Record 42-Inch Bore Helps Connect LNG Terminal, Pipelines

Shared Risk, Cooperation Make Complicated Project Possible
April 2009 Vol. 64 No. 4

Although the original permit required approximately 12 months, the regulatory agencies involved in the project were very cooperative and approved the revised plan in just 30 days. Machicado credited the prompt approval of the revised plan to the fact that the agencies involved were comfortable with the project and were well aware that the revised plan offered a much lower environmental impact. “The revised plan shortened the overall length of the pipeline 330 feet, and eliminated the need for a work pad supported by barges. Despite this environmental upgrade, some of the regulatory agencies imposed regulations and specifications that had to be met prior to starting the single drill construction project,” he pointed out.

For instance, the U.S. Army Corps of Engineers specified the crossing reach a minimum depth of 65 feet within 25 feet of the banks of the Intracoastal Waterway. “In this way, there would be no danger to the existing pipelines on the floor of the waterway,” Machicado said. Also, the planned crossing would have to tunnel beneath 11 existing pipelines on the banks and floor of the Intracoastal Waterway, including a 36 inch diameter U.S. Department of Energy (DOE) crude oil pipeline serving the U.S. Strategic Petroleum Reserve, the largest emergency supply of petroleum in the world. In addition, LDD also had to provide the DOE with copies of the new drill profile and the date the activity would take place. According to Greenwell, a DOE official was required onsite to observe the drilling and ensure that there was no damage to the pipeline serving the petroleum reserve.

LDD also was required by Sempra and the Federal Energy Regulatory Commission to provide a detailed environmental plan for the drilling project. Laney also received notice that throughout the drilling process its own environmental crews were required to observe and make continuous physical inspections to ensure that there was no inadvertent drilling fluid releases (frac outs) in the wetlands or the Intracoastal Waterway.

Crossing

In May 2008, LDD mobilized equipment and supplies to the drill site on the east side of the waterway. This included one of the largest HDD rigs in the world, capable of 1.7 million pounds of pullback force.

Drilling the 9 5/8 inch pilot bore took 14 days. This initial 6,669 foot drilling operation was precisely on target. LDD’s crew made several reaming passes, swabbed with barrel reamer to ensure the bore path was clean and ready to accept the pipe section.