For flow measurement of gas leaving a wellhead separator, is the flowmeter normally upstream or downstream of the pressure control valve? Also what does the reported flowrate of say 200 Mcfd actually mean?
I work for a small company that writes software for oil and gas wells. At the moment we are writing models for the wellhead separator and associated flowmeters and control valves. I have a question about the measurement of the flowrate of gas leaving the separator. Are these flowmeters normally upstream or downstream of the pressure control valve?
Secondly, I have seen flowrates reported by these flowmeters of, say 200 Mcfd, which is unfortunately a volume measurement so is subject to interpretation of what it actually means (wouldn’t be a problem if it was a mass rate). Does this represent the actual volume of gas flowing at the line pressure and temperature? Or does it represent a value which has been somehow corrected to a stock tank value? If so, how is this normally done?