Influence of physico-mechanical properties of tuff on penetration rate - a case study in Southern Johor Bahru, Malaysia

Abstract

The relationship between physico-mechanical properties of tuff and penetration rate of air percussion drilling was investigated during an exploratory well drilling work at Southern Johor Bahru. The rocks were tested for weathering grade, average grain size, porosity, quartz content and point load strength test. The penetration rate was found to increase linearly with an increase in weathering rate, average grain size and porosity. Meanwhile, it decreases dlinearly with an increase in quartz content and point load strength index. The coefficient of determination, R2 between weathering grade, average grain size, porosity, quartz, point load strength index and penetration rate were found to be 0.4875, 0.1838, 0.0186, 0.0863 and 0.6324 respectively in simple linear regression analysis. The findings from a multivariate regression analysis showed good correlation (R2=0.79) between the tested parameters and penetration rate of tuff.