| Abstract |
Recent scientific projects have required extensive intermittent coring in the deep, hot geothermal areas. Two projects are the Salton Sea Scientific Drilling Project (SSSDP) and the Southeastern edge of the Hot Dry Rock Project (HDR) under development in North Central New Mexico at Fenton Hill west of Los Alamos, New Mexico. This coring in full size well bores has demonstrated that coring under the conditions which exist in geothermal formations are extremely difficult, time consuming and costly. The coring techniques applied to these projects use the best available technology from the petroleum industry and some newly improved developments. Efforts to improve recovery and efficiently were made by varying coring methods by changing core head types along with operations changes of rotary speeds, weight on core had and circulation rates. Primary problems limiting the coring operations were core "jamming" in the barrel and in the catcher and slow penetration rates. |