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Geothermal Turbodrill Field Tests

Maurer, William C.; McDonald, William J.; Neudecker, Joseph W.; Rowley, John C.; Carwile, Clifton

Key words
Drilling; Downhole Motors; High Temperature; USA; New Mexico; Fenton Hill; Hot Dry Rock; Granite; Dynamometer; Directional Drilling; High Torque; Roller Core Bits; US DOE; LASL; Terra Tek
Conference
Geothermal Resources Council Transactions
Year
1979
Session
Drilling; Downhole motors
Language
English

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Abstract

A new advanced geothermal turbodrill designed to operate at temperatures in excess of 500°F has been field tested in the LASL's EE-2 hot, dry rock well. The operating characteristics of 5-3/8 and 7-3/4 inch turbodrills were measured on a dynamometer test stand, and then these tools were used to drill Texas Pink granite in the laboratory at rates in excess of 50 ft/hr. This compares to 10 ft/hr with conventional bits. A 7-3/4 inch turbodrill was then used to drill a 57 foot interval in granodiorite at LASL's Fenton Hill Hot Dry Rock geothermal site with a 12-1/4 inch insert roller bit. The turbodrill drilled at an average rate of 23 ft/hr compared to 10 ft/hr for conventional bits operated at 60 rpm. Plans are being made to use these turbodrills in the directional portions of LASL's hot, dry rock geothermal wells.

Copyright 1979, Geothermal Resources Council. Readers who download papers from this site should honour the copyright of the original authors, and may not copy or distribute the work further without the permission of the original publisher.

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