This is the technology used to increase the oil production rate. It involves the injection of compressed gas into lower sections of tubing. Upon entering the tubing the compressed gas helps to push the oil to the surface and aerates the oil thus lowering the effective density.
In this case the depth of the well is of no problem, and it is suitable for both on and offshore environments, lifting costs for a large number of wells is generally low. It however requires that lift gas be near the oil fields and gas compression equipment must be near. For small fields this may not be practical or efficient.
The complete system usually consists of a compression station, an injection manifold and tubing string with unloading valves. Other pieces of equipment:
- Main operating valves
- Wire line adaptations
- Check valves
- Surface control equipment
- Deep injection depths can be achieved
- Varying the valve depth placement can affect the well productivity
- Gas Volumes injected can be properly metered
- Intermittent gas injection can be used to “kick-off” a well
Typically it is applied to wells with a reasonable degree of bottom hole pressure maintenance, and a productivity index (PI) of approximately 0.5bbl/day/psi or greater.