A bit trip (also called drill-bit trip or tripping for bit) is the complete round-trip operation of pulling the entire drill string out of the hole (POOH) to replace a worn or damaged bit, then running back in hole (RIH) with a new bit. Bit trips represent significant non-productive time and are among the most costly routine operations in drilling.
Trip Time and Cost
Trip time depends on well depth and rig capability:
- Shallow wells (<5,000 ft): 4-8 hours round trip
- Medium depth (5,000-15,000 ft): 12-24 hours round trip
- Deep wells (>15,000 ft): 24-48+ hours round trip
At typical deepwater day rates of $500,000-800,000, a single bit trip can cost $250,000-400,000. Even onshore operations at $25,000-50,000/day face trip costs of $50,000-150,000 per bit change.
Avoided Trips as Value Metric
The number of avoided bit trips has emerged as a key performance indicator for drilling technology evaluation. Each eliminated trip delivers direct savings equal to trip time multiplied by rig rate, plus avoided connection wear and reduced stuck pipe risk during trips. For a 20,000 ft geothermal well, eliminating two bit trips through improved bit life can save 48+ hours and $100,000-200,000.
Why Trips Occur
Bit trips are triggered by worn cutters (normal wear), broken or lost cutters (impact damage), bearing failure (roller cone bits), or inadequate ROP indicating dull bit. Premature trips from vibration damage are particularly costly as they sacrifice remaining bit life.
Automation Impact
Autonomous drilling systems reduce required bit trips by extending bit life through vibration mitigation and optimal parameter control. NexTitan has demonstrated dramatic reductions in trips per section by preventing the stick-slip and impact loading that cause premature bit failure.