Speaker
Description
The resistivity index (RI) is a crucial parameter for characterizing the electrical properties of geological formations. Accurate measurement of RI is essential for understanding fluid distribution and behavior in porous rocks, with direct implications for applications such as hydrocarbon reservoir evaluation and enhanced oil recovery. These assessments are vital for optimizing resource extraction while minimizing environmental impact. Typically, the analysis of RI curves relies on the saturation exponent derived from Archie's law, which relates the electrical properties of rocks to their fluid saturation. Sandstone formations, in particular, often exhibit saturation exponents close to 2 due to their water-wet nature, which promotes the formation of water films at the rock-oil interface. As a result, analyzing RI under low water saturation conditions remains a significant challenge, as deviations in RI curves are commonly observed. These deviations are strongly influenced by the presence of those thin water films at the rock-oil interface, which significantly affect the overall conductivity of the system. In numerical simulations, most pore-scale fluid distribution methods do not account for the natural formation of these films, whereas more advanced methods capable of generating water films, such as numerical solutions for the fluid flow within the pore space, are computationally expensive and often impractical for large-scale simulations. Consequently, the electrical properties of these water films are often oversimplified or neglected in conventional modeling approaches, leading to discrepancies between modeled and experimental results.
In this work, we address these challenges by implementing a robust numerical simulation framework to calculate resistivity index curves for digital rock samples. This framework includes the development of a methodology that accounts for the presence of water films at the rock-oil interface. These water films are numerically introduced into the pore structure of the digital rock sample, enabling a more realistic representation under partially saturated conditions. A conductivity relation for the water films derived from the Langmuir equation is used to model the film conductivity as a function of film thickness and water conductivity. The resistivity index curves generated from simulations of different digital rock samples exhibited saturation exponents close to 2, aligning with empirical observations reported in the literature.
| Country | Brazil |
|---|---|
| Water & Porous Media Focused Abstracts | This abstract is related to Water |
| Acceptance of the Terms & Conditions | Click here to agree |
