More than three-quarters of U.S. oil wells, collectively, make just 6% of the country's oil. They're called marginal wells because of how small their output is. But they're a big deal.

The sucker rod pump lifts the oil from the reservoir through the well to the surface. Usually pumping about 20 times a minute, the pumping units are powered electronically or via gas engine ...

The oil pan is attached to the bottom of the engine with bolts and is the reservoir for oil that gets pumped throughout the engine to lubricate, clean and cool moving parts. A pump forces the oil ...

Pump jacks, also known as beam pumps, play a crucial role in extracting crude oil from reservoirs where natural pressure is ...