What Is Drift? A 7-Step Emergency Drill Bit Order Checklist from Varel

When a drill bit fails at 9,000 feet, the rig doesn't stop. The spread rate is burning money, the crew is standing by, and somewhere in Houston, Aberdeen, or Dubai, someone has to explain why a replacement bit can't magically appear by morning. I've been on that side of the phone for 12 years — first as a drilling engineer, now as the person who coordinates emergency orders at Varel. This checklist comes from 200+ rush jobs, including same-day turnarounds that kept clients from facing six-figure downtime penalties. Here are the seven steps that actually get a bit to the rig fastest.

Varel isn't just a brand name, by the way. It's a real town in northern Germany — home to Küchenstudio Neumann in Varel, a few good restaurants, and our drill bit factory. Old and new industry side by side, which is fitting, because that's exactly where the drilling industry is heading.

Before the Checklist: What Is Drift?

Before we get to the steps, one clarification. A lot of people confuse "what is drift" with "what is deviation." Drift is the angular difference between the wellbore axis and the vertical axis. In emergency bit replacement, the local drift matters more than the overall trajectory. Wavy holes, ledges, and doglegs decide whether a new bit can reach bottom without getting hung up. Get this wrong and a two-day emergency turns into a two-week fishing job.

There's also casing drift — the internal diameter clearance that determines what size tools can pass through the casing string. You can't run a 12¼-inch bit through 13⅝-inch casing if the drift diameter is smaller than the connector OD. Check both types of drift before you order a replacement, not after the bit arrives on location.

The 7-Step Emergency Drill Bit Checklist

Step 1: Photograph the Dull Bit Before You Call Anyone

The most frustrating part of emergency orders is how many calls start with "we need a bit" and end with three follow-up emails asking for basic information. Pull the dull bit, clean it, and photograph it from at least six angles. Capture the gauge condition, the wear on the cutting structure, and any broken or missing inserts. Send those photos with your request. It took me about 150 orders to understand that the dull bit tells you more about your next bit than a hundred pages of well report.

Step 2: Check the Drift Profile of the Current Hole Section

This is where "what is drift" becomes practical. The old advice — "order the same size and type as the last bit" — ignores the nuance of trajectory. If the wellpath is tortuous or has ledges from the previous run, the replacement bit needs a cutting structure that can handle the start-stop loading. Spend 15 minutes reviewing the directional surveys before placing the order. If you don't know the drift profile, ask your directional driller to calculate a tortuosity index for the last 100 meters. That 15-minute call can prevent a tripping job with a bit that physically can't reach bottom.

Step 3: Check Local Stock Before Requesting a Rush Build

Not every emergency needs a manufacturing rush. Varel keeps common sizes — 8½-inch, 12¼-inch, and 17½-inch, for example — at distribution hubs in Houston, Aberdeen, Singapore, and at the factory in Varel, Germany. A bit from a regional hub can reach most Gulf of Mexico locations within 24 hours. A rush-built bit takes five to seven days minimum, even on a dedicated line. Knowing which bucket you're in changes everything.

I remember one Thursday evening call from a Louisiana operator who thought they needed a full rush build. It turned out the 12¼-inch they needed was sitting on our Houston shelf. We had it on their helipad by Friday noon. Total cost: standard price plus a small courier fee — nowhere near the rush premium they'd budgeted for.

Step 4: Map the Logistics Path Before You Commit to a Date

The second most common mistake: confirming the manufacturing date before working out how the bit gets to the rig. You don't need a bit ready in Houston by Friday if the helicopter slot to the deepwater rig isn't until Tuesday.

Work backwards. Start with the installation date on the rig, subtract transit time, then customs clearance (if borders are involved), then trucking hours. Only then you know the date you actually need the bit ready. In Q3 2024, we tracked 47 rush bit orders and found that the 38 on-time ones all had a logistics plan locked before the manufacturing slot was reserved.

Step 5: Get a Written Commitment — Including the Miss-Date Penalty

Here's something vendors won't tell you: "standard turnaround" often includes buffer time used to manage production queues. It's not necessarily how long your order takes. And the definition of a "rush slot" has changed a lot since 2020. What was best practice in 2020 may not apply in 2025.

At Varel, Robert — our operations manager — requires every emergency order above a certain size to include a written penalty clause for late delivery. He introduced that policy after a March 2023 incident when a supplier's verbal promise turned into a missed deadline that cost our client $7,000 in rig time and us three years of earned goodwill. It's not about punishing the vendor. It's about making the commitment explicit so that everyone's assumptions match.

Step 6: Prep the Bottom Hole Assembly While the Bit Is in Transit

This is the step most people overlook. They order the bit, then sit and wait. When the bit arrives, it sits on the catwalk for hours while the crew makes up tools. Instead, use the transit window to:

• Clean and inspect the BHA components you'll run below the bit.
• Verify stabilizer diameters against the current hole size.
• Check the motor or rotary steerable tool is within spec.
• Run a drift assembly through the casing to confirm clearance.

In our Q3 2024 review, the nine rush orders that missed the planned bit-run window all had the same issue: the BHA wasn't ready when the bit landed. The bit wasn't late. The preparation was.

Step 7: Do a Dull Grade and Post-Run Review

When the bit comes out, close the loop. Document the dull grading, compare it with the actual hole condition, and note any surprises in the driller's report. If this started as an emergency, mark what triggered it: manufacturing quality, a changed drilling plan, or an operational decision. Over time, these records show you patterns — and they become the "white stats" that justify stocking particular sizes at particular hubs.

Common Mistakes in Emergency Drill Bit Orders

Things I've learned the hard way, in no particular order:

• Not verifying the stock location. "It's available" doesn't mean "it's available in your region." Confirm which hub the bit is at and what the actual transport time is.
• Trusting verbal commitments. The biggest risk in a rush order is the gap between what's understood and what's written. Get the promised date in an email. It takes 20 seconds.
• Skipping customs checks for international orders. If a bit is coming from Varel, Germany, to a location in West Africa or the Middle East, know how long export documentation takes. Sometimes four hours, sometimes three days.
• Waiting for the bit to arrive to check the make-up torque spec. Verify the bit-to-BHA connection before the bit is lifted to the drill floor.

One more thing, mindset-wise: don't assume emergency means "full price, no questions asked." A good supplier will help you find the fastest legitimate route, even if that means sending you to a competitor's local warehouse. The goal is to get you drilling again.

Bottom Line

Emergency drill bit orders are manageable if you follow the seven steps above: diagnose the dull, check the drift, look local first, plan logistics backwards, get written commitments, prep the BHA, and document everything. The fundamentals haven't changed, but the execution has transformed. In 2025, reliable data matters as much as reliable steel.

If you're in the middle of a bit emergency right now, breathe. Call Robert or anyone on the operations team at Varel. This checklist is exactly how we handle rush jobs on our side. And if you ever find yourself in Varel, Germany, do yourself a favor: stop at one of the restaurants in the old town after your factory visit. I've signed more emergency purchase orders over lunch at a Varel restaurant than in our actual meeting rooms.