By mid-2017, Sabal Trail, which Spectra is co- developing with a unit of NextEra Energy, will move up to 1 Bcf/d of gas more than 500 miles from a new interconnection on the Transco mainline in west-central Alabama to near Orlando. OPEN, a 78-mile, 30-in.-dia project now under construction, will improve the gas-flow plumbing in eastern Ohio, and NEXUS will move up to 1.5 Bcf/d of Marcellus/Utica gas some 250 miles across northern Ohio and southeastern Michigan.

"In New England, we have the [Algonquin Incremental Market, AIM] and Atlantic Bridge projects," both of which will add capacity and flexibility to Spectra's Algonquin Gas Transmission (AGT) system, Faraca says. "And we are developing Access Northeast"—another expansion of the AGT system—with New England electric distribution utilities Eversource and National Grid to help ensure that power generators in the region have enough gas to meet their needs on cold winter days.

"With so much supply on the doorstep of the market, and with the opportunity to repurpose pipelines due to changes in flow patterns, there will not be as much need for new long-line pipelines as in the past," says INGAA's Santa. "Still, there will be some significant new long-distance pipeline projects, such as the 550-mile Atlantic Coast Pipeline (ACP) that will transport Marcellus shale gas to markets in Virginia and North Carolina."

The $4.6-billion ACP project shows the sheer magnitude and complexity of these jobs from a planning, permitting, design and construction perspective. The project, which by late 2018 will move 1.5 Bcf/d of Marcellus and Utica gas, is being developed by a joint venture of four energy giants: Dominion, Duke Energy, Piedmont Natural Gas and AGL Resources. It will run along mostly new right-of-way—and often very rugged terrain—beginning in Harrison County, W. Va., then running southeast across central Virginia and then south across east-central North Carolina to Robeson County, near the South Carolina border.

From Large Bore to Small

In West Virginia and Virginia, the diameter of the ACP's steel pipe will be 42 in.; the diameter will shrink to 36 in. in North Carolina and to 20 in. for a spur or lateral from the main pipeline to the Hampton Roads region in coastal Virginia. To move the gas along the pipeline, three large compressor stations will be built: one at the start of the line in Harrison County, another in central Virginia and the third near the Virginia-North Carolina state line.

The project-approval process for ACP is just getting underway at FERC. The joint-venture development team got FERC's authorization in November to begin the pre-filing process; the team's actual filing for FERC approval of the project will be made this summer. With regulatory review and approval, construction could begin as soon as the fall of 2016.