George D Guthrie

• PhD
• Los Alamos National Laboratory

Humankind has lived with the danger of endemic, epidemic and pandemic disease for thousands of years. The effects of these outbreaks have often devastated human populations. Sixteen pandemic events causing an estimated 147 million deaths have occurred since the eighth century, The Black Death and the influenza pandemic of 1918-1920 probably having...

Hydrocarbon production from shale reservoirs is inherently inefficient and challenging since these are low permeability plays. In addition, there is a limited understanding of the fundamentals and the controlling mechanisms, further complicating how to optimize these plays. Herein, we summarize our experimental and computational efforts to reveal u...

Characterizing fluid flow in a porous material with permeability is fundamental to energy and hydrological applications, yet direct measurements of permeability are very difficult to conduct in situ. However, attending fluid flow through a material are various mechanical responses, e.g., strain fields, acoustic emission. These mechanical responses...

We present a novel workflow for forecasting production in unconventional reservoirs using reduced-order models and machine-learning. Our physics-informed machine-learning workflow addresses the challenges to real-time reservoir management in unconventionals, namely the lack of data (i.e., the time-frame for which the wells have been producing), and...

The risk of infection associated with occupations can, and does, extend to certain leisure and sports activities. Generally, such pastimes are regarded as important for human health and mental wellbeing. However, infections may, rarely, be acquired during leisure activities that include water sports and water-related relaxation, and certain sports.

Historically, the weighing out and manipulation of dangerous chemicals frequently occurred without adequate protection from inhalation or accidental ingestion. The use of gloves, eye protection using goggles, masks or visors was scant. From Canary Girls and chimney sweeps to miners, stone cutters and silo fillers, these are classic exemplars of the...

Laboratory-acquired infections are as old as laboratories themselves. As soon as the culture of microorganisms was introduced, so too was their transfer to laboratory workers. It is only in relatively recent history that such infections have been fully understood, and methods of spread and their prevention or avoidance developed. This paper endeavo...

Mineral precipitation within hydraulically fractured shale may affect fluid flow pathways and impact long-term hydrocarbon production. The ability to predict geochemical reactions causing problematic mineral precipitation will lead to active reservoir management strategies for improving production. Using the Marcellus Shale as a case study, laborat...

The geochemical and isotopic characteristics of groundwaters in Chimayó, New Mexico, reflect processes that affect water quality in the Tesuque Aquifer, which overlies a leaking natural CO2 source in a structurally complex region. In this study, select isotopes (δ¹³C, ⁸⁷Sr/⁸⁶Sr, ²³⁴U/²³⁸U) are applied to groundwaters to better understand CO2 transp...

The international commitments for atmospheric carbon reduction will require a rapid increase in carbon capture and storage (CCS) projects. The key to any successful CCS project lies in the long term storage and prevention of leakage of stored carbon dioxide (CO 2). In addition to being a greenhouse gas, CO 2 leaks reaching the surface can accumulat...

Due to international commitments on carbon capture and storage (CCS), an increase in CCS projects is expected in the near future. Saline aquifers and depleted hydrocarbon reservoirs with good seals and located in tectonically stable zones make an excellent storage formation option for geological carbon sequestration. However, stored carbon dioxide...

We present constant-flow experiments of high-pressure CO2-saturated fluid through fracture channels in Portland cement with three different fracture geometries and with three different flow rates. The experiments were conducted in etched cement wafers within a microfluidics device. The evolution of pH was observed optically using phenolphthalein dy...

One of the main purposes of hydraulic fracturing in unconventional resources such as shale is to improve the connectivity between existing natural fractures and the production well. Since the inherent permeability of shale is extremely low, this newly formed fracture connectivity provides faster paths for the hydrocarbon stored in preexisting natur...

Multiphase flow is ubiquitous in subsurface energy applications and natural processes, such as oil recovery, CO2 sequestration, and water flow in soils. Despite its importance, we still lack a thorough understanding of the coupling of multiphase flow and reaction of transported fluids with the confining media, including rock dissolution and mineral...

