The United States will replace Saudi Arabia this year as the world's leading oil producer. The forecast is based on total oil supply, which includes crude plus natural gas liquids and biofuels, Bloomberg reported.

The news agency was citing projections unveiled by PIRA Energy Group at a seminar held in New York. According to PIRA, the United States is expected to have average daily liquids production of 12.1 million barrels in 2013. This exceeds the Saudi Arabian figure by 300,000 barrels and stands 1.6 million barrels above the projected number for Russia. PIRA expects U.S. liquids production to grow at a faster rate compared to Saudi Arabia and Russia beyond 2020, keeping the country in the lead through 2030.

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The consultancy firm attributes the improved U.S. position to the shale oil boom. Thanks to the combined impact of horizontal drilling and fracking, U.S. output has benefited from the exploration of shale formations located in the central regions of the country. Over the past four years, shale liquids production has risen by 3.2 million barrels per day, which is the largest increase since Saudi Arabia boosted production between 1970 and 1974.

As for crude and condensate, PIRA expects the United States to have a daily output of 7.4 million barrels in 2013. The forecast for natural gas liquids is 2.5 million, while the biofuels prognosis is for one million barrels. The PIRA estimate also includes nearly 1.3 million of "refinery gains," which is a measure of the ability of refineries to streamline production via high-conversion capabilities.