Member Info for seisprocessor

dai2belts,

I've just been going through the posts for the past day and saw your question from yesterday.

Assuming the well is drilled in the right place and helium is found, the priority is to make a discovery and fill in some of the blanks in the resource estimate modelling. If the gas can be sampled and tested for content, then any gas columns found can be graded in terms of the thicknesses of the individual reservoir units which correspond to helium shows and amount of gas in the pore spaces.

What we do know is that a wireline log will be run at TD.

Mineral wireline logging is a process in which an electric probe or “sonde” is lowered into a borehole in order to make measurements of physical rock mass properties and borehole fluid properties. Measurements employ electromagnetic fields (directly or induced), radiation (natural and introduced via a chemical source) and sonic energy to interrogate the rock mass without physically breaking it. The sonde is lowered on a cable or “wireline” which transmits both power to the sonde and data from it to the surface recording systems. They must be calibrated and compensated for borehole effects in order to become quantitative measurements. Logs might describe or estimate the lithology, the local structure, rock strength, borehole direction and various fluid parameters such as temperature and conductivity. Wireline logs are routinely used in the mineral exploration industry to describe coal seams in terms of depth, thickness and ash content.

Slimline logs used in the wireline will consist of Caliper, Conductivity, Density, Dipmeter, Gamma ray, Neutron, Porosity, Resistivity, Sonic and Structural.
The sonic will give the velocity of sound in the rock and the ability to extrapolate depths. The logs will show the gross thicknesses of the formations very well. The main target zones in the Lake Bed, Red Sandstone and Karoo Supergroup will consist of several interbedded sandstone and shale sequences. The Gamma log could be used to check the Uranium and Thorium content every 15cm in various formations of interest, which would pick out the shale and non-shale material and help to define the sandstone reservoir units.

A good explanation is given on the Weatherford site and might help to reassure you on the risk of running wireline down a slimline 4 inch hole clogged with drilling fluids.

https://www.weatherford.com/en/documents/brochure/products-and-services/formation-evaluation/slimline-logging-services/

For the risk averse, it's important to understand the key objectives of the first 4 exploration wells....

Ezhik posted yesterday about his concern with the fundamentals and the following comments:
' You are then hoping that the faults and traps make a seal such that the drilling operation can enter a productive gas zone, have the ability to shut off or open up the trapped gas and ultimately get it to flow through the well head and production tree into a some sort of buffer tank '
These comments will be relevant for the later appraisal drills but not for the exploration phase.

If we were drilling for hydrocarbons with a wildcat well in a new basin, there would be a whole host of reasons why the drill might not be a success, from geology, source rocks, reservoirs, hydrocarbon generation window, timing of migration, fault movement, traps, seals, borehole instability issues, cementation, overpressure, water content etc. And there would be a binary outcome with results coming from wireline after reaching TD. Failure on any one of these points, or even a 'technical success' would inevitably see the SP tank.

For the next 4 wells, the aims are:
1. Report on helium shows encountered during drilling
2. Correlate any helium shows to reservoir zones with favourable porosity/permeability characteristics from wireline run at TD.
3. Obtain some kind of helium sample that would allow an assessment of content.

If objective no.2 is achieved on any of the 4 wells, then a discovery will be announced and the SP will rocket.
Objective no.3 will be a huge bonus as the slimline borehole will only be 10cm in diameter and the walls covered in drilling mud.

We are not drilling for hydrocarbons and the comments about traps/seals and flow tests and commerciality will be relevant for the appraisal stage, by which stage the basin should be considerably de-risked.

Of course, all the points raised by Ezhik are interlinked, and none of us are experts, so it's good to raise concerns on this BB.

With 4 wells to come on a variety of different structures, DM's statement that we will have our discovery by June, July or August speaks volumes about the confidence that he and his team have!

My post last night got buried in the banter, so no harm in re-posting this morning for others who may not have seen the summary on Reddit by RLBreakout.
https://www.reddit.com/r/HeliumOne/comments/nlg6j5/core_finance_interview_with_david_minchin
My additional comments below:
Malcy mischievously stated drilling to commence in July but grinned when DM corrected him with an early June date. Looks like that was a private joke about the Hannam note!

Vertical hole of 1200m depth - if this is scheduled to take 4 weeks, then that assumes a drilling rate of 42m/day or 141 feet/day. Mineral rig is drilling a slimline exploration 4 inch (10cm) hole only.

There will be a few announcements made: a) if helium shows are encountered early, and confirmed by the on-site geologist, then it will be announced as such - they will announce shows as they come; b) At TD completion they will run wireline tests. If a helium show is encountered next to the target reservoir zone then it will be announced as a discovery; c) they will try to extract a sample of helium flowing to surface for testing. The flow rates won't be meaningful as the hole diameter is small and the walls will be caked with mud and they don't have the facilities for cleaning the well bore. But there will be another announcement on the test results of any helium extracted.

So a helium show early on might conceivably come when the shallowest bentonite ash/clay layers are penetrated at 300-350m, or after 1 week. Failing that, then next one might be at their first target zone around 700m or, say, after 2 weeks/day 16. After that there is a series of vertical stacked targets to be drilled through.

Flow testing to be done during appraisal using a larger diameter borehole, then 3D seismic to be carried out next year after as much appraisal work as possible is performed this year.
Fully funded for exploration and appraisal drilling this year.

DM's only concern seems to be the trap structures not being charged if gas has been allowed to escape up the strike/slip fault walls. The likelihood of success at other wells isn't affected and they will be targeting a variety of trapping mechanisms.
I like the bit about the share price going from 20p to something unknown at an exponential rate:-)
Seispro

I was going to post some relevant comments about the interview with Malcy today, but it seems that the poster RLBreakout on Reddit has kindly summarized it very well already and saved me the trouble!
So instead, I've just added some extra observations to the ones already listed.
https://www.reddit.com/r/HeliumOne/comments/nlg6j5/core_finance_interview_with_david_minchin

Malcy mischievously stated drilling to commence in July but grinned when DM corrected him with an early June date. Looks like that was a private joke about the Hannam note!

Vertical hole of 1200m depth - if this is scheduled to take 4 weeks, then that assumes a drilling rate of 42m/day or 141 feet/day. Mineral rig is drilling a slimline exploration 4 inch (10cm) hole only.

There will be a few announcements made: a) if helium shows are encountered early, and confirmed by the on-site geologist, then it will be announced as such - they will announce shows as they come; b) At TD completion they will run wireline tests. If a helium show is encountered next to the target reservoir zone then it will be announced as a discovery; c) they will try to extract a sample of helium flowing to surface for testing. The flow rates won't be meaningful as the hole diameter is small and the walls will be caked with mud and they don't have the facilities for cleaning the well bore. But there will be another announcement on the test results of any helium extracted.

So a helium show early on might conceivably come when the shallowest bentonite ash/clay layers are penetrated at 300-350m, or after 1 week. Failing that, then next one might be at their first target zone around 700m or, say, after 2 weeks/day 16. After that there is a series of vertical stacked targets to be drilled through.

Flow testing to be done during appraisal using a larger diameter borehole, then 3D seismic to be carried out next year after as much appraisal work as possible is performed this year.
Fully funded for exploration and appraisal drilling this year.

DM's only concern seems to be the trap structures not being charged if gas has been allowed to escape up the strike/slip fault walls. The likelihood of success at other wells isn't affected and they will be targeting a variety of trapping mechanisms.

I like the bit about the share price going from 20p to something unknown at an exponential rate:-)

dai2belts,

I thought the Hannam note was very positive, apart from the comment in the first sentence about drilling starting early July!
However DM stated clearly in his chat with Zak Mir that it's early June.
Hannam say that the CoS of 15% for Tai is because the company haven't given them an update on the chances of success on the prospects.
DM came over as very certain that we will have our discovery by the end of the 4 drill campaign, and he's convinced the helium is there in trapped and sealed reservoirs. I guess he sees the risk as being more related to unforeseen problems with drilling the well or borehole stability issues, meaning if the first one isn't successfully drilled, then the next one will be.

Why is he so certain?

The helium is present at Itumbula; the 2D seismic shows the migration paths and the geology. The 2D infill shows the trapping mechanism and 3-way closures; the gravity data confirms the reservoir strata. They seem confident in the series of sealed reservoir (sandstone and shale) sequences throughout their target zones.