We present a physics-informed machine learning (PIML) workflow for real-time unconventional reservoir management. Reduced-order physics and high-fidelity physics model simulations, lab-scale and sparse field-scale data, and machine learning (ML) models are developed and combined for real-time forecasting through this PIML workflow. These forecasts...

In carbon capture and sequestration (also known as carbon capture and storage, or CCS), developing effective monitoring methods is needed to detect and respond to CO2 leakage. CO2 leakage detection methods rely on geophysical observations and monitoring sensor network. However, traditional methods usually require the development of site-specific ph...

Experiment 2 of the EGS Collab project is aimed at testing stimulation by hydro-shearing of existing natural fractures, versus Experiment 1, which is focused on hydraulic fracturing a rock mass to enhance permeability. The main criterion for the testbed selection in Experiment 2 is the presence of an interconnected network of fractures, at least 10...

Experimental difficulties and safety issues while working with H2S under acid gas exposure conditions (HPHT) have greatly limited the understanding of their impacts on wellbore integrity. To address this, an experimental study was designed to prepare and maintain H2S gas and H2S –containing fluids exposure experiments under relevant subsurface cond...

We present an approach based on machine learning (ML) to distinguish eruption and precursory signals of Chimayó geyser (New Mexico, U.S.A.) under noisy environmental conditions. This geyser can be considered a natural analog of CO 2 intrusion into shallow water aquifers. By studying this geyser, we can understand upwelling of CO 2 -rich fluids from...

Science of Carbon Storage in Deep Saline Formations: Process Coupling across Time and Spatial Scales summarizes state-of-the-art research, emphasizing how the coupling of physical and chemical processes as subsurface systems re-equilibrate during and after the injection of CO2. In addition, it addresses, in an easy-to-follow way, the lack of knowle...

In carbon capture and sequestration, building an effective monitoring method is a crucial step to detect and respond to CO2 leakage. CO2 leakage detection methods rely on geophysical observations and monitoring sensor network. However, traditional methods usually require physical models to be interpreted by experts, and the accuracy of these method...

In carbon capture and sequestration (also known as carbon capture and storage, or CCS), developing effective monitoring methods is needed to detect and respond to CO2 leakage. CO2 leakage detection methods rely on geophysical observations and monitoring sensor network. However, traditional methods usually require development of site-specific physic...

Tracer tests are standard methods for characterizing flow paths along connected high-permeability zones in the subsurface. In this study, we propose a fast and simple method to analyze tracer tests from the DOE's EGS Collab project, and feed the characterized flow paths back into thermal breakthrough predictions. In this project, two phases of cont...

We present an approach based on machine learning (ML) to distinguish eruption and precursory signals of Chimay\'{o} geyser (New Mexico, USA) under noisy environments. This geyser can be considered as a natural analog of $\mathrm{CO}_2$ intrusion into shallow water aquifers. By studying this geyser, we can understand upwelling of $\mathrm{CO}_2$-ric...

This study analyzes the dynamics and mechanisms of the interactions of carbonated brine with hydrated-Portland-cement; in particular, the study focuses on self-sealing, a process whereby hydrated-Portland cement reacts with carbonated brine to for silica and calcium carbonate in sufficient quantities to seal the flow pathway. The analysis is based...

Molecular dynamics simulations using classical force fields were carried out to study energetic and structural properties of rotationally disordered clay mineral-water-CO2 systems at pressure and temperature relevant to geological carbon storage. The simulations show that turbostratic stacking of hydrated Na- and Ca-montmorillonite and hydrated mon...

Multiphase Gibbs ensemble Monte Carlo simulations were carried out to compute the free energy of swelling for Na-montmorillonite and Na-beidellite interacting with CO2 and H2O at pressure and temperature conditions relevant for geological storage aquifers. The calculated swelling free energy curves show stable monolayer and bilayer configurations o...

