The United States is poised to become the biggest oil producer in the world within the next decade. The Paris-based International Energy Agency says the United States will surpass Saudi Arabia’s oil production by around 2020 with the aid of controversial extraction techniques such as “fracking” and horizontal drilling. Much of the oil in question is tightly concealed in rock formations that may be blasted with chemical-laden fluid and drilled into horizontally as part of the extraction process. Critics have raised concerns about how such forms of drilling will impact human health and the environment. President Obama, however, renewed his commitment to “freeing ourselves from foreign oil” in his re-election victory speech last week. Energy Department data shows U.S. imports of crude have fallen 11 percent this year, and the country is on track to produce the most oil since 1991.