Search NASA⌕ Search

SEARCH · Search NASA

Results for “subsurface flow”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

The Big Group of People Looking at How to Control Putting the Parts of the Air That Are the Same as What You Breathe Out Into Small Spaces in Rocks

Representing the Nanoscale Control of Geologic CO2 (NCGC), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of NCGC is to build a fundamental understanding of molecular-to-pore-scale processes in fluid-rock systems, and to demonstrate the ability to control critical aspects of flow, transport, and mineralization in porous rock media as applied to the injection and storage of carbon dioxide (CO2) in subsurface reservoirs.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2018

Assessment of Multiple Monitoring Methods for Detection of Brine and CO2 Leakage

We assess the effectiveness of four surface-based geophysical methods and in situ monitoring of pressure and chemical changes for detecting brine and CO2 leakage from legacy wells into underground sources of drinking water (USDW) overlying a CO2 storage reservoir. This is the first such effort to evaluate and compare six monitoring methods for detection of CO2 leakage. This assessment, conducted in support of the USDOE National Risk Assessment Partnership (NRAP), utilizes 3000 synthetic data sets, generated in an uncertainty quantification (UQ) model framework. This framework combines the results of (1) a CO2 storage reservoir model of a hypothetical storage operation of 5 MT/yr for 50 years into the 1700-m deep Vedder Fm. at a site near Kimberlina, California with (2) wellbore leakage models of a legacy well and (3) multi-phase flow and reactive transport models of brine and CO2 plume migration in aquifer layers overlying the storage reservoir. Leakage drives subsurface changes, quantified by pressure plumes, CO2-saturation plumes, and total dissolved solids (TDS) plumes, the latter being related to changes in pH and species concentrations. Depending on the depth of leakage, aquifer permeability, and regional groundwater gradient, pressure plume volumes can become larger than the CO2 and TDS plumes; however, reaching detectable thresholds may take too long to be useful. For a single monitoring well located 500 m downgradient of a leaky legacy well, a depth of 570 m is found to be optimal for sampling pressure and chemical changes. We assess four surface-based geophysical monitoring methods: electrical resistivity tomography (ERT), magnetotellurics (MT), gravity, and seismic methods. Sensors cover a 4-km × 2-km area. Both ERT and MT methods are sensitive to changes in CO2 saturation and TDS concentration, whereas gravity and seismic methods detect changes in CO2 saturation. The six monitoring methods complement each other in space and time, and we find that a minimum of 20 kT of CO2 leakage is required for the leakage plume to be detected. Of the four surface-based geophysical methods, gravity monitoring appears to be the most sensitive to CO2 leaks, while the usefulness of in situ pressure and chemical monitoring will depend on the level of unfilterable background noise. Geophysical monitoring methods may detect a leak anywhere in a large area and in a large depth range, but the effectiveness of pressure and chemical monitoring depends on the number of monitoring wells, where those wells are located, and the depth of sampling. Surface-based geophysical monitoring methods are cost-effective alternatives to in situ pressure and chemical monitoring methods.

NRAP, CCS, monitoring, geophysical methods, gravit↗
DOE OSTI2022

Development of lean, efficient, and fast physics-framed deep-learning-based proxy models for subsurface carbon storage

In this work, we present deep-learning-based surrogate models for CCUS developed with four different algorithms and a physics-framed two-phase flow problem involving displacement of water by CO 2 . The deep-learning models were trained using 3D datasets describing the pressure plume, CO 2 saturation plume, and water extraction rate generated by numerical simulation. The hyperparameters defining the architecture of the neural networks were optimized to determine the slimmest network size and training parameters that give the most efficient performance at the least training cost. To develop a robust model that closely mimics the governing physical laws, the discretized form of the two-phase fluid transport equation was used to formulate the supervised deep-learning task. The algorithms investigated in this study predicted the data to above 95% accuracy, with the multi-layer perceptron model demonstrating the best performance by balancing training speed, prediction time, and prediction accuracy with lean network capacity. Furthermore, the surrogate models simultaneously predict reservoir pressure and CO 2 saturation in every grid block, including the surface well extraction rate and bottomhole pressure, at all simulation times for a given static model realization in just a few seconds on a standard desktop computer. A key outcome of this study is that limits can be placed on network design parameters to avoid over designing neural networks, with associated efficiencies in training and prediction times. This is very useful because large volumes of data may be generated in CCUS projects and over-design of neural network architectures imposes penalties that are antithetical to the goal of near-real time forecasting.

