent for the invention No. 34527), which solves the problem of bit “hanging” in the central part of the bottom hole, which significantly reduces the productivity of the rock. Implementation of the mentioned PDC bit improvements, i.e. improvements in the configuration of PDC cutters or their rotation during drilling, as well as developments that allow the bit to hang during drilling, will significantly increase the productivity of drilling with these rock cutting tools and the durability of their cutting tools.