Experiments in Thermal Spallation of Various Rocks

摘要

The greatest limitation of the spallation process is its inability to spall (or to consistently spall) many rocks encountered in petroleum drilling and mining operations. The New Mexico Institute of Mining and Technology has conducted a series of experiments to investigate the possibility of expanding the use of the spallation process to the penetration of rocks generally considered not to be spallable. The methods used during this work were 1) spoiling at temperatures below that produced by the stoichiometric burning of fuel oil and air, and 2) spoiling by alternately heating and quenching the rock surfaces. No success was experienced in spoiling at the lower temperatures, but initial tests showed the alternate heating and chilling system to be successful, particularly in penetrating travertine limestone. However, continued testing indicated that, unless the rocks are extremely uniform in composition, spailing will result in highly irregular holes or holes that cannot be directionally controlled.