58 GEOSCIENCES↗
DOE OSTI2015

Uniaxial Creep as a Control on Mercury Intrusion Capillary Pressure in Consolidating Rock Salt

The nature of geologic disposal of nuclear waste in salt formations requires validated and verified two-phase flow models of transport of brine and gas through intact, damaged, and consolidating crushed salt. Such models exist in other realms of subsurface engineering for other lithologic classes (oil and gas, carbon sequestration etc. for clastics and carbonates) but have never been experimentally validated and parameterized for salt repository scenarios or performance assessment. Models for waste release scenarios in salt back-fill require phenomenological expressions for capillary pressure and relative permeability that are expected to change with degree of consolidation, and require experimental measurement to parameterize and validate. This report describes a preliminary assessment of the influence of consolidation (i.e. volume strain or porosity) on capillary entry pressure in two phase systems using mercury injection capillary pressure (MICP). This is to both determine the potential usefulness of the mercury intrusion porosimetry method, but also to enable a better experimental design for these tests. Salt consolidation experiments are performed using novel titanium oedometers, or uniaxial compression cells often used in soil mechanics, using sieved run-of-mine salt from the Waste Isolation Pilot Plant (WIPP) as starting material. Twelve tests are performed with various starting amounts of brine pore saturation, with axial stresses up to 6.2 MPa (~900 psi) and temperatures to 90°C. This corresponds to UFD Work Package 15SN08180211 milestone “FY:15 Transport Properties of Run-of-Mine Salt Backfill – Unconsolidated to Consolidated”. Samples exposed to uniaxial compression undergo time-dependent consolidation, or creep, to various degrees. Creep volume strain-time relations obey simple log-time behavior through the range of porosities (~50 to 2% as measured); creep strain rate increases with temperature and applied stress as expected. Mercury porosimetry is used to determine characteristic capillary pressure curves from a series of consolidation tests and show characteristic saturation-capillary pressure curves that follow the common van Genuchten (1978, 1980) formulation at low stresses. Higher capillary pressure data are suspect due to the large potential for sample damage, including fluid inclusion decrepitation and pore collapse. Data are supportive of use of the Leverett “J” function (Leverett, 1941) to use for scaling characteristic curves at different degrees of consolidation, but better permeability determinations are needed to support this hypothesis. Recommendations for further and refined testing are made with the goal of developing a self- consistent set of constitutive laws for granular salt consolidation and multiphase (brine-air) flow.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Interfacial and Activation Energies of Environmentally Abundant Heterogeneously Nucleated Iron(III) (Hydr)oxide on Quartz

