PDC Drill Bit New Break record on Bozi Mountain after speed up
On December 30, 2020, Bozi 1801 well used a new type of multi-corrugated drill bit + vertical drill + constant wall thickness, low speed, high torque screw combination to drill to 4739 meters, 13 1/8 inch wellbore single trip footage of 885 meters, mechanical drilling The speed is 3.5-4.5 meters per hour, setting a new record for the footage and ROP of a single bit under the condition of drilling fluid for a large-size borehole in the Bozi block.
The geological design of the well predicts that the lithology encountered in the three-open 13 1/8-inch borehole is dominated by conglomerate. The new high-impact multi-edge bit ST616ZX used in this well has a double-row tooth structure, with multi-edge teeth as the main cutting teeth. Through the compound rock breaking mechanism, the rock breaking efficiency is improved, and the impact resistance is at least 5 times higher than that of conventional PDC teeth. Conical teeth are arranged on the outer side of the blade shoulder to reduce the whirling damage of the drill bit. Optimize and increase the cobalt removal depth of the cutting teeth, and enhance the abrasive resistance of the cutting teeth. At the same time, the anti-rotation design of the drill bit is optimized, and the stability of the drill bit and the rock breaking efficiency are improved. Compared with the average index of 13 1/8-inch borehole in the adjacent well Bozi 18, the drill footage has increased by 251% and the machine speed has increased by 76%.