I've tried to interpret the seismic display given in the presentation as best I can, and it looks pretty good to me. But it's still a limited snapshot of a small window of data and not enough to say for certain if the helium is present in commercial quantities. So the answer to my question probably lies with all the rest of the data library that the company has to hand.
If this was a petroleum basin, then there would be all sorts of other attributes that could be produced to identify DHI's (direct hydrocarbon indicators). They're produced by analyzing the variations in reflected data and rock properties when hydrocarbon fluids are present. In our case, we don't have liquids present, just potentially helium in a gaseous state - so the equivalent in a petroleum basin would be condensate. Some of the most popular techniques like AVO (amplitude versus offset) won't be relevant here (as there's no liquids and therefore no shear wave variations), but there is a lot that can be done using the differences in acoustic impedance to produce various amplitude, phase and frequency displays that will all help to point to the bigger picture.

Back in the early '90's, I spent a couple of years in an office in London doing specialist processing , matching well log data to seismic and doing inversion techniques, AVO and producing all sorts of funky colour data displays. The technology has moved on tremendously since then, and nowadays I'm involved in 4D surveys where the 4th dimension is time - so a 3D survey is repeated every few years and the differences show how much depletion there is in a reservoir in a producing field.
Looking for helium in seismic data is a completely new concept to me, but I hope the company will have a lot of key diagnostic information that they're keeping to themselves and which gives them their confidence in the upcoming drilling campaign!

@dai2belts

Good observations!
I had to wade through a lot of banter before finding your post - almost missed it today!

On the dip line section, if you look above the shallowest shaded blue target, you'll see a prominent thin black line at about 0.6s. The black corresponds to a strong negative trough (low impedance contrast), and could be interpreted as a layer of bentonite. The area within the shallow target all looks faded, which I find quite curious, as if the impedance/velocity has been lowered by the presence of gas.

The lower target has more prominent events just below the yellow line, but these events are red - black - red, which show a strong positive acoustic contrast and I would regard them as more likely to be an interbedded sequence of sandstone and shales. The Karoo sequence predates the onset of more recent volcanism, so I wouldn't expect to see bentonite there.
However this target also looks faded within the blue dotted line circle and quite a contrast with the same prominent event at 1.3s on the right side of the circle.

Neither targets look to be the effect of a scaling shadow, caused by trying to balance out the relative amplitudes of quiet and noisy layers - scaling shadows tend to be flat horizontal zones in time.

The trap locations are based on the tension component of strike-slip movement of the horst block causing the spectacular rollovers and closure, rather than the up-thrown shift in the layers along the fault lines.

It doesn't matter what is below the blue line, as that is likely to be heading into basement territory, and by then, so much helium will hopefully be found that they won't care what's there deeper down:-)

All IMHO & DYOR.

@dai2belts
It's good to have someone else looking at the data, and hopefully we learn more from DM's comments as a result of our collective efforts on this board!

I had a listen to the transcript and DM is talking about the subtle features of bright reflectance at 34.29. At 35.40 he is also referring to the light (meaning high contrast) areas in the red sandstone. The lower highlighted zone he identifies as the Karoo supergroup, and the zone between the red sandstone and lake bed sediments is harder to define, so the shallower target might be either.

Anyway, his main point is the vertical sequence on the strike line direction where the broad rollover structures caused by the strike-slip faulting have created 3 way closures all the way down, and that there might be many more sandstone and sealed reservoirs with effective seals present throughout. This makes it a 'must drill' as a single vertical well will hit every one of these targets.

The bright area he refers to are the zones of high acoustic impedance contrast, meaning the bright red/black lines between 0.3-1.1s, caused by low density, low velocity strata. He thinks these are possibly bentonitic volcanic ash zones which are very fine clay layers with low permeability and therefore make an excellent seal! That is good news for mitigating the risk of helium escaping from the trapped areas.

Also he mentioned the size of the closures on this prospect - 5km in one direction (dip) and 2-3km (strike). So potentially 15 sq km and not just 10 sq km.

To please @Scott22 and add some balance to the post, of course this is still a wildcat well in a new basin with no well-tie log data, and the questions remain: will the well discover helium and will it flow in commercial quantities?
The risk of missing the targets on 2D data and drilling through the fault walls is mitigated by the additional infill data.
DM, to his credit, has provided us with some analysis of the seismic data in his presentation and put forward the geological reasons for what he and his team believe to be a very good chance of success.

As always, these are my opinions and DYOR.

