Noble Helium Ltd (ASX:NHE, OTC:NBHEF) has refined its upcoming Kinambo helium drilling campaign in Tanzania after 3D seismic reprocessing and gravity anomaly analysis identified 2 optimised firm well locations and reduced operational risk.
The work has prompted a modification to the first well location at Kinambo, on the western flank of the company’s 100%-owned North Rukwa Project, with rig mobilisation now expected in July 2026 and the Kinambo-1 well scheduled to spud in August 2026.
Seismic work improves targeting
The reprocessing of the Kinambo 3D seismic volume has improved imaging of deeper sections, particularly around the Nsungwe and Galula formations, which are key targets in the campaign.
Executive chairman Dennis Donald said the work, carried out by specialists in structurally complex environments, had “significantly improved” previously unrefined imaging of deeper sections.
“The enhanced deeper fault imaging has allowed the company to optimise final well locations and significantly reduce operational risk factors when drilling,” Donald said.
“We adjusted the location of the first well based on the new data, which better defined the target and structure. Site preparation for the new well location is underway and we now expect to mobilise the rig in July and spud the Kinambo-1 well in August.”
Cross-section of the Kinambo structure as partially imaged on 3D seismic, with the gravity gradiometry reduction in a crestal location modelled as plausibly explained by gas within the structure.
Two-well program adjusted
Kinambo could not be fully tested with a single vertical well because the crest of the structure migrates to the northeast with increasing depth.
However, Kinambo-1 will be drilled to target the crest of shallower levels to a total depth of 850 metres. The well will also allow the drilling team to gain familiarity with the operational requirements of the Schramm T130 XD drill rig.
Kinambo-2 is planned around 400 metres to the northeast and will appraise any gas intersections identified in Kinambo-1 before targeting deeper levels to total depth in the Galula Formation at about 1,750 metres.
The Galula Formation lies directly on basement at Kinambo and is expected to be in direct receipt of deep helium-enriched fluids and gases from basement and Karoo source rocks.
Deeper targets in focus
The company said the deeper and older Nsungwe/Galula formations are a known regional seal and reservoir pair in the basin.
Noble’s updated charge model for North Rukwa, together with previous proprietary charge modelling by Oxford University, indicates gas-phase helium potential at these levels, making them a primary focus of the campaign.
The latest interpretation suggests the Galula structure appears partly decoupled from the Nsungwe and rises toward a possible structural high north of the 3D seismic volume. Noble said that if Galula yields highly helium-enriched fluids, there may be potential for a separate deep gas pool along strike.
The company also said previously identified gas indicators on seismic, including flat spots and class II AVO responses, now coincide with a gravity gradiometry anomaly at Kinambo.
Gravity inversion constrained by seismic suggests gas reservoirs at multiple depths are the most plausible cause of the Gzz “hole” in the crest of the structure.
Helium and nitrogen anticipated
Noble expects helium and nitrogen to be the key gases at depth, increasing its interest in drilling to the Nsungwe and Galula formations.
Carbon dioxide potential increases in shallower horizons. While CO2 could dilute helium content, Noble noted it is a proven gas-forming mechanism in several commercial helium projects globally and that an established commercial CO2 market exists in Tanzania and East Africa.
What's ahead
Noble is preparing the revised Kinambo-1 site ahead of expected rig mobilisation in July 2026.
The first well is due to spud in August 2026, targeting shallow crestal levels, while Kinambo-2 is designed to follow up any gas intersections and test deeper parts of the structure.
Results from the 2-well program will be used to assess helium potential across multiple depths at Kinambo and guide the company’s next exploration steps at North Rukwa.