Transport properties, such as permeability, are significant in evaluating the production capacity of petroleum reservoir rocks. When a new reservoir is discovered, the most crucial parameter that needs to be determined by reservoir engineers is the rock permeability. Because the permeability of rocks is controlled not only by porosity, but also, and perhaps more importantly, by pore size distribution (PSD) and pore connectivity, a quantitative understanding of the PSD in petroleum reservoir rocks is critical in the evaluation of reservoir capacity. For example, two sandstones having similar porosities can have different permeabilities because of the variance in the PSD, degree of cementation, and tortuosity (PoA) of the porous media, all of which are critical to determining hydrocarbon production of the rocks. Within this context, a new method combining digital image analysis with an empirical equation was used to evaluate the pore geometry in thin sections of ten sandstone samples as a function of pore size distribution in three dimensions (3D) and tortuosity in 2D. Comparing the results of the PSD (3D), tortuosity (PoA), and the degree of cementation for ten samples shows that the extensive calcite cement in sample 1 is the primary control on porosity and permeability of the sample. On the other hand, the dominant pore diameter (R2=0.73), the value of the PSD slope (pore population density/mean length of pore, R2=0.70), and PoA (R2=0.64) are the leading controlling factors in permeability of the remaining nine samples. In this study, the samples having similar porosities (samples 3 and 5, and samples 4 and 6) have different distributions of pore sizes and different pore tortuosity, resulting in significant differences in the dominant pore diameters (149.3 m and 42.6 micrometrem, and 52.9 micrometrem and 138.2 micrometrem, respectively), the values of the PSD slope ( -11 and -44, and -36 and -13, respectively) and PoA (52 mm-1 and 140 mm-1, and 118 mm-1 and 62 mm-1, respectively). These data reveal that permeability increases with increasing dominant pore diameter and the PSD slope, while PoA decreases with increasing permeability. In addition to providing an estimation of permeability for the sandstones with similar porosity, this method can be extended to evaluate pore size distribution as a function of depth in a drill core, percent of pores in each class interval and pore types and pore geometry.

Petrophysical Characterization and Fluids Transport in Unconventional Reservoirs presents a comprehensive look at these new methods and technologies for the petrophysical characterization of unconventional reservoirs, including recent theoretical advances and modeling on fluids transport in unconventional reservoirs. The book is a valuable tool for geoscientists and engineers working in academia and industry. Many novel technologies and approaches, including petrophysics, multi-scale modelling, rock reconstruction and upscaling approaches are discussed, along with the challenge of the development of unconventional reservoirs and the mechanism of multi-phase/multi-scale flow and transport in these structures. - Includes both practical and theoretical research for the characterization of unconventional reservoirs - Covers the basic approaches and mechanisms for enhanced recovery techniques in unconventional reservoirs - Presents the latest research in the fluid transport processes in unconventional reservoirs

HANDBOOK OF PETROLEUM GEOSCIENCE This reference brings together the latest industrial updates and research advances in regional tectonics and geomechanics. Each chapter is based upon an in-depth case study from a particular region, highlighting core concepts and themes as well as regional variations. Key topics discussed in the book are: Drilling solutions from the Kutch offshore basin Geophysical studies from a gas field in Bangladesh Exploring Himalayan terrain in India Tectonics and exploration of the Persian Gulf basin Unconventional gas reservoirs in the Bohemian Massif This book is an invaluable industry resource for professionals and academics working in and studying the fields of petroleum geoscience and tectonics.