Eccentric casing drilling systems are designed for overburden drilling where borehole collapse or instability may occur.

The rear surface of the sliding blocks is designed with guiding geometry, providing effective guidance during pull-out and enabling smooth and easy retrieval.

The casing coupling is manufactured from higher-grade material than the casing itself and heat-treated, ensuring reliable and secure connections.

Compared with other concentric casing drilling systems, this design significantly improves cuttings evacuation efficiency and flow capacity.

The concentric three-wing casing drilling system is suitable for soft to medium formations such as clay, flowing sand, small gravel, and highly weathered rock (f ≤ 3).