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Item Beyond the Surface: Non-Invasive Low-Field NMR Analysis of Microbially-Induced Calcium Carbonate Precipitation in Shale Fractures(Springer Science and Business Media LLC, 2024-07) Willett, Matthew R.; Bedey, Kayla; Crandall, Dustin; Seymour, Joseph D.; Rutqvist, Jonny; Cunningham, Alfred B.; Phillips, Adrienne J.; Kirkland, Catherine M.Microbially-induced calcium carbonate precipitation (MICP) is a biological process in which microbially-produced urease enzymes convert urea and calcium into solid calcium carbonate (CaCO3) 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 ℃. 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 CaCO3 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.Item Beyond the Surface: Non-Invasive Low-Field NMR Analysis of Microbially-Induced Calcium Carbonate Precipitation in Shale Fractures(Springer Science and Business Media LLC, 2024-07) Willet, Matthew R.; Bedey, Kayla; Crandall, Dustin; Seymour, Joseph D.; Rutqvist, Jonny; Cunningham, Alfred B.; Phillips, Adrienne J.; Kirkland, Catherine M.Microbially-induced calcium carbonate precipitation (MICP) is a biological process in which microbially-produced urease enzymes convert urea and calcium into solid calcium carbonate (CaCO3) 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 ℃. 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 CaCO3 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.Item A thermochronological history of burial and exhumation at Kevin Dome, Northwest Montana including the origin of CO2 in Upper Devonian Duperow Formation and the Bakken Petroleum system at the Dome(Montana State University - Bozeman, College of Letters & Science, 2022) Adeniyi, Elijah Olusola; Chairperson, Graduate Committee: Mary S. Hubbard; This is a manuscript style paper that includes co-authored chapters.Kevin Dome is a geologic structure and historic hydrocarbon producer in northwest Montana. This structure is also a known CO 2 reservoir, yet its development has not been constrained with thermochronological techniques and the origin of the natural (~ 283 x 109 m 3) CO 2, of the Upper Devonian Duperow Formation, is not well understood. This work seeks to create a temporal understanding of the burial and exhumation history of Kevin Dome including the hydrocarbon generation and CO 2 emplacement. I constrained the burial and exhumation history at Kevin Dome with low-temperature thermochronology, carbonate clumped isotope thermometry, and thermobarometric proxies. I also tested for microbial, thermogenic, and magmatic CO 2 source(s) as well as CH 4 and N 2 gas sources at the dome with major gas composition, stable and noble gas isotopic geochemistry methods. I found that Kevin Dome rocks were buried to oil and gas generation windows before exhumation during the Late Cretaceous-Paleocene (~65 - 72Ma) and the Oligocene-Miocene (~ 15 - 26Ma) at an average rate of ~ 0.27 mm/yr. My study supports an evolved forebulge-dome origination model for Kevin Dome that is driven by the Late Cretaceous-Paleocene emplacement of the Rocky Mountain overthrust in a Foreland Basin setting in northwestern Montana (and proximal Canada) and an Oligocene-Miocene erosional or epeirogenic event not previously recognized in northwest Montana. I estimated ~4 - 5 km more overburden erosion than was previously thought in the region and suggest that the Oligocene-Miocene exhumation terminated hydrocarbon generation at Kevin Dome. In terms of CO 2 origin, my data supports a magmatic origin for the Duperow CO 2, with emplacement during the Sweetgrass Hills igneous complex intrusion(~52 Ma). I also found that the CH4 and N2 gases at Kevin Dome were mainly thermogenic in origin. A CO 2 solubility model showed that ~98% of the CO 2 has been dissolved into the groundwater in the Bakken petroleum system's hydrocarbon-bearing reservoirs at Kevin Dome during migration. I present a novel approach of integrating modern t-T sