Centralizers

S.D.U. Under-Ream Centralizers

Advanced Engineering for Complex Wellbore Environments

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PDG’s S.D.U. Range of Under-Ream Centralizers represents a major step forward in well construction technology—engineered to deliver superior performance in today’s most challenging wellbore conditions. Designed for under-reamed, enlarged or close-tolerance sections of the well, these precision-manufactured tools ensure optimal casing centralization, improved cement placement, and long-term well integrity across vertical, deviated, horizontal, and extended-reach wells.

 

Purpose-Built for Performance

Under-ream wells demand more than conventional bow-spring solutions. Once a section of the hole is enlarged, standard centralizers struggle to maintain adequate standoff, resulting in poor annular cement coverage and compromised zonal isolation. The S.D.U. Under-Ream Centralizer is designed to pass through restrictions and return to full gauge in the enlarged section, providing consistent restoring force, maximum standoff, and reliable cement displacement.

Manufactured from a single piece of Premium Alloy Steel, these units deliver high strength, superior flexibility, and exceptional fatigue resistance under extreme downhole conditions.

 

Why PDG Under-Ream Centralizers Stand Apart

• One-piece laser-cut construction for precision and durability

• Exact bow standoff tolerance, ensuring reliable and repeatable performance

• Automated heat treatment for proven mechanical consistency, full traceability and no variability between batches

• Compliant with API 10D – 7th Edition testing standards

• Designed to squeeze through restrictions and return to near-original OD

• Fully tested for restoring force in under-ream simulation environments

 

Manufacturing Excellence

Every product undergoes 100% inspection at every production stage, backed by automated quench-and-temper heat treatment, in-house metallurgical validation and a complete digital QA record. This ensures repeatable, reliable field performance regardless of application or region. PDG’s manufacturing strategy is based on precision, traceability and innovation, not replication.

 

Applications

• Under-reamed / Wash-out open hole sections

• Close-tolerance wellbores

• Highly deviated and horizontal wells

• ERD and deepwater wells

• Casing operations requiring rotation or reciprocation

• Wells with high-risk cement placement zones

 

Future-Focused Innovation

PDG continues to expand our premium accessory range with patent-pending tooling developments, close-tolerance engineered solutions, and advanced testing technology.