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RNE - RENU ENERGY LIMITED


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In reply to: geojac on Friday 23/06/06 05:57pm

Good on you Geojac, I'm in the early middle age bracket. I'm sure there is opportunities out there for all vintages. It is not in my nature to be a short term trader being the nervy type myself. I do hope you find your niche & do very well.

Its a great challenge & can be so interesting hey.

GDY could be a very good trading stock as it tends to feed & swing on good verses bad news fairly regularly.

Best regards, dawno http://www.sharescene.com/html/emoticons/smile.gif

 

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They were good references, Moo. Carbon taxes directly affects competitors' costs in fossil fuel energy generation. When it gets as close as NZ the Australian government is more likely to consider similar proposals. Noted public figures making comment on global warming, particularly in the US helps to keep the leading pot boiling.

 

Neutron,

I hadn't considered anything as dramatic as explosives. They are probably so controllable these days that you could sculpture with them! Can they part a drill bit from the string without splaying the pipe into the wall?

 

Juke

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MODELLING STAGE 4 (not yet officially proposed)

 

It may be of value to construct a simple model in order to visualise the HFR volumes, the temperature changes, and the time scales involved.

 

Suppose we want to supply 10% of Australia's electrical energy consumption. This represents approx 8 times the generating capacity of the 280 MW Stage 3 demonstration plant. [it is necessary to distinguish between energy and power (power = energy generated per unit time.)]

 

The energy required is, E

= 0.1 x 200M MWh

= 0.1 x 200 x 10^6 x 3.6 x 10^9 Joules

= 72 x 10^15 J

= 72 PetaJoules per annum

 

Now, the heat content per cubic km of granite

= 2.2 PJ per C

 

Therefore the volume of rock required to reduce its temperature by one C to provide 10% of Ausralia's electrical energy

= E / 2.2 x 10^15

= 72 / 2.2

= 33 cubic km.C per annum

 

Or, 3.3 cubic km for 10C temperature drop per annum.

 

Long Term Effects.

If we consider the geothermal tenements, GEL 97 and 98 to be an area of at least 20 x 50 km^2 (>1000 km^2),

and develop a rectangular strip (slab) of just 2.5 km x 20 km of that (= 50 km^2),

and allow an annual cooling of 5C,

the depth of granite affected, d is such that,

 

surface area x d x temp. change = 33, so that d

= 33 / (50 x 5)

= 0.130 km

= 130 m

 

This means that over 20 years a slab of granite 50 square km and 130 m thick will cool from 250 C to 150 C. At that point all existing wells could be drilled down further by another 150m, say, to a new heat zone, and another 20 years of energy could be extracted, and so on. At each lower level the initial temperature increases slightly. Note that it has already been demonstrated that the natural granite fractures always appear on the horizontal plane. See diagrams p.16 in 2004 Annual Report.

 

The above has assumed 100% conversion efficiency. If this in fact is 50%, then the depth advancement cycle becomes 10 years. Presumably, like painting the Sydney Harbour Bridge, the well extension process becomes a continuous one.

 

The analysis covers the provision of only 10% of Australia's electrical energy needs and only 50 square km of the 1000-2000 square km of tenements in the Cooper Basin has been used. Additional high heat flow HFR sites exist around Australia, some much closer to populated regions.

 

I hope the model is understood. Several rather simple assumptions have been made. Developing narrow rectangular slices from the heat field may not be the best shape to take but it clearly demonstrates that we have at least 20 such slices available. The mechanism for removing the heat (circulating water/brine) is not relevant to the model, but the efficiency with which this is done and converted to electrical energy certainly is.

 

The prospects for clean HFR energy appears excellent.

 

Juke

 

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In reply to: juke on Monday 26/06/06 12:23am

Good post Juke!

 

Resource is there just got to get there.... :\

 

As you point out the hot rocks hold a lot of energy and are huge in breadth and depth. Drilling down further in 20 years might be a lot easier then than now.

