A 9-hour circulation test that followed stimulation proved fluid flow and energy transfer from an EGS reservoir in hot dry granite …
Propylitic Alteration
A term borrowed from studies of hydrothermal ore deposits that refers to an assemblage of secondary hydrothermal minerals which forms in igneous rocks. This assemblage is made up of chlorite, illite, feldspar (both Na and K-rich varieties), epidote, calcite and pyrite, imparting a dark green tint to the appearance of altered rocks. It is commonly developed in volcanic-plutonic sequences that host high-temperature geothermal reservoirs.
Geothermal Glossary
Word of the Week – District Heating
District heating A scheme for distributing centrally produced thermal energy via a network of pipes to heat residential and commercial buildings. Such schemes are energy efficient and ideally suited for utilizing geothermal resources.
Word of the Week – Dolomite
Dolomite A carbonate mineral similar to calcite in which magnesium partially substitutes for calcium.
Word of the Week – Drill Bit
Drill Bit A tool that is placed on the end of a string of pipe to drill a well. Rotary drill bits are commonly used in oil and gas and geothermal drilling. Coring bits are used to obtain cylindrical core samples of rock that preserve mineralogical and textural...