Completion of drilling Tai-1A Exploration Well
11 August 2021
Helium One Global Ltd
("Helium One" or "the Company")
Completion of drilling Tai-1A Exploration Well
Helium One (AIM: HE1) is pleased to announce the completion of drilling of the Tai-1A exploration well to a depth of 1121m at its 100% owned Rukwa Project in Tanzania .
Highlights:
· Tai-1A completed to a depth of 1121m with helium shows identified in all three target formations
· Helium shows encountered over five intervals in the Karoo Formation.
· A 130m thick claystone unit was encountered above the top Karoo sands, indicating good seal presence for the Karoo reservoir.
· Wireline logging of the uppermost Karoo indicates good reservoir potential with 15-20% porosities.
· Petrophysical analysis indicates no free gas in the uppermost thinly bedded Karoo sands associated with helium shows.
· Helium shows within the deeper and thicker sandstone units of the main Karoo reservoir were not able to be logged due to poor and deteriorating hole conditions.
· Results of Tai-1A to be evaluated and incorporated into our ongoing exploration strategy which may include redrilling of Tai to test identified targets
David Minchin, Chief Executive Officer, commented:
"We are encouraged to see multiple zones with helium shows whilst drilling through the Karoo Formation. Tai-1 has successfully identified helium shows within all three target formations which confirms the presence of a working helium system in the Rukwa Basin.
"Frustratingly, due to poor and deteriorating hole conditions, including large washouts across much of the Karoo, we were not able to run wireline tools downhole beyond 882m and have subsequently not been able to log the main Karoo Formation.
"Thinly-bedded sands in the uppermost Karoo that we were able to log have no indications of free gas. Petrophysical analysis indicates that these helium shows are associated with gas-cut-brine or 'fizz-gas', which is formation water saturated with helium. These were the only helium shows that we could reach with wireline tools. Deeper show intervals identified in thicker and cleaner sandstone units of the main Karoo Formation were not logged.
"With deteriorating hole conditions and no free gas identified we could not drill stem test at Tai-1A leaving untested shows. We have learnt a lot about the subsurface of the Rukwa Basin which we can carry forward into planning our ongoing exploration programme, which may include redrilling of Tai prospect to test identified targets."
Details
Helium One has completed exploration drilling at its maiden Tai-1A exploration well in the Rukwa Basin. The well has successfully identified helium shows within all three target formations, including five helium show intervals identified in the primary Karoo targets, as well as secondary targets in the Lake Bed and Red Sandstone Formations.
The uppermost Karoo was marked by a thick (130m) claystone sequence, demonstrating seal presence which is supported by our seismic interpretation. Wireline logging of the uppermost Karoo indicates good reservoir potential with 15-20% porosities in thinly bedded sandstone units. It was not possible to log the main Karoo reservoir.
Wireline logging operations commenced after reaching a total depth (TD) of 1121m. Unfortunately, borehole washouts, which are associated with these thinly interbedded sand-claystone sequences, have resulted in a series of ledges to develop in the wellbore. The wireline tools hung-up on these ledges and after several attempts to clean the hole, Helium One were unable to progress the tools beyond 880m.
Wireline data was therefore only available over the uppermost helium show from 824-845m. This helium show was identified in thinly bedded (1-3m) sands within the upper Karoo claystone sequence, and above the better developed, thicker sandstone units of the Karoo Formation. Petrophysical analysis presented no clear indications of free gas within this helium show and anomalous helium in the drilling mud seems to be related to gas-cut-brine. Gas-cut-brine is considered to be formation water saturated with helium, but without helium having formed a separate gas phase.
Without wireline data it is not possible to assess the helium gas-bearing potential of the deeper, thicker, reservoir intervals with demonstrated helium shows in the main Karoo Formation. As no free gas was identified, and due to safety concerns caused by the deteriorated hole conditions, no drill stem test was conducted and no samples of brine or gas have been recovered to surface.
