Oil Production by Flowing and Artificial Lift Technologies: Analysis of Modern Oilfield Exploitation Methods
Oil Production by Flowing: Efficient Utilization of Natural Energy
Oil production by flowing is a method of lifting crude oil from the bottom of the well to the wellhead and transporting it to the gathering station relying on the natural energy of the oil reservoir. This exploitation method is most common in the initial stage of reservoir development. When the reservoir pressure is high enough, the crude oil can naturally spurt out of the ground without any external power assistance.
The key conditions for oil production by flowing include:
- The reservoir pressure must be higher than the pressure of the fluid column in the well.
- The reservoir needs to have an effective driving mechanism (such as dissolved gas expansion or reservoir pressure drive).
- The gas – oil ratio needs to reach a certain level, and the expansion of the gas can help reduce the pressure of the fluid column.
- The advantages of oil production by flowing are low cost and high efficiency. However, the disadvantage is that as the exploitation progresses, the formation pressure will gradually decrease, and the flowing ability usually can only last for 1 – 5 years. When the reservoir energy is insufficient, it is necessary to transition to the artificial lift oil production stage.
Artificial Lift Technologies: Screw Pumps and Other Advanced Methods
When the natural energy of the reservoir is insufficient, artificial lift technologies become the key to
continuous exploitation. The following are the main artificial lift methods
- Screw Pump System
The screw pump forms sealed chambers during the rotation of the meshing screws. As the screws rotate, the chambers move axially, thus transporting the crude oil from the inlet to the outlet. It is especially suitable for:
Exploitation of high – viscosity crude oil.
Oil wells with a high sand content.
Occasions where high oil production efficiency is required.
The screw pump system has advantages such as a simple structure, convenient maintenance, and low energy consumption, and is an important exploitation equipment for modern oilfields, especially heavy oil fields.
Other Artificial Lift Technologies
Rod – pumped Well Pump: Driven by a surface pumping unit, the sucker rod moves reciprocally, suitable for medium – and low – production oil wells.
Electric Submersible Pump: It has a large displacement and high head, suitable for high – production oil wells and deep well exploitation.
Hydraulic Piston Pump: Powered by high – pressure liquid, it has high efficiency and flexibility.
Gas Lift Oil Production: High – pressure gas is injected into the annulus between the casing and the tubing, suitable for reservoirs with a high gas – oil ratio.
Jet Pump: It has a simple structure and low cost, suitable for special reservoir conditions.
Electric Submersible Screw Pump: Combining the power of the electric submersible pump and the characteristics of the screw pump, it is suitable for complex reservoir conditions.
