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Geochemical Impact Of Super Critical C02 Injection Into The St Peter Sandstone Formation Within The Illinois Basin
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Book Synopsis Geochemical Impact of Super-critical C02 Injection Into the St. Peter Sandstone Formation Within the Illinois Basin by : Richard Michael Thomas
Download or read book Geochemical Impact of Super-critical C02 Injection Into the St. Peter Sandstone Formation Within the Illinois Basin written by Richard Michael Thomas and published by . This book was released on 2014 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deep injection of waste CO2 and fluids from regional energy plants into the St. Peter Formation of the Illinois Basin, could effectively provide long term deep geologic storage. This research aims to explore the viability of this proposed injection. There are some basic criteria that must be met to effectively store waste in a geologic reservoir. First, the reservoir must have sufficient porosity and permeability for both injectivity and for migration of the injected fluid through the reservoir. Second, the reservoir must be overlain by some form of impermeable seal or cap layer(s). Third, the reservoir should be sufficiently isolated from interaction with surface and near surface water. Finally, the formation must contain enough storage volume to handle significant amounts of injected material. Massive sandstone formations that host large saline aquifers have the potential to serve as high capacity storage sites. Much of the research targeting the potential suitability and storage capacity attributes of these formations has been promising, but reproducibility of the results has been less than ideal. Some of this variability has been attributed to petrological differences in the sandstone reservoirs that are not readily evident when studying the target formation over a geographically significant area. Based on the criteria, a promising candidate for injection and storage is the St. Peter Sandstone of the Illinois Basin. This study investigates the viability of liquefied CO2 storage within the St. Peter Sandstone on a micro scale. Initial porosity and permeability of the formation plug samples ranged from 16% to 19% and 26 to 981 millidarcies (mD), respectively. The wide difference in permeability is attributed to variations in strength of the cement, in this case quartz overgrowth in the sandstone. This preliminary evidence indicates that the storage capacity of the formation will remain constant or increase depending on injection location, suggesting that the St. Peter Formation will lend itself well to future storage.
Book Synopsis Hydrology of the Forest City Basin, Mid-continent, USA by : Christopher R. Burrows
Download or read book Hydrology of the Forest City Basin, Mid-continent, USA written by Christopher R. Burrows and published by . This book was released on 2012 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to perform a preliminary assessment of the stratigraphy, storage capacity, hydrology and mineraology of this basin to determine its suitability and structural trapping capacity for geologic sequestration of carbon dioxide. The basin is stratigraphically suited in that it contains the St. Peter Sandstone, a high permeability aquifer which is overlain by multiple low permeability units. These should act as a seal to prevent the upward migration of injected CO2. Construction of a three dimensional stratigraphic model produces storage capacity estimates within the St. Peter ranging from 5.2 to 830 megatonnes CO2. Groundwater modeling results highlight potential areas of flow stagnation and a predominately lateral flow regime within the St. Peter Sandstone. This, coupled with relatively low flow velocities in most model scenarios, indicates that CO2 as a dissolved phase in groundwater is not likely to escape the basin through lateral migration in less than 1,000 years, the commonly accepted performance standard for sequestration (Hepple and Benson, 2005). Mineralogical analysis also indicates a grain matrix composed almost entirely of quartz which is non-reactive with CO2; this indicates that dissolution of the grain matrix upon injection is not likely to occur and result in any loss of conductivity or porosity through grain collapse. The preliminary results presented in this study indicate that the Forest City Basin is indeed suitable for carbon sequestration and warrants further investigation.
