# Presentation: 397989

## Statement of the Problem andExpected Result of the Workshop

- <date/time>

- _Statement of the Problem and__Expected Result of the Workshop_

- R.Baria, E.Major, M.Fehler & N.Toksoz

## HDR/HFR/EGS - The Basic Concept 

***Use the natural fracture systems in the basement rocks ***

***Enlarge their transmissivity and connectivity***
***through water injection ***

***Install a multi-well system****** ***

***Use submersible pumps to adjust the ***
***water pressure in the fracture system****** ***

***Through pumping and lifting, force the ***
***water to migrate through the enhanced ***
***fracture system and capture the heat ***

## HDR/HFR/EGS  Extensive Resource 

- In THE USA  “the U.S. Geological survey has calculated that the _*heat energy in the upper 10 kilometres of the earth’s crust in the U.S. Is equal to over 600 000 times the country’s annual non-transportation energy consumption*_. Probably no more than a tiny fraction of this energy could ever be extracted economically.  However, just one hundredth of 1% of the total is equal to half the country’s current non-transportation energy needs for more than a century, with only a fraction of the pollution from fossil-fuelled energy sources.”  (McLarty et al., 2000)
- In W.EUROPE _*900twh*_ _*(i.E. The Europe’s nuclear industry contribution in 1995)*_ of annual base load electricity independent of climate and vegetation could be produced _*from less than 12 500 km2*_ (exploited on 1 km thickness) selected among the most favourable areas in western
- 	Europe

- 15000 GWh (i.e. Thermal Energy produced by burning 1 275 000 tons of oil) can be exploited by only 20°C of temporary cooling of only1 km3 of rock. At 200°C it is enough to produce more than 10 MW  of base-load electricity during more than 20 years.

- 900TWh (i.e. the Europe’s nuclear industry contribution in 1995) of annual base load electricity independent of climate and vegetation could be produced from less than 12 500 km2 (exploited on 1 km thickness) selected among the most favourable areas in Western Europe.

- A recent Shell study indicates that, only for Western Europe, the areas where the temperature is likely higher than 200°C at less than 5 000m have an extension higher than 125 000 km2**.**

- Harnessing HDR/HFR technologies now in Western Europe will represent a major contribution to an energetic cooperation with Central, Eastern Europe and Turkey towards a massive reduction of CO2 production.

**The HDR base module**

**European HDR/HFR /EGS at Soultz**

**Sedimentary cover**
**1400 m deep**

**1.5 + 4.5 **

**MWe**

**Geophones**

**Geophones**

**Production**

**~50 kg/s**

**Production**

**~50 kg/s**

**100 kg/s**

**600 m**

**200**

**o**

**C**

**5000m depth**

**670 m**

## 1993

**1995**
**1996**
**2000**
**2003**

## Results From Major Sites

## What Are the Major Targets or Difficulties

- Drilling cost of deep wells in granite
- 	5000 m deep deviated wells, GPK3 = ~5m €, GPK4 = ~ 6m €

- Create large heat exchanger; between GPK2 & GPK3 ~ 3.5 km3
- 	with borehole separations in excess of 600 m

- 3.	Acceptable flow impedance; between GPK2 & GPK3 ~ 0.28 MPa/l/s

- 4.	Water losses; presently zero

- 5.	Bottom hole temperature ~ 202 oC

- 6.	Expected output ~ 5-6 MWe,  Expected life ~20 years

- Anticipated but not taken seriously is: effect of generating
-      larger seismic events and public perception (show stopper ?)

## What Are the Problems?

- For this technology to be accepted by the public, we need to:

- Understand mechanisms associated with the generation          	of larger induced seismic events

- Identify circuitous (indirect) conditions which may influence it

- Clarify seismic hazard criteria for induced events

- Procedure/guide lines for new sites: site investigation, public 	awareness, public acceptance

- Propose a way forward to solve above difficulties

## Expected Results of the Workshop

-  Get consensus view on likely mechanisms for large induced seismic events

- 2.	Get consensus opinion on the circuitous (indirect) parameters which may influence the generation of larger events.

- 3.	Having quantified properties of large induced seismic events, do we need to re-evaluate seismic hazard criteria?

- 4.	 Is it possible or necessary to have a procedure for public acceptance for existing and new exploration of sites

- 5.	Can we devise scenarios whereby we can work together to address some of the issues mentioned above.

- 6.	Is IEA/GIA a good vehicle to implement joint research & sharing of data ?.

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