A significant factor contributing to short bit life and attendant high costs for geothermal drilling is the lack of seals for elevated temperatures. To assist development of a high-temperature seal, a test facility was constructed to simulate the seal environment in a roller bit during geothermal drilling. Although none of the tested elastomers appear suitable for compression seals above 200°C, extensive testing was performed to determine their exact limits. Several new heterogeneous seal designs were found usable to higher temperatures.

No abstract

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. 5. Fracture Detection Tech is iq u es Resistivity logging Borehole Televiewers 6. Seismic Techniques Surface imaging 4 0 seismic Dowithole seismic tecliiiiques Downliole wave sources Microseismic m on itoriiig Drill-bit seisniics 7. Reservoir Definition and Operation Tracers Explicit-fracture tracer test Do wii k ole fluid analyzer 8. Numerical Simulation Explicit representation of fractures Fracture opeiiiiig as a fuiictioii of effective stress Shear deformation aiid associated jacking of fractures Relationship between fracture aperture and conductivity Ch arineling in fractures Tltermo-elastic effects Mineral deposition and dissolution Tracer module Multi-phase flo w