Book Synopsis Pre-test Geological and Geochemical Evaluation of the Caprock, St. Peter Sandstone and Formation Fluids, Yakley Field, Pike County, Illinois by : David K. Davies
Download or read book Pre-test Geological and Geochemical Evaluation of the Caprock, St. Peter Sandstone and Formation Fluids, Yakley Field, Pike County, Illinois written by David K. Davies and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Geomechanical, Geochemical, and Hydrological Aspects of Co2 Injection Into Saline Reservoirs by : Maziar Foroutan
Download or read book Geomechanical, Geochemical, and Hydrological Aspects of Co2 Injection Into Saline Reservoirs written by Maziar Foroutan and published by . This book was released on 2021 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon dioxide Capturing, and Sequestration (CCS) is a promising technique that helps mitigate the amount of CO2 emitted into the atmosphere. CCS process mainly involves capturing CO2 at the industrial plant, followed by transportation and injection into a suitable geological storage, under supercritical conditions. Saline aquifers are among the best geological storage candidates due to their availability, high storage capacity and injectivity. Despite the CCUS technology promise, several public safety concerns remain to be address, including but not limited to reservoir/wellbore stability and integrity, CO2 leakage, ground deformation (uplift) and induced seismicity. The injected supercritical CO2 is trapped through different mechanisms in the host reservoir including (i) structural and stratigraphic trapping, (ii) residual trapping, (iii) solubility trapping, and (iv) mineral trapping. Dissolution of CO2 into the formation brine creates an acidic environment, which is highly reactive. The potential mineral dissolution in reservoir rocks can enhance the storage capacity and reservoir injectivity, while the secondary precipitation of minerals can decrease the storage capacity and injectivity. However, the geochemical processes triggered by CO2 injection can potentially degrade the mechanical properties of the reservoir rock, which can consequently disturb the wellbore-stability, reservoir integrity, and lead to significant reservoir compaction. Furthermore, injecting CO2 changes the stress-regime by increasing pore-pressure in the reservoir and its surroundings, which can potentially reactivate the existing faults, leading to induced seismicity. In this research, experiments were performed to evaluate the variation of porosity and pore-connectivity of intact sandstone specimens upon injecting CO2-enriched brine. In addition, the permeability evolution during the CO2-enriched brine injection process was evaluated under different reservoir condition. The mechanical impacts of injecting CO2-enriched brine were evaluated by comparing the mechanical properties (i.e., elastic, strength, seismic and time dependent properties) before and after injecting CO2-enriched brine. In addition, to evaluate the response of fractured reservoirs to CO2 injection, CO2-enriched brine was injected into a limestone and varyingly cemented (i.e., calcite and quartz cemented) sandstone specimens that were artificially fractured. The experimental results were used to numerically simulate CO2 injection into a core-scale porous medium to investigate the changes in CO2 concentration and mass transfer mechanism under different porosity, permeability, and injection pressure values. The experimental results of injecting CO2-enrihed brine to the intact (non-fractured) specimens revealed permeability enhancement and mechanical weakening caused by mineral dissolution. The extent of changes in permeability and mechanical properties of rock specimens varied under different reservoir conditions (i.e., pressure, salinity, and temperature). The mechanical weakening increased the possibility of induced seismicity, which consequently resulted in decreasing the allowable injection pressure of CO2. However, the permeability increase resulted in enhancing CO2 mass transfer and accelerating the solubility trapping in the brine aquifer.
Book Synopsis Annual Report by : Kentucky Geological Survey
Download or read book Annual Report written by Kentucky Geological Survey and published by . This book was released on 2010 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Geologic and geochemical studies of the New Albany Group (Devonian black shale) in Illinois to evaluate its characteristics as a source of hydrocarbons by : Illinois State Geological Survey
Download or read book Geologic and geochemical studies of the New Albany Group (Devonian black shale) in Illinois to evaluate its characteristics as a source of hydrocarbons written by Illinois State Geological Survey and published by . This book was released on 1977 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Geochemical Trends in Chesterian (Upper Mississippian) Waltersburg Crudes of the Illinois Basin by : Richard Frederick Mast
Download or read book Geochemical Trends in Chesterian (Upper Mississippian) Waltersburg Crudes of the Illinois Basin written by Richard Frederick Mast and published by . This book was released on 1968 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Site Characterization Study for CO2 Injection Into the Oriskany Formation by : William Carr
