2D circularity and turtuosity of pores: Phase 1 of 4 phases investigation on pore structure controls on transport behavior of carbonates

This paper presents preliminary image analysis results of pore circularity and tortuosity on two bioclastic wackstone samples from offshore East Malaysia. Circularity and tortuosity are two examples of pore structural parameters that are believed to influence rocks’ ability to transmit fluids. By implication, their characterization could lead to improved understanding of fluid transport behaviour within porous media. Results show that there is a good correlation between circularity and tortuosity with the pore geometry, however does not demonstrate a direct relationship to facies. Although both are bioclastic wackstone, but both exhibits different petrophysical properties (porosity and permeability) and different tortuosity values. One sample exhibits complex pore system while the other a simple pore system. This commonly leads to large uncertainties in reservoir models that uses facies as the basis of reservoir characterisation. We will extend this investigation in several phases by measuring static and dynamic petrophysical properties of the carbonate samples and develop a 3D model of the pore system that has the capability to predict fluid storage and fluid flow in the rock. In addition, we also present the use of fractal dimension and pore connectivity grading as another pore structure assessment parameters for East Malaysia carbonate rocks.