Planning and drilling geothermal energy extraction hole EE-2: a precisely oriented and deviated hole in hot granitic rock

Technical Report · Thu Apr 01 04:00:00 EST 1982

DOI:https://doi.org/10.2172/5349667· OSTI ID:5349667

Helmick, C; Koczan, S; Pettitt, R

During the preceding work (Phase I) of the Hot Dry Rock (HDR) Geothermal Energy Project at Fenton Hill, two holes were drilled to a depth of nearly 3048 m (10,000 ft) and connected by a vertical hydraulic fracture. In this phase, water was pumped through the underground reservoir for approximately 417 days, producing an energy equivalent of 3 to 5 MW(t). Energy Extraction Hole No. 2 (EE-2) is the first of two deep holes that will be used in the Engineering-Resource Development System (Phase II) of the ongoing HDR Project of the Los Alamos National Laboratory. This phase of the work consists of drilling two parallel boreholes, inclined in their lower, open-hole sections at 35/sup 0/ to the vertical and separated by a vertical distance of 366 m (1200 ft) between the inclined parts of the drill holes. The holes will be connected by a series of vertical, hydraulically produced fractures in the Precambrian granitic rock complex. EE-2 was drilled to a depth of 4660 m (15,289 ft), where the bottom-hole temperature is approximately 320/sup 0/C (608/sup 0/F). Directional drilling techniques were used to control the azimuth and deviation of the hole. Upgrading of the temperature capability of existing hardware, and development of new equipment was necessary to complete the drilling of the hole in the extremely hot, hard, and abrasive granitic formation. The drilling history and the problems with bits, directional tools, tubular goods, cementing, and logging are described. A discussion of the problems and recommendations for overcoming them are also presented.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5349667
• Report Number(s): LA-9302-HDR; ON: DE82014911
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150901* -- Geothermal Engineering-- Drilling Technology & Well Hardware
BOREHOLES
BUILDING MATERIALS
CAVITIES
CEMENTS
COMMINUTION
DIRECTIONAL DRILLING
DRILL BITS
DRILL CORES
DRILLING
DRILLING EQUIPMENT
ENERGY SYSTEMS
EQUIPMENT
FRACTURING
GEOTHERMAL SYSTEMS
GEOTHERMAL WELLS
GRANITES
Geothermal Legacy
HOT-DRY-ROCK SYSTEMS
HYDRAULIC FRACTURING
IGNEOUS ROCKS
LOST CIRCULATION
MATERIALS
PIPES
PLUTONIC ROCKS
ROCKS
WELL CASINGS
WELL DRILLING
WELL LOGGING
WELLS