Concept and principle of primary oil and gas recovery:

The primary oil and gas recovery system refers to the gas-liquid exchange between the oil tanker and the underground oil tank of the gas station. The tank truck has a closed unloading, and the tank truck and the underground storage tank form a closed system. As the gasoline in the tank truck flows to the underground storage tank, the pressure in the tank truck decreases and the pressure in the underground storage tank increases.

Utilize the pressure difference between the underground storage tank and the tank truck to make the volatilized oil and gas return to the tank truck through the pipeline. Most of the oil and gas in the tank is replaced in the tank truck, which is called the first stage (primary) oil and gas recovery.