EDITORIAL COMMENT: Second gas well should produce the goods
Invictus Energy, which has been leading the exploration of Zimbabwe’s deep Cahora Bassa basin for natural gas and heavier gas condensates, starts drilling its second well this week having sorted out the technical challenges that will allow the required fluid samples to be extracted.
The first well, Mukuyu-1, confirmed for all practical purposes that gas, condensates and, surprisingly, helium existed in the basin but the samples of the actual products needed to confirm the presence of hydrocarbons for commercial purposes could not be extracted owing to technical hitches.
In any case the second well, Mukuyu-2, would be required. It is 27km away from the first well and thus will help map the gas field, and see just how large it is.
The samples are needed not just for the commercial investors, but also to get an accurate measure of what hydrocarbons are present, and in what proportions and quantities.
There might well be need for further wells to establish the extent of the hydrocarbon field, and to find out how the heavier hydrocarbons are distributed.
Gases can move around fairly easily, so their composition does not vary dramatically across a gas field, but the next batch of hydrocarbons, the condensates, can have variations. It appears that pure liquid hydrocarbons, crude oil in popular terminology, is unlikely, at least in commercial quantities.
This is not a serious problem if Zimbabwe wants to produce liquid fuels, such as petrol, kerosene (jet fuel) or diesel as small hydrocarbon molecules can be slammed together to make the bigger molecules, just a very large molecules in many crudes can be split, or cracked, to produce the smaller molecules needed for fuels.
We should also remember that the exploration in Zimbabwe, and then the future commercial extraction, will be occurring as the world starts winding down demand for liquid fuels as environmental treaties seek the replacement of a global fleet of internal combustion engines with electric vehicles to sharply reduce carbon emissions.
Even if the electricity was generated from coal stations, the world would still win significantly, since internal combustion engines are around a third as efficient as electric motors.
Many countries are looking at banning all new internal combustion engines at target dates carrying between 2030 and 2035, and while there will still be a legacy fleet gradually diminishing as old vehicles wear out or are phased out, the emphasis will be on generating electricity.
Here natural gas is a winner. For a start a natural gas power stations has less than half the carbon footprint of a coal station, is simpler to operate and is cheaper and quicker to build.
So a major gas strike in the Muzarabani Mbire area will be very important for Zimbabwe, producing cheaper power than coal more efficiently.
We cannot stop renovating the older units at Hwange, and even planning a further coal extension since it takes some time to confirm gas, drill commercial wells and build gas stations.
But we need to feed in the gas stations into our strategic planning, and start with some on the coal-bed methane deposits in Matabeleland North.
The other advantage of a natural gas power station is that the gas can come out of the well and into the power station with very little processing and zero refining. This means that once there is a commercial well you just need the pipeline to connect it to a power station and you can switch on. Fluids need refineries to produce fuels.
A gas station is basically a jet engine attached to a generator with some gearing between the two. The civil works are minimal with no cooling towers and other complications of a coal-thermal.
So using off the shelf equipment a respectable gas station can be built in less than a year; they are actually that simple. They can also be switched on and off quickly, not quite as quickly as a hydro station but a lot faster than a coal station.
The presence of natural gas along seaboard in Mozambique is one reason why that country has been moving so fast to become a power exporter with its generating capacity centred on hydro-power from Cahora Bassa Dam and the natural gas fields further south.
Already Invictus and Geo Associates, who are doing the actual drilling in Zimbabwe, have hinted very strongly that once they have established the extent of the commercial possibilities, they will be seeking rapid exploitation of the field, initially as a gas field feeding power stations.
As they point out, Southern African has a power deficit and so a ready market for whoever has a surplus.
Zimbabwe also needs to expand its power output very quickly. The extension of Hwange Thermal may have ameliorated the emergency position, but obviously Zimbabwean electricity demand is going to rise, and rise quite quickly.
We already have the Manhize steelworks coming into production soon, and there are other industrial and mining investments in the pipeline.
Provision exists for these to buy power directly from Mozambique, and from private stations in Zambia. They are all planning solar stations for some of there needs, but it would really be convenient if there were a couple of decent natural gas stations up there near the gas fields, or along a pipeline from the gas fields, that could take up the load.
They could also sell power to South Africa, able to compete because South Africa relies largely on coal and gas is a lot more efficient than coal and so the gas-generated power is cheaper.
Some of the gas can be used to manufacture ammonia for nitrogen fertilisers, which is one reason why Sable Chemicals has signed a note of interest with Invictus as a potential customer, and the gas and the heavier condensates can be the foundation of a chemical industry in Zimbabwe, a chemical industry that could produce liquid fuels but also a wide range of other products and if we are smart be able to switch between products rapidly.
It takes time, several months, to drill a 4km deep hole into the earth, and that is the sort of depth the Muzarabani wells need to be to pass through all layers of rock in the basin, and then the results will need to be analysed.
But we can start planning now, thinking of pipeline rights of way, of where are the best sites for power stations, and where should the hydrocarbon chemical industry be centred.
Using the exploration time and the time needed to sort out the investment financing wisely, will mean that when we are technically ready to go we have the needed approved plans waiting.