The latest Investing Matters Podcast with Jean Roche, Co-Manager of Schroder UK Mid Cap Investment Trust has just been released. Listen here.
i think you'll find that it was nt-2 that suffered from high mud weights, not nt-1.
nt-1 was the discovery well. it's primary target was a sand pinchout at the base tertiary, updip from sands encountered at likonde, with the location defined by seismic amplitudes on a sp**** grid of 2d seismic. as it turned out, the well was probably drilled a little too far updip just beyond the sand pinchout, such can be the vagaries of amplitude analysis on sp**** grids of onshore 2d seismic in such a complex stratigraphic environment.
it would possibly make sense to re-enter nt-1 as a possible producer, but only if the well was re-entered and sidetracked, to penetrate the reservoir updip, as after the disappointment of the base tertiary, aminex made the decision - supported by solo - to deepen the well to a very poorly defined possible channel feature some 150m below the then bottomhole depth, as there were sufficient drilling supplies on site and the well was within budget, and a dryhole would not have been good news for aminex or the markets. it was at this point that tullow withdrew. aminex deepened the well and penetrated the gas-bearing reservoir 155m deeper. there was only 3m or so to test because being - as it turned out - the location at this target level was on the very edge of the trap, close to the gas-water contact. you have to remember this was a wildcat exploration well, and at the time the available seismic imaging was poor and the detailed stratigraphy poorly defined, and the well was never intended to go so deep, it was only after a revised in-house review of data by aminex based on drilling information that the proposal to deepen the well was made. the sands at this depth had not been proposed as a secondary target, and up to this point all the commercial successes in the region had been in shallower tertiary sands. an updip sidetrack at nt-1, subject to a valid location based on the new 3d seismic, and within the technical capability of the drilling rig, could be a very sensible low-cost option to complete nt-1 as a future producer.
Tom Mackay is the only Director with geological expertise, but I very much doubt that he has been hands-on for quite a few years now personally evaluating 2D or 3D seismic data or conducting petrophysical analyses of well logs, etc! What sort of exploration department is there beneath him? Is there anyone? It is all well and good having oil & gas financial and legal experience, but that does not help you evaluate oil and gas potential of a new country or exploration licence, read a well log or interpret seismic, or plan an exploration programme. Exploration opportunity reviews, exploration analysis and interpretation and evaluation of basic geological and geophysical data to evaluate risk of success (or failure!) is a full-time occupation and requires specialist support, ideally with a degree of local knowledge and experience. I am not sure that Aminex has that strength in-house any more.
Does Aminex still have access to anyone in-house with any real exploration expertise, other than the technical team at ARA who own 29%(?). All Aminex's in-house exploration knowledge and experience was lost after Battercharjee took over as CEO and relied on a series of independent consultants who seemed happy enough to write one-off reports and take the money, but not to stay stick around and see things through, (and lack of revenue income from Kiliwani North probably didn't help either).
This is old, old news! Oil seeps in Rufiji and Ruvuma Basins have been recorded for years, Aminex published a lot of work since their first field trip to the region in 2003, and the ex-Aminex personnel involved have continued to work on the source rock story of the region and have published papers on this as recently as 2022 detailing the potential of all the various source rocks believed to be present. There isn't much new in the Sabuni 2023 paper. The source rock history is complex, but much of the gas is derived from source rocks that were originally oil prone. Also, despite the claims of some people it is unlikely that Cenozoic source rocks have the capability (i.e., kerogen type or presence) to generate oil in anything but small quantities in localised areas in Rufiji and Ruvuma.
Not quite so, the well was never classified as a 'duster'. It was a wildcat frontier well, the prognosed reservoir lithology was not present at the predicted depth, Aminex made a decision independently and in advance of any communication from Solo to propose deepening the well based on careful re-examination of the available 2D seismic over about 4 days, using the knowledge gained from comparison of lithologies encountered to seismic whilst drilling to the original planned TD, and Neil Ritson from Solo fully supported the proposal, having also developed a similar re-evaluation. The well to the original planned TD (just below target zone) was drilled under budget and there were supplies on site to allow another 250-300m drilling before the next crew change. The top gas was encountered approx. 155m below the original planned TD, within less than 5m of the depth prognosed by Aminex from the re-evaluated 2Dseismic. Aminex gave a detailed presentation at the East African Community Petroleum Conference in Arusha, Tanzania, in February 2013.