Oil wells are structures created to extract crude oil from underground reservoirs. They are drilled into the earth's surface, reaching deep into rock formations where oil is trapped. Once a well is drilled, various methods are used to bring the oil to the surface, including pumping and natural pressure. The process of drilling an oil well involves specialized equipment and techniques to ensure safety and efficiency. After extraction, the oil is transported to refineries for processing into products like gasoline and diesel fuel. Oil wells can vary in depth and production capacity, depending on the geological conditions of the area.