Analysis on Fractional Resistance of Horizontal Directional Drilling Tools in Underground Mine

In order to guide the selection of the directional driling parameters in underground mine, borehole tracing control and judgment of the in-borehole perfor mances, a study and prediction should be conducted on the fractional resistance of the drilling prop.Based on the study achievements of the drilling prop fractional resis tance model applied in the petroleum industry, according to the features of the horizontal directional drilling technology in underground mine, the stressed infinitesimal e lement section of the drilling prop was analyzed and a soft rod model of the drilling prop fractional resistance was established.A study was conducted on the inversion al gorithm of the fractional coefficient and the calculation formula of the fractional resistances under the three normal performances was inferred.A prediction was conduct ed on the orifice loading under the lifting up of the direction drilling and directional drilling normal performances in Gaohe Mine. The results showed that the average dev iation of the predicted value was 0.50 MPa less than the actual measured value and the prediction accuracy of the orifice loading, could meet the accuracy requirement of the site construction.