The Rongchang block that ENI and PetroChina will study "has proven to be the most promising in the country," the Italian company said.
China's government is promoting shale gas exploration in hopes of curbing rising dependence on imported oil and gas.
Its companies control access to promising fields but lack the advanced technology needed to extract shale gas. So they are forging partnerships with global energy companies that supply know-how.
China's No. 2 state-owned energy producer, Sinopec Ltd., announced a partnership in December with U.S. oil giant ConocoPhilips Co. to explore for shale gas in a different portion of the Sichuan basin.
In December, PetroChina agreed to invest $2.2 billion for a 49.9 percent stake in a Canadian shale gas field being developed by Encana Corp.
Last month, another Chinese state-owned oil producer, CNOOC Ltd., completed a $15.1 billion acquisition of Canadian energy producer Nexen. It was Canada's biggest overseas energy deal to date.
Calgary-based Nexen also operates in western Canada, the North Sea, Africa and the Middle East.