Poorly crystalline iron(III) (hydr)oxide nanoparticles are ubiquitous in environmental systems and play a crucial role in controlling the fate and transport of contaminants. Yet, the thermodynamic and kinetic parameters, e.g., the effective interfacial (α^') and apparent activation (E a ) energies, of iron(III) (hydr)oxide nucleation on earth-abundant mineral surfaces have not been determined, which hinders an accurate prediction of iron(III) (hydr)oxide formation and its interactions with other toxic or reactive ions. Here, for the first time, we report experimentally obtained α^' and E a for iron(III) (hydr)oxide nucleation on quartz mineral surfaces, by employing a flow-through, time-resolved grazing incidence small angle X-ray scattering (GISAXS). GISAXS enabled the in situ detection of iron(III) (hydr)oxide nucleation rates under different supersaturations (σ, achieved by varying pH 3.3-3.6) and temperatures (12-35ºC). By quantitative analyses based on classical nucleation theory, α^' was obtained to be 34.6 mJ/m 2 and E a was quantified as 32.8 kJ/mol. The fundamental thermodynamic and kinetic parameters obtained here will advance our fundamental understanding of the surface chemistry and nucleation behavior of iron(III) (hydr)oxides in subsurface and water treatment systems, as well as their effects on the fate and transport of pollutants in natural and engineered water systems. The in situ flow-through GISAXS method can also be adapted to quantify thermodynamic and kinetic parameters at interfaces for many important solid–liquid environmental systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Can Simple Machine Learning Tools Extend and Improve Temperature-Based Methods to Infer Streambed Flux?

Temperature-based methods have been developed to infer 1D vertical exchange flux between a stream and the subsurface. Current analyses rely on fitting physically based analytical and numerical models to temperature time series measured at multiple depths to infer daily average flux. These methods have seen wide use in hydrologic science despite strong simplifying assumptions including a lack of consideration of model structural error or the impacts of multidimensional flow or the impacts of transient streambed hydraulic properties. We performed a “perfect-model experiment” investigation to examine whether regression trees, with and without gradient boosting, can extract sufficient information from model-generated subsurface temperature time series, with and without added measurement error, to infer the corresponding exchange flux time series at the streambed surface. Using model-generated, synthetic data allowed us to assess the basic limitations to the use of machine learning; further examination of real data is only warranted if the method can be shown to perform well under these ideal conditions. We also examined whether the inherent feature importance analyses of tree-based machine learning methods can be used to optimize monitoring networks for exchange flux inference.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Beyond the Surface: Non-Invasive Low-Field NMR Analysis of Microbially-Induced Calcium Carbonate Precipitation in Shale Fractures

Microbially-induced calcium carbonate precipitation (MICP) is a biological process in which microbially-produced urease enzymes convert urea and calcium into solid calcium carbonate (CaCO 3 ) deposits. MICP has been demonstrated to reduce permeability in shale fractures under elevated pressures, raising the possibility of applying this technology to enhance shale reservoir storage safety. For this and other applications to become a reality, non-invasive tools are needed to determine how effectively MICP seals shale fractures at subsurface temperatures. In this study, two different MICP strategies were tested on 2.54 cm diameter and 5.08 cm long shale cores with a single fracture at 60 °C. Flow-through, pulsed-flow MICP-treatment was repeatedly applied to Marcellus shale fractures with and without sand (“proppant”) until reaching approximately four orders of magnitude reduction in apparent permeability, while a single application of polymer-based “immersion” MICP-treatment was applied to an Eagle Ford shale fracture with proppant. Low-field nuclear magnetic resonance (LF-NMR) and X-Ray computed microtomography (micro-CT) techniques were used to assess the degree of biomineralization. With the flow-through approach, these tools revealed that while CaCO 3 precipitation occurred throughout the fracture, there was preferential precipitation around proppant. Without proppant, the same approach led to premature sealing at the inlet side of the core. In contrast, immersion MICP-treatment sealed off the fracture edges and showed less mineral precipitation overall. This study highlights the use of LF-NMR relaxometry in characterizing fracture sealing and can help guide NMR logging tools in subsurface remediation efforts.

