Oxygen detected in produced gas in a gas lift well

[engr2GW]

Hello,

Is there any circumstance (drilling error, reservoir/formation characteristics, completions operation, etc.) in a shale or conventional producing well under which oxygen can be detected at intervals over a long period of time, e.g. months?

this is a gas lift well and the if the compressor is ruled out as the source of the oxygen, can this (albeit rare) happen, that oxygen is coming from the production from the well?

thanks for your help.

As much as possible, do it right the first time...

 

[sraesttam]

To answer your question: I don't know. It seems more likely that the simplest explanation is the right one, though. Do you have a produced gas analysis from when the well was naturally flowing? Can you get a gas analysis of the suction and discharge sides of the compressor and at the casing valve and see if your oxygen concentration is changing through the system?

I have run into the same issues as described below in thread 432056. Oxygen at atmospheric pressure was entering into a wellhead that had 50 PSI on it through an ESP electrical cable packoff. Therefore, I recommend using a FLIR camera or gas sniffing equipment to detect and repair the leaks and I think your oxygen problem might go away.

Link

 

[MortenA]

I dont think that the O2 comes from the source. I would consider these:

1) Measurement/sampling error
2) From injected chemicals and/or fracking water
3) If your downstream gas system include flare gas recovery (low pressure) then i might consider this (disregarding what you said about the compressor) p<atm at some point wher air might get in

1) and perhaps 2) would be my main suspects

Best regards, Morten