Objective
The use of geothermal energy to provide 85% of the heating requirements of glasshouses covering 16 hectares, representing an annual energy consumption of 26,000 MWh. Back-up will be provided by existing installations. To achieve this end result the drilling of two wells (production and injection) is necessary, with a spacing of +- 1,500 m at the top of the reservoir.
Reinjection is essential for the maintenance of sufficient pressure in the reservoir and regarding the salinity of the geothermal water. Estimated characteristics are:
temperature : 66 deg. C.
pump assisted flow rate : 200 m3/h
salinity : 30 g/l.
Average energy savings of 3,500 TOE are expected. Anticipated payback is 10 years.
Geothermal loop tests began in March 1981, with the following results :
Production flow-rate : 165 m3/h
Reinjection rate : 90 m3/h at 44 bars and 45 C; 65 m3/h discharged into the river Loire. These results indicated :
A) temperature higher and flow-rate lower than expected, but output of well improved when functioning fully;
B) reinjection rate much lower than production flow-rate .
Production pump breakdowns at the end of march 1981 delayed the start of the demonstration project phase. Pumping resumed in february 1982, but was soon brought to a standstill by two successive breakdowns of the electrical apparatus. In December 1982, once replacements had been installed, production pumpimg and heating of the glasshouses resumed at the maximum flow-rate, with the fluid discharged with reinjection into well M2. Further production and reinjection tests in may and june 1982 helped to define the problem more clearly and to point the way to possible answers. No clogging was observed withwell M2 used for production (at over 100 m3/h, 13 D.m. and a + 1.6 skin), but the figures deteriorated when the well was used for reinjection (transmissivity : 7.8dm; skin + 28 pressure : rose rapidly in line with the reinjection flow-rate to reach 55 bars at 45 m3/h). It was also found that the productive zones are at the same level as the reinjection zone. Some 17 m of deposits (sands, hydroxides, etc...) were detected at the bottom of well M2. The clogging affecting the finishing casing and annulus was of mechanical origin and appears to be due to the presence of fines fron an unknown source.However tests on core samples revealed clays in well M1 along with the other types of deposits. Two solutions have been put forward. The first would be to work over the well heavily, by removing the filter screens, reboring the reservoir and insertion of screens with gravel pack. The solution would call for controlling the movement of fines from the production well to the reinjection well.The second solution would be an attempt to inject the waters from the trias into the superjacent dogger limestones. Quite apart from the fact the potential of the limestone is not known, this solution would also raise the problem of the compatibility between the water in each of the two reservoirs. The second solution has the advantage of lower costs, estimated at FF 5 millions, which would probably be paid by the national authorities bearing in mind the far wider interest of a demonstration of how to overcome the reinjection problem in this type of sandstone reservoir.
The project's lack of success is attributed to the impossibility of reinjecting the geothermal water in the reservoir at a sufficient flow-rate. The injection well has foundations in sand and problems associated with plugging it must be solved prior to new tests or experiments. (Studies are being conducted by IRG - the Geothermal Research Institute, to find solutions related to brine injection).
The production well M1 was completed between November 1979 and January 1980 to a depth of 1667 m encountering Triassic sandstone and clay between 1440 and 1615 m had shown the following well characteristics:
temperature at bottom of the well : 74 deg.C.
salinity : 37 g/l
aquifer net pay : 36 m
porosity : 15%
transmissivity : 15.2 D.m. with a + 2.5 skin
artesian flow-rate : 45 m3/h
airlift assisted flow-rate : 150 to 200 m3/h.
Well output is estimated at 80% of its potential following mud damage (the borehole was sunk through the full depth of the aquifer before the 9 5/8" casing was installed down to 1440 m). Directional drilling of reinjection well (M2) was completed between October and December 1980 to a depth of 1,600 m, encountering triassic sandstone and clay between 1,416 and 1,582 m. M2 characteristics are :
temperature : 72 deg. C.
salinity : 38 g/l
aquifer net pay : 34 m
porosity : 17%
transmissivity : 10 to 13 D.m. with a O skin
artesian flow-rate : 47 m3/h
(no long-termdevelopment air lift test).
Piercing of the reservoir occurred following installation of 7" casing above the reservoir.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
This project has not yet been classified with EuroSciVoc.
Be the first one to suggest relevant scientific fields and help us improve our classification service
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
45560 SAINT-DENIS-EN-VAL
France
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.