Testing,Planning,and Redrilling of Geothermal Test Hole GT-2,Phases IV and V. Progress Report.

摘要

Holes GT-2and EE-1comprise the two deep drill holes of the Los Alamos Hot Dry Rock Geothermal Energy Extraction Experiment. EE-1had been directionally drilled to intersect a hydraulic fracture extending outward from near the bottom of GT-2,thus completing the underground circulation loop. After the drilling of EE-1, a 16-month period of experimental testing ensued to determine the characteristics of the reservoir. This period is designated as Phase IV and includes work done in GT-2and EE-1. As a result of this testing,it was determined that parallel fracture zones existed at the bottoms of both holes,and that the impedance to flow between the holes was too high for a meaningful flow experiment. A plan was then adopted to directionally drill out of GT-2at a depth of about 2600 m (8500ft) to intersect the fracture zone near the bottom of EE-1to create a better connection. The directional drilling strategy,cementing practices,bit selections,coring procedures,and logging results comprise the Phase V work. (ERA citation 04:022541)