HDD Shore Approaches in the Biscayne Bay Marine Sanctuary

In the summer of 2005, two (2) HDD shore approaches (2200 feet & 2300 feet long) were constructed to the Port of Miami from the Marine Sanctuary in Biscayne Bay and under the main shipping channel. 24-inch diameter steel casings, pre-installed with two (2) 8-inch diameter steel ducts, were installed at each crossing to house 138 kV and 69kV power line circuits. Two horizontal rigs were utilized and worked in unison to drill the shore approaches. An 880,000-pound rig was setup on land inside the Miami container port and a 70,000-pound rig was setup on a barge staged in the Biscayne Bay. Several challenges were faced in view of having to work within one of the busiest ports in the US along a congested shipping channel with strict regulations imposed by the Department of Environmental Protection (DEP) and the Department of Environmental Resource Management (DERM) for operating in this highly environmentally sensitive area. DEP and DERM were involved in all activities occurring in these "clear & pristine waters of Florida." The regulations were very demanding and included no movement of equipment at night, trained on site observers for manatees (large, herbivorous, marine mammals) with a complete marine project shutdown in the event of any manatee sightings, and a restricted work zone in the marine sanctuary to allow containment of any drilling fluid returns or fractures while minimizing the extent of sea grass damage. This paper describes the operational procedures that were designed to enable construction within the confines of the permitted activities and used to deliver the successful completion of the HDD shore approaches.