Venezuela’s state-run oil company PDVSA has launched one of its largest oil tenders ever, seeking to buy some 8m barrels of US or Nigerian light crude for delivery from April through June, according to a document cited by Reuters. This would amount to about 90,000b/d, up from the 50,000 b/d of crude PDVSA bought last year.

Crudes requested in the tender are US West Texas Intermediate and Nigeria’s Qua Iboe and Brass River in 550,000 to 1m barrel cargoes to be discharged at PDVSA’s Bullen Bay terminal in Curacao.

Additionally, PDVSA has a separate open tender to buy one to three cargoes, of 700,000 to 1m barrels each, of Russia’s Urals crude with deliveries starting in April, Petroleum World reported. Previously, the company received regular Urals crude cargoes from firms Rosneft and Lukoil during the second half of 2015.

In 2015, PDVSA purchased mainly African and Russian grades as diluents for its extra heavy oil output and processed them at its Caribbean refineries. But since a backlog of vessels formed in late 2015 following payment delays to its suppliers, PDVSA has been struggling to find providers for prompt deliveries. The firm is now proposing several payment mechanisms to oil and trading companies, including swaps, prepaid sales, letters of credit and open credit.