According to Bloomberg on November 12， China Petrochemical Corp.， Asia’s biggest refiner， agreed to buy a 30 percent stake in Galp Energia SGPS SA (GALP)’s Brazilian unit， its second investment in offshore oil fields in Latin America’s largest economy in as many years.Sinopec Group， as the Beijing-based company is known， said yesterday it will invest a total of US$5.2 billion in Galp’s Brazil unit， including a subscription for new shares and a shareholder loan.Chinese energy companies have bid at least US$16 billion for overseas oil and gas assets this year to expand reserves and supply the world’s largest energy consumer. Galp’s Brazilian holdings include a share in the biggest discovery in the western hemisphere since 1976. Sinopec last year agreed to invest US$7.1 billion in the Brazilian unit of Spain’s Repsol YPF SA.“The US$5.2 billion cash-in we will get from Sinopec is paramount for our strategy in Brazil，”Galp Chief Executive Officer Manuel Ferreira de Oliveira said in an e-mail to Bloomberg News.“It will give us a rock-solid capital base as we enter a decisive investment period at the Santos basin. This operation values our existing Brazilian assets at US$12.5 billion and is really a landmark for the company and for our shareholders.”China Petroleum Chemical Corp.， the Hong Kong-listed unit of Sinopec Group， rose 3.1 percent to close at HK$8.28 yesterday， compared with the 0.9 percent gain in the benchmark Hang Seng Index. Galp， Portugal’s biggest oil company， slumped 11 percent to close at 13.25 euros in Lisbon， the biggest intraday drop since October 2008.“Sinopec Group has been looking at upstream assets globally and will continue to invest billions and billions in overseas acquisitions，” said Gordon Kwan， Mirae Asset Securities Ltd.’s head of regional energy research in Hong Kong. “Ultimately， the parent will inject those assets into the listed company when those assets become profitable.”Goldman Sachs Group Inc. said it values Galp’s Brazil business at US$15.7 billion. That’s more than the US$12.5 billion enterprise value Galp gave to its unit after today’s deal， according to a statement today. Sinopec paid the equivalent of US$8.10 a barrel for Galp’s discovered resources in Brazil， Goldman said. Adding in likely further discoveries， the figure is about $4.30 a barrel， it said.Galp has stakes in four offshore blocks in Brazil’s Santos Basin， including a 10 percent share in Lula， the largest crude discovery in the Americas since Mexico’s Cantarell field in 1976. Lula， formerly known as Tupi， holds an estimated 6.5 billion barrels of recoverable oil and equivalents. Galp is also a partner with Petroleo Brasileiro SA， Brazil’s state-controlled oil company， in Cernambi， which holds 1.8 billion barrels of estimated reserves.On July 29， Galp raised its 2020 output target after “exceptional” progress in Brazil and expects working interest production of more than 300，000 barrels of oil equivalent a day by the end of the decade.Bank of America Corp.， JPMorgan Chase Co. and UBS AG advised Galp on the sale. For China， the deal with Portugal’s biggest oil company surpasses China Investment Corp.’s 2.3 billion-euro ($3.1 billion) investment in GDF Suez SA’s oil and gas production and exploration subsidiary announced last month.Sinopec Group’s purchase of a stake in Repsol’s Brazilian unit last year was China’s largest overseas oil deal since the refiner bought Addax Petroleum Corp. for C$8.3 billion (US$8.1 billion) in 2009 to gain reserves in Iraq’s Kurdistan and West Africa.The company said it may get 21，300 barrels of oil equivalent a day of oil from its share in overseas fields， with peak output expected in 2024 at 112，500 barrels a day.Sinopec Group may bid for a share in Marathon Oil Corp.(MRO)’s Angolan operations， according to two people with knowledge of the asset sale. Companies including BP Plc have invested in deepwater exploration off the Angolan coast， making the country the second-biggest African oil producer after Nigeria.“Nobody can buy at a discount， and everybody has to pay a premium to buy now，” Kwan said.“If you don’t want to pay a premium， you can go make your own discovery， but the process is going to take a long time.”