Abstract

The first buried asbestos-cement (Transite) pipeline used in high temperature (approximately 300/sup 0/F) service for transport of geothermal fluids was installed in the fall of 1975, and has seen 1/sup 1///sub 2/ years of service. The line is 4000 ft long, between the deep geothermal wells No. 1 and No. 2, in the Raft River Valley of Idaho. The experience in using this pipeline has been satisfactory, and methods have been developed for minimizing the thermal expansion/thermal shock breakage problems. Recommendations on improved design and construction practices for future pipelines are given. The substantially reduced cost (factor of 2) of an asbestos-cement pipeline compared to the conventional steel pipeline, plus the esthetically desirable effect of a buried pipeline dictate adoption of this type as standard practice for moderate temperature geothermal developments. The Raft River Geothermal Project intends to connect all future wells with pipelines of asbestos-cement, insulated with 1 to 2-inches of urethane, and buried between 2 and 3 ft. Total cost will be approximately $110,000/mile for 10-inch diameter pipe, $125,000/mile for 12-inch diameter. Document type: Report