A gas lift pump is a system used to bring liquids, often oil or water, up from the bottom of a well. It achieves this by injecting compressed gas into the liquid column within the well.
How a Gas Lift Pump Works
Based on the provided reference, the core mechanism of a gas lift system involves:
- Purpose: Gas lifts are used to raise liquids from the bottoms of wells. This is particularly useful when the natural reservoir pressure is insufficient to push the liquid to the surface.
- Process: Compressed gas is introduced into the liquid near the bottom of the well. As shown in Figure 6 (though Figure 6 is not provided here), this gas mixes with the liquid, forming a lighter, less dense mixture.
- Lifting Action: The reduced density of the gas-liquid mixture makes it buoyant compared to the surrounding liquid column. The pressure difference created by this lighter column allows the reservoir pressure (or the weight of the surrounding liquid) to push the mixture upwards towards the surface.
Key Components and Principles
While the basic definition is simple, understanding the principles helps clarify how gas lift pumps function effectively:
- Gas Injection Point: Gas is typically injected at a specific depth, often controlled by valves (called gas lift valves) placed along the tubing string within the well.
- Density Reduction: The primary principle is the reduction of the average density of the fluid column by introducing gas bubbles. This makes it easier for the bottomhole pressure to lift the fluid.
- Continuous Flow: Gas lift can be designed for continuous injection or intermittent injection, depending on the well's production characteristics and the desired flow rate.
In essence, a gas lift pump doesn't use a mechanical pump at the bottom of the well; instead, it utilizes the energy of compressed gas to lighten the fluid column and facilitate its ascent to the surface.
