Paper: Down -- Well Gas Separation

The oil occurring in oil reservoirs is associated with varying quantities of water and gas. Both the water and the gas entering the well bore must be produced in order to produce the oil. In the early life of a field, when the reservoir pressure is high, the gas is used as a means of lifting the fluid. This is generally accomplished by shutting in the casing and permitting sufficient pressure to build up in the annulus between the casing and the tubing. When this occurs, oil, gas and water rise up the tubing in a frothy mixture and pass through the flow bean into the lead line. In this case, an actual bottom hole mixing rather than a bottom hole separation occurs.