Drill bit with protruding insert stabilizers

A rotary cone rock bit for drilling subterranean formations comprising:

• a bit body having an upper pin end for connection to a drill string and a plurality of lower leg portions, each leg portion including a shirttail with a tip at its lower end adjacent to the gage of the rock bit and a shoulder adjacent the upper pin end of the bit;
• a journal pin on each leg portion;
• a cutter cone rotatably mounted on each journal pin;
• and
• a first bearing insert protruding laterally from the shirttail portion of the bit body approximately half way between the lower tip of the shirttail and the shoulder;
• a plurality of additional bearing inserts between the first bearing insert and the shoulder, the outer ends of each of the bearing inserts being substantially at the gage diameter for bearing on a wall of a borehole, and wherein the protruding ends of the bearing inserts are rounded for minimizing reaming of a borehole diameter.

A rotary cone rock bit for drilling subterranean formations comprising:

• a bit body having an upper threaded pin end for connection to a drill string and a plurality of lower leg portions, each lower leg portion including a shirttail outer face portion extending from a lower tip adjacent to the gage of the rock bit to a shoulder below the pin end, and a recessed channel extending longitudinally between adjacent shirttail portions toward the pin end;
• a cutter cone rotatably mounted on each leg portion for drilling rock formation and forming a borehole;
• and
• a first bearing insert protruding laterally from a shirttail portion of the bit body between the recesses approximately half way between the lower tip of the shirttail and the shoulder, the outer end of the bearing insert being rounded for bearing against a borehole wall without appreciable reaming of the borehole wall.

A rotary cone rock bit for drilling subterranean formations comprising:

• a bit body having an upper pin end for connection to a drill string and including a plurality of journal pins each extending downwardly and inwardly from a lower leg portion of the bit and having a bearing surface, each leg portion including a shirttail extending from a rounded tip at its lower end adjacent to the gage of the rock bit and a shoulder at its upper end adjacent the pin end;
• a cutter cone rotatably mounted on each journal pin, each cutter cone comprising:
• a bearing surface adjacent the bearing surface on the journal pin,
• a plurality of cutter inserts in the cutter cone for drilling rock formation on the bottom of a borehole, and
• a plurality of heel row inserts in a portion of the cutter cone adjacent to the gage of the rock bit;
• a pressure-compensated grease reservoir for each set of bearing surfaces in a portion of the bit body between the pin end and the shoulder at the upper end of the shirttail, and in fluid communication with such bearing surfaces;
• a grease in the grease reservoir and adjacent the bearing surfaces;
• the bit body gradually decreasing in diameter from a larger gage diameter adjacent the lower tips of the shirttails to a smaller diameter adjacent to the shoulders;
• and
• a plurality of bearing inserts protruding laterally from the gradually decreasing diameter portion of bit body between the lower tip of each shirttail and the respective shoulders, the outer ends of the bearing inserts being non-cutting and substantially at the gage diameter.