Re: GDY - Geodynamics Limited
Hi all,
From what I read, PTR are trying to do similar things, but are targeting shallow hot rocks that lie above the deeper, hotter granites. The idea is that this saves money because they don't have to drill so deep and don't go through so many drill bits etc. However, I found the story a little hard to follow, because these shallow hot rocks that PTR are interested in only have temperatures of like 60 degrees or 80 degrees... much lower than the 200-220 degrees that GDY is targeting. Now, PTR is quoting the temperature of the rocks, but also the thermal gradient (e.g. 180 degrees per km) as if this is the key to their energy generation. What I don't understand is how they will be able to generate power from 60 degree rocks? This won't generate steam. Are they planning to use some other method of power generation (i.e. by using air or something in conjunction with the thermal gradient)? How likely is this approach to succeed and will it hamper investment into GDYs much needed infrastructure to link them to the national grid?
What source are you reading and getting the 80 ° figure from?
Petratherm’s website (
http://petratherm.com.au/projects/paralana.htm) has a figure for Paralana-1B at 60 °C. That’s for an exploration well drilled 3 years ago only to 500m to test the viability of the field. That well was extended to 1800m in 2006 and it reached 109 °C - enough to boil water.
You’ve got it right that geothermal gradient figures are critical because drilling is expensive and risky – Geodyanmics “lost” part of the drilling rig in Habenero-2 which set them back a wee bit.
The drilling rig for Paralana-2 (the main production well) was just secured from Ensign and that was announced on the ASX a few weeks ago (Geodynamics have their own, slightly more powerful rig by the same manufacturer which gave them a head start and is going to let them drill like crazy over the next year in Joloika). Paralana-2 is going to target a deeper formation than Paralana-1B and going by the geothermal gradient reached at 1800m (~50 °C/km) they’re estimating
Paralana-2 to reach about 200 °C at their target depth of 3.6km. No funky Russian methods or milk pasteurisation required.
Paralana-2 is going to spud in Feburary 09 as the first production well and then Paralana-3 in early 2010 as the other well (you need one to pump the water in and then another to suck it back out the formation).
Have a look at the Petratherm Paralana Brochure – a corker image on Page 3
http://petratherm.com.au/brochures/PTRParalanabrochure.pdf
It shows the exploration well Paralana-1B, the Phase 2 expansion and the new well they are drilling in Feb.
Now to draw comparisons between the two, if Petratherm can get their estimated 200 °C at 3600-4000km, that’s on par with Habenero-2 at 4200km. We probably aren’t going to see Petratherm to start flowing in the Cooper until at least mid 2010 but the plan is there, they have enough funding to see them through then and the economics of the project at Paralana once the drilling has been completed are more favourable.
Network connection is a huge cost, you lose money in transmission, you lose power in transportation, stability is sketchy over long distances etc. Petratherm is located alot closer to Adelaide and the National Market than Geodynamics.
PIRSA’s Geothermal Department have a great map that demonstrates part of this
http://www.pir.sa.gov.au/__data/assets/pdf_file/0003/81327/geothermal_exploration.pdf