Midstream-focused SemGroup Corp. (NYSE: SEMG) will construct, own and operate the Maurepas Pipelines on the Louisiana Gulf Coast, the company said March 26.

Maurepas will support Motiva Enterprises LLC's efforts to interconnect and optimize its refinery operations.

The 34.2-mile long, 24-inch wide pipeline will cross the Mississippi River connected to Locap. It will terminate at Motiva's refinery in Norco, La.

Two intermediates pipelines will run between the Norco and Convent refineries. They will be 35 and 34 miles long, respectively, and 6 inches wide. 12-inch, 35 mile intermediates pipeline between Motiva's Norco and Convent refineries.

Long-term transportation agreements with Motiva are supporting the project, SemGroup said. Maurepas is scheduled to be operational in 2016’s fourth quarter.

This project is SemGroup’s first asset development in the Gulf Coast area, said CEO Carlin Conner.

"This $500 million investment will expand SemGroup's scale and customer base, creating a more diversified midstream company while adding to our inventory of assets to drop down to our MLP, Rose Rock Midstream, in the future. We remain focused on expansion projects that create value for our customers, are executed at mid-to-high single digit EBITDA multiples and generate attractive returns for our shareholders."

SemGroup Corp. is based in Tulsa, Okla.

Motiva Enterprises LLC is based in Houston.