full announcement, page-3

Scorcer, having the pre-eminent scientific body in Australia such as CSIRO conducting studies for this project gives me comfort that the work will be done with the utmost professionalsim and scientific integrity.
Reading further I think that when they mention fractures as sub-horizontal, they mean in a horizontal plane within levels I suppose. If this is really what is the case down there then I think this means that the injected water fractures in a wide area sideways. The studies along with injecting all the water also involves a series of seismic sensors which are used to ping sound waves from the surface and see what the changes are down below from the fracturing. From this seismic work and testing of the cored granite from Blanche 1 they can use their clever mathematics to try and work out the displacement of the injected water within the fractures to assist with well design for subsequent holes.
The latter is the same science that geodynamics used when testing where the fractures were from the water injection at habanero holes.

I don't think this fracture stimulation work will create a heat exchanger system like what GDY has now at Habanero but it is a critical step in developing an understanding of the area for designing and planning the next step for the deeper holes.
As to why they are doing this now at 1900 metres and not 4500-5000 metres, my understanding is that the current seismic studies of the granites is that the granites keep going well below the current depth of Blanche but the heat gets higher the lower you go.
If the csiro studies show the fracturtes are really in this sub horizontal plane then it will be a critical step in securing important advances for the company via either government grants (like gdy and ptr) or like getting seriously funded partners to come in and join the party (like Woodside and Origin with gdy or Beach with ptr).
The SA government really wants the geothermal sector to get moving and make some juice. More importantly than this for the state is to see BHP expand OD.
Lots of issues at OD with tight labor markets, access to water,increasing infrastructure costs and availability of energy- to name but a few.
From a strategic perspective, I think governments look at everything and try and evaluate all scenarios to obtain desired outcomes. The outcome the SA government wants most is the expansion of OD. If geothermal can realistically assist with the energy requirement at OD then I suspect the SA government would be trying to assist in this process.
My personal views only.
I look at it this way, if the rocks are hot enough and they fracture the right way and the water flows at the right rate and blahblahblahblah, then I suspect the government will actively try and assist grk ( as i am sure they are doing so with worthy projects at Innaminka for gdy and Paralana for ptr). The SA government is very pro-development and regarded by many in the minerals industry to be the best state govt in the country.
So banging on my old drum, being 8klms from the grid is the big advantage.
make up your own mind but that is the basis for my comment about turning understanding on its head.
cheers
omg