The principal backer of the controversial $3.68 billion Dakota Access Pipeline (DAPL) that only recently began flowing Bakken crude oil, Energy Transfer Partners (ETP) last Friday launched a binding supplemental open season aimed at expanding the capacity of the four-state, nearly 1,200-mile pipeline that terminates at a marketing hub in south-central Illinois.

“We have somewhere close to 100,000 b/d of capacity left to sell, and we’re talking to customers that are interested in it,” said a spokesperson for Texas-based ETP. “We expect the volumes to come from the Bakken.”

She confirmed that these volumes are in addition to the 470,000 b/d capacity ascribed to the 30-inch diameter pipeline that completed construction late last month with the tunneling under a dammed portion of the Missouri River at Lake Oahe in south-central North Dakota. DAPL’s operators now are focusing on increasing the line’s capacity up to 570,000 b/d.

ETP announced last Friday that its two units, Dakota Access LLC and Energy Transfer Crude Oil Co. LLC (ETCO), launched the binding open season, which requires subscribers in additional capacity to sign confidentiality agreements, and for which there is no publicly disclosed closing date for the solicitation.

“The supplemental open season includes local tariff service on DAPL from the Bakken/Three Forks play to Patoka, IL,” ETP’s announcement said. “It also provides interested parties with the opportunity for joint tariff service from the Bakken/Three Forks play to Nederland, TX, through a commitment to both Dakota Access and ETCO pipeline systems.”

The supplemental open season began last Wednesday, directing prospective shippers to an e-mail address to execute the confidentiality agreements.

DAPL’s expansion plans were mentioned on Monday at a two-day Law Seminars International conference on “Tribal Energy in the Southwest” that got underway in Albuquerque, NM. Denver-based attorney Troy Eid, who has represented both tribes and companies in energy project negotiations over recent years noted that the disputed oil pipeline is now going to “add capacity which means more pumps and putting more oil through DAPL than was originally discussed” during the ongoing debate over the project.

Eid concluded that because of the way DAPL has evolved as a focal point for protest by Native American tribes nationally, future energy projects involving tribal lands and interests are going to be more difficult to complete for energy companies.