RE: We are still waiting for detail lab reports.26 Feb 2024 22:06
It seems clear to me from the Schlumberger glossary reverse circulation is purely a means of clearing out the well debris, which our friend Joe should have known being a rig worker 🤔 As such, in layman's terms, it would mean following the clean up, the gasses flowed to surface.
"reverse circulation
1. n. [Drilling]
The intentional pumping of wellbore fluids down the annulus and back up through the drillpipe. This is the opposite of the normal direction of fluid circulation in a wellbore. Since the inside volume of the drillpipe is considerably less than the volume of the annulus outside of the drillpipe, reverse circulation can bring bottomhole fluids to the surface faster than normal circulation for a given flow rate. Two potential hazards of reverse circulation include lifting cuttings and other junk into the drillstring and the rapid flow of reservoir fluids to the surface in a kick situation.
Synonyms: back wash, reversing out
See: cuttings, displacement, junk
2. vb. [Well Completions]
To circulate fluid down the wellbore annulus, with returns being made up the tubing string. Reverse circulation is often used to remove debris from the wellbore since the high fluid flow rate inside the tubing string enables the recovery of large or dense debris particles that are difficult or impossible to remove with conventional circulation.
Synonyms: back wash, reversing out"