Oil pipelines and oil casing are both indispensable pipes in oil production. Oil pipelines are pipes that are lowered into the oil casing of oil wells during normal production of oil wells. In self-flowing wells, oil flows into the ground through oil pipelines and enters the gathering and transportation stage. In machine-extracted wells, oil pipelines, sucker rods, and deep well pumps (i.e., "three-pumping" equipment) are composed to pump oil to the ground and enter the gathering and transportation stage.

Oil casing is a pipe placed in the mine after drilling. The oil casing and the well wall are sealed with cement, and then the perforating gun is used to perforate the target layer, so that the oil flows through the rock layer, cement ring, and oil casing into the bottom of the well, and then enters the oil pipeline to the ground. The main functions are: 1. Structural reinforcement of the well wall to prevent geological structure collapse; 2. Seal different oil layers and water layers to achieve stratified mining; 3. It is conducive to the implementation of fracturing, acidification and other measures and maintainability. 5. Create an oil flow channel to cooperate with the oil pipeline to achieve the goal of oil production.

The order is: after the oil well is firmly dug, the oil casing is put in, the oil casing and the well wall are sealed with cement, and the oil pipeline is put in the oil casing. The oil pipeline is equipped with oil seals, pumps and other special tools for underground mines, and a sucker rod is put in the oil pipeline, which pulls the piston of the pump up and down repeatedly. In this way, the oil is pumped to the ground.