Chevron Corporation said a $1 billion deal with Argentina’s YPF SA, a vertically integrated state-owned oil and gas company, is in jeopardy over an embargo of $19 billion worth of Chevron assets in the South American country. The deal struck in December would have the two companies working together to explore shale deposits…but it’s being put in question after a Buenos Aires court ruled last month that $19 billion worth of assets would be frozen to settle claims in a long-simmering battle over environmental contamination in northern Ecuador. The court order freezes up to 100 percent of Chevron's capital and dividends in Argentina, all of its stake in a local pipeline operator, 40 percent of oil sales and 40 percent of the cash the American company has or may eventually have in Argentine banks…Chevron Chief Executive…said at an investor’s conference earlier this week that it needs access to that capital and would not move forward with the YPF deal without it…Argentina and Ecuador have a treaty that allows rulings in one country to be enforceable in the other…