MICP↗
DOE OSTI2013

Modeling of Microbially Induced Calcite Precipitation for the Immobilization of Strontium-90 Using a Variable Velocity Streamtube Ensemble (Final Technical Report)

Biogeochemical modeling using PHREEQC2 and a streamtube ensemble approach is utilized to understand a well-to-well subsurface treatment system at the Vadose Zone Research Park (VZRP) near Idaho Falls, Idaho. Treatment involves in situ microbially-mediated ureolysis to induce calcite precipitation for the immobilization of strontium-90. PHREEQC2 is utilized to model the kinetically-controlled ureolysis and consequent calcite precipitation. Reaction kinetics, equilibrium phases, and cation exchange are used within PHREEQC2 to track pH and levels of calcium, ammonium, urea, and calcite precipitation over time, within a series of one-dimensional advective-dispersive transport paths creating a streamtube ensemble representation of the well-to-well transport. An understanding of the impact of physical heterogeneities within this radial flowfield is critical for remediation design; we address this via the streamtube approach: instead of depicting spatial extents of solutes in the subsurface we focus on their arrival distribution at the control well(s). Traditionally, each streamtube maintains uniform velocity; however in radial flow in homogeneous media, the velocity within any given streamtube is spatially-variable in a common way, being highest at the input and output wells and approaching a minimum at the midpoint between the wells. This idealized velocity variability is of significance in the case of ureolytically driven calcite precipitation. Streamtube velocity patterns for any particular configuration of injection and withdrawal wells are available as explicit calculations from potential theory, and also from particle tracking programs. To approximate the actual spatial distribution of velocity along streamtubes, we assume idealized radial non-uniform velocity associated with homogeneous media. This is implemented in PHREEQC2 via a non-uniform spatial discretization within each streamtube that honors both the streamtube’s travel time and the idealized “fast-slow-fast” pattern of non-uniform velocity along the streamline. Breakthrough curves produced by each simulation are weighted by the path-respective flux fractions (obtained by deconvolution of tracer tests conducted at the VZRP) to obtain the flux-average of flow contributions to the observation well.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Effect of Formation Heterogeneity on CO 2 Dissolution in Subsurface Porous Media

Dissolution trapping is one of the most dominant mechanisms for the secure storage of CO 2 injected in porous subsurface formations saturated with brine. This trapping mechanism is enhanced by convective mixing, which occurs due to the gravitational instability between the different fluid layers in the aquifer. The reservoir permeability also plays a crucial role in the dissolution rate and overall fluid flow dynamics during the density-driven convection in porous media. Herein this study investigates the role of complex heterogeneity, i.e., irregular permeability distribution in CO 2 dissolution, using a novel experimental approach to create medium permeability heterogeneity in Hele–Shaw cells. Complex subsurface transport phenomena such as a preferential dissolution path, CO 2 sweep efficiency, changes in finger morphology, and CO 2 concentration distribution are visualized by creating heterogeneous media. Experimental results showed that reservoir permeability heterogeneity causes significant channeling effects and poor sweep efficiency. A scaling relationship between average finger growth rate (Gr) and permeability (k) was obtained as Gr [m s –1 ] = 266.8k [m 2 ] + 1.20 × 10 –6 . Furthermore, the mass of CO 2 dissolved is calculated using the spectrophotometric method to characterize the convective instability. The convective flux was analyzed by comparing the experimental dissolution flux with the theoretical diffusion flux, calculating a maximum Sherwood number of 6.8. The study’s findings improve the current understanding of the CO 2 convection morphology in heterogeneous media, allowing better assessment of long-term CO 2 storage.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

A Multiple Lines of Evidence Approach for Conceptual Site Models in Performance Assessments - 19070