The objective of the EGS Collab project is to establish a suite of intermediate-scale (~10-20 m) field test beds coupled with stimulation and interwell flow tests to provide a basis to better understand fracture stimulation methods, resulting fracture geometries, and processes that control heat transfer between rock and stimulated fractures. Experi...

Conventional seismic techniques for detecting the subsurface geologic features are challenged by limited data coverage, computational inefficiency, and subjective human factors. We developed a novel data-driven geological feature detection approach based on pre-stack seismic measurements. Our detection method employs an efficient and accurate machi...

Conventional seismic techniques for detecting the subsurface geologic features are challenged by limited data coverage, computational inefficiency, and subjective human factors. We developed a novel data-driven geological feature detection approach based on pre-stack seismic measurements. Our detection method employs an efficient and accurate machi...

The Area of Review is one of the most important aspects of a geologic CO2 storage site permit application and regulatory requirement. The US Environmental Protection Agency (EPA) has implemented an Area of Review (AoR) requirement for Class VI CO2 injection wells for geologic sequestration. Reservoir permeability is one of the most important parame...

Managing risks at geologic CO2 storage sites requires making decisions based on the quantitative predictions of long-term performance that not only take into account various subsurface hydrologic, geochemical processes and interactions but also the related uncertainties. The US DOE (United States Department of Energy) funded National Risk Assessmen...

Carbon capture and storage (CCS) technologies provide effective options for reducing carbon dioxide (CO2) emissions and mitigating global climate change. Geologic CO2 storage involves the injection of supercritical CO2 into deep geologic formations overlain by sealing formations and geologic traps that prevent the CO2 from escaping. The ability of...

Hydraulic fracturing applied to organic-rich shales has significantly increased the recoverable volume of methane available for U.S. energy consumption. Fluid-shale reactions in the reservoir may affect long-term reservoir productivity and waste management needs through changes to fracture mineral composition and produced fluid chemical composition...

While the majority of shale formations will serve as reservoir seals for stored anthropogenic carbon dioxide (CO2), hydrocarbon-bearing shale formations may be potential geologic sinks after depletion through primary production. Here we present the United States-Department of Energy-National Energy Technology Laboratory (US-DOE-NETL) methodology fo...

The US DOE-funded National Risk Assessment Partnership (NRAP) has developed an integrated assessment model (NRAP-IAM-CS) that can be used to simulate carbon dioxide (CO 2) injection, migration, and associated impacts at a geologic carbon storage site. The model, NRAP-IAM-CS, incorporates a system-modeling-based approach while taking into account th...

The goal of this paper is to assess the utility of Reduced-Order Models (ROMs) developed from 3D physics-based models for predicting transient thermal power output for an enhanced geothermal reservoir while explicitly accounting for uncertainties in the subsurface system and site-specific details. Numerical simulations are performed based on Latin...

The goal of this paper is to assess the utility of Reduced-Order Models (ROMs) developed from 3D physics-based models for predicting transient thermal power output for an enhanced geothermal reservoir while explicitly accounting for uncertainties in the subsurface system and site-specific details. Numerical simulations are performed based on Latin...

Enhanced Geothermal Systems (EGS) present a significant and long-term opportunity for widespread power production from new geothermal sources. EGS approach makes it possible to tap otherwise inaccessible thermal resources in areas that lack traditional geothermal systems. It is estimated that within the USA alone the electricity production potentia...

A new conceptual model is developed for ASR formation based on geochemical principles tied to aqueous speciation, silica solubility, kinetically controlled mineral dissolution, and diffusion. ASR development is driven largely by pH and silica gradients that establish geochemical microenvironments between paste and aggregate, with gradients the stro...

