Estimate and Analyze The Impact to the Brittleness Index of Digital Rock Image of Carbonate

Abstract

Digital rock physics is a modern method of determining the elastic properties, an important parameter to analyze the brittleness index, combining the digital technique with the numerical method. This paper analyses the effect of mineral content, water saturation, fluid type, and porosity. Carbonate digital images with 501 × 450 × 482 pixels which are divided into sub-cubes of 50 pixels3 are used. Calculating stress and strain with a numerical approach to producing the modulus elastic, and then the brittleness index can be approximated. The result shows calcite and ankerite are stiffer than quartz but not resistant to shear stress. An increase in the fluid saturation decreases the modulus value linearly in the oil case but suddenly in the gas case. For porosity variation, the greater the porosity in a material or rock will make it less rigid and not easily deformed. The effect on brittleness increases when water is replaced by fluids (either oil or gas) but decreases when there is more calcite, and ankerite and also goes down if the porosity gets bigger. So this study concludes, calcite, ankerite, and increasing porosity make the material more ductile but fulfilling with fluid will make it a little more brittle.