The article is dedicated to the results of mechanical logging implementation on the Olon-Shibirskoye coalfield. Previous investigations had shown that non-core drilling could potentially provide information on the geological composition of a coalfield and on the ash content of coal by the means of mechanical logging. Since then, the equation of the correspondence between drilling velocity and ash content has been modified as the result of analyzing a greater amount of data. The next step of the research was examining the implementation of mechanical logging for operational exploitation on the Olon-Shibirskoye coalfield. For this stage, thirty-one boreholes were drilled with the implementation of mechanical logging. Results of this drilling were compared to the geological exploration data that had been obtained earlier in the same area and several drilling process requirements had been developed. The drilling process should be constant, without any intervention of a drill operator, otherwise the results might appear corrupt. The intervention caused by rocks falling into a borehole is aimed at removing drilled solids from the borehole. In order to prevent rocks from getting into boreholes, a number of well parameters, which may lead to the falling of rocks, should be taken into consideration: well depth, the number of coal beds that well crosses, fractures, faulting or other dislocations of rocks, as well as the inclination of a borehole axis.