To ensure the safety of underground mining, there are different technologies to reduce the risk of sudden rock outbursts. Coal mines are equipped with degasification system and often have a number of boreholes for efficient and effective gas drainage. The development of in-seam directional drilling technology results in an increase in the length of the wells drilled from underground workings. Up-to-date rigs allow drilling more than 1000 meters with a minimum deviation from the desired path. Most often, these wells are immediately connected to the general degasification system and are not used to obtain the unique data from unaffected rock mass.
The aim of the study is to develop techniques and methodical approaches to an evaluation of geomechanical condition and physical properties of a rock mass at a considerable distance from the underground workings. Designed equipment will allow obtaining data on the mechanical stress acting in the massif based on the hydraulic fracturing method as well as gas recovery and temperature depending on the stress state of rocks. This will improve the quality of gas-dynamic activity forecast of methane-bearing coal seams.
As a result, the work provides a new way of logging in long methane drainage boreholes with original automatic delivery system based on the straddle packer assembly.
Distinctive features of the equipment to be developed are: the possibility of complex profile measurements along the borehole, automatic delivery system which does not require the use of expensive directional drilling rigs. Construction of experimental logging tool is scheduled for 2015.
Underground coal mines are hazardous production facilities which are potentially harmful for employees. Despite the fact that the solution for preventing unfortunate incidents and for minimizing their consequences has received considerable attention of scientists and engineers, the number of accidents caused by explosions of methane in the current working areas remains unacceptably high. The most destructive and powerful methane explosions occur during longwall mining with high production rate, and these types of accidents have become very common.