 

Like everyone i'm holding my breath to see if the stem can be removed. Then presumably it will be another side-track. Should rename the hole from Hab2 to AntHill 1. hahah

 

If that fails i guess it means a redrill (probably with a bigger drill). I am wondering if the redrill will be from the surface or whether the casing can be removed from Hab1 and that used as a pilot hole.

 

We will find out in time i guess. Meantime, I'm finding it very interesting watching all the tricks of the trade.

 

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What a bummer.

 

Plenty of time to dwell on the big picture, I suppose. . . . . . . . . .

 

QUOTE
"The decision to stop the current snub drilling operations is a major set-back for all stakeholders involved as it will delay the proof of economic heat extraction from the extensive geothermal resources underlying the Cooper Basin. However, it should only be regarded as a delay and not as a threat to the viability of the geothermal project."

 

What's the likely cost of drilling another hole?

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In reply to: monkey man on Thursday 29/06/06 08:35pm

I would like to think that GDY can make the decision wether to sidetrack again or start afresh rather soon. Personally, as I have said in previous posts, I believe sidetracking is a big part of the trouble that has been experienced and all efforts should be made to avoid it wherever possible.

 

I must hasten to state again, I am only a follower of all this and have no experience in drilling at all.

 

So, I would vote for a new hole. More costly as I understand that drilling down some 3,700 meters into the granite, or even deeper and then casing this initial part of a well is a major investment in the hole.

To abandon the existing hole would be a painful decision. However you can't re-use this existing section without having to sidetrack when the initial garbage is encountered from previous problems.

 

There does seem to be some agreement though among chat room experts like myself that in future it would probably be wise to not go under 81/2" bit size at any stage. So that a more robust, larger diameter drill pipe could be used giving greaterstrength, rigidity and stability in the drill stem to combat the conditions whatever they are that see the 6'' bit and its stem being jammed and/or shearing off from time to time.

 

If this thinking was reasonably correct I then wonder wether the existing gear can make a beneficial start. Maybe having the first leg cased by the time the 'new' rig turns up.

 

Wishful thinking probably.

 

geojac.

 

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In reply to: geojac on Thursday 29/06/06 09:14pm

Last comment...

 

The focus seems to be on the rig size, bit size, rods etc....

 

My comment would be that drilling is an art, most drillers just punch down holes nice and quick (get paid per meter you see), pull out and onto next hole.

 

This is all well and fine for the shallow stuff (say less then 200m) but when we get beyond this, a drillers skill becomes more relevant.

 

Now with a project as ambitious as this, no time and expense should be spared finding the best driller money can buy.

 

The really, really good ones can "feel" the subtle changes in the earths composition through the levers. This is what makes the difference between getting stuck, or pulling out a few rods and conditioning the hole some more.

 

Geos/Mine Engineers might sound articulate and knowledgable, but they have never been on the levers. Its like asking a GP about the intricacies of brain surgery - waste of time. Better of asking a brain surgeon.

 

Not saying that GDY haven't been through this thought process - just some more food for though.

 

Fascinating project though, really hope they pull it off - I will be watching for sure...

 

 

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Ah well, the probability of suspension was looming. Now, with hindsight, an 8-1/2 ins single run hole would have been cheap by comparison.

 

The ann is not precise on what will be done next, except that a big rig will do it. Since, in the present demand situation the rig will be 3-5 months in coming, they do not have to decide immediately whether to start another side track from the bottom of the existing casing, or begin again from the surface. If the latter, then I vote for an 8-1/2 ins hole.

 

The budget for Hab 2 at June 04 was $9.2M plus contingencies. After the string of bad luck the cost must be at least double that. Would an 8-1/2 ins hole add 30-50% cost (i.e. $13M total)? However, I suspect the need for sidetracks would be most improbable.

 

Note that the original Hab 2 hole was drilled to within 2m of final depth in 96 days. Hence any technique to reduce the time element (two years at present) will be worth it.

 

Be ye cheerful! It will be done!

 

Pity GHT who have total starting funds of <$3M and budgeted just $1M for their first deep hole. (I don't hold.)

 

Chatty,

Future magnetic surveys in the area will indicate a curious ants' nest style ferrous body at great depth.

 

Juke

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