According to sources, supermajor Chevron has asked Petrobras to prove Pasadena refinery to be operational before taking possession of the facility. Chevron announced in January to spend $350 million for the proposed acquisition of 112,229 barrel-per-day (bpd) Pasadena refinery from Petrobras. Sources revealed that the ownership transfer was stalled after the refinery went under planned overhaul.