EDITORIAL COMMENT: Gas strike opens doors, we must move fast

The major gas strike at the Mukuyu-2 site in the Cabora Bassa Basin underlying parts of the Mbire and Muzarabani districts allows Zimbabwe to start planning now for a new energy future, adding gas-powered generating stations to its hydro and coal-thermal mix, and start working out how to build a chemical industry.

Invictus Energy of Australia has had faith in its exploration of the basin, created in the Triassic era 200 million to 250 million years ago in a truncated branch rift at the start of the break up of Gondwanaland. This eastern Africa branch rifting never created another continent but did create several basins some of which contain hydrocarbons. The Cabora Bassa Basin is one of them.

Invictus managed to hit paydirt, retrieve samples of a range of hydrocarbons, mostly gas and light condensates, with only two wells, which some might consider lucky, but that “luck” was underpinned by the very considerable work Invictus did in advance using the most modern technology to map the layers of sedimentary rock in the basin now more than 4km deep.

The company had a very good idea of where to drill when it raised the considerable finance to sink the two wells.

There was still the possibility that at some stages the harder rock domes trapping gas and condensates might have leaked over a couple of hundred million years, but there is now proof that the gas and condensates remained trapped, at least in reasonable quantities.

The precise quantities likely to be there still need to be confirmed as Invictus continue with their exploration and reading of results, but the experts are now sure from the samples retrieved that these reserves will be viable.

The first major product once commercial extraction starts must be natural gas, as this can be used as soon as it is piped to the surface with very little processing, basically just simple cleaning.

Heavier condensates and fluids need refining and other processing, such as being built into longer chain hydrocarbons, but methane with some impurities can just be piped and used as gas fuel.

A natural gas power station can be built in less than a year, and some have been built in nine months. But that is from the point where the order is approved, where the site is known, the finance is arranged and the fuel pipeline is known to be ready on time. So there is a lot of preliminary work that can start, now.

The units of these stations are basically a pure jet engine, without the turbofans that are now fitted on modern airliners, connected to a generator via appropriate gearing. The civil engineering is little more than a solid foundation for stability and a roof to keep the rain off. The assembly of off-the-shelf components without fancy civil engineering is what makes their construction so fast.

Natural gas stations still burn carbon fuels but their carbon footprint is around half that for the equivalent power output of a coal station. So environmentally they are considered a better bet as they allow a country to meet its carbon limiting goals more easily, an important point as the world gears up to fight global warming.

Zimbabwe needs another major power station soon. We hope that commercial exploitation of the gas field can start in time so we can add a major gas station to the major hydro and major coal thermal station we already have, rather than the second major coal thermal.

It will also cost less than a coal station, and less than a major Zambezi River dam wall.

Now the Ministry of Energy and Power Development needs to join the Ministry of Mines and Mining Development in detailed monitoring of the progress of the exploration to find out when commercial extraction of gas can start.

It will not be immediate, but in these sort of strikes the natural gas is always the first product when commercial exploitation starts. This means there is time to do the planning for the station and other uses of the products of the strike.

Detailed planning for a power station can actually start soon. Once we know fairly closely where the first wells will deliver gas to the surface, the well-head, we will know where the pipeline, long or short, needs to start from the well-head to the power station.

Decisions need to be made on where to site the power station, and so how long the pipeline needs to be. The main backbone national grid, those huge 330kV lines, needs to be extended to the power station site along with the super-sized junction needed to connect the power station. So there will be calculations required on costs, and where the costs of a longer grid line exceed the costs of a gas pipeline.

All this can be done now, well before the final commercial exploitation of the gas field starts, so that we do not then have months or years of delays, or even hiring teams of external experts to fuel debate.

A lot of this can be done with Zimbabwean talent in Zimbabwe. We need to have the power station, or the first units of the station, ready when the commercial supplies of gas are ready.

The other early use of natural gas will be the manufacture of ammonia. Already Sable Chemicals in Kwekwe have had preliminary talks with Invictus and there is an understanding that Sable would want a pipeline to that city.

It still needs to be calculated whether it is cheaper to build a pipeline to Kwekwe and upgrade and extend the Sable ammonium nitrate fertiliser plant there, or build a new ammonia and fertiliser factory near the well-head and truck out the fertiliser. That must be done now. Either way we can be self-sufficient in ammonium fertilisers and be an exporter. But again we need to be ready.

Other products from the condensates can be used to build up a chemical industry and that can include a refinery to push together a lot of the lighter products that are likely to predominate to refine liquid fuels, although here we need to keep a watchful eye on the date when the world switches to electric vehicles for all new vehicles with a diminishing market for petroleum fuels as older vehicles wear out.

The extra electric power from the gas will probably be more valuable than any liquid fuels.

The point about the Invictus success is that a lot of doors are going to open and as a country, the Government, private sector and investors working together, need to be ready to push these doors open as soon as possible and then use the new great resource for maximum benefit and minimum environmental harm.

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