Application of a New Grain-Based Reconstruction Algorithm to Microtomography Images for Quantitative Characterization and Flow Modeling

Abstract

Application of a New Grain-Based Reconstruction Algorithm to Microtomography Images for Quantitative Characterization and Flow Modeling Karsten Erik Thompson; Karsten Erik Thompson Louisiana State University Search for other works by this author on: This Site Google Scholar Clinton S. Willson; Clinton S. Willson Louisiana State University Search for other works by this author on: This Site Google Scholar Christopher David White; Christopher David White Louisiana State University Search for other works by this author on: This Site Google Scholar Stephanie Nyman; Stephanie Nyman The University of Waikato Search for other works by this author on: This Site Google Scholar Janok Bhattacharya; Janok Bhattacharya The University of Texas at Dallas Search for other works by this author on: This Site Google Scholar Allen H. Reed Allen H. Reed Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, October 2005. Paper Number: SPE-95887-MS https://doi.org/10.2118/95887-MS Published: October 09 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Thompson, Karsten Erik, Willson, Clinton S., White, Christopher David, Nyman, Stephanie, Bhattacharya, Janok, and Allen H. Reed. "Application of a New Grain-Based Reconstruction Algorithm to Microtomography Images for Quantitative Characterization and Flow Modeling." Paper presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, October 2005. doi: https://doi.org/10.2118/95887-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractX-ray computed microtomography (XMT) is used for high-resolution, non-destructive imaging and has been applied successfully to geologic media. Despite the potential of XMT to aid in formation evaluation, currently it is used mostly as a research tool. One factor preventing more widespread application of XMT technology is limited accessibility to microtomography beamlines. Another factor is that computational tools for quantitative image analysis have not kept pace with the imaging technology itself.In this paper, we present a new grain-based algorithm used for computer reconstruction and analysis of granular materials (e.g., consolidated or unconsolidated sands) and subsequent network generation. The algorithm differs significantly from other methods because the first step is to extract the fundamental granular structure from a 3D data set, which provides a wealth of information such as grain sizes, aspect ratios, orientations, surface areas, etc. Knowledge of the basic granular structure serves as a foundation for characterizing the void morphology and creating physically representative pore networks. The algorithm is applied to a sample of sandstone from the Frontier Formation in Wyoming, USA, which was imaged using synchrotron XMT. Morphologic and flow-modeling results are presented.IntroductionSubsurface transport processes such as oil and gas production are multiscale processes. The pore scale governs many physical and chemical interactions and is the appropriate characteristic scale for the fundamental governing equations. The continuum scale is used for most core or laboratory scale measurements (e.g., Darcy velocity, phase saturation, bulk capillary pressure, etc.). The field scale is the relevant scale for production and reservoir simulation.Multiscale modeling strategies aim to address these complexities by integrating the various length scales. While pore-scale modeling is an essential component of multiscale modeling, quantitative methods are not as well developed as their continuum-scale counterparts. Hence, pore-scale modeling represents a weak link in current multiscale techniques.The most fundamental approach for pore-scale modeling is direct solution of the equations of motion (along with other relevant conservation equations), which can be performed using a number of numerical techniques. The finite element method is the most general approach in terms of the range of fluid and solid mechanics problems that can be addressed. Finite difference and finite volume methods are more widely used in the computational fluid dynamics community. The boundary element method is very well suited for low-Reynolds number flow of Newtonian fluids (including multiphase flows). Finally, the lattice-Boltzmann method has been favored in the porous-media community because it easily adapts to the complex geometries found in natural materials.A less rigorous approach is network modeling, which gives an approximate solution to the governing equations. It requires discretization of the pore space into pores and pore throats, and transport is modeled by imposing conservation equations at the pore scale. Network modeling involves two levels of approximation. The first is the representation of the complex, continuous void space as discrete pores and throats. The second is the approximation to the fluid mechanics when solving the governing equations within the networks. The positive trade off for these significant simplifications is the ability to model transport over orders-of-magnitude larger characteristic scales. Consequently, the two approaches (rigorous modeling of the conservation equations versus network modeling) have complimentary roles in the overall context of multiscale modeling. Direct methods will remain essential for studying first-principles behavior and sub-pore-scale processes such as diffusion boundary layers during surface reactions. Network modeling will provide the best avenue for capturing larger characteristic scales (which is necessary for modeling the pore to continuum scale transition). Keywords: network modeling, upstream oil & gas, pore location, coordination number, algorithm, tessellation, characterization, resolution, fluid dynamics, pore structure Subjects: Reservoir Fluid Dynamics, Information Management and Systems, Flow in porous media This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.