Derrick petrolifera - pumpjack / asino che annuisce, pozzo petrolifero nelle pianure del Wyoming, USA - simbolo iconico dell'estrazione del petrolio greggio - Foto stock

Fremont County, Wyoming, USA: pumpjack, also known as a nodding donkey or horsehead pump, formally called Beam Pumping Unit (BPU) is a mechanical device used to extract oil from underground reservoirs when pressure is insufficient to bring it to the surface naturally. Commonly seen in oil fields, the pumpjack operates through a motor-driven counterweight system that moves a beam up and down, creating suction that draws oil from a well. This method is widely used in mature fields with declining production, helping to maintain a steady flow of oil. Oil well in the Moneta Divide oil and gas field located in central Wyoming, within Fremont and Natrona counties. Estimated to hold billions of barrels of oil and trillions of cubic feet of natural gas, the field has been targeted for both oil and natural gas extraction through traditional drilling and hydraulic fracturing. Operated by Aethon Energy, the project has been a subject of environmental scrutiny, with concerns over water use, waste disposal, and impacts on local ecosystems. Despite these challenges, Moneta Divide is seen as a major contributor to Wyoming’s long-term energy production and economic stability.