How do perforations allow oil and gas to enter production tubing?

In petroleum engineering, the casing of a well is sealed with cement against the productive formation to prevent unwanted fluid movement between rock layers. Because this seal blocks the flow of hydrocarbons, perforations are necessary to establish a connection between the reservoir and the wellbore.12

To create these openings, a perforator tool is lowered into the well on a wire line. Once positioned at the target depth, the tool fires bullets or detonates explosive charges that penetrate through the casing wall and the surrounding cement. These perforations create open paths that allow oil and gas to flow from the formation into the wellbore. Once the well is prepared, production tubing is inserted, providing a conduit for the petroleum to travel to the surface. If the formation's natural permeability is insufficient, additional techniques like fracking may be used to further enhance flow through these perforations.132