Scientific Core Hole Valles Caldera # 2b (VC-2b), New Mexico: Drilling and Some Initial Results
- Key words
- Exploration; Drilling; USA; Nevada; Sandoval; Valles; Casing; Diamond Bits; Beutonite; Diamond Core Drilling; BOPE; H2S Detection; Core Hole; Age Dating; Chemistry; Resurgent Dome; Caldera
- Location
- Valles Caldera, New Mexico
- Conference
- Geothermal Resources Council Transactions
- Year
- 1989
- Session
- Exploration; Drilling; Core sampling; Geological surveys; St
- Language
- English
Abstract
Research core hole VC-2b, the third in the U.S. Department of Energy's Continental Scientific Drilling Program efforts in the Valles caldera, was continuously cored to 1,762 km on the western flank of the caldera's resurgent dome in 1988. Bottom hole temperature is about 295°C within Precambrian (1.5 Ga) quartz monozonite, deep within the liquid dominated portions of the Sulphur Springs hydrothermal system. VC-2b may be the deepest, hottest, continuously cored hole in North America. Core recovery was 99.2%. The only major drilling problems encountered were when temperatures at the bit exceeded 225°C below depths of about 1000m. The result of these conditions was loss of viscosity and/or lubricity in the mud, apparently caused by breakdown of the high temperature polymers.
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