By TEBAOFLEX Jyen. Originally published on March 21, 2026.
Oil resistance and drilling-mud resistance are not interchangeable claims. Offshore cables may encounter reference mineral oils, actual drilling-fluid formulations, completion brines and cleaning chemicals. A useful specification identifies the exposure and the evidence required for the offered construction.
Start with the contract edition
NEK identifies NEK TS 606:2025 as its seventh edition, replacing the 2022 edition. Its scope concerns offshore cable requirements and references the IEC 60092 family. A project may specify an earlier edition, but a report must identify which edition and requirements were used; the words “NEK 606 compliant” alone are insufficient.
Do not treat a catalogue’s “SHF2-Mud” wording as a complete test schedule. Verify the applicable sheath category, mandatory requirements, optional enhanced exposures and any purchaser additions against the actual specification.
Name the test fluid precisely
An IRM reference oil is a controlled test medium, not a substitute for every mud used on a rig. Calcium-bromide brine requires its specified concentration and composition. Commercial drilling fluids can have different base liquids and additives; do not combine product names such as CarboSea and EDC 95-11 into an assumed universal ester-fluid recipe.
As a manufacturer-specific example, Prysmian describes its Bostrig Type P-MR product as tested for 56 days at 70°C in named ester-based muds. That supports the need to identify both fluid and conditions. It is not proof that every Type P cable, every NEK cable or any TEBAOFLEX cable has the same qualification.
Read changes and retention correctly
For each measured property, identify the unexposed reference, specimen preparation, exposure duration and temperature, conditioning after removal and calculation method. Mass increase, volume change, tensile-strength change and elongation change describe different effects and cannot be substituted for one another.
A 70% retained tensile strength means a 30% decrease from the reference, not a 70% improvement. The allowable limit must come from the specified requirement. Do not apply one universal swell limit to every brine, oil and mud, or claim a batch passed without its traceable results.
- Exact cable construction and sheath material identification.
- Standard edition, clause and any agreed project-specific conditions.
- Fluid name, concentration or formulation and traceable preparation.
- Sample identity, exposure history and pre/post-exposure measurements.
- Acceptance limits and an explicit result for every required property.
Chemical resistance is separate from fire performance
A flame-spread test, circuit-integrity test, smoke test and halogen-related test answer different questions. BFOU and RFOU descriptions must be tied to the particular datasheet and evidence. A mica barrier or a family designation does not establish a universal 180-minute survival rating under fire, shock and water.
Likewise, a generic polymer name does not prove either chemical resistance or inevitable failure. Claims about proprietary nanoclay, filler treatment or cross-linking must be supported by the actual construction and qualification. Type P and NEK designs should be compared requirement by requirement, not declared automatically equivalent.
Apply the evidence to the actual route
Identify where cables can encounter pooled mud, sprays, hot fluids, cleaning agents or mechanical damage. Select the construction and accessories for those conditions, including glands, joints and supports. The suitability of a protected accommodation route does not establish suitability on a drill floor.
Inspection and cleaning must follow the operator’s approved procedures, isolation requirements and equipment instructions. Do not tighten electrical glands or direct cleaning jets at equipment as a generic maintenance step. Where a sheath is damaged or chemically softened, have its condition assessed rather than assuming a passed material test guarantees continued service.
Sources and further documentation
Discuss your application
Send the operating conditions, installation drawing and required acceptance evidence to TEBAOFLEX. WhatsApp: +86 185 9591 3361. Request documentation for the exact offered construction before ordering.