Pumping oil from underground reservoirs typically involves a mechanism that lifts the liquid to the surface, often using a rod and a simple pump system.
One common method involves a hollow chamber fitted with a simple valve. This mechanism operates in conjunction with a rod that moves up and down.
The Basic Pumping Mechanism
The core of this system relies on cyclical movement to bring crude oil to the surface.
- Descent: Each time the rod descends into the wellbore, the simple valve opens, allowing crude oil (along with potential water and natural gas) to enter and fill the hollow chamber.
- Ascent: As the rod begins to lift, the valve closes, trapping the contents inside the chamber. The upward movement of the rod then lifts this trapped liquid column towards the surface.
- Cycle: This process repeats, with each upstroke bringing more liquid closer to the surface, eventually allowing it to flow out.
Think of it like using a straw – you create a vacuum to pull liquid up, but in this case, a physical chamber and valve actively capture and lift the liquid in increments.
Surface Processing
Once the mixture reaches the surface, it's not just crude oil; it often contains water and natural gas from the reservoir.
- At the surface, any water and natural gas obtained are separated from the crude oil.
This separation is crucial because refineries process crude oil, not the entire mixture. Various techniques, such as using separators that exploit the different densities of oil, water, and gas, are employed for this step.
Storage and Transport
After separation, the valuable crude oil is prepared for the next stage.
- The separated crude oil is then pumped into holding tanks.
These tanks serve as temporary storage before the oil is moved to refineries for processing into fuels and other products. The movement from holding tanks to the refinery is usually done via pipelines, tanker trucks, or ships.
In summary, pumping oil using this type of system involves a downhole pump that fills and lifts liquid in cycles, followed by surface separation of oil from water and gas, and storage before transport.
