Prediction of Mechanical Properties of Sedimentary Type Rocks Using Rotary Drilling Parameters

The estimation of strength properties of sedimentary rocks is most often needed during the preliminary phase of many rock engineering projects carrying out in sedimentary regions. The main drawback of determining the rock properties in a test center is the requirement of the number of superior quality rock core specimens. In this experimental investigation, the uniaxial compressive strength (UCS) and tensile strength of sedimentary rocks are estimating using well-identified drilling variables and acoustic parameters obtained during the rotary type rock drilling. The drilling variables such as thrust, torque, and vibration parameters are used to develop the mathematical models of strength properties of rock. A drill type dynamometer was used to measure the drilling variables, and the vibration parameter would measure using the NI-9234 data acquisition system. The prediction efficiency of the mathematical model is evaluating using performance indices. Results show that the used experimental method can estimate the considered responses (UCS and tensile strength) with the acceptable percentage errors of 10.52% and 11.27% respectively, and may be useful to measure the UCS and BTS of sedimentary rocks in a laboratory capacity without test core samples.