You're welcome dai2belts!
Thanks for the transcript copy/paste tip.
You probably deserved a beer or two after ploughing through all my comments last night:-)
Looking at the basement geology and the fact that helium seeps are 10% concentrations at Itumbula, I can't see why they would be any less at Tai.
In fact, with Kasuku, Miombo and Tai being closer to the rift valley wall and sources of helium liberation by hydrothermal fluids, you'd expect them to be at least the same concentration.
Add in the fact that the recovery factor of gas in the porous sandstone reservoirs is likely to be closer to 40% than 20% and that the drill might discover more sandstone units and of thicker sequence; then any cautious, pessimistic estimates tend to just get bigger and bigger as knowledge gets added and the field develops.

and the 2nd part....
So a question if you don't mind and whenever, no rush, will be here for a long time.
Looking at Strike, line 14, about 0.4s, those black and red lines are from the same deposits/time?

Yes, the black and red lines belong to the same strata i.e. same age.
Then at about 0.3s above the trap the missing lines are erosion rather than slipping down through movement into 0.4s?
The missing lines above 0.3s are due to the time gap from when the Red Sandstone group was tilted and then the lake bed sediments were laid down uniformly on top after the faulting and possibly some erosion of the Sandstone ceased.

One question really.
Looking again, I might be seeing lines pushing up, which makes the missing ones erosion?

There are the two fault lines causing a discontinuity in the strata. There isn't much downthrown movement in the strike direction, but on Line 13 dip line, the interpreter has pencilled in a large downthrown difference on the left/western side of the major strike/slip fault - see how the red/yellow/pale blue lines jump down a long way.

The other clue to depths is in the cartoon schematic of the geology on page 12, showing the base of the Red Sandstone formation at only 500m depth. The rift valley wall runs NW-SE and Tai is about the same distance from the basement walls as Kasuku and Miombo, so I would expect the same depths of lake bed sediments for Tai as shown in the map on page 11 for Kasuku & Miombo.
Itumbula is further out towards the centre of the basin with a markedly thicker sequence of overlying lake bed sediments.
The cartoon shows most of the blue shaded targets as within the top Karoo supergroup formation - Kasuku has 3 such zones.
So for me, and it is imho, that the strong red/black lines below 0.3-0.4s belong to the Red Sandstone Group and that the interpreter has illustrated the 2 targets in the upper and lower Karoo supergroup formation, one below the red line and one below the yellow line.
The cartoon doesn't show prospects at the top of the Red Sandstone formation, other than Kasuku & Itumbula.
The two targets at Tai are broad structural ones and not subtle stratigraphic ones, and they're not dependent on salt or seals in the lake bed sediments. Hopefully that's why they're termed 'must drill' targets!

dai2belts,
thanks for the questions!
I've just been reading the posts of the day and come across your comments, so will do my best to answer them!

Do you know why the seismic sections do not seem to show the length and width of the closure, to me both the strike and dip sections show similar size targets, but I dont know what the y-axis scale is?

Yes, both strike and dip sections show similar size targets, but i think the NW-SE trending Line 14 strike line is the direction with 5km closure and Line 13 dip line is shown the similar size but more likely to have the 2km closure in the SW-NE direction at right angles to the main faults.

The y-axis going down is two way travel time from 0 to 2500 milliseconds at the bottom.
The x-axis going along the top is distance, and the numbers annotated are shot point numbers, although they're plotted at a scale of 80 traces/km so they're all crammed in so you can't make out the numbers. No matter, the clue is in the scale bar in the yellow contour inset map.

Above the SP numbers on Line 14, you'll see some annotations with a vertical dash |
These correspond to the locations of the dip lines 09,10,11,12 & 13. The distance between dip lines 11 and 13 is 2500m, and on line 14 this spans half of the target area, so the full target area with the perfect dip closure is 5km.

Hi QuosimodosDream,

Thanks for pointing that out - you're right. I not very good with volumetrics, just wanting to understand how much helium is potentially there.

Sunday seismic thoughts - part 4 of 4:

Now for the fun part taking a wild stab at calculating the volumetric of Tai on the back of a beer mat!

Areal extent = 2 x 5km = 10sq km
Vertical depth = 230m+270m = 500m
Volume = 10000m x 10000m x 500m = 50 billion cu. m

Reduce by factors e.g. porosity 18%; recovery factor 20%, helium content 4%
50 billion cu. m x 0.18 x 0.2 x 0.04 = 72 million cu. m

Convert to mcf: 72 million x 0.0353 = 2.541 million mcf.

Value = 2.5416 million x $250/mcf after costs = $635m or £453m

So that's 4 times the m/c of £118 million for one well.