Demonstration of the long-term performance of remediated radioactive waste sites relies on models that evaluate vadose zone and groundwater flow and contaminant transport for thousands of years. Model qualification, verification, and comparisons with data are essential elements to demonstrating the accuracy of long-term performance assessments (PAs). However, comparisons with data are generally limited due to incomplete characterization data and long-time scales. Since PAs support decision making to assure long-term protection of both human health and the environment, a conceptual site model (CSM) is needed to explain the hydrodynamic behavior and account for subsurface heterogeneities in sufficient detail to support confident decisions. In the case of the Waste Management Area (WMA) C PA, where the focus of the effort is on characterizing flow and transport through a thick vadose zone, site-specific data are sparse and larger-scale geologic descriptions are adopted with the risk of losing small scale features that may affect contaminant transport. Features such as horizontal bedding and sloping interfaces between contrasting material types, as well as vertically oriented features such as clastic dikes, may be difficult to delineate from sparse characterization data, but may affect the extent to which contaminants are transported. The PA conducted to identify long-term impacts associated with the closure of the single-shell tank (SST) farm at WMA C adopted an equivalent homogenous medium approach to represent the major stratigraphic units at the site. This approach explicitly represents major stratigraphic units but assigns hydraulic properties that implicitly account for the presence of small-scale heterogeneities and their impact on flow and contaminant transport to the groundwater. The objective of this study is to evaluate the available site-specific and analogue data that can be used to characterize heterogeneity and to assess its impact on fate and transport of contaminants that may lead to different conclusions when compared to the results of the equivalent homogeneous media approach. To this end, a multiple lines of evidence approach was used to construct alternative CSMs based on an evaluation of several types of data. These data include 1) general characteristics and features of the major stratigraphic units from historical descriptions; 2) borehole geologic logs; 3) particle size distribution measurements; 4) moisture content measurements; 5) spectral gamma data; and 6) concentrations of key constituents (i.e., Tc-99) in both the vadose zone and groundwater impacted by past releases. Based on an analysis of the available data, lines of evidence are evaluated for consistency and integrated in a consistent manner into scientifically defensible CSMs. Numerical models are then used to evaluate the impact that the explicit representation of heterogeneities has on contaminant transport. Together, the field data and the numerical modeling results indicate that heterogeneity caused by the small-scale features do not have a significant (i.e. greater than a factor of 2) impact on transport below WMA C relative to peak concentrations and arrival times for potential releases from waste tanks. The results of this study underscore the value of using multiple lines of evidence based on the quantity and quality of available data in developing alternative CSMs and evaluating their relative impact on key transport metrics such as arrival times and peak concentration. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Consensus Equilibrium for Subsurface Delineation

Heterogeneity and insufficient site characterization limit our knowledge of the subsurface. Inversion techniques, which minimize the mismatch between observations and model predictions, have become an essential tool of subsurface characterization. Most optimization-based approaches fail to incorporate various implicit priors and capture the geological complexity. We overcome these limitations by deploying the plug-and-play and consensus equilibrium (CE) strategies, which provide a flexible framework for image reconstruction. Our CE methodology for spatial delineation of geologic formations consists of an image denoiser and a variational auto-encoder (deep learning-based emulator). The former ameliorates the reconstruction noise, yielding well-defined geological structures; its mathematical equivalence with the proximal operator allows the deployment of advanced denoisers (e.g., CNN-based denoiser) that do not correspond to a regularization objective. The latter defines a geology prior that imposes a geological constraint, for example, continuity and shape of geological features, onto the reconstructed image. Here, we conduct a series of numerical experiments dealing with transient two-dimensional flow driven by a pumping well and natural hydraulic head gradient. They demonstrate the CE framework's ability to delineate, both probabilistically and deterministically, complex subsurface environments with sufficient quality.

42 ENGINEERING↗
DOE OSTI2016

Multifluid geo-energy systems: Using geologic CO 2 storage for geothermal energy production and grid-scale energy storage in sedimentary basins

