The Design Of PDC Bit For Drilling Pyrogenetic Rock In Nanpu Oil Field

To the technical difficulties of high intensity, high hardness, poor drillability, slow ROP and low drilling efficiency of igneous rock of Guantao group in Nanpu Oil field, this paper conducts individuation design and field test research on a new type of PDC bit. First of all, an experimental mensuration on physical mechanics parameters such as drillability, time difference of sound wave and density of igneous strata of Guantao group in Nanpu has been made. And studies the correlative relation of the rock drillability level, compressive strength and logging data by large numbers of core test, develops a mathematical model which could predict drillability of stratum by the logging data, and analysis the drillability of Guantao group in Nanpu with the mathematical model. Then, optimize research to the cutter arrangement of PDC bits which adapts to the basalt formation of Guantao group in Nanpu has been done through the bedstead test of PDC drill bits. In accordance with the optimum result, this paper has developed the 12-1/4″type PDC bit which has achieved good results in the sandstone, shale and basalt stratum of middle and upper Guantao Group in Nanpu. Compared with the cone bit, the new PDC drill bit rise 60% in ROP, improve more than doubled in the footage. The 12-1/4 "P3653ZZ type PDC drill bits have been developed which have achieved good results in the basalt and conglomeratic sand of middle and lower Guantao Group in Nanpu. The ROP of the bit is up to 6.45m/h with 358 meters footage of one bit which achieves the best level in history. Now the bits have been widely expanded and used and obtain better economic and social benefits.