Tunneling & Direct Pipe

direct-pipe machine

NorthStar creates fluid programs for direct-pipe, large diameter tunneling, and micro-tunneling projects. These programs provide accurate volume and additive amount estimates based on geological analysis. Each program is tailored to meet project challenges and includes a slurry and lubrication fluid system breakdown with fluid properties, recommended additive concentrations, and alternative formulations. A geotechnical walkthrough is also provided to help crews prepare for and troubleshoot potential problems.

Slurry Fluids

Tunneling slurry fluid

Slurry fluids can be customized to suit different geological conditions. Inhibitive slurries reduce cutter clogging and formation swelling, leading to fewer delays and faster progress. Stabilizing fluids form a low-permeability filter cake to prevent fluid migration into the formation. This increases bore stability and reduces the risk of sloughing or hole collapse.

Annular Lubricating Fluids

Annular Lubricating Fluid

Annular fluid systems reduce jacking forces and enhance bore stability by filling the space between the formation and the machine with a lubricating fluid. This fluid reduces the coefficient of friction and allows the machine or pipe to slide more easily along the bore. The lubricating fluid also creates a filter cake on the bore wall to prevent groundwater ingress and fluid loss. In porous formations, the annular fluid can form a grout-like consistency, further increasing bore stability.