We present an approach that uses the huge fluid and thermal storage capacity of the subsurface, together with geologic carbon dioxide (CO 2 ) storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources, as well as excess energy on electric grids. Captured CO 2 is injected into saline aquifers to store pressure, generate artesian flow of brine, and provide a supplemental working fluid for efficient heat extraction and power conversion. Concentric rings of injection and production wells create a hydraulic mound to store pressure, CO 2 , and thermal energy. This energy storage can take excess power from the grid and excess/waste thermal energy, and dispatch that energy when it is demanded and thus enable higher penetration of variable renewable energy technologies (e.g., wind, solar). CO 2 stored in the subsurface functions as a cushion gas to provide enormous pressure-storage capacity and displace large quantities of brine, some of which can be treated for a variety of beneficial uses. Geothermal power and energy-storage applications may generate enough revenues to compensate for CO 2 capture costs. While our approach can use nitrogen (N 2 ), in addition to CO 2 , as a supplemental fluid, and store thermal energy, this study focuses using CO 2 for geothermal energy production and grid-scale energy storage. We conduct a techno-economic assessment to determine the levelized cost of electricity of using this approach to generate geothermal power. We present a reservoir pressure-management strategy that diverts a small portion of the produced brine for beneficial consumptive use to reduce the pumping cost of fluid recirculation, while reducing the risk of seismicity, caprock fracture, and CO 2 leakage.

15 GEOTHERMAL ENERGY↗
DOE OSTI2020

Petrographic and spectral study of hydrothermal mineralization in drill core from Hawaii: A potential analog to alteration in the martian subsurface

Abstract Continuous rock core was collected for 1764 m (5786’) on the Pohakuloa Army Training base near the center of the big island of Hawaii. The core traverses basaltic lava flows from the volcano's shield-building phase, and perched aquifers and higher temperature groundwaters were encountered. The collected samples record water-rock interactions of basaltic materials in a setting that may be a model for groundwater interactions on Mars. We collected visible and infrared point spectra of materials in the lowest portion of the core, where alteration was noted to become more prominent. We identified three types of phyllosilicate spectral signatures and three types of zeolites. The phyllosilicates show similarity to those identified on Mars using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Based on the field survey, 25 depths were selected for sampling and petrographic analysis of thin sections. The spectral data and thin section work have a strong agreement in the types of materials identified by the two different techniques. Both the spectral and petrographic data indicate low to moderate temperature geothermal alteration occurred in the lower half of the core. The field spectra are a useful reconnaissance tool for selecting mineralogic diversity for subsequent higher resolution and more time-consuming laboratory analysis.

Geochemistry & Geophysics↗
DOE OSTI2019

Feasibility Assessment of Long-Term Electrical Resistivity Monitoring of a Nitrate Plume

Long-term monitoring solutions at contaminated sites are necessary to track plume migration and evaluate the performance of remediation efforts. Electrical resistivity imaging (ERI) can potentially provide information about plume dynamics; however, the feasibility and likelihood of success is seldom evaluated before conducting a field study. Coupling flow and transport models with geoelectrical models provides a powerful way to assess the potential effectiveness of an actual ERI field campaign. in this paper, we present a coupled approach for evaluating the feasibility of monitoring nitrate migration and remediation using 4D time-lapse ERI at a legacy nuclear waste facility. This kilometer-scale study focuses on depths below the water table (~70 m). A flow and transport model is developed to perform simulations of nitrate migration and removal via a hypothetical pump-and-treat system. A tracer injection is also simulated at the leading edge of the nitrate plume to enhance the conductivity contrast between the native subsurface and the groundwater fluids. Images of bulk conductivity provide limited information concerning plume migration while time-lapse difference images, which remove the static effects of geology, provide more useful information concerning plume dynamics over time. A spatial moment analysis performed on flow and transport and ERI models matches well during the tracer injection; however, inversion regularization smoothing otherwise limits the value in terms of locating the center of mass. We find that the addition of a tracer enables ERI to characterize plume dynamics during pump-and-treat operations, and late-time ERI monitoring provides a conservative estimate of nitrate plume boundaries in this synthetic study.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Drake passage and central american seaway controls on the distribution of the oceanic carbon reservoir

