Horizontal Directional Drilling

Ocean Sciences Center

Ocean Sciences Center

Location

St. Johns, Newfoundland, Canada

Timeline

2010

Methods

Horizontal Directional Drilling Pilot hole drilling Excavation Underwater remote control vehicle with camera

Scope

Michels installed a 1,554-foot-long water intake line for the Ocean Sciences Centre at Memorial University of Newfoundland. The pilot hole drilling and reaming was conducted through red to purple sandstone, characterized as fine to medium grained with pebble-size inclusions and massive structure resulting in little or no bedding. MOHS hardness was tested to 6.5 on the hardness scale and had between 6,500 to 22,200 psi compressive strength. The exit hole was planned to let daylight out in a heavy tidal area and wave-influenced cove of the coast of Newfoundland. Release of drill fluid in the ocean was a primary concern. Specialized procedures perfected by Michels were used to mitigate the release of fluid into the water body, as there could be no guarantee of zero release. Those procedures included stopping the pilot hole 45 feet from exiting through the ocean floor and forward reaming with a 22" reamer just short of exit before retracting back to the entry location. An underwater remote-controlled vehicle with camera was used to verify final location of the pipe during a three-day window of calm sea that prevailed at just the right time.