Ohio has a long-standing and impressive history of oil and gas production that dates back to the earliest commercial oil well near Macksburg in 1860.
The story of how petroleum is created and trapped below the surface is found within the layers of sedimentary rocks that date back in time nearly 600 million years.
Geologic time is so vast that geologists find it useful to describe it in terms of time periods lasting tens of millions of years. If you think of the time periods as chapters in a book and the rock layers as individual pages, it helps to understand Ohio’s rich history of oil and gas exploration and production.
The book of Ohio oil and gas begins with the Cambrian period about 570 million years ago. What we know as Ohio today was very different in the Cambrian. Ohio was near the edge of the early North American continent and was covered by warm waters of an ancient ocean. It is here that layers of dolomite and sandstone accumulated to form the oldest oil and gas reservoirs of Ohio; the Trempealeau, Rose Run and Beekmantown. These reservoirs are the deepest in Ohio and saw little drilling activity until the discovery of oil within the Trempealeau Dolomite in Morrow County during the early 1960’s.
The Morrow County discovery ultimately produced about 30 million barrels of oil and 35 billion cubic feet of gas. The Rose Run Sandstone became a popular but risky target beginning in 1965. The Rose Run reservoir forms a narrow band that runs from Ross County northeast to Ashtabula County. All three of the Cambrian reservoirs remain active drilling targets today.
The Cambrian period is followed by the Ordovician, a period that began about 500 million years ago and is marked in Ohio by early tectonic collisions that ultimately formed the Appalachian Mountains. The region remained submerged beneath the sea, and important rock formations such as the Trenton Limestone and the organic-rich Utica and Point Pleasant Shale formations were deposited as sediments on the ocean floor.
The Utica-Point Pleasant matured into a major source rock for oil and gas that later migrated into the older Trenton Limestone below and the younger Clinton Sandstone above. Though the Utica–Point Pleasant has the potential to be a major unconventional producer, the Trenton Limestone and the Clinton Sandstone remain Ohio’s largest and most-famous oil and gas discoveries.
A vast amount of oil was discovered within the Trenton Limestone near Lima in the northwestern part of the state in the late 1880s. The play became known as the Lima-Trenton Oil Field and was the largest oil field in the world at that time. The field produced an estimated 375 million barrels of oil before being depleted in 1936. More than 71,000 wells have been drilled in the Trenton Limestone, and it remains a relevant target today.
As the Ordovician drew to a close, the Clinton Sandstone was deposited within the shallow seas that continued to cover the region during the Silurian period 438 to 408 million years ago. The Clinton Sandstone has low permeability and is thus considered to be “tight.” Early production from the late 1880s until the 1940s had limited success. However, the advent of hydraulic fracturing stimulation in the early 1950s combined with high petroleum prices and federal government drilling incentives produced a major drilling boom for the Clinton Sandstone in the 1970s and 1980s.
Drilling reached its peak with 4,366 wells drilled in 1981. In total, more than 80,000 wells have been drilled in the Clinton Sandstone. It remains Ohio’s most important producer to this day with more than 4,600 wells drilled since the new millennium.
The clear sea waters that created the limestone and dolomite deposits of the Silurian period gradually gave way to more turbid waters and deposition of the clay-rich shale during the Devonian period that followed. During this time, the Huron, Chagrin and Cleveland members of the Ohio Shale were deposited.
The organic material within the shale formations gradually matured to produce oil and gas that has been produced from traditional vertical wells drilled into the Ohio Shale starting in the late 1800s until today.
The Devonian period drew to a close 360 million years ago and gave way to the Mississippian period as the seas that occupied Ohio were gradually being filled with sediments shed from the ancestral Appalachian Mountains to the east and highlands to the north. As the bordering land encroached on the sea, rivers laden with sand created the deposits of the Berea Sandstone.
The Berea was a natural trap for oil and gas migrating from the Ohio Shale below and has been a major petroleum producer throughout much of eastern Ohio. Natural gas was first discovered in the Berea Sandstone near East Liverpool in the late 1800s.
Drilling of the Berea took off in the 1950s and has continued to be an important producer of petroleum right up to the present. In total, nearly 13,000 wells have been drilled into the Berea throughout eastern Ohio.
The geological history of petroleum creation, migration and accumulation spans more than 200 million years. The oil and gas industry discovered and produced most of the traditional petroleum in a mere 150 years. Technological advances and historically high oil process have created new and exciting opportunities for petroleum exploration and production for Ohioans in the form of unconventional shale-gas drilling of the Utica–Point Pleasant.
The “Utica” has the potential to dwarf all earlier petroleum discoveries. The next few years will be very interesting and may create a whole new chapter in the book of Ohio oil and gas.