What Is an Oil Field?
Let me explain what an oil field is: it's a tract of land dedicated to extracting petroleum, such as natural gas or crude oil, from beneath the earth's surface. While some debate the precise origins of oil, most experts view petroleum as a fossil fuel derived from dead organic material, often from ancient seabeds buried thousands of meters deep.
Identifying Viable Oil Fields
You need to know that identifying viable oil fields is a critical part of the upstream oil industry. This process determines where extraction can be economically feasible.
Key Takeaways
- An oil field is a piece of land beneath which fossil fuels can be extracted for economic value.
- Most of the world's oil is concentrated in oil fields located in the Middle East, along with other large deposits discovered beneath the ocean's surface.
- Oil exploration to discover new drilling sites can be expensive and risky, but also quite lucrative if a large reserve is identified.
Understanding Oil Fields
An oil field consists of a reservoir of fossil fuel trapped deep in the Earth's rocky layers, sealed by an impermeable rock layer that has preserved it over millennia. When I talk about an oil field in the industry, I imply it has economic scale—for example, a field might contain a million barrels of oil, valued at the current market price times its volume.
Right now, there are over 65,000 oil fields worldwide, with many of the largest in the Middle East, where tens of thousands have been found. However, 94% of known reserves are in fewer than 1500 major fields. These locations have sparked geopolitical conflicts and environmental issues in the past. Oil can also be found under the ocean floor, where deep-sea rigs handle exploration and extraction.
Complications of Establishing an Oil Field
Establishing an oil field is a massive logistical challenge and a risky endeavor if the field underperforms expectations. You'll often need to build infrastructure for decades of extraction, production, and maintenance. Integrated oil companies have entire divisions for this, handling construction and specialized services to run a profitable operation. These fields feature equipment like drilling rigs, offshore platforms, pump jacks, exploratory wells, pipelines, and support facilities.
In recent years, technologies like horizontal drilling, hydraulic fracturing (or fracking), and proppant—a mix of water and sand to keep fractured pathways open—have boosted productivity. Coupled with seismic monitoring, these have improved efficiency, leading to an oil supply glut that lowered prices. Companies in this space focus on tech to cut production costs amid price pressures.
Example of an Oil Field
Take the Ghawar Field in Saudi Arabia, which began production in 1951—it's the largest oil field discovered so far, yielding over 80 billion barrels of oil by 2018. There are also offshore examples, like the Safaniya field, the world's largest offshore one, located in the Persian Gulf off Saudi Arabia's coast and estimated to hold more than 50 billion barrels.
