(2014013) GAS FLOW THROUGH A SUCKER ROD PUMPING SYSTEM
Gas interference in a downhole beam pump causes lower liquid production, lower fillage and energy efficiency, possible mechanical damage, and a lighter gradient up the tubing. A gas separator is used to divert as much gas as possible up the casing and not into the pump. Gas locking has been reported but pump leakage would seem to prevent this in many cases.
This paper shows how to calculate the following: (1) the total gas before the pump and separator; the total gas is the gas in solution plus free gas; (2) the gas through the pump and produced up the tubing; (3) the pressure gradient up the tubing; (4) the gas up the annulus; this allows one to see how much of the total gas (free and gas in solution) gets into the pump after the separator. The gas up the annulus is due to gas separator and natural separation efficiency.
The results shows how to better estimate the fluid load for a sucker rod pump system design and to see how much of the gas is pumped up the tubing through the pump and how much of the gas is separated to the annulus.