All the above 4 posts are just my own opinions based on a very limited snapshot of the data in a powerpoint presentation. We won't know for sure about anything until the formations are drilled next month, so anyone's guess is as good as mine! As always, DYOR.

Sunday seismic thoughts - part 3 of 4:

In the latest presentation by HE1, there was a comment on page 16 about Tai:
'Faulted 3-way dip closure concurrent with a gravity high'
I wanted to find out more about the use of gravity analysis as a geophysical technique here and to try to understand this comment better. It's been a long time since I did a gravity survey at university!
I purchased and read a scientific paper yesterday, which describes an area in NW Italy with helium and geothermal activity and very similar circumstances to the Rukwa valley.
Volcano–tectonic structures, gravity and helium in geothermal areas of Tuscany and Latium (Vulsini volcanic district), Italy - ScienceDirect: www.sciencedirect.com/science/article/pii/S0375650599000140

In this location there is a rift valley graben, sedimentary basin, good carbonate reservoir rocks, NW-SE faulting and also, unusually, the ideal distance from volcanic activity to generate hydrothermal fluids at above 100C for releasing helium.
In Italy, radioactive decay of the source rocks has produced small amounts of helium which have been liberated by the hydrothermal fluids and have migrated through the strata and up fault walls that have reached the surface. Measuring helium in the soil over 1000 locations produced a positive helium anomaly centred on the location of the faults.

The big difference here is that the Italian source rocks are only 600 thousand years old whereas in the Rukwa valley, the Pre-Cambrian source rocks are up to 2600 million years old.
So in Rukwa there is an additional period of some 2 billion years for a large amount of helium to be generated from radioactive decay and released by relatively recent volcanism.

In Italy, the helium soil sample measurements were made in parts per billion, whereas in the Rukwa basin, helium seeps at Itumbula are up to 10 per cent where faults have reached the surface!
The high positive gravity anomalies in Italy matched the faulting patterns and the presence of potential sandstone reservoir rocks with higher densities of 2.5g/cc and carbonate sequences at 2.6g/cc. A low negative anomaly would have indicated the presence of low density rocks such as bentonitic volcanic ash for example.

So to return to the Tai prospect again, the gravity high associated with the faulted 3 way dip closure must refer to the trapping structure and helps to confirm the presence of thick sequences of sandstone reservoir rocks with densities around 2.5g/cc in both the upper Red Sandstone and Karoo supergroup formations.

Again, nothing definite, but another attribute that points to something encouraging!

Sunday seismic thoughts - part 2 of 4:

The Tai prospect didn't feature much on the old legacy data. However, advances in data processing techniques, computer power and processing algorithms have greatly enhanced this prospect on the reprocessed data.
In the mid '80s noise filtering and data scaling techniques could be pretty brutal and a lot of assumptions were needed in the final processing stages.
Crucially, the re-processed data would have preserved the true amplitude characteristics of the data, so it's now possible to see subtle changes in the displays.
The amplitude of the red/black/white reflected signals are displayed as acoustic impedance, which is density multiplied by velocity of sound in the rock.
So harder rock layers like sandstone and limestone will have higher impedance values since they're more dense and the speed of sound through the rock is also faster. Less dense rocks like fine shales and mudstones will have lower values.
Let's look at the blue highlighted areas again. The dark blue dotted line seems to show a boundary between events outside, which have a stronger signal and events inside, which appear to be noticeably dimmer in amplitude. The reservoir rock between the two major faults is continuous, so the density hasn't changed, but the impedance values have dropped indicating that perhaps the velocity of sound in the highlighted zones has reduced. If hydrocarbon gas is present in a reservoir, then commonly the velocity is reduced, so this could indicate the presence of gas in both zones.
Looking above the two blue circles, the amplitudes look normal. There doesn't appear to be any gas escape structures or discontinuities in the overlying strata, so if gas is present in the reservoir zone, then there's no evidence of the sealing of the trap failing.
The two highlighted prospects span a vertical two way travel time of approx. 0.2 seconds each, from 0.6-0.8 seconds and 1.1-1.3 seconds. At a rough guess, the velocity of sound through the Red Sandstone formation would be in the order of 2200-2400 meters/sec and the velocity of the sands in the Karoo formation a bit higher, say, 2600-2800 meters/sec.
So the actual depths of the reservoir zones highlighted should be in the order of 230m and 270m respectively.

