May 2009 Vol. 236 No. 5

Features

Contractor Completes 42-Inch Bore To Connect LNG Terminal, Pipelines

When Sempra Energy’s Pipelines and Storage business unit needed to install a new pipeline from Sempra LNG’s new Cameron LNG receipt terminal to existing interstate pipelines north of the facility, they were well aware the project presented special challenges.

Connecting the $850 million LNG terminal taking shape on a 275-acre industrial-zoned site along the Calcasieu River near Lake Charles, LA to a major pipeline junction capable of accessing 65% of U.S. gas markets, required 36 miles of 42-inch pipeline. Cameron LNG is slated to commence commercial operation later this year.

The construction of the pipeline was awarded to the pipeline division of the Norman, OK-based Henkels & McCoy Inc. As the general contractor for this project, Henkels & McCoy selected Laney Directional Drilling (LDD), Houston, to perform all of the horizontal directional drills on the project.

The pipeline required the installation of 16 horizontal directional drills ranging in length from 1,300-5,000 feet. Of these drills, a 2,000-foot crossing of the Salt Ditch Canal and the 5,000-foot crossing of the Intracoastal Waterway were expected to be particularly challenging.

The original plan called for both the Salt Ditch Canal and the Intracoastal Waterway crossings to be staged from an island accessible only by boat or barge. In order to accommodate the Laney HDD rig and support equipment, the entire drill site had to be constructed with materials and equipment that was barged up the Intracoastal Waterway to the drill site location. Plans called for the crew to set up the drill rig and work on the island site where they would first drill the Salt Ditch crossing and then turn the rig around and drill the Intracoastal Waterway crossing.

Initial Concerns

Hernan Machicado, project manager for Sempra Pipelines & Storage, expressed concerns about the costs and logistics of the two drilling projects. In an effort to reduce costs associated with the transportation of matting, equipment and employees, plus the expenses involved in piping fresh water and waste drilling fluid, Machicado explored the possibility of installing the pipeline with a single drill that would extend 6,700 feet.

Grady Bell, project engineer for Laney Directional Drilling, said his company had completed a previous drill totaling 5,200 feet of 42-inch pipe for an LNG project about 70 miles south of Houston. A 6,100-foot drill had been completed near Orange, TX and had set the latest in a series of HDD records. “No one had ever attempted a drill of 6,700 feet of 42-inch pipe,” he observed when this drill was scheduled to take place.

From the onset, it was clear that everyone involved in the potentially record-setting drill – Sempra Pipelines & Construction, LDD and Henkels & McCoy – would take on some shared risk and that a comprehensive risk analysis would be required. After his analysis, Paul Greenwell, LDD’s project manager, concluded that while the length of the drill was significant and the risks were reasonably high, the drill could be installed if all the risks could be identified and mitigated.

In addition, the need for large amounts of fresh water for the drilling process posed overwhelming challenges in this highly environmentally sensitive area. Although several avenues were explored to solve the water issue, the solution involved piping water two miles from the Sempra LNG terminal to the drill site where it was stored in frac tanks.

Another significant challenge involved pulling the 3.5 million-pound pipe into the underground bore hole. Environmental challenges included the project location in a protected wetlands area where flocks of Great Blue Heron nest. The area also is used by local duck and goose hunters.

Despite the multiple challenges, the development team decided the most efficient and cost effective way to proceed required a single-drill crossing.

Complications

Because the earlier design that called for two separate drills had been finalized and approved by the U.S. Army Corps of Engineers, U.S. Fish & Wildlife, U.S. Environmental Protection Agency and the Federal Energy Regulatory Commission (FERC), the developer had to seek approval of the revised plan.

Although the original permit required 12 months, the regulatory agencies involved in the project were 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 said.

For instance, the 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 U.S. Department of Energy (DOE) crude oil pipeline serving the Strategic Petroleum Reserve, the largest emergency supply of petroleum in the world. In addition, LDD 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 FERC to provide a detailed environmental plan for the drilling project. Laney received notice that throughout the drilling process its own environmental crews were required to observe and make continuous physical inspections to ensure 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.

Pullback began on July 10 and, despite a minor delay, was completed four days later and ahead of schedule. The entire project took 56 days to complete and set a distance record for a large-diameter HDD crossing with 42-inch pipe, surpassing the old record by 570 feet.

“Part of the reason the job progressed so well was due to the close cooperation of all of the participants,” Bell stressed. “The teamwork of everyone involved, from the owner through to the regulatory agencies and environmentalists, made this project possible.”

Bell also commended the tenacity and persistence of the entire crew, including: Joe Harris, drilling superintendent for LDD; Darrell Stevenson, project manager, Henkels & McCoy; George Doll, spread boss at Henkels & McCoy; and Wayne Logan, onsite field manager for Sempra Pipelines & Storage.

“This project clearly demonstrated how companies can help each other,” Machicado said. “Some workers expressed doubts when we first started to talk about a single drill versus two separate drills, but by the time the project commenced, everyone involved was firmly committed to making it work.

“The project was well-executed and ahead of the start of commercial operations later this year for the Cameron LNG plant.”