CARACAS, Venezuela (AP) — Venezuela’s state-run oil company signed a series of multibillion-dollar agreements Wednesday with foreign and domestic firms to develop oil fields in the South American nation’s petroleum-rich Orinoco region.

Oil Minister Rafael Ramirez said Petroleos de Venezuela will create joint ventures with two consortiums of mostly foreign companies to develop two blocks in the Carabobo area of the Orinoco Belt — one of the world’s largest known oil deposits.

Ramirez said one block will be developed by a consortium that includes Spain’s Repsol, Malaysia’s Petronas and three Indian companies — Oil and Natural Gas Corp, Oil India Ltd and Indian Petroleum Corp.

The other block will be worked by a consortium made up of US-based Chevron, Venezuela’s Suelopetrol and Japanese companies Mitsubishi, Jogmec and Inpex.

Petroleos de Venezuela and the two consortiums plan to invest a total of US$30 billion on the joint ventures, which are expected to produce 400,000 barrels of oil a day by 2016, Ramirez said. PDVSA will hold a majority stake in both projects, he said.

President Hugo Chavez proudly noted the US Geological Survey (USGS) reported last month that the Orinoco Belt likely holds 513 billion barrels of recoverable heavy crude — nearly twice as much as the proven reserves of Saudi Arabia.

The USGS came up with a range of estimates for “technically recoverable” oil in Orinoco from 380 billion to 652 billion barrels — and determined a mean estimate of 513 billion barrels.

Slumping world crude prices have forced Venezuela’s Government to reach out to multinational oil firms it once demonised as capitalist profiteers because the state company desperately needs the cash, technology and expertise of private companies to pump the Orinoco region’s heavy, tar-like crude.

“Foreign investment is absolutely necessary for us,” Chavez said. “We wouldn’t be able to develop the Orinoco Belt ourselves.”

Mazhar al-Shereidah, an oil economist at Central University in Caracas, said Venezuela is looking for foreign partners because “the amount of heavy oil in the belt is so gigantic that it exceeds the capacity of any single oil company.”

Chavez — a self-proclaimed Marxist — nationalised four Orinoco projects operated by private oil companies in 2007, prompting the US companies Exxon Mobil and ConocoPhillips to abandon the country and sue for compensation.

William Edwards, an oil analyst with the US-based Edwards Energy Consultants, said the foreign companies that signed on Wednesday might be taking a risk because Venezuela’s socialist leader could launch another wave of state takeovers.

“I’d say it’s very risky because once you’re investing money in the country, the Government is your partner,” Edwards said in a phone interview from Katy, Texas. “They could set one set of rules to invite you in, then they can change the rules, and that’s risky.”