Sunday seismic thoughts - part 1 of 4:

I promised to have another look at the seismic data in the latest HE1 6th May presentation and post some further thoughts. No matter if you're a geologist, geophysicist, investor, day trader or simply like gambling on the wife's pension fund, the recent decision to switch to the Tai prospect means that next month our investment decision hangs on the information provided in this presentation and a couple of seismic displays. There's not too many comments about it, and really the Tai prospect/lead has gone from a tiny blip on the Prospect map on page 11 to a 'must drill' location, but it is possible to glean some more information out of the seismic data.
I'm happy to share my thoughts if it helps others to understand what they're looking at, but bear in mind it's only a snapshot of limited data, and I'm not privy to the library of 2D data, well log data, geological and seismic interpretations or gravity data that the company has.
In order to explain the basics for those who don't profess to know much about seismic theory, I'll avoid using technical terms or too much detail.

Take a look at the seismic displays on page 16. The red, black and white background data represent the rock strata with red indicating strong positive reflected signals, black indicating strong negative reflections and white being neither strongly positive or negative.
The interpreter has drawn 3 lines - red for the top of the Red Sandstone formation, yellow for the top of the Karoo supergroup formation, and pale blue for the base of the Karoo formation.
The dark blue dotted lines indicate the stacked targets in the reservoir rocks shaded in blue inside.
Energy released by the vibrating pad of a vibroseis truck gets transmitted down through the earth and reflected back off each rock interface where there's a change in density or the speed of sound in the rock. The reflections are tiny and recorded by sensitive receivers on cables on the ground. The earth acts like a big sponge and most of the energy is absorbed, so the reflections from deeper events have to be amplified a lot to be visible on the displays.
A lot of geophysics goes into getting rid of unwanted signal and enhancing real events.

SeagullsFan & highlandmatt,

The technical risks with drilling might include loose, poorly sorted sediments and/or water content causing borehole instability issues, overpressured shales, an unusually high pressure regime, cementation issues, the risk of wireline tools getting stuck or failing to do a flow test.
I don't really see any of those being a problem here, given the geology at Tai.
The risks for me would be inadvertently drilling through the fault wall or drilling in the wrong place and missing the optimum location in the reservoir due to basing the decision on 2D data.
Look at 88e in Alaska last month - they had to drill 600 feet lower than they expected before encountering the reservoir rocks, went through a fault wall and failed to flow test. That is the difference between patchy 2D data and finely spaced 3D seismic.
I think the additional 2D infill survey carried out will be sufficient to avoid the same problem here.
Another issue raised has been the presence of adequate seals to trap the helium. I'll post some more analysis over the weekend that hopefully will reassure you and others about the seismic evidence available to us.

Mr SpaceTomato,

Don't let this poster get away with an unsubstantiated notion of corruption - the implications can be very serious.
I've been working offshore Africa for a very long time - Morocco, Mauritania, Senegal, Ghana, Nigeria, Gabon, Angola, Namibia, S.Africa, Mozambique, Madagascar - and been in Arusha,Tanzania as well.
For the past 10-12 years at least, all oil companies have strict anti-corruption policies developed that have to be adhered to.
All customs officers and officials seeking any kind of benefit have it gently but firmly explained that companies cannot indulge them, and nowadays it has been reluctantly accepted.
Maximum 'gift' allowed is up to 50 dollars or maybe a carton of cigarettes.
Of course it happens on a large scale at government level, especially in Angola, but if any oil company was found to have engaged in making a bribe, the consequences would be immediate loss of the operating license.
The same would apply to HE1, and they have a CEO in DM that has just spent 3 months living with his family in-country and has built up a network of contacts that allow the company to carry out their business to the highest of standards.
Later on, when I get a chance, I'll post some more thoughts and analysis on the seismic data for Tai and glad that you and others have appreciated the input.

Thanks for the welcoming comments to this board!
I've spent the past 30 years working offshore on seismic boats doing geophysical QC for 3D & 4D surveys.
On Thursday afternoon I was flying to the Shetland Isles and missed the presentation, so was grateful to other posters who chipped in with updates.
If any seismic info comes our way in the course of the drills then I'll be happy to contribute to the discussions!

I'll try to answer Dai2belt's question about the faults not reaching the surface...

There's 2 seismic sections in the presentation: Line 13 dip line and Line 14 strike line.
The vertical scale is two way travel time(TWT) in milliseconds(ms).

