I'm Flow testing a gas well, and the pressure keeps dropping.....?

Question

I'm flow testing a gas well, and the pressure keeps dropping while the rate is staying the same. What should I do? Should I keep testing? Increase the choke? Thanks in advance!

Answer 1

What is happening is that you have reached the critical flow rate thru that orfice and that orfice in your measure device is therefore not dependent upon the well's capacity. I would obtain a pressure/velocity/flow for that particular orfice instrument and size accordingly to match that well.

What you need to do is to increase that orfice size so that its volume thru will show a significant drop in flow rate as the pressure drops. That is size the orfice accordingly to that given well. There is a wide range in which this will happen for a variable flow and a good indication of well flow rate can be determined if the flow orfice is properly sized.