The U.S. oil industry was born in Pennsylvania. On August 27, 1859, Edwin Drake drilled the first successful commercial oil well in Titusville, a small town in the northwestern part of the state. That moment changed the world. Within a few years, Pennsylvania was producing millions of barrels of oil. The industry that grew from that single well eventually became one of the largest in human history.
The Marcellus Shale Revolution
Today, Pennsylvania is not known primarily for oil. It is known for natural gas. The Marcellus Shale, a rock formation that sits under most of the state, is one of the largest natural gas fields in the world. Horizontal drilling and hydraulic fracturing (fracking) unlocked the Marcellus beginning around 2008. Within a decade, Pennsylvania went from a minor gas producer to one of the top two or three states in the country. The Marcellus Shale has enough gas to supply the entire United States for many years.
How Much Does Pennsylvania Produce?
Pennsylvania produces roughly 20 billion cubic feet of natural gas per day — about 20 percent of all U.S. gas production. That puts it just behind Texas. Oil production is relatively small compared to western states, but the northeastern part of the state still has active oil wells in the original Drake oil region. The Utica Shale, which lies beneath the Marcellus, is another emerging target for both oil and gas.
Who Regulates Pennsylvania Wells?
The Pennsylvania Department of Environmental Protection (DEP) — Bureau of Oil and Gas Management oversees oil and gas drilling in the state. Unlike Texas, which uses an elected commission, Pennsylvania's regulator is a division of the state environmental agency. This means the focus is heavily on environmental protection, groundwater safety, and air quality. The DEP requires operators to file detailed well records and production reports. Public data is available at dep.pa.gov.
The Appalachian Basin
Pennsylvania sits in the heart of the Appalachian Basin, which stretches from New York down through West Virginia, Virginia, and Kentucky. This is the oldest oil and gas producing region in North America. The geology is complex, with multiple stacked formations at different depths. Understanding the Appalachian Basin requires studying over 160 years of well records — many of which are now digitized and publicly available.