Oil, Gas, and Petrochemical Cases: A Complete Guide

A Schlumberger wireline logging crew working the Permian Basin lost a $45,000 sonic tool when the Pelican-style case it was riding in cracked open on a washboard dirt road. The tool wasn’t just expensive — it was calibrated, scheduled for a 12-well logging program, and backed by a $2,500/day standby rig. The case failure cost the operator over $18,000 in downtime alone. This is the reality of oil and gas equipment transport: you’re not protecting a box of tools, you’re protecting a calibrated, certified, six-figure asset that has to arrive at the wellsite ready to run.

After 15 years building custom aluminum cases for oilfield service companies, drilling contractors, and petrochemical operators, we’ve learned what actually fails in the field. It’s rarely the aluminum panel itself. It’s the corner joints on rough roads, the foam that compresses after 20 trips, the latches that vibrate open, and the gasket that lets in dust and moisture on a 300-mile access road. This guide covers what you actually need to specify when you’re buying cases for downhole tools, MWD/LWD systems, surface test equipment, and hazardous-area instrumentation.

What Actually Breaks on Oilfield Equipment Cases

We’ve tracked failure modes across more than 4,000 oilfield cases we’ve built or repaired. The data is clear:

• Foam compression set (34% of failures) — Standard PE foam loses 25-40% of its cushioning after 15-20 field trips. The tool starts shifting inside the case, and the next hard impact transfers directly to the instrument body.
• Corner split on rough roads (22%) — Cases rated for 50g shock on a lab drop tower fail at 15g on washboard roads because the vibration is continuous, not impulsive. Riveted corners work loose; welded corners crack if the weld penetration is less than 2mm.
• Latch failure from vibration (18%) — Standard draw latches vibrate open on dirt roads. We’ve seen cases arrive at the wellsite with both latches hanging open and the tool held in only by the foam friction.
• Dust and moisture ingress (14%) — Without a continuous EPDM gasket and positive-locking lid, dust and drilling mud get inside. One grain of silica in a connector can cause a $2,000 recalibration.
• Handle/strap failure (7%) — Cases weighing 35-60kg need welded steel handle brackets, not riveted aluminum. A riveted handle pulling loose at 40kg is a common field injury.
• Other (5%) — Wheel failure, hinge wear, label degradation, and custom insert delamination.

Case Study: MWD/LWD Tool Transport for a Permian Basin Operator

Specification Guide: What to Demand from Your Supplier

ATEX and Hazardous Area Considerations

If your equipment is used in Zone 1 or Zone 2 hazardous areas, the case itself doesn’t need ATEX certification — but it does need to avoid creating additional hazards. Key considerations:

• Static dissipation — Aluminum cases are naturally conductive, which is actually an advantage in hazardous areas. Ensure the case has a grounding point if your equipment requires it.
• No spark-generating hardware — Avoid zinc-plated steel latches that can generate sparks on impact. Use stainless steel or aluminum hardware.
• Ventilation — If the equipment generates heat or contains batteries, the case needs pressure relief vents. A sealed case with a lithium battery inside can become a pressure vessel in temperature extremes.
• Labeling — The case should clearly identify the equipment inside, its certification status, and any handling requirements. We use engraved aluminum nameplates, not adhesive labels that fall off in the field.

Sour Service and Corrosion Engineering

In H₂S and CO₂ environments (sour service), standard aluminum cases will corrode from the inside out if drilling fluids or produced water get inside. Our approach:

• Interior coating — Epoxy powder coat on all interior surfaces, 80-100μm thickness, rated for H₂S exposure
• Stainless steel hardware — 316 stainless for all latches, hinges, handles, and fasteners in sour service
• Sealed foam

— Closed-cell EVA foam that doesn’t absorb fluids. Open-cell foam in sour service is a corrosion trap

• Drain points — If the case will be used outdoors, include a sealed drain plug at the lowest point so accumulated moisture can be removed