Dallas-based Sunoco is an affiliate of Energy Transfer, which billionaire Kelcy Warren controls.
The joint venture, formed on July 1, is expected to be immediately accretive to distributable cash flow for both Energy Transfer and Sunoco.
It will operate more than 5,000 miles of crude oil and water gathering pipelines with crude oil storage capacity exceeding 11 million barrels.
Energy Transfer will hold a 67.5% interest in the joint venture, with Sunoco holding the remaining 32.5%.