CAMBORNE SCHOOL OF MINES GEOTHERMAL ENERGY "HOT DRY ROCK" PROJECT. VOL 1 - OVERCOMING STRESS MEASUREMENTS AT S. CROFTY MINE. VOL. 2 - GENERAL REPORT ON WELL DRILLING AND CASING. VOL. 3 - HYDROFRACTURE STRESS MEASUREMENT TESTS IN HOLE RH-12. VOL. 4 - HYDRAULIC RESULTS. VOL. 5 - MICROSEISMIC RESULTS. VOL. 6 - LOW FLOW RATE HYDRAULIC TESTS (RT-2019 - RT-2014)
The European Economic Community and the United Kingdom Department of Energy have jointly financed a research programme on the stimulation of hot dry rock geothermal reservoirs. The site in Cornwall has a high natural heat flow and underlying granite batholith pervasively jointed in two dominant directions. The natural jointing can be hydraulically stimulated to form interlinking paths between multiples of pairs of wells. The design objectives for the reservoir: 20-80 l/s through a system with a heat transfer area in excess of two million m**2, emplaced in a rock volume of more than 200 million m**3. The research wells were drilled (2000 m bottom hole temperature 79 degrees C). Stress and equilibrium temperature measurements, geophysical logging coupled with low flow injection tests were made, the injection well pretreated. The stimulation then proceeded at up to 100 l/s and 200 000 m**3 of water was injected into the system. By microseismic activity the reservoir size was delineated; approximately 25% of the injected fluid has been recovered since November 1982. The system consists of two overlapping planar features, separated by a thin diffusive barrier. The reservoir size objectives have been obtained but the impedance to flow is still higher than required and the diffusive water loss is excessive.
Bibliographic Reference: EUR 9703 EN (1985) MF, EUROFFICE, LUXEMBOURG, POB 1003, VOL. 1: 119 PP., BFR 300; VOL. 2: 203 PP., BFR 450; VOL. 3: 174 PP., BFR 300; VOL. 4: 197 PP., BFR 300; VOL. 5: 236 PP., BFR 450; VOL. 6: 115 PP., BFR 300.
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Record Number: 1989124005100 / Last updated on: 1987-01-01
Available languages: en