Between 300-400ms TWT, you can see a strong reflector subject to the strike/slip faulting with high acoustic impedance across the whole section. On the left part of Line 14 strike line the shallow sediments above this reflector onlap unconformably onto it. Also on the right hand part of Line 13 dip line, there is also a visible unconformity.

So this means there is a bit of a time gap between the strata below the strong event (which were subject to the two strike/slip faults) and the rest of the younger sediments deposited afterwards on top.

To convert two way time into depth, multiply the seismic velocity by time in seconds and divide by 2.
Given that the velocity of the very shallow lake bed sediments at the top will be in the range of 1500-1800 metres per second, then 400ms on the vertical scale translates to 1800 x 0.4 x 0.5 = 320m.

It's interesting that the two highlighted areas of interest shaded in blue don't have the strong positive amplitude anomalies associated with hydrocarbon gas in a liquid state but rather are noticeably dimmer than the surrounding seismic data. So this could indicate the presence of helium in gaseous form coupled with the gravity anomaly mentioned.

Another difference with drilling for helium is that we are likely to get updates of helium shows during drilling, unlike drilling for hydrocarbons when the first update wouldn't be until the LWD results after reaching TD. So the notion of having to wait 4 weeks after spud for results at the end of June might not be the case, and for anyone thinking of investing after the spud date it would be advisable not to hesitate for too long, otherwise they might find themselves very quickly being left behind!

Mr SpaceTomato was asking recently if there were any geologists invested here. Well I'm a geophysicist and I invested after reading through the AIM admissions doc. I topped up again on Friday morning when the price dipped!

The potential here is tremendous with some truly unique and unusual circumstances...a rift valley with ancient Precambrian basement rocks and helium that has been generated in uplifted Paleoproterozoic era metamorphic rocks circa 1.6 - 2.5 billion years old. Also a huge amount of helium liberated by hydrothermal heat flow thanks to being just exactly the right distance from the nearest volcano to generate temperatures of 110c. A dynamic basin province with tilted fault blocks, excellent reservoirs, filled traps, migration paths and 8-11km of overlying basin filled sediment.

Until last week, my choice would have been to drill Kasuku first, because it has quite large stacked targets; tilted fault blocks with excellent sandstone reservoirs; closer to the rift wall where the helium generation is; less sediment overburden so less problems with well bore stability, and less complex post rift faulting. The larger reservoirs with less steep dips on the tilted fault blocks make it a bigger target for 2D imaging and a higher margin of error for the exact positioning of a vertical well, compared to say, Itumbula, with more steeply dipping target zones, where the well location would have to be spot on.

Kasuku also had sufficient sampling with infill data for 2D data, whereas Itumbula doesn't imo.
I can well imagine that there's a tremendous improvement in s/n ratios and data quality in the reprocessed data compared to the legacy mid '80s datasets.

So now it's all change with Tai being the 'must drill' prospect after the reprocessing results!
On the seismic data it looks like they're going for two even larger targets, one in the Permian Karoo formation and the other in the upper part of the Red Sandstone formation from Cretaceous to late Tertiary. Hopefully there's a good seal with fine grained shale lake bottom sediments.
The strike/slip faulting causes the target zones to rollover and create a flatter, larger reservoir with 3 way dip closure, rather than the syn-rift pull-apart faulting. Also the faults don't appear to extend to the surface, unlike at Itumbula, so there may well be further additional helium shows at very shallow depths too.
All subjective opinions of course, but these are my reasons for investing. Geology is an inexact science and the seismic data results as only as accurate as the assumptions being made about the earth model.
DYOR.

Well, if you were watching the shares traded a few minutes ago, there was a 700 code followed shortly afterwards by a 800 code. For the believers only!
1. 100 - I need Shares.
2. 200 - I need Shares badly but do not take the stock down.
3. 300 - Take (or I am taking) the stock down at least 30% so I can load shares.
4. 400 - Keep trading it sideways.
5. 500 - Gap the stock. Gap can be up or down, depending on direction of 500 signal.
6. 505 - I am short on shares
7. 600 - Apply resistance at the ASK to keep the price from increasing.
8. 700 - Move the price up.
9. 777 - Also recognized as a signal to move the price up.
10. 800 - Prepare for an increase in trading volume.
11. 900 - Allow the stock to float and trade freely.
12. 911 - Pending News/Press Release On The Way
13. 1000 - Don't let it run
14. 2100 - Let it run