Onshore Oil Production: From Exploration to Extraction Onshore oil production begins with exploration and surveying, where geologists and geophysicists use seismic surveys, satellite imaging, and exploratory drilling to identify underground oil reservoirs. Once a promising site is confirmed, the drilling process begins using a drilling rig to bore deep into the earth, often reaching thousands of meters. A specialized drilling fluid (mud) helps cool the drill bit, carry rock cuttings to the surfa