Objective To heat a group a 2,700 housing units, a school complex and a hospital and, should the aquifer prove suitable, a swimming pool and a further 1,350 dwellings.The geothermal energy reservoir is expected to provide 31,000 MWh/y which would cover 45% of present requirements. The annual energy saving is estimated at 3,150 TOE. Payback is estimated at 8 years.Due to lack of permeability in the limestone formations (Upper Jurassic) the well has been abandoned.Stimulation by acid was not successful. New data acquired in the Rhodanian Valley are:- Miocene and Barremian formations were 4 times thicker than expected (730 m);- The area south of Avignon is composed of deep faulting blocks unknown at the surface;- The geothermal gradient is lower than forecast (3 C/100 m rather than 3.60/100 m).The reservoir lying in the Upper Jurassic limestone formation (Tithonique Kimmeridgian) between 1,720 m and 1,870 m was tapped by two 30 deg. directional wells, drilled to 1,900 m. The intention was to inject a corrosion inhibitor with the reinjection fluid and to increase the reinjection rate. From the results obtained from oil prospecting tests acquifer characteristics are expected to be: permeability - 150 mD; transmissivity - 200 m; flow-rate - 150 m3/h; drawdown - 125 m; salinity - 50 - 60 g/l; temperature - 75 C. (+- 3 C). Reinjection temperature will be approximately 30 deg.C. The well was drilled to a final depth of 2,250 m and fitted with a 7" casing down to 1,783 m and left as a 6" open hole to 2,250 m.The target reservoir is the Kimmeridgian limestone below 2,000 m (380 m deeper than forecast). Production trials showed the following:static level - 140 m; (non-stabilised) air-lift-assisted flow rate after acidification - 25 m3/h. Final trials indicated that only one section at 1,890 m was productive (70 C and 60 g/l salinity) yielding a steady 15 m3/h after acid treatment, with a corresponding drawdown of 35 Kg/m2. The complete lower section of the limestone reservoir is unproductive, with a maximum temperature of 90 deg.C. at 2,248 m. Programme(s) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Topic(s) 2.2 - HEATING Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator VILLE D'AVIGNON EU contribution No data Address PLACE DE L'HORLOGE 84000 AVIGNON France See on map Total cost No data
