| Title | Geothermal Turbodrill Field Tests |
|---|---|
| Authors | Maurer, William C.; McDonald, William J.; Neudecker, Joseph W.; Rowley, John C.; Carwile, Clifton |
| Year | 1979 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | 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 |
| 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. |