Bit Run and BHA Report Generator: IADC Dull Grading to PDF

PDF Generators
Run details
Operating parameters
IADC dull grade (bit out)
BHA summary
Remarks

The bit run report: memory for the next section

Every bit that comes out of the hole tells a story about the rock it drilled and the way it was run, and the bit run report is where that story gets written down before the bit disappears into a shipping basket. The generator above builds the full record: run performance with footage and average ROP computed automatically, the operating parameters the driller actually used, the eight-field IADC dull grade, and the BHA that carried it all. Print it to PDF and it becomes the document the next well in the field gets planned from.

Diagram of a PDC drill bit next to the eight fields of the IADC dull grading system: inner and outer cutter wear, dull characteristic, location, bearing seals, gauge, other characteristic, and reason pulled
The IADC dull grade condenses bit condition into eight fields. It is how the next bit on the well gets chosen.

The arithmetic is deliberately simple. Footage is depth out minus depth in, and average ROP is footage divided by drilling hours, so a 1,250 ft run over 62 hours averages 20.2 ft/hr. What makes the report valuable is pairing that performance number with the dull grade, because footage without condition is half a story. A bit that averaged 20 ft/hr and came out graded 1-2-WT-A is a success that could have stayed longer; the same ROP with 4-6-BT-S means the shoulder cutters were breaking and the run was pushed too far.

Reading the dull grade

  • The first two digits score cutter wear on a 0 to 8 scale, inner two-thirds of the face first, then the outer third. A 1-2 is barely worn; anything 4 or above means significant cutter loss.
  • The dull characteristic is the dominant wear mode: WT is normal wear, BT broken cutters, LT lost cutters, ER erosion, RO ring out. This letter pair carries most of the diagnostic content.
  • Location tells you where the damage sits: nose, taper, shoulder, or gauge. Shoulder damage on a PDC often points to interfacial severity or whirl; gauge wear points to abrasive formations or under-gauge hole.
  • Bearing and seals apply to roller cones; PDC bits carry an X. Gauge is either I for in gauge or the amount under in sixteenths of an inch.
  • Reason pulled closes the loop: TD for section total depth is the happy ending, PR for penetration rate means the bit gave up first, TQ or PP flag torque and pump pressure problems worth investigating beyond the bit.

Graded honestly and consistently, these eight fields let a drilling engineer sitting in an office two years later reconstruct what the rock did to the bit, and the pattern across several wells is what justifies changing bit type, cutter size, or operating practice. Graded generously to make a run look good, they poison exactly that dataset. The convention exists so that a 2-3-WT-A means the same thing in every company and every basin.

The BHA half of the report

The bottom hole assembly section matters as much as the bit. Motor bend and speed, stabilizer placement, and where the jars sit all change how weight reaches the bit and how the assembly builds or drops angle. Recording the BHA alongside the dull grade is what lets you separate bit problems from assembly problems: a shoulder-damaged bit below an aggressive motor bend is a different diagnosis from the same bit on a rotary assembly. Write the BHA from the bit up, component by component, the way it stood in the derrick.

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