Caracas - Venezuela’s state-run oil company, PDVSA, has fallen months behind on shipments of crude and fuel under oil-for-loan deals with China and Russia, according to internal company documents reviewed by Reuters. The delayed shipments to such crucial political allies and trading partners - which together have extended Venezuela at least $55 billion in credit - provide new insight into PDVSA’s operational failures and their crippling impact on the country’s unraveling socialist economy. Because oil accounts for almost all of Venezuela’s export revenue, PDVSA’s crisis extends to a citizenry suffering through triple-digit inflation and food shortages reminiscent of the waning days of the Soviet Union. The total worth of the late cargoes to state-run Chinese and Russian firms is about $750 million, according to a Reuters analysis of the PDVSA documents. At the end of January, PDVSA was late on nearly 10 million barrels of refined products that the company owes the firms - with shipments delayed by as much as 10 months, according to the documents.