Research on determination fluency factors about value of drilling cuttings weight and index of drill cuttings absorption and release;

Application of the value of drilling cuttings weight and desorption index for drill cuttings to preventing coal and gas outburst

As result of backward equipment and wrong operation,the forecast results become unreliable when the index of drilling yields is used in forecasting coal or rock outburst.

The blasting effect was checking using sight instrument, electromagnetic emission (EME) technique and drilling sludge methods.

This paper discusses anew method of caculating critical rotational speed on the basis of studying the transportation rule of long screw drilling sludge and points out that critical rotational speed changesradially along the blade,and it is the function of feed speed.