Whilst Helium One is disappointed not to have identified free gas within the Karoo Formation of Tai-1A, data acquired from this well enhances our understanding of the helium system in the Rukwa Basin. By encountering helium shows in the Lake Bed, Red Sandstone and Karoo Formations, combined with petrophysical analysis confirming the presence of a seal and demonstrating good reservoir potential, we are encouraged that we have identified a working helium system in the Rukwa Basin.
For further information please visit the Company's website: www.helium-one.com
Contact
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Helium One Global Ltd David Minchin, CEO |
+44 20 7920 3150 |
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Beaumont Cornish Ltd (Nominated Adviser) James Biddle Roland Cornish |
+44 20 7628 3396 |
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Canaccord Genuity Limited (Joint Broker) Adam James |
+44 20 7523 8000 |
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Peterhouse Capital Limited (Joint Broker) Lucy Williams |
+44 20 7220 9792 |
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Tavistock (Financial PR) Nick Elwes |
+44 20 7920 3150
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Notes to Editors
Helium One has identified a globally unique, large-scale, high-grade, primary helium project in Tanzania with the potential to become a strategic asset in resolving a supply-constrained market.
Helium One's assets are located within the rift basins on the margin of the Tanzanian Craton. Through Helium One's subsidiary companies Gogota (Tz) Limited, Stahamili (Tz) Limited and Njozi (Tz) Limited, the Company has secured 18 Prospecting Licences covering more than 4,512 km² in three distinct project areas: the Rukwa, Balangida and Eyasi projects. These are located near surface seeps with helium concentrations ranging up to 10.5% He by volume.
The Rukwa Project is located within the Rukwa Rift Basin covering 3,448km2 in south-west Tanzania. The project is considered to be an advanced exploration project and the company has identified 4 prospects and 21 leads based on historical drilling, reprocessed seismic lines, high resolution gravity survey, and surface seep analyses.
SRK Consulting have reported a 'Best Estimate' Un-risked Prospective Resource of 138 Bcf (2U/P50) for the Company's Rukwa Project, meaning that the project has potentially strategic global implications with the ability to significantly resolve helium supply/demand issues.
All Helium One's licences are held on a 100% equity basis and are in close proximity to the required infrastructure.
Helium One is listed on the AIM market of the London Stock Exchange with the ticker of HE1 and on the OTCQB in the United States with the ticker HOGLF.
Technical Glossary
Gas Chromatograph - A piece of analytical equipment that uses a carrier gas to separate the chemical components of a sample mixture to determine how much helium and other gasses are present
Mass Spectrometer - A piece of analytical equipment that is used to measure the mass-to-charge ratio of ions in a sample. The results are presented as a mass spectrum from which gas composition is calculated
Faulted Three Way Dip Closure - A domal structural trap faulted along a single side
Stacked Targets - A target with multiple reservoir intervals that can be tested with a single vertical well
Helium Show - Elevated amounts of helium detected in mud logging on micro gas-chromatograph or mass spectrometer
Pay Zone - A zone identified in wireline logging as a gas saturated reservoir supported by strong helium shows in mud logging
Drill Stem Test - flow testing using inflatable packers to isolate a prospective reservoir horizon and attempt to flow helium to surface
Itumbula Helium Seeps - Location where helium macro seeps have been identified at up to 10.6%He at surface
Connection Gas - Elevated levels of helium detected in mud during recirculation following the addition of a drill pipe. Helium infiltrates the well while mud is stationary and shows a temporary peak when drilling recommences.
Sidetrack - A branch out from the main well drilled by deflecting off a wedge or cement plug
Technical Sign off
Lorna Blaisse, the Principal Geologist of the Company, who has over 15 years of relevant experience in the Oil and Gas Industry, has approved the information contained in this announcement. Lorna Blaisse is a fellow of the Geological Society of London and a member of Petroleum Exploration Society of Great Britain.
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