Water filling wells has been an issue for geologic hydrogen...

Water filling wells has been an issue for geologic hydrogen explorers so wanted to dig a little deeper asking ChatGPT if Hyterra could have proceeded with re-entry if water had filled the well. Answer below.

DISCLAIMER: This is AI, it can be wrong. DYOR!

Background: Water Invasion in Past Hydrogen Wells

In prior global hydrogen exploration efforts (notably in Mali, Russia, Australia and France):

• Explorers encountered hydrogen showings, but wells often quickly filled with formation water.

• This diluted gas concentrations, increased bottomhole pressure, and made gas flow to surface impossible.

• Result: Testing and commercialisation stalled, despite promising initial H₂ readings.

In such cases, work-over operations were often not pursued further unless there was a clear path to isolating gas zones from water (e.g. via cement plugs, packers, or sidetracks).

What About HyTerra at Sue Duroche 3?

Based on the latest operational update and prior disclosures:

No mention or indication of excessive water inflow:

• The well reached TD on May 1 with no HSE or mechanical issues.

• Hydrogen was detected at multiple depths, and up to 96.1% purity in mud gas samples.

• HyTerra is proceeding with:

  • Converting the well to a monitoring well via a work-over.

  • Installing long-term surface pressure and gas composition monitoring equipment.

• No reference to water shut-in, water displacement, or fluid isolation complications.

Implications:

• If the well had filled with water or lost pressure support, it would have complicated or delayed the re-entry and conversion plan.

• Instead, they’re moving immediately to “Monitor” phase, which:

  • Requires unobstructed pressure communication with the reservoir.

  • Suggests free gas or gas-in-solution is still present.

  • Indicates that water is not dominating the wellbore or masking pressure signals.

Would They Progress With the Work-Over If Water Was Dominant?

❌ In Most Cases: No

• If Sue Duroche 3 had flooded:

  • Gas monitoring would yield little to no signal.

  • It would not be cost-effective to install pressure and composition tools with water dominating the formation response.

  • The company would likely pivot to sidetrack, abandon, or drill a new well instead of converting it to a monitor.

✅ So the fact they are proceeding indicates:

• No major water-cut issue has been encountered (at least at this stage).

• The reservoir has enough pressure and dry gas response to justify the re-entry investment.

• The hydrogen is likely present in isolated zones, not completely water-swept.

✅ Conclusion

If Sue Duroche 3 had filled with water, HyTerra would almost certainly not be proceeding with the current work-over and monitoring program.

The very fact that:

• They’re committing more capex,

• Mobilising a rig for re-entry, and

• Planning long-term surface monitoring,

strongly suggests they’ve avoided the early failure mode that has plagued other natural hydrogen wells globally.

That bodes well not just for this well, but also for Blythe 13-20 — which could confirm wider lateral continuity of a productive (and dry) hydrogen system.

Would you like a briefing note comparing global case studies (e.g., Mali’s Bourakebougou field vs. HyTerra) or a risk matrix on potential flow test outcomes from Sue Duroche 3?