A bit run (also called bit run length) is the total footage drilled by a single drill bit before it requires replacement due to wear, damage, or performance degradation. This metric is fundamental to drilling economics because longer bit runs mean fewer time-consuming and costly trips to change bits.
One-Bit Run / One-Bit Lateral
The ultimate goal in many drilling programs is the one-bit run—completing an entire section (or entire lateral in horizontal wells) with a single bit. A one-bit lateral eliminates mid-section trips entirely, compressing drilling schedules and reducing risk. Industry benchmarks show that achieving consistent one-bit laterals can reduce section time by 15-25% compared to multi-bit approaches.
Economic Impact
Each bit trip in a deep well can cost $50,000-150,000 when accounting for trip time at rig rates, connection wear, and lost drilling time. In geothermal wells exceeding 15,000 ft TVD, trip costs escalate further due to extended pipe handling time. Extending bit runs from 2,000 to 4,000 feet can eliminate multiple trips per well, delivering six-figure savings.
Factors Affecting Bit Life
Bit run length depends on formation abrasiveness, drilling parameters (WOB, RPM), vibration exposure, and hydraulic efficiency. Hard rock formations typical of geothermal drilling impose severe demands—unmitigated stick-slip can reduce bit life by 50% or more through accelerated cutter damage.
Automation Advantage
Autonomous drilling systems extend bit runs by maintaining optimal parameters continuously and eliminating the vibration-induced damage that shortens bit life. NexTitan has demonstrated 200%+ improvement in footage per bit in hard rock applications by preventing stick-slip and maintaining consistent cutting action throughout the run.