Published February 20, 2026
Drilling through loose overburden, boulders or water-bearing sand is where normal open-hole methods fail — the hole collapses as fast as you drill it. Casing while drilling (CWD) solves this by advancing the casing and the borehole together.
Concentric systems
A pilot bit and ring bit drill ahead while the casing follows. The ring retracts for withdrawal. Ideal for water wells, geothermal and micro-piles in mixed ground.
Symmetric (Symmetrix) systems
A wing bit and concentric ring give deeper, more stable casing in harder overburden — a cost-effective choice for deeper foundations and geothermal loops.
When to use CWD
- Unconsolidated or collapsing formations.
- Boulders and cobbles in the overburden.
- Water-bearing sand that washes out open holes.
For a matched casing system to your hole size and depth, request a quote and tell us the ground conditions.