The U.S. oil giant started work last year in Vaca Muerta, in Neuquen province, in the southern Patagonia region.
Vaca Muerta is a huge deposit that ranks Argentina second in the world for shale gas reserves and fourth for potential shale oil reserves.
The United States is the world leader in shale oil and shale gas reserves, and in related technology.
Testing of the nonconventional well, which would require fracking, showed potential for a flow of 770 barrels per day, the company said in a statement.
“It is a very important (potential) well, in terms of likely volume, on a par with the best (non-conventional) in the United States,” said industry expert Eduardo Barreiro.