A coupled carbon/climate model is used to explore the impact of Drake Passage opening and Central American Seaway closure on the distribution of carbon in the global oceans. We find that gateway evolution likely played an important role in setting the modern day distribution of oceanic dissolved inorganic carbon (DIC), which is currently characterized by relatively low concentrations in the Atlantic ocean, and high concentrations in the Southern, Indian, and Pacific oceans. In agreement with previous studies, we find a closed Drake Passage in the presence of an open Central American Seaway results in suppressed Atlantic meridional overturning and enhanced southern hemispheric deep convection. Opening of the Drake Passage triggers Antarctic Circumpolar Current flow and a weak Atlantic meridional overturning circulation (AMOC). Subsequent Central American Seaway closure reinforces the AMOC while also stagnating equatorial Pacific subsurface waters. These gateway-derived oceanographic changes are reflected in large shifts to the global distribution of DIC. An initially closed Drake Passage results in high DIC concentrations in the Atlantic and Arctic oceans, and lower DIC concentrations in the Pacific/Indian/Southern oceans. Opening Drake Passage reverses this gradient by lowering mid-depth Atlantic and Arctic DIC concentrations and raising deep Pacific/Indian/Southern Ocean DIC concentrations. Central American Seaway closure further reinforces this trend through additional Atlantic mid-depth DIC decreases, as well as Pacific mid-depth DIC concentration increases, with the net effect being a transition to a modern distribution of oceanic DIC.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

GEOS: A performance portable multi-physics simulation framework for subsurface applications

GEOS is a simulation framework focused on solving tightly coupled multi-physics problems with an initial emphasis on subsurface reservoir applications. Currently, GEOS supports capabilities for studying carbon sequestration, geothermal energy, hydrogen storage, and related subsurface applications. The unique aspect of GEOS that differentiates it from existing reservoir simulators is the ability to simulate tightly coupled compositional flow, poromechanics, fault slip, fracture propagation, and thermal effects, etc. Extensive documentation is available on the GEOS documentation pages (GEOS Documentation, 2024). Note that GEOS, as presented here, is a complete rewrite of the previous incarnation of the GEOS referred to in (Settgast et al., 2017).

58 GEOSCIENCES↗
DOE OSTI2019

Tracking Diverse Minerals, Hungry Organisms, and Dangerous Contaminants Using Reactive Transport Models

Beneath our feet is a fascinating world of flowing water, cosmopolitan microbes, and complex mineral assemblages. Yet we see none of it from above. Our quest to investigate these complex subsurface interactions has led to the development of reactive transport models. These are computer algorithms that allow us to explore, in a virtual way, the natural dynamics of Earth's systems and our anthropogenic impact on those systems. Here, we explain the concepts behind reactive transport models—which include the transport of aqueous species and the descriptions of biogeochemical reactions involving solutes, surfaces and microorganisms—and introduce to reactive transport applications in terrestrial and marine environments.

58 GEOSCIENCES↗
DOE OSTI2024

Carbon Storage Core Characterization Efforts at NETL

The multi-scale Computed Tomography (CT) and core flow facility in the Geocharacterization Laboratory at NETL, Morgantown yields porosity, permeability, and fracture properties of rock core samples obtained from the subsurface while maintaining the integrity of the sample. Additionally, geophysical bulk rock properties are analyzed with the laboratory’s GeoTEK multi-sensor core logger in a comparable fashion to downhole methods. NETL researchers collaborate with stakeholders within the carbon storage, oil and gas, and critical minerals sectors. Since 2017, over 1.88 miles of core have been analyzed within the laboratory and all data is publicly available through the Technical Report Series (TRS) on the Energy Data eXchange (EDX). Additionally, the website, RokBase, was curated to extrapolate and visualize the high-resolution data from field operations. The characterization of the Lively Grove #1 (LG#1) well provides a case study into the full capabilities of the Geocharacterization Laboratory. During the comprehensive study of LG#1 ~1-2 mm in diameter, vertical to bedding, cylindrical structures were identified throughout the St. Peter Formation. These structures are pervasive throughout the St. Peter Formation at depth and are characterized as the trace fossil, Skolithos.

Isom, Shelby L↗