Floor oil usually means that the oil in the well is spurted out of the ground due to excessive pressure in the subterranean formation (ie, "blowout"), or before the start of production in some wells (usually the first well in the newly discovered oil zone) ), consciously spurting oil out of the wellhead ("blow-off"), in order to observe how much oil the tank can produce at a certain time. There is always some oil that cannot be recovered after the blowout and discharge, which forms the oil. But this method is basically not used now.

In addition, there are always some equipment in the oil well, such as the oil pipe that flows oil from the bottom hole oil layer to the wellhead equipment, the pump rod of the oil pump, etc., and some oil will be scattered on the ground when the equipment is taken out from the well. If the wellhead equipment of oil pipelines and production wells run, run, drip or leak, some oil will leak to the ground. In order to steal oil, some lawless elements open a valve that controls the flow of oil at the wellhead or dig a hole in the oil gathering pipeline, which will form a large amount of oil. It is estimated that China's annual oil production for various reasons is more than 100,000 tons, and direct economic losses amount to tens of millions of yuan.