https://cyberleninka.org/article/n/22310.pdf

Pore-scale imaging and modelling

Carbon dioxide is often promoted as a sustainable solvent, as CO 2 is non-flammable, exhibits a relatively low toxicity and is naturally abundant. However, injudicious use of carbon dioxide in a process or product can reduce rather than enhance overall sustainability. This review specifically examines the use of CO 2 to create greener processes and products, with a focus on research and commercialization efforts performed since 1995. The literature reveals that use of CO 2 has permeated almost all facets of the chemical industry and that careful application of CO 2 technology can result in products (and processes) that are cleaner, less expensive and of higher quality.

Supercritical and near-critical CO2 in green chemical synthesis and processing

In this paper, theoretical and experimental approaches to flow, hydrodynamic dispersion, and miscible and immiscible displacement processes in reservoir rocks are reviewed and discussed. Both macroscopically homogeneous and heterogeneous rocks are considered. The latter are characterized by large-scale spatial variations and correlations in their effective properties and include rocks that may be characterized by several distinct degrees of porosity, a well-known example of which is a fractured rock with two degrees of porosity---those of the pores and of the fractures. First, the diagenetic processes that give rise to the present reservoir rocks are discussed and a few geometrical models of such processes are described. Then, measurement and characterization of important properties, such as pore-size distribution, pore-space topology, and pore surface roughness, and morphological properties of fracture networks are discussed. It is shown that fractal and percolation concepts play important roles in the characterization of rocks, from the smallest length scale at the pore level to the largest length scales at the fracture and fault scales. Next, various structural models of homogeneous and heterogeneous rock are discussed, and theoretical and computer simulation approaches to flow, dispersion, and displacement in such systems are reviewed. Two different modeling approaches to these phenomena are compared. The first approach is based on the classical equations of transport supplemented with constitutive equations describing the transport and other important coefficients and parameters. These are called the continuum models. The second approach is based on network models of pore space and fractured rocks; it models the phenomena at the smallest scale, a pore or fracture, and then employs large-scale simulation and modern concepts of the statistical physics of disordered systems, such as scaling and universality, to obtain the macroscopic properties of the system. The fundamental roles of the interconnectivity of the rock and its wetting properties in dispersion and two-phase flows, and those of microscopic and macroscopic heterogeneities in miscible displacements are emphasized. Two important conceptual advances for modeling fractured rocks and studying flow phenomena in porous media are also discussed. The first, based on cellular automata, can in principle be used for computing macroscopic properties of flow phenomena in any porous medium, regardless of the complexity of its structure. The second, simulated annealing, borrowed from optimization processes and the statistical mechanics of spin glasses, is used for finding the optimum structure of a fractured reservoir that honors a limited amount of experimental data.

Flow phenomena in rocks : from continuum models to fractals, percolation, cellular automata, and simulated annealing

This article reviews the storage of captured CO2 in coal seams. Other geologic formations, such as depleted petroleum reservoirs, deep saline aquifers and others have received considerable attention as sites for sequestering CO2. This review focuses on geologic sequestration of CO2 in unmineable coalbeds as the geologic host. Key issues for geologic sequestration include potential storage capacity, the storage integrity of the geologic host, and the chemical and physical processes initiated by the deep underground injection of CO2. The review topics include (i) the estimated CO2 storage capacity of coal, along with the estimated amount and composition of coalbed gas; (ii) an evaluation of the coal seam properties relevant to CO2 sequestration, such as density, surface area, porosity, diffusion, permeability, transport, rank, adsorption/desorption, shrinkage/swelling, and thermochemical reactions; and (iii) a treatment of how coalbed methane (CBM) recovery and CO2-enhanced coalbed methane (ECBM) recovery a...

Sequestration of Carbon Dioxide in Coal with Enhanced Coalbed Methane RecoveryA Review

[1] Relative permeabilities are the key descriptors in classical formulations of multiphase flow in porous media. Experimental evidence and an analysis of pore-scale physics demonstrate conclusively that relative permeabilities are not single functions of fluid saturations and that they display strong hysteresis effects. In this paper, we evaluate the relevance of relative permeability hysteresis when modeling geological CO2 sequestration processes. Here we concentrate on CO2 injection in saline aquifers. In this setting the CO2 is the nonwetting phase, and capillary trapping of the CO2 is an essential mechanism after the injection phase during the lateral and upward migration of the CO2 plume. We demonstrate the importance of accounting for CO2 trapping in the relative permeability model for predicting the distribution and mobility of CO2 in the formation. We conclude that modeling of relative permeability hysteresis is required to assess accurately the amount of CO2 that is immobilized by capillary trapping and therefore is not available to leak. We also demonstrate how the mechanism of capillary trapping can be exploited (e.g., by controlling the injection rate or alternating water and CO2 injection) to improve the overall effectiveness of the injection project.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2005WR004806

Impact of relative permeability hysteresis on geological CO2 storage

Enhanced Oil Recovery

A revision of the 1989 classic, Enhanced Oil Recovery by Larry Lake, this text, Fundamentals of Enhanced Oil Recovery, retains the original work's emphasis on fractional ow theory and phase behavior to explain enhanced oil recovery (EOR) processes. There is additional coverage on cutting edge (or current) topics, such as low-salinity EOR, steam-assisted gravity drainage, and expanded coverage on thermodynamics and foam EOR. With its frequent reinforcement of two fundamental EOR principles, lowering the mobility ratio and increasing the capillary number, it is an excellent resource for undergraduate classes. Fundamentals of Enhanced Oil Recovery Larry W. Lake, Russell Johns, Bill Rossen and Gary Pope 2014 496 pp.; Softcover ISBN: 978-1-61399-328-6 Society of Petroleum Engineers

Fundamentals of Enhanced Oil Recovery

Reservoir Simulation of CO2 Storage in Deep Saline Aquifers

In this study, we present quantification methods for nanoparticle stability analysis using non-intrusive analytical techniques: attenuated total reflectance, Fourier transform infrared (ATR-FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectrophotometer, zeta potential analyses, and dynamic light scattering (DLS). We use these techniques to study the stability of silica nanoparticle dispersions and the effects of pH, temperature, and electrolytes that would be encountered in oil field brines in a reservoir. Spectral analysis of the Si–O bond at wavenumber of 1110 cm−1 with the ATR-FTIR indicates a structural change on the surface of silica particles as the dispersion pH changes, which agrees with zeta potential measurements. We define a critical salt concentration (CSC) for different salts, NaCl, CaCl2, BaCl2, and MgCl2, above which the silica dispersion becomes unstable. Three distinct stages of aggregation occur in the presence of salt: clear dispersed, turbid, and separated phases. Divalent cations Mg2+, Ca2+, and Ba2+ are more effective in destabilizing silica nanoparticle dispersion than the monovalent cation Na+. The CSC for Na+ is about 100 times more than for Ca2+, Ba2+, and Mg2+. Among the divalent cations studied, Mg2+ is the most effective in destabilizing the silica particles. The CSC is independent of silica concentration, and lowers at high temperature.

Larry W. Lake

Papers

Enhanced Oil Recovery

Fundamentals of Enhanced Oil Recovery

Reservoir Simulation of CO2 Storage in Deep Saline Aquifers

Stability of aqueous silica nanoparticle dispersions

Reservoir Simulation of CO 2 Storage in Aquifers