US oil is pumping at record levels, putting the country on track to surpass Russia as the world's top oil producer as soon as this year by one recent account from the International Energy Agency. Booming U.S. production and restraints on oil production abroad have allowed the country's oil production to surge to the top spot. The shift marks a heady departure from the soaring prices, limited supply and fears of "peak oil" that marked the 1970s, when disruptions sparked by the Arab oil embargo in 1973 and Iranian revolution in 1979 caused prices to soar, or from more recent times, when U.S. production lagged far behind that of top producers such as Russia and Saudi Arabia. The surge dates to developments in the late 2000s, when advances in hydraulic fracturing, or fracking, and horizontal drilling techniques in the U.S. opened huge reserves of oil – and natural gas – deposited in shale rock formations. U.S. energy producers were suddenly able to access giant supplies of oil that they hadn't been able to get to before, either due to a lack of technology or because the price was prohibitive.