What Does Gas Lift Method Mean?
The gas lift method is an artificial lift method used to raise fluids through the well from the formation. It employs additional high-pressure gas to supplement formation gas.
During gas lift operations, the oil production rate increases as the gas injection rate increases. As the injection rate of gas increases, the producing oil well will experience a decrease in gravitational pressure drop while experiencing an increase in frictional pressure drop.
Gas lift is a method that is reliable and simple and does not require the use of a downhole pump. Compressed air is injected into the lower section of the tubing to enhance the productivity of the well by mixing with the liquid column and reducing its density and viscosity, making it easier for the fluid to reach the surface.
Trenchlesspedia Explains Gas Lift Method
The gas lift method is of two types namely:
- Intermittent gas injection gas lift
- Continuous gas injection gas lift
The intermittent gas injection gas lift equipment consists of a compressor, choke, and valve in the mandrel. The compressor imparts high pressure to the gas which is injected in choke by which the casing pressure increases and opens the gas lift valve.
The gas enters the tubing through the valve propelling the liquid slug to the surface. Intermittent gas lift increases bottom hole pressure and propels liquid to the surface. In continuous gas injection, the fluid flows continuously from the well bottom to the surface. A small volume of high-pressure gas is injected into the tubing to lighten the fluid column aiding in delivering liquid to the surface.
This method is used in wells with high or very high reservoir pressure compared to the depth of well.