Download or read book A Site Characterization Study for CO2 Injection Into the Oriskany Formation written by William Carr and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Oriskany Sandstone, defined as a quartz arenite aquifer formation, is located throughout the Appalachian Basin, with primary oil and gas production in New York, Pennsylvania, Ohio, and West Virginia. For years, it has been used as a hydrocarbon production and gas storage formation due to its favorable petrophysical properties. The structural complexity of the Oriskany is mainly present along the Appalachian Mountain range due to the stresses involved during their orogeny. Because of this, structural and stratigraphic influence of the formation causes regions of low permeability and porosity, thus leading to unfavorable conditions for both oil and gas production and injection. This study looks to focus on the Oriskany Sandstone region to explore the feasibility of CO2 sequestration. With the imperative to reduce CO2 emissions throughout the world, especially within the United States, there is a shift in focus from production of oil and gas to the use of the subsurface for carbon sequestration. Proof of long-term safety and efficiency is key to development of CO2 sequestration projects and requires proper coring, logging, and seismic analysis for deployment of well plans within specified regions. Techniques for tracking the CO2 and pressure plumes are necessary. This study focuses on analyzing the limited information available for a region of the Oriskany formation and synthesizes a reservoir model to define the feasibility of the Oriskany formation as a sequestration site in North Central Pennsylvania. The low values of permeability and porosity in the region lead to the consideration of hydraulic fracturing to attempt to expand the contact area into the reservoir. The significance of this study, which uses seismic, log, and geostatistical analysis to populate the reservoir simulator, determines the injectability of the formation and its storage capacity. Provided the limited data to characterize the formation in the vicinity of an existing well, a range of analyses was conducted, which include Bayesian analysis to populate a reservoir model with petrophysical properties and sensitivity analysis with respect to well injection capabilities. These analyses provide a wide range of results to compare when more data becomes available to better understand the formation at the location of the well. In addition, economics are considered, including the influence of monitoring wells and the influence of abandoned wells in the vicinity of the injection well. With an ammonia plant acting as the source of CO2, producing approximately 3,200 tons of CO2 per day, various injection cycles and fracturing scenarios are analyzed, resulting in anywhere from 6% to 25% dissolution into the formation brines, a key component when attempting to trap the CO2 over a long term. Although the current study's analysis of this area of the Oriskany may not be suited for CO2 sequestration, further evaluation of the effects of natural fractures, heavily present within this area, needs to be performed before a final decision is made.
Book Synopsis Petrophysical Modeling and Simulation Study of Geological CO2 Sequestration by : Xianhui Kong
Download or read book Petrophysical Modeling and Simulation Study of Geological CO2 Sequestration written by Xianhui Kong and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global warming and greenhouse gas (GHG) emissions have recently become the significant focus of engineering research. The geological sequestration of greenhouse gases such as carbon dioxide (CO2) is one approach that has been proposed to reduce the greenhouse gas emissions and slow down global warming. Geological sequestration involves the injection of produced CO2 into subsurface formations and trapping the gas through many geological mechanisms, such as structural trapping, capillary trapping, dissolution, and mineralization. While some progress in our understanding of fluid flow in porous media has been made, many petrophysical phenomena, such as multi-phase flow, capillarity, geochemical reactions, geomechanical effect, etc., that occur during geological CO2 sequestration remain inadequately studied and pose a challenge for continued study. It is critical to continue to research on these important issues. Numerical simulators are essential tools to develop a better understanding of the geologic characteristics of brine reservoirs and to build support for future CO2 storage projects. Modeling CO2 injection requires the implementation of multiphase flow model and an Equation of State (EOS) module to compute the dissolution of CO2 in brine and vice versa. In this study, we used the Integrated Parallel Accurate Reservoir Simulator (IPARS) developed at the Center for Subsurface Modeling at The University of Texas at Austin to model the injection process and storage of CO2 in saline aquifers. We developed and implemented new petrophysical models in IPARS, and applied these models to study the process of CO2 sequestration. The research presented in this dissertation is divided into three parts. The first part of the dissertation discusses petrophysical and computational models for the mechanical, geological, petrophysical phenomena occurring during CO2 injection and sequestration. The effectiveness of CO2 storage in saline aquifers is governed by the interplay of capillary, viscous, and buoyancy forces. Recent experimental data reveals the impact of pressure, temperature, and salinity on interfacial tension (IFT) between CO2 and brine. The dependence of CO2-brine relative permeability and capillary pressure on IFT is also clearly evident in published experimental results. Improved understanding of the mechanisms that control the migration and trapping of CO2 in the subsurface is crucial to design future storage projects for long-term, safe containment. We have developed numerical models for CO2 trapping and migration in aquifers, including a compositional flow model, a relative permeability model, a capillary model, an interfacial tension model, and others. The heterogeneities in porosity and permeability are also coupled to the petrophysical models. We have developed and implemented a general relative permeability model that combines the effects of pressure gradient, buoyancy, and capillary pressure in a compositional and parallel simulator. The significance of IFT variations on CO2 migration and trapping is assessed. The variation of residual saturation is modeled based on interfacial tension and trapping number, and a hysteretic trapping model is also presented. The second part of this dissertation is a model validation and sensitivity study using coreflood simulation data derived from laboratory study. The motivation of this study is to gain confidence in the results of the numerical simulator by validating the models and the numerical accuracies using laboratory and field pilot scale results. Published steady state, core-scale CO2/brine displacement results were selected as a reference basis for our numerical study. High-resolution compositional simulations of brine displacement with supercritical CO2 are presented using IPARS. A three-dimensional (3D) numerical model of the Berea sandstone core was constructed using heterogeneous permeability and porosity distributions based on geostatistical data. The measured capillary pressure curve was scaled using the Leverett J-function to include local heterogeneity in the sub-core scale. Simulation results indicate that accurate representation of capillary pressure at sub-core scales is critical. Water drying and the shift in relative permeability had a significant impact on the final CO2 distribution along the core. This study provided insights into the role of heterogeneity in the final CO2 distribution, where a slight variation in porosity gives rise to a large variation in the CO2 saturation distribution. The third part of this study is a simulation study using IPARS for Cranfield pilot CO2 sequestration field test, conducted by the Bureau of Economic Geology (BEG) at The University of Texas at Austin. In this CO2 sequestration project, a total of approximately 2.5 million tons supercritical CO2 was injected into a deep saline aquifer about ~10000 ft deep over 2 years, beginning December 1st 2009. In this chapter, we use the simulation capabilities of IPARS to numerically model the CO2 injection process in Cranfield. We conducted a corresponding history-matching study and got good agreement with field observation. Extensive sensitivity studies were also conducted for CO2 trapping, fluid phase behavior, relative permeability, wettability, gravity and buoyancy, and capillary effects on sequestration. Simulation results are consistent with the observed CO2 breakthrough time at the first observation well. Numerical results are also consistent with bottomhole injection flowing pressure for the first 350 days before the rate increase. The abnormal pressure response with rate increase on day 350 indicates possible geomechanical issues, which can be represented in simulation using an induced fracture near the injection well. The recorded injection well bottomhole pressure data were successfully matched after modeling the fracture in the simulation model. Results also illustrate the importance of using accurate trapping models to predict CO2 immobilization behavior. The impact of CO2/brine relative permeability curves and trapping model on bottom-hole injection pressure is also demonstrated.
Book Synopsis Geological Sequestration of Carbon Dioxide by : Luigi Marini
Download or read book Geological Sequestration of Carbon Dioxide written by Luigi Marini and published by Elsevier. This book was released on 2006-10-12 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contents of this monograph are two-scope. First, it intends to provide a synthetic but complete account of the thermodynamic and kinetic foundations on which the reaction path modeling of geological CO2 sequestration is based. In particular, a great effort is devoted to review the thermodynamic properties of CO2 and of the CO2-H2O system and the interactions in the aqueous solution, the thermodynamic stability of solid product phases (by means of several stability plots and activity plots), the volumes of carbonation reactions, and especially the kinetics of dissolution/precipitation reactions of silicates, oxides, hydroxides, and carbonates. Second, it intends to show the reader how reaction path modeling of geological CO2 sequestration is carried out. To this purpose the well-known high-quality EQ3/6 software package is used. Setting up of computer simulations and obtained results are described in detail and used EQ3/6 input files are given to guide the reader step-by-step from the beginning to the end of these exercises. Finally, some examples of reaction-path- and reaction-transport-modeling taken from the available literature are presented. The results of these simulations are of fundamental importance to evaluate the amounts of potentially sequestered CO2, and their evolution with time, as well as the time changes of all the other relevant geochemical parameters (e.g., amounts of solid reactants and products, composition of the aqueous phase, pH, redox potential, effects on aquifer porosity). In other words, in this way we are able to predict what occurs when CO2 is injected into a deep aquifer.* Provides applications for investigating and predicting geological carbon dioxide sequestration* Reviews the geochemical literature in the field* Discusses the importance of geochemists in the multidisciplinary study of geological carbon dioxide sequestration
Book Synopsis Geochemical Interactions Between Supercritical CO2 and the Midale Formation I : Introduction to Fluid-rock Interaction Experiments by : C. A. Rochelle
Download or read book Geochemical Interactions Between Supercritical CO2 and the Midale Formation I : Introduction to Fluid-rock Interaction Experiments written by C. A. Rochelle and published by . This book was released on 2002 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Hydrocarbon Source Potential and Organic Geochemical Nature of Source Rocks and Crude Oils in the Illinois Basin by :
Download or read book Hydrocarbon Source Potential and Organic Geochemical Nature of Source Rocks and Crude Oils in the Illinois Basin written by and published by . This book was released on 1991 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Formation Damage Due to CO2 Sequestration in Saline Aquifers by : Ibrahim Mohamed Mohamed
Download or read book Formation Damage Due to CO2 Sequestration in Saline Aquifers written by Ibrahim Mohamed Mohamed and published by . This book was released on 2013 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon dioxide (CO2) sequestration is defined as the removal of gas that would be emitted into the atmosphere and its subsequent storage in a safe, sound place. CO2 sequestration in underground formations is currently being considered to reduce the amount of CO2 emitted into the atmosphere. However, a better understanding of the chemical and physical interactions between CO2, water, and formation rock is necessary before sequestration. These interactions can be evaluated by the change in mineral content in the water before and after injection, or from the change in well injectivity during CO2 injection. It may affect the permeability positively due to rock dissolution, or negatively due to precipitation. Several physical and chemical processes cover the CO2 injection operations; multiphase flow in porous media is represented by the flow of the brine and CO2, solute transportation is represented by CO2 dissolution in the brine forming weak carbonic acid, dissolution-deposition kinetics can be seen in the rock dissolution by the carbonic acid and the deposition of the reaction products, hydrodynamic instabilities due to displacement of less viscous brine with more viscous CO2 (viscous fingering), capillary effects and upward movement of CO2 due to gravity effect. The objective of the proposed work is to correlate the formation damage to the other variables, i.e. pressure, temperature, formation rock type, rock porosity, water composition, sulfates concentration in the water, CO2 volume injected, water volume injected, CO2 to water volumetric ratio, CO2 injection rate, and water injection rate. In order to achieve the proposed objective, lab experiments will be conducted on different rock types (carbonates, limestone and dolomite, and sandstone) under pressure and temperature that simulate the field conditions. CO2 will be used at the supercritical phase and different CO2-water-rock chemical interactions will be addressed. Quantitative analysis of the experimental results using a geochemical simulator (CMG-GEM) will also be performed. The results showed that for carbonate cores, maintaining the CO2/brine volumetric ratio above 1.0 reduced bicarbonate formation in the formation brine and helped in minimizing precipitation of calcium carbonate. Additionally, increasing cycle volume in WAG injection reduced the damage introduced to the core. Sulfate precipitation during CO2 sequestration was primarily controlled by temperature. For formation brine with high total dissolved solids (TDS), calcium sulfate precipitation occurs, even at a low sulfate concentration. For dolomite rock, temperature, injection flow rate, and injection scheme don't have a clear impact on the core permeability, the main factor that affects the change in core permeability is the initial core permeability. Sandstone cores showed significant damage; between 35% and 55% loss in core permeability was observed after CO2 injection. For shorter WAG injection the damage was higher; decreasing the brine volume injected per cycle, decreased the damage. At higher temperatures, 200 and 250°F, more damage was noted than at 70°F. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148153
Book Synopsis Impact of Carbon Dioxide Sequestration on Reservoir Brine Composition at an Enhanced Oil Recovery Site in Fayette County, Illinois by :
Download or read book Impact of Carbon Dioxide Sequestration on Reservoir Brine Composition at an Enhanced Oil Recovery Site in Fayette County, Illinois written by and published by . This book was released on 2010 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Mechanisms for CO2 Sequestration in Geological Formations and Enhanced Gas Recovery by : Roozbeh Khosrokhavar
Download or read book Mechanisms for CO2 Sequestration in Geological Formations and Enhanced Gas Recovery written by Roozbeh Khosrokhavar and published by Springer. This book was released on 2015-10-28 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives background information why shale formations in the world are important both for storage capacity and enhanced gas recovery (EGR). Part of this book investigates the sequestration capacity in geological formations and the mechanisms for the enhanced storage rate of CO2 in an underlying saline aquifer. The growing concern about global warming has increased interest in geological storage of carbon dioxide (CO2). The main mechanism of the enhancement, viz., the occurrence of gravity fingers, which are the vehicles of enhanced transport in saline aquifers, can be visualized using the Schlieren technique. In addition high pressure experiments confirmed that the storage rate is indeed enhanced in porous media. The book is appropriate for graduate students, researchers and advanced professionals in petroleum and chemical engineering. It provides the interested reader with in-depth insights into the possibilities and challenges of CO2 storage and the EGR prospect.
Book Synopsis Geologic Carbon Sequestration by : V. Vishal
Download or read book Geologic Carbon Sequestration written by V. Vishal and published by Springer. This book was released on 2016-05-11 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exclusive compilation written by eminent experts from more than ten countries, outlines the processes and methods for geologic sequestration in different sinks. It discusses and highlights the details of individual storage types, including recent advances in the science and technology of carbon storage. The topic is of immense interest to geoscientists, reservoir engineers, environmentalists and researchers from the scientific and industrial communities working on the methodologies for carbon dioxide storage. Increasing concentrations of anthropogenic carbon dioxide in the atmosphere are often held responsible for the rising temperature of the globe. Geologic sequestration prevents atmospheric release of the waste greenhouse gases by storing them underground for geologically significant periods of time. The book addresses the need for an understanding of carbon reservoir characteristics and behavior. Other book volumes on carbon capture, utilization and storage (CCUS) attempt to cover the entire process of CCUS, but the topic of geologic sequestration is not discussed in detail. This book focuses on the recent trends and up-to-date information on different storage rock types, ranging from deep saline aquifers to coal to basaltic formations.
Book Synopsis An Evaluation of the Carbon Sequestration Potential of the Cambro-Ordovician Strata of the Illinois and Michigan Basins by :
Download or read book An Evaluation of the Carbon Sequestration Potential of the Cambro-Ordovician Strata of the Illinois and Michigan Basins written by and published by . This book was released on 2014 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies summarized herein were conducted during 2009-2014 to investigate the utility of the Knox Group and St. Peter Sandstone deeply buried geologic strata for underground storage of carbon dioxide (CO2), a practice called CO2 sequestration (CCS). In the subsurface of the midwestern United States, the Knox and associated strata extend continuously over an area approaching 500,000 sq. km, about three times as large as the State of Illinois. Although parts of this region are underlain by the deeper Mt. Simon Sandstone, which has been proven by other Department of Energy-funded research as a resource for CCS, the Knox strata may be an additional CCS resource for some parts of the Midwest and may be the sole geologic storage (GS) resource for other parts. One group of studies assembles, analyzes, and presents regional-scale and point-scale geologic information that bears on the suitability of the geologic formations of the Knox for a CCS project. New geologic and geo-engineering information was developed through a small-scale test of CO2 injection into a part of the Knox, conducted in western Kentucky. These studies and tests establish the expectation that, at least in some locations, geologic formations within the Knox will (a) accept a commercial-scale flow rate of CO2 injected through a drilled well; (b) hold a commercial-scale mass of CO2 (at least 30 million tons) that is injected over decades; and (c) seal the injected CO2 within the injection formations for hundreds to thousands of years. In CCS literature, these three key CCS-related attributes are called injectivity, capacity, and containment. The regional-scale studies show that reservoir and seal properties adequate for commercial-scale CCS in a Knox reservoir are likely to extend generally throughout the Illinois and Michigan Basins. Information distinguishing less prospective subregions from more prospective fairways is included in this report. Another group of studies report the results of reservoir flow simulations that estimate the progress and outcomes of hypothetical CCS projects carried out within the Knox (particularly within the Potosi Dolomite subunit, which, in places, is highly permeable) and within the overlying St. Peter Sandstone. In these studies, the regional-scale information and a limited amount of detailed data from specific boreholes is used as the basis for modeling the CO2 injection process (dynamic modeling). The simulation studies were conducted progressively, with each successive study designed to refine the conclusions of the preceding one or to answer additional questions. The simulation studies conclude that at Decatur, Illinois or a geologically similar site, the Potosi Dolomite reservoir may provide adequate injectivity and capacity for commercial-scale injection through a single injection well. This conclusion depends on inferences from seismic-data attributes that certain highly permeable horizons observed in the wells represent laterally persistent, porous vuggy zones that are vertically more common than initially evident from wellbore data. Lateral persistence of vuggy zones is supported by isotopic evidence that the conditions that caused vug development (near-surface processes) were of regional rather than local scale. Other studies address aspects of executing and managing a CCS project that targets a Knox reservoir. These studies cover well drilling, public interactions, representation of datasets and conclusions using geographic information system (GIS) platforms, and risk management.
