Drilling and Completion of the Urach III HDR Test Well

Conference · Thu Jan 01 04:00:00 EST 1981

OSTI ID:886094

Meier, U; Ernst, P L

The hot dry rock (HDR) test well, urach III, was drilled and completed in 1979. The borehole is located in Southwest Germany in the geothermal anomaly of Urach. The purpose of project Urach was to study drilling and completion problems of HDR wells and to provide a test site for a HDR research program. The Urach III borehole was drilled to a total depth of 3,334 meters (10,939 feet), penetrating 1,700 meters (5,578 feet) into the granitic basement. Extensive coring was required to provide samples for geophysical and geochemical studies. Positive displacement downhole motors were used for coring and normal drilling operations. It was found that these motors in combination with the proper bits gave better results than conventional rotary drilling. Loss of circulation was encountered not only in sedimentary rocks but also in the granite. After drilling and completion of the borehole, a number of hydraulic fracturing experiments were performed in the open hole as well as in the cased section of Urach III. A circulation loop was established by using the single-borehole concept. It is not yet clear whether new fractures have actually been generated or preexisting joints and fissures have been reactivated. Evaluation of the results of this first step is almost completed and the planning of Phase II of the Urach project is under way.

• Research Organization: DOEEEGTP (USDOE Office of Energy Efficiency and Renewable Energy Geothermal Tech Pgm)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 886094
• Report Number(s): SAND-81-0036C; CONF-810105-6
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
DRILL CORES
EXPLORATORY WELLS
FEDERAL REPUBLIC OF GERMANY
GEOTHERMAL WELLS
Geothermal Legacy
HOT-DRY-ROCK SYSTEMS
HYDRAULIC FRACTURING
TEST FACILITIES
WELL COMPLETION
WELL DRILLING