The offers were contained in a bilateral energy accord signed in Beijing late on Thursday following talks with Chinese President Hu Jintao, the presidential press office in Caracas said.
Under the deal, China National Petroleum Corporation (CNPC) will work with Venezuela's ministry of energy and mining, the Chinese foreign ministry said.
The oil agreements were among a series of deals signed with the aim of deepening cooperation in energy and mining resources.
China is keen to secure a steady supply of raw materials to fuel its booming economy while Venezuela wants to diversity its markets.
Venezuela, the world's fifth largest oil exporter, ships more than half its daily oil output to the US, but since taking office the leftist Chavez has sought to reduce its economic dependence on the nearby US market.
Lake Maracaibo is the centre of
Venezuela's oil and gas industry
"Venezuela is making a major energy offer to China because China has become the world's second biggest energy importer," the Venezuelan president said in Beijing on Thursday.
Change of policy
Energy-hungry China is also keen to diversify its energy imports away from the volatile Middle East by striking exploration and supply deals in Latin America, Africa and Southeast Asia.
China became a net importer of oil in the mid-1990s. Imports now account for more than one-third of the country's oil and gas consumption.
Under the deal signed in Beijing, Venezuela has authorised Chinese firms operating oilfields in the South American nation to start producing associated gas along with crude oil. This gas would be sold locally to power basic industries.
China National Petroleum Corporation already operates two Venezuelan fields, Intercampo Norte and Caracoles.
"Venezuela is making
a major energy offer
to China because China has become the world's second biggest
Venezuelan President Hugo Chavez
Venezuela also offered an agreement to supply 120,000 barrels of fuel oil a month to China.
According to Chavez, Chinese firms will be allowed to exploit 15 mature oil fields at Zumano in the east of the country, where he estimated reserves of more than a billion barrels.
"Most of that oil will go to China," the Venezuelan statement quoted him as saying.
The two nations were also continuing a venture to build a plant in Venezuela to produce orimulsion, Venezuela's trademark boiler fuel. It would be ready in September 2005 and would produce six million tonnes a year for China, Chavez said.