Geothermal resources. Grado-1 borehole Future plans. Dep. of Civil and Environmental Engineering University of Trieste

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1 VII FIST - GEOITALIA Rimini 9-11 Settembre 2009 Geothermal potential of the carbonatic platform buried beneath the Veneto and Friuli coastal areas: results from the Grado-1 Borehole Geothermal resources Site survey Grado-1 borehole Future plans B. Della Vedova (dellavedova@units.it), R. Nicolich, E. Castelli, A. Cimolino, E. Barison Dep. of Civil and Environmental Engineering University of Trieste

2 University of Trieste Resources Site survey Grado borehole Geothermal resources in Italy Heat Flow and Magnetic signature Tuscan-Tyrrh Hot spot is young (<10 Ma) VII FIST - Mantle uplift and Lithospheric Thinning Rifting + NE migration of Appenninic front Magmatic intrusions vulcanoes GEOITALIA Rimini Sett B. Della Vedova 2/19

3 University of Trieste Resources Site survey Grado borehole Shallow HF disturbances (Della Vedova et al., 2001) Hydrogeological circulation (azur) Sedimentation rate (green) Low T convective systems (yellow) Volcanic areas+high T systems (violet) They induce strong lateral T changes DATASET: 2700 T grad. Meas. (700 offshore) 255 new ENI boreholes ( ) Estimated error: 5-20 mw m -2 B. Della Vedova 3/19

4 University of Trieste Resources Site survey Grado borehole Hydrothermal circulation in NE Italy C e s a r o lo 1 l. m. C a r g n a c c o l. m k m K m (Della Vedova, 2006) B. Della Vedova 4/19

5 University of Trieste Resources Site survey Grado borehole Hydrothermal circulation Sections Top Mesozoic carbonates (m b.s.l.) (Nicolich et al., 2004) B. Della Vedova 5/19

6 University of Trieste Resources Site survey Grado borehole S Heat Conduction Conceptual model N Alluvium Sandstones Convection of fossil waters Carbonates Marls & Flysch Dolostones Geochimical data esclude major hydraulic connection between the 2 aquifer systems B. Della Vedova 6/19

7 Seismic and Gravity surveys Depth to the top of the Carbonatic platform Residual Bouguer Gravity Anomalies Grado is located on the inner flank of NW-SE orientated Structural High (in colour): Adriatic Carbonate Platform B. Della Vedova 7/19

8 University of Trieste Resources Site survey Grado borehole High resolution Seismics in Grado Pleist.? GRADO-1 BH Complex Inverse Fault System involving also Carbonate Basement: Paleoc-Eoc Up. Creta External Dinaric Thrust Fractured RESERVOIR VII FIST - GEOITALIA Rimini 9-11 Sett B. Della Vedova 8/19

9 Grado-1 Geothermal Borehole: Stratigraphy Paleoc./Eoc. Nummulites Alveolina GRADO-1 CORE-3 Orbitolites Up. Creta Rudiste, Moncharmontia Cuneolina B. Della Vedova 9/19

10 Geophysical Logging Logging interval: m 3 RUNS comprehensive of: DualLatero, 4CAL, TTRM, Orientation, GR and G-Spectrometry, Density, Neutron, Vp/Vs, XMAC, CBIL Circulation losses by Abrupt fractures change & faults in ROCK Fracture PROPERTIES joints isoorientated Secondary Permeability in carbonates is good B. Della Vedova 10/19

11 logging results Limestones - 2 families (at least ) with different textures, fabrics, pore types and porosity - Water bearing fractures B. Della Vedova 11/19

12 In situ Temperature monitoring Permanent PT100 Platinum Resistance Thermometers (T-1, T-3) + Diver measurements B. Della Vedova 12/19

13 - 1st m bkb: Tmax=41.4 C (T-1) Spontaneous outflow Q~ 14 l/s Air Lifting Q= 23 l/s - 2nd m bkb: Tmax=44.8 C (T-1) Spontaneous outflow Well pump at 49 m bkb Open Hole Pumping tests Monitoring of T, P and Hydraulic Head, Q out + ph, Cond, TDS Q= 25 l/s Qp= l/s Flowmeter 4 ½ and Well pump (30 kw, working interval l/s) 30 l/s 40 l/s B. Della Vedova 13/19

14 SHEMAT Thermal Modelling Faulted model: low permeability discontinuities Grado-1 and Cesarolo Geotherms B. Della Vedova 14/19

15 The Grado Project (European funding DOCUP-2, ): District heating of Grado city Geothermal Doublet in the Paris Basin? GEOTHERMAL DOUBLET 1st Vertical borehole (1110 m) completed 2nd Re-injection borehole + network 2010? B. Della Vedova 15/19

16 Grado-1 Outflow: 90 ton/h (25 l/s) Pressure: 2.8 bar Pumping rate: 150 ton/h (42 l/s) Temp.: C Composition: 16 NaCl If T=15 C. Power equivalent: P = Q c T P 2 MWt Oil equivalent: 1500 TEP/a (8800 barrels/a) (If used year around) B. Della Vedova 16/19

17 Future plans? Drill 1 or more re-injection wells (star configuration?): start 2010 (?) Design + realize D.H. plant (Heat exchangers, HPs,...+ other uses) Distribution network Monitoring long-term thermal and hydraulic sustainability B. Della Vedova 17/19

18 Concluding Remarks GRADO-1 borehole results light up the external Dinaric compressive front interesting the Grado Lagoon and the Aquileia mainland Regional seismicity keeps pervious fault & fracture systems, favouring deep hydrothermal circulation Relevant low enthalpy resources (T+ton/h) exist in buried carbonatic platform beneath Veneto-Friuli plain GRADO Project should be completed with the re- injection well(s) + distribution network (2010 on) B. Della Vedova 18/19

19 Thanks for your attention LacusTimavi Aquileia Golfo di Trieste Grado-1 (2008) Terme Romane di Monfalcone (180 a.c.) Tabula Peutingeriana B. Della Vedova 19/19