Heat Mining The process of extracting geothermal heat by the heating of initially cold water that flows through fractures in hot rock below the surface. Heat transfer is achieved by...
Geothermal Glossary
Word of Week – INSAR
INSAR Interferometric synthetic aperture radar is a technique that is deployed from aircraft or satellites in order to generate interferogram images. These are used to interpret surface...
Word of the Week – Illite
Illite A potassium-bearing mica-like clay mineral that is a product of hydrothermal alteration. It commonly replaces feldspars and other alumino-silicate minerals and it forms above ~220°C....
Word of the Week – Interlayered Clay
Interlayered Clay A mixture of different clays such as illite, chlorite, and montmorillonite that are structurally interlayered and form via rock alteration at moderate temperatures in...
Word of the Week – Lava Flow
Lava Flow A product of an erupting volcanic cone or fissure made up of liquid molten rock that flows downhill and eventually solidifies due to cooling.
Word of the Week – Lost Circulation
Lost Circulation Refers to the loss or escape of drilling fluid into permeable zones made up of fractured or porous rock encountered during drilling.
Word of the Week – Liquid-Dominated Reservoir
Liquid-Dominated Reservoir Typical of the large proportion of conventional geothermal resources in which wells are self-flowing or pumped depending on reservoir temperature. Self-flowing...
Word of the Week – Magma
Magma Molten rock typically having a temperature between 800° and 1100° C (~1500-2000° F). Magma is the source of high-grade geothermal energy in conventional resources.
Word of the Week – Mafic
Mafic A geological term referring to igneous rocks that are equivalent to basalt and diorite in composition.
Word of the Week – Microseismicity
Microseismicity Tiny earthquakes that result from slip or shear along a fracture caused by an uneven distribution of stress. The displacements are very small scale and unfelt at the...
Word of the Week – Mud Pots and Mud Pools
Mud Pots and Mud Pools Depressions filled with hot bubbling mud commonly associated with steaming ground. The mud is mostly made up of clay minerals which form as an alteration product and...
Word of the Week – MWD
MWD Refers to Measurement While Drilling which for directional drilling includes geospatial information that is used to steer the bottom hole assembly (BHA). Inclination and azimuth are...