Deep drilling technology for hot crystalline rock

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6780261

Rowley, J C

The development of Hot Dry Rock (HDR) geothermal systems at the Fenton Hill, New Mexico site has required the drilling of four deep boreholes into hot, Precambrian granitic and metamorphic rocks. Thermal gradient holes, four observation wells 200 m (600 ft) deep, and an exploration core hole 800 m (2400 ft) deep guided the siting of the four deep boreholes. Results derived from the exploration core hole, GT-1 (Granite Test No. 1), were especially important in providing core from the granitic rock, and establishing the conductive thermal gradient and heat flow for the granitic basement rocks. Essential stratigraphic data and lost drilling-fluid zones were identified for the volcanic and sedimentary rocks above the contact with the crystalline basement. Using this information drilling strategies and well designs were then devised for the planning of the deeper wells. The four deep wells were drilled in pairs, the shallowest were planned and drilled to depths of 3 km in 1975 at a bottom-hole temperature of nearly 200/sup 0/C. These boreholes were followed by a pair of wells, completed in 1981, the deepest of which penetrated the Precambrian basement to a vertical depth of 4.39 km at a temperature of 320/sup 0/C.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6780261
• Report Number(s): LA-UR-84-2564; CONF-840572-4; ON: DE84016475
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150303* -- Geothermal Exploration & Exploration Technology-- Exploratory Drilling & Well Logging
150901 -- Geothermal Engineering-- Drilling Technology & Well Hardware
BOREHOLES
CAVITIES
DRILLING
ENERGY SYSTEMS
FEDERAL REGION VI
GEOTHERMAL GRADIENTS
GEOTHERMAL SYSTEMS
Geothermal Legacy
HEAT FLOW
HOT-DRY-ROCK SYSTEMS
NEW MEXICO
NORTH AMERICA
TEMPERATURE GRADIENTS
USA
WELL DRILLING