Carbon capture, utilization and storage (CCUS) in saline reservoirs in sedimentary formations has the potential to reduce the impact of fossil fuel combustion on climate change by reducing CO2 emissions to the atmosphere and storing the CO2 in geologic formations in perpetuity. At pressure and temperature (PT) conditions relevant to CCUS, CO2 is le...

Multiphase Gibbs ensemble Monte Carlo simulations were carried out to compute the free energy of swelling for Na-montmorillonite and Na-beidellite interacting with CO2 and H2O at pressure and temperature conditions relevant for geological storage aquifers. The calculated swelling free energy curves show stable monolayer and bilayer configurations o...

We use a reactive diffusion model to investigate what happens to CO2 injected into a subsurface sandstone reservoir capped by a chlorite- and illite-containing shale seal. The calculations simulate reaction and transport of supercritical (SC) CO2 at 348.15 K and 30 MPa up to 20,000 a. Given the low shale porosity (5%), chemical reactions mostly occ...

The United States Department of Energy's National Energy Technology Laboratory (DOE-NETL) is developing a volumetric- based methodology for calculating prospective CO2 storage resource of organic-rich shale formations. Similar to natural gas, carbon dioxide (CO2) can be stored in organic-rich shale as free-gas within fractures and pores and as a so...

Risk assessment for geologic CO2 storage including quantification of risks is an area of active investigation. The National Risk Assessment Partnership (NRAP) is a US-Department of Energy (US-DOE) effort focused on developing a defensible, science-based methodology and platform for quantifying risk profiles at geologic CO2 sequestration sites. NRAP...

One concern regarding unconventional hydrocarbon production from organic-rich shale is that hydraulic fracture stimulation could create pathways that allow injected fluids and deep brines from the target formation or adjacent units to migrate upward into shallow drinking water aquifers. This study presents Sr isotope and geochemical data from a wel...

Molecular dynamics simulations using classical force fields were carried out to study energetic and structural properties of rotationally disordered clay mineral-water-CO2 systems at pressure and temperature relevant to geological carbon storage. The simulations show that turbostratic stacking of hydrated Na- and Ca-montmorillonite and hydrated mon...

The National Risk Assessment Partnership (NRAP) is a US-Department of Energy (US-DOE) effort focused on developing a science-based methodology for quantifying risk profiles at geologic CO2 sequestration sites. Risk profiles are calculated using an integrated assessment modelling (IAM) approach which treats a geologic CO2 storage site as a system an...

Improved understanding of basic fluid-rock interactions can lead to more accurate models of the coupled fluid-flow and geomechanics in engineered geological systems. We studied carbon dioxide (CO2) interaction with source clay samples from The Clay Minerals Society. The manometric, infrared (IR) and X-ray diffraction (XRD) data indicated that montm...

Among the many scenarios that have been proposed to reduce the amount of carbon dioxide (CO2) emissions to the atmosphere, carbon-capture and storage (CCS) in geological reservoirs represents the method most technologically feasible and capable of accommodating the large amounts of CO2 that are generated on an annual basis by combustion of fossil f...

In nature the structures of the expandable clay minerals can deviate from ideal layer-stacking and form turbostratic structures, where layers can be twisted by a certain degree relatively each other. Rotation of one layer relative to the adjacent layer creates an interlayer structure that is defined by the Moiré pattern formed by the ditrigonal rin...

Preliminary estimates of CO2 storage potential in geologic formations provide critical information related to Carbon Capture, Utilization, and Storage (CCUS) technologies to mitigate CO2 emissions. Currently multiple methods to estimate CO2 storage and multiple storage estimates for saline formations have been published, leading to potential uncert...

Natural isotope tracers, such as strontium (Sr), can facilitate the tracking of brine migration caused by CO2 injection in carbon storage sites and assist in identifying the origin of formation waters associated with oil and gas exploration. However, it might be necessary to analyze tens of samples with complex chemical compositions over a short pe...

