1989: Saudi Refining, Inc. purchased 50% of the Port Arthur refinery from Texaco to form a joint venture with Texaco called Star Enterprise.
2001: Texaco purchased by Chevron.
2002: Chevron's interest sold to Shell. The new joint venture was called Motiva Enterprises LLC.
2017: Saudi Refining, Inc., buys out Shell's interest in the Port Arthur refinery. The basis being that the joint venture unraveled after a multi-billion dollar facility expansion, operating cost increases, and the 2015 United Steelworkers strike damaged corporate relations between the Saudi Refining and Shell. Saudi Refining, Inc. retains the Motiva Enterprises LLC name.
Today: Over five years later, nothing has changed.
ETA: The Port Arthur refinery isn't the largest refinery in Texas, but in all of North America.