The amount of technically recoverable United States oil-and-gas reserves is 35 percent greater than in 2011, the U.S. Energy Information Administration (EIA) said Monday.

The report credited the spike to new geologic and well-drilling results, as well as the adoption of hydraulic fracturing.

The U.S. clocked in at second behind Russia in global technically recoverable shale oil reserves, with 58 billion barrels. It registered fourth behind China, Argentina and Algeria, with 665 trillion cubic feet of technically recoverable shale gas.

“Technically recoverable” refers to oil-and-gas reserves accessible with current technology. That differs from economically recoverable, which is when energy firms can develop the hydrocarbons at a profit.