The bailer is lowered into a slurry of oil and mud 1000 feet down. Holes on the end are opened by a plunger that is pushed up when the bailer hits bottom. An old engine from a dumptruck lifts the bailer up and it is dropped onto the retaining pond. The plunger opens the holes when the bailer is dropped and oil squirts out like the money shot in a porn movie. The oil slurry is put into 55 gallon drums, and the oil is collected from the top after it separates from the mud.
Another 55 gallon drum boils oil for distillation into diesel fuel and gasoline. The Diesel is used to run the well. The gas is used in motorbikes.
Saying all this is a bit messy is an understatement. Local farmland is destroyed and the best minimum wage job around is working the oil. There are no good jobs for the locals. The locals do not know what peak oil is. All they know is that they are screwed.
The Dutch started this clusterfuck over 100 years ago.