Project Description
GTS was contracted to inspect the horizontal directional drills (HDDs) on an 11-mile, 24-inch project through environmentally sensitive areas of Northern California. The longest drill was 7,765-ft in length and was accomplished via the intercept method. The intercept method requires two pilot holes originating from each end of the project to intercept in the center. GTS plotted daily pilot-hole progress to confirm alignment.

GTS Involvement
GTS drafted HDD specifications and provided inspection services to monitori annular pressures, jetting pressure, thrust, and drilling fluid viscosity. The specification provided a superior finished product and aided pilot-hole approval in a few hours after completion, thus reducing contractor downtime prior to reaming.