Heat Extraction from Microseismic Estimated Geothermal Reservoir Volume

Abstract

Estimates of microseismic reservoir volume may delineate the extractable heat content of a geothermal reservoir above some application specific abandonment temperature. Data from three petrothermal fields involving microseismic monitoring data and thermal extracting data are examined: the Fenton Hill Hot Dry Rock Project in New Mexico, USA, the Rosemanoes Quarry Project in Cornwall, England, and the forthcoming Russkie Komarovtsy Project in Zakarpate, Ukraine, USSR. Fenton Hill has excellent data for microseismic events for the stimulated Phase IIB reservoir which is ready for a long term production test. Heat extraction simulation is compared to estimates obtained by other means. Rosemanoes has both microseismic data as wells an observed cool down over a three year circulation heat extraction experiment. Matching of the cool down curve provides estimates of the reservoir volume and mean fracture spacing. Russkie Komarovsty will be a large volume hydrofractured reservoir with an estimated seismic volume essentially equal t the actual fractured volume. Cooldown simulation based on heat physical calculations at LMI should provide an independent estimate of the seismic volume.