Venezuela’s state-oil firm PDVSA has bought a 500,000-barrel cargo of U.S. crude from trading company PetroChina for delivery April 1-10 at its terminal in the Caribbean island of Curacao, traders told Reuters on Monday.

The purchase is separate from a large tender launched by PDVSA to buy some 8 million barrels of U.S. and Nigerian crudes that was awarded last week to British firm BP and China Oil.

Both PetroChina and China Oil are units of state-run China National Petroleum Corporation (CNPC).

The cargo to be delivered by PetroChina next month can contain West Texas Intermediate (WTI) or a blend made from this crude, the sources added.

PDVSA, which needs foreign light crude to use as a diluent for its extra heavy oil and to process at its Caribbean refineries, started buying WTI in January.

Since then it has received two 500,000-barrel cargoes and another one of the same size on tanker Orpheas is expected to arrive in Curacao this week.

The company postponed another tender to buy 2.1 million to 3 million barrels of Russia’s Urals crude, also for delivery during the second quarter, the traders said. Bids for that tender will now be accepted until next week.

If PDVSA awards them all, the tenders more than double the company’s crude imports in the second quarter to some 120,000 barrels per day (bpd).

And to cover a slowdown at its domestic refining network amid equipment failure and electricity problems since the beginning of the year, the company also has an open tender to import a 300,000-barrel cargo of ultra-low sulfur diesel (ULSD) for April delivery.

PDVSA’s second largest domestic refinery, Cardon, has two of four crude distillation units out of service due to operational problems, workers told Reuters on Sunday. Venezuela’s largest facility, Amuay, was working at half capacity as of March 14 according to an internal report.

(Reporting by Marianna Parraga; Editing by Andrea Ricci)

Source: Reuters