It is challenging to predict the degree to which shallow groundwater might be affected by leaks from a CO2 sequestration reservoir, particularly over long time scales and large spatial scales. In this study observations at a CO2 enriched shallow aquifer natural analog were used to develop a predictive model which is then used to simulate leakage sc...

One idea for mitigating the increase in fossil-fuel generated CO2 in the atmosphere is to inject CO2 into subsurface saline sandstone reservoirs. To decide whether to try such sequestration at a globally significant scale will require the ability to predict the fate of injected CO2. Thus, models are needed to predict the rates and extents of subsur...

Experimental Preliminary Findings: • Marcellus CO2 sorption capacity ranges from 50 to 325 SCF/short ton; • Organic rich facies have highest CO and methane; • CO2 sorptive capacity – both correlate strongly to sample TOC and not to clay content; • CO2/CH4 sorption ratio ranges from 1.32 to 4.20; • Hysteresis in shale permeability as a function of n...

Concern about the role of greenhouse gases in global climate change has generated interest in sequestering CO(2) from fossil-fuel combustion in deep saline formations. Pore space in these formations is initially filled with brine, and space to accommodate injected CO(2) must be generated by displacing brine, and to a lesser extent by compression of...

A vital aspect to public and regulatory acceptance of carbon sequestration is assurance that groundwater resources will be protected. Theoretical and laboratory studies can, to some extent, be used to predict the consequences of leakage. However, direct observations of CO2 flowing through shallow drinking water aquifers are invaluable for informing...

Laboratory experiments were performed in order to determine the alteration in cement exposed to acid gas (H2S–CO2) and pure CO2 under simulated reservoir conditions. Cement samples were exposed for a period of 28 days at a temperature of 50 °C and a pressure of 15 MPa using pure CO2 and H2S–CO2 (21 mol% H2S) to simulate acid gas. The cement samples...

This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in...

Interfaces play a critical role in many geochemical and clay mineral processes. Adsorption, dissolution, precipitation, nucleation, and growth mechanisms, in particular, are controlled by the dynamic interplay of structure, thermodynamics, kinetics, and transport at the clay mineral-water interface. These mechanistic details are typically beyond th...

Understanding of physical and chemical reactivity of clay-bearing materials with regard to the CO2 sequestration in geological formations is critical for validation of the field-scale reactive transport models. The clay mineral content can play an important role in defining both the reservoir storage capacity and trapping mechanisms and the sealing...

In this paperwe describe CO2-PENS, a comprehensive system-level computational model for performance assessment of geologic sequestration of CO2. CO2-PENS is designed to perform probabilistic simulations of CO2 capture, transport, and injection in different geologic reservoirs. Additionally, the long-term fate of CO2 injected in geologic formations,...

This article was submitted without an abstract, please refer to the full-text PDF file.

This article was submitted without an abstract, please refer to the full-text PDF file.

Sequestration of CO2 in geologic reservoirs is one of the promising technologies currently being explored to mitigate anthropogenic CO2 emissions. Large-scale deployment of geologic sequestration will require seals with a cumulative area amounting to hundreds of square kilometers per year and will require a large number of sequestration sites. We a...

Reactions and reaction rates within aquifers are fundamental components of critical hydrological processes. However, reactions simulated in laboratory experiments typically demonstrate rates that are much faster than those observed in the field. Therefore, it is necessary to conduct more reaction rate analyses in natural settings. This study of geo...

A core sample including casing, cement, and shale caprock was obtained from a 30-year old CO2-flooding operation at the SACROC Unit, located in West Texas. The core was investigated as part of a program to evaluate the integrity of Portland-cement based wellbore systems in CO2-sequestration environments. The recovered cement had air permeabilities...

Melanophlogite, a clathrasit, possesses a framework of corner-linked silica tetrahedra forming framework cavities that can enclose small guest molecules. Synchrotron X-ray diffraction experiments of the guest-free melanophlogite have been conducted at pressures up to 12 GPa and temperatures up to 1473 K. Upon compression at room temperature, melano...

The Zero Emissions Research and Technology (ZERT) project at the Los Alamos National Laboratory is studying the injection of CO2 into geologic repositories. We are formulating the problem as science based decision framework that can address issues of risk, cost, and technical requirements at all stages of the sequestration process. The framework, c...

Long-term integrity of wellbore cements is one of the major concerns for geologic sequestration of CO2. This paper presents analyses of cement core recovered from a well used in a long-term CO2 enhanced oil recovery operation. A sidetrack system was used to obtain core from a 55 year-old well with 30 years of CO2 exposure as both an injector and a...

Large-scale implementation of geologic storage in the U.S. implies seals with a cumulative area amounting to hundreds of square kilometers per year and will require a large number of storage sites. These factors highlight the need for a robust and reliable method for evaluating the suitability of specific sites to ensure that they will perform to r...

The Zero Emissions Research and Technology (ZERT) project at the Los Alamos National Laboratory is studying the injection of CO2 into geologic repositories. We are formulating the problem as science based decision framework that can address issues of risk, cost, and technical requirements at all stages of the sequestration process. The framework is...

Introduction Fossil fuels produce CO 2 , which is a significant greenhouse gas that contributes to global warming. Environmentally benign use of fossil fuels requires that CO 2 be captured and sequestered. The reactivity of CO 2 with minerals is important to several sequestration strategies. These include aboveground mineralization in which mined r...

Unless the economic development of the majority of the world's population is prohibited, thereby forcing thereby forcing them to remain in poverty, world energy consumption and therefore carbon dioxide greenhouse gas emission rates could easily increase by an order of magnitude during this century. Given that we have already increased global atmosp...

We present an update on the development of technologies required for the Zero Emission Carbon (ZEC) concept being pursued by ZECA Corporation. The concept has a highly integrated design involving hydrogasification, a calcium oxide driven reforming step that includes simultaneous C02 separation, coal compatible fuel cells for electricity production...

In this report, the authors evaluate the resource potential of extractable magnesium from ultramafic bodies located in Vermont, the Pennsylvania-Maryland-District-of-Columbia (PA-MD-DC) region, western North Carolina, and southwestern Puerto Rico. The first three regions occur in the Appalachian Mountains and contain the most attractive deposits in...

The catalytic hydrocracking (HC) of diphenylmethane (DPM) and hydrodesulfurization (HDS) of dibenzothiophene (DBT) over Ni, Mo, and Ni–Mo sulfide catalysts supported on a mixed ultrastable Y (USY) zeolite and γ-Al2O3 were studied. The catalysts were characterized using NH3 temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (X...

A geochemical method for staining various products of the alkali-silica reaction is presented. The method is based on both the composition of alkali-silica-reaction (ASR) gel and one of its properties (the ability to exchange cations with a fluid). Specifically, one stain (sodium cobaltinitrite) reacts with exchangeable potassium in the gel to form...

This guide is designed to familiarize scientists with the geology, structure, alteration, and fluids typical of California serpentinites for purposes of carbon dioxide sequestration (Lackner et al., 1995). Goff et al. (1997) and Goff and Lackner (1998) describe the geology and geochemistry of some of the serpentinites from this area. Mechanisms of...

This paper presents a geochemical method for staining various products of the alkali-silica reaction. The method is based on both the composition of ASR gel and one of its properties (the ability to exchange cations with a fluid). The stained concrete can be observed in normal light and serves as both a rapid field screening method and a useful aid...

A method using concentrated aqueous solutions of sodium cobalt nitrite and rhodamine B is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR). These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-r...

Fossil fuels continue to provide major sources of energy to the modern world even though global emissions of CO{sub 2} are presently at levels of 19 Gt/yr. Future antipollution measures may include sequestering of waste CO{sub 2} as magnesite (MgCO{sub 3}) by processing ultramafic rocks to obtain reactable Mg. Huge ultramafic deposits consisting of...