| Popis: |
The process of stemming a deep hole with magnetite, which was initially hotter or cooler than the ambient downhole temperature, was investigated experimentally. The specific objective of the experiment was to determine the temperature changes that occur as the magnetite falls downhole. A numerical model of heat transfer was developed to calculate the stemming temperature changes and was calibrated with the experimental results. Experimental data show that initially hot stemming, 122/degree/F, arrives at a downhole depth of 1284 feet at approximately 74/degree/F when stemmed at 100 tons/hour for an 8 foot diameter hole. Initial downhole temperatures were near 66/degree/F. For initially cold stemming, the temperature of stemming arriving downhole was also close to ambient downhole temperature conditions. The developed calculational model can be applied to predict stemming temperature changes as a function of hole depth, hole diameter, type of stemming material, initial stemming temperature, stemming rate, and ambient hole wall temperature conditions as a function of depth. 8 figs., 5 tabs. |
