Geology and oil traps
An oil well is a term for an oil reservoir in the bedrock. Unfortunately, many believe that an oil well is a hole in the ground that is emptied with a hose, as if it were a gas tank. In other words, many believe that we work with oil wells that are in a reserve tank because we go into old, existing oil fields.
The illustration below shows how oil adheres to the wall because of dense rock. Since matter always migrates to where the pressure is lowest, small oil particles migrate upwards through porous rock in the layers of rock, until the particles have adhered on the wall of a so-called “oil trap.” This oil trap is a structure in the rock formation and has occurred through movements in the earth’s crust, which can look differently.