Continued evaluation of potential for geologic storage of carbon dioxide in the southeastern United States

Southern States Energy Board Duke Energy Santee Cooper Power Southern CompanyBureau of Economic Geolog

Frio Brine Pilot: lessons learned and questions restated

Bureau of Economic Geolog

Expert-based development of a standard in CO2 sequestration monitoring technology

Bureau of Economic Geolog

Stratigraphy of Bedded Halite in the Permian San Andres Formation, Units 4 and 5, Palo Duro Basin, Texas

Seven cored wells through the bedded halite of the San Andres Formation have allowed an unusual, detailed analysis of the fabrics in halite. A descriptive classification system identified eight textural types of halite. These are: chevron halite rock, color-banded/vertically oriented halite rock, chaotic mudstone-halite rock, equant muddy halite rock, equant anhydritic halite rock, displacive halite in other sediments, cavity-filling halite cement, and fibrous fracture-filling halite cement. Genetic interpretation of the depositional environment in which halite textures formed resulted from analysis of the relationships between textures and comparison to ancient, modern, and experimental halite analogs. Chevron and color-banded/vertically oriented halite are recognized as textures formed subaqueously as halite precipitated on the floor of brine pools. Chaotic mudstone-halite rock, equant muddy halite rock, equant anhydritic halite rock are recognized as diagenetic alteration products formed by karstification and diagenetic recrystallization occurring at least partly in the subaerial environment. Displacive halite in other sediments, cavity-filling halite cement, and fibrous fracture-filling halite cement are products of precipitation of halite within the sediment during early diagenesis. Very detailed logging of the halite fabrics and anhydrite and mudstone interbeds and partings in the seven cored wells allowed correlation on a meter scale between cores. A basin-wide pattern of alternation between zones of anhydritic halite with preserved brine pool fabrics and zones of halite with mudstone interbeds and altered textures was identified. These alternating zones can be traced as much as 100 km between the wells, providing evidence that the entire study area was one broad low relief evaporitic shelf. Net mud maps of the muddy intervals suggest that the geometry of mudstone beds might be broad, poorly-defined lobes. Isopachs of the anhydrite interbeds show variation in the facies pattern in each genetic cycle. Some anhydrite beds thicken toward southern Swisher County, while others are thickest to the west, in Deaf Smith County.Bureau of Economic Geolog

Non-converging hysteretic cycles in random spin networks

Behavior of hysteretic trajectories for cyclical input is investigated as a function of the internal structure of a system modeled by the classical random network of binary spins. Different regimes of hysteretic behavior are discovered for different network connectivity and topology. Surprisingly, hysteretic trajectories which do not converge at all are observed. They are shown to be associated with the presence of specific topological elements in the network structure, particularly with the fully interconnected spin groups of size equal or greater than 4.Comment: 4 pages, 3 figure

Evaluation of Preferential Flow in Playa Settings Near the Pantex Plant

Analysis of water movement through the unsaturated zone is critical for understanding recharge and contaminant transport at DOE's Pantex Plant. Although preferential flow pathways such as root tubules, cracks, and fissures (Seven, 1991) may not be important volumetrically from a groundwater recharge standpoint, such flow may play a critical role in rapidly transporting contaminants to the groundwater and bypassing much of the soil matrix. Previous studies found that flow along preferential pathways may be up to two orders of magnitude higher than that predicted by homogeneous flow models (Richard and Steenhuis, 1988). In order to accurately evaluate pathways for contaminant transport, it is necessary to understand the spatial distribution of preferential flow pathways. The objective of this study was to delineate the spatial distribution of preferential pathways and evaluate the controls on such pathways.Bureau of Economic Geolog

Continuous pressure monitoring for large volume CO2 injections

Elevated formation fluid pressure resulting from large-volume injection of carbon dioxide (CO2) for sequestration is a key factor affecting storage seal integrity (containment risk) and ultimate capacity. Current methods for predicting pressure evolution (e.g. natural gas storage, EOR, groundwater withdrawal/recharge) have unique considerations (temporal cyclicity, associated production) and have only recently been applied for the injected volumes, durations, and extents of sequestration projects. Monitoring pressure dynamics (buildup during injection and subsequent falloff upon cessation) is a fundamental and relatively inexpensive technique for monitoring storage performance. Our research employs multiple numerical techniques to predict the evolution of pressure within reservoirs and to evaluate the potential impact on confining systems (seals), thus constraining site-specific sequestration storage integrity and capacity. We focus on the use of pressure measurements for pragmatic integrative monitoring of reservoir, seal, and well performance. The results presented here focus on real-time pressure and temperature evolution in a dedicated observation well, combining observations from both the injection interval and a monitoring interval 120 m higher for early detection of unanticipated migration out of the injection zone via wellbores or confining system. Results indicate that for the Cranfield reservoir, increases (and by inference, decreases corresponding to pressure loss due to out of zone migration) in injection rates of 100’s of tons per day are observable from less than a kilometer distance from the source.Bureau of Economic Geolog

Potential sinks for geologic storage of carbon dioxide generated by power plants in North and South Carolina

Duke Energy Progress Energy Santee Cooper Power SCANA CorporationBureau of Economic Geolog

Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain

Large thermal changes driven by a magnetic field have been proposed for environmentally friendly energy efficient refrigeration, but only a few materials which suffer hysteresis show these giant magnetocaloric effects. Here we create giant and reversible extrinsic magnetocaloric effects in epitaxial films of the ferromagnetic manganite La0.7Ca0.3MnO3 using strain mediated feedback from BaTiO3 substrates near a first-order structural phase transition. Our findings should inspire the discovery of giant magnetocaloric effects in a wide range of magnetic materials, and the parallel development of nanostructured bulk samples for practical applications.Comment: 32 pages, 1 Table, 5 figures, supplementary informatio

Thermodynamics of interacting magnetic nanoparticles

We apply the concepts of stochastic thermodynamics combined with transition-state theory to develop a framework for evaluating local heat distributions across the assemblies of interacting magnetic nanoparticles (MPs) subject to time-varying external magnetic fields. We show that additivity of entropy production in the particle state-space allows separating the entropy contributions and evaluating the heat produced by the individual MPs despite interactions. Using MP chains as a model system for convenience, without losing generality, we show that the presence of dipolar interactions leads to significant heat distributions across the chains. Our study also suggests that the typically used hysteresis loops cannot be used as a measure of energy dissipation at the local particle level within MP clusters, aggregates, or assemblies, and explicit evaluation of entropy production based on appropriate theory, such as developed here, becomes necessary