April 16 (Reuters) - Venezuela's oil refineries worked at 31 percent of their combined 1.62 million-barrel-per-day capacity in the first quarter, well below 2017 levels, according to an internal document from state-run firm PDVSA viewed by Reuters.
PDVSA's refining operations have been degraded in recent years due to lack of cash for spare parts and maintenance, and insufficient light oil for the facilities. Staff departures, which have particularly affected the firm's refineries, have become the most recent obstacle to sustaining output levels.
The company's Amuay, Cardon, Isla, Puerto la Cruz and El Palito refineries processed 510,000 bpd of crude in the first quarter, down sharply from a 631,000 bpd average in all of 2017, the document said.
The very low processing rate, worse than in Mexico, where growing fuel imports have displaced domestic production, has led to a lack of refined products to fulfill the country's export commitments, according to the report.
In May, PDVSA will face a deficit of 14,000 bpd - mainly diesel and jet fuel- for export contracts, even though Venezuela's fuel consumption this year has remained well below the peak of 750,000 bpd registered a decade ago.
Declining domestic demand should have left a surplus for shipping abroad. Instead, the deficit continues to cause delays in exports, with customers receiving only a portion of the cargoes promised.
The lack of spare parts and feedstock to operate the refineries properly is PDVSA's most recurrent problem. But a lack of crude has become another big issue, forcing the firm to boost oil imports, according to the document.
PDVSA did not respond a request for comment.
PDVSA lowered its expectation for refining in May compared with April to 647,000 bpd, 39.9 percent of capacity, due to longer-than-expected maintenance projects.
The firm was hoping to restart one of the Amuay refinery's five atmospheric distillation units in April, but has postponed it without setting a new deadline. At Cardon, a vacuum distillation unit is out of service, while the reformer and a diesel hydrotreater are working with limitations.
At the 335,000-bpd Isla refinery in Curacao, the restart of several units under maintenance since February and April was delayed to May, including two crude units, an alkylation unit, a catalytic cracker and two hydrotreaters, the document showed.
At El Palito and Puerto la Cruz, an acute lack of medium crude has forced a halt to key units.
(Reporting by Marianna Parraga; editing by Gary McWilliams and Dan Grebler)