Updated Standard Operating Procedure for In-Field H₂ and He Gas Analysis

The following updated procedure was introduced during the second phase of sampling, ensuring precise and consistent measurement of hydrogen and helium gases from historical drill holes:

1. Drill Collar Identification: Navigate to the designated drill collar, photograph the collar cap showing the Hole ID, GPS coordinates, and record the information.

2. Initialise Equipment: Power on the FD-311-He and FD-600M-H2 analysers. Allow the units to complete their pre-startup checks and ensure both devices display a 0.00 reading before proceeding.

3. Insert Collection Tube: Insert the gas collection tube into the collar, avoiding contact with any water. Lower the tube to a depth of up to 20 cm or a safe depth, as deemed necessary.

4. Conduct Initial Gas Measurement: Take an initial 3-minute gas reading using the analyser to capture hydrogen and helium concentrations.

5. Clear and Reset Analyser: If gas readings are detected, complete the initial 3-minute measurement. Remove the analyser from the collar and clear it by pumping fresh air through the device for 30 seconds. Ensure the unit returns to a 0.00 reading.

6. Repeat Measurement: Reinsert the collection tube and conduct a second 3-minute reading. Record any changes in the readings, noting whether they increase, peak, remain consistent, or decrease over time.

7. Collar Height Measurement: Measure and record the collar height above ground level to ensure accurate depth readings.

8. Water Depth Determination: Pretest the In Situ 200 water depth device to ensure the sensor is functional. Insert the probe into the collar until the water level alarm sounds. Retrieve the probe until the alarm stops and record the water level depth. Subtract the collar height for accurate depth readings and note them in the field book.

9. Blockage Detection: Lower the water meter into the hole. If the device encounters a blockage before reaching 100 meters, retrieve the meter and record the depth at the top of the collar. Subtract the collar height for an accurate reading.

10. Water Agitation: If no blockages are detected, lower the device to the full 100-meter depth to agitate the water in the drill string.

11. Collar Sealing: Retrieve the water meter and cover the collar with a heavy-duty polythene plastic bag, securing it tightly with a cable tie and tape to ensure an airtight seal. This process helps ensure the gas sample collected more accurately reflects downhole gas concentration.

12. 24-Hour Wait Period: Record the time of the procedure and return after 24 hours to sample the accumulated gases from the drill hole.

13. Gas Sampling Setup: Upon returning, turn on the helium (He) and hydrogen (H₂) analysers, ensuring both are functioning properly and display a 0.00 reading.

14. Final Gas Sampling: Check the plastic cover for condensation buildup, and gently tap it to dislodge any excess. Insert both the He and H₂ needle probes into the plastic cover, ensuring they avoid contact with the collar wall or condensation. Conduct a 3-minute gas test and observe whether readings rise, peak, or lower during this time.

15. Analyser Reset and Repeat: Remove the needle probes and clear the analysers with fresh air until they return to 0.00. If anomalous readings were observed, reinsert the probes and conduct a second 3-minute reading. Clear the analysers again after testing.

16. Completion: After the final test, remove the probes, clear the analysers, and securely replace the collar cap. Record all data.

Hexagon Purus ASA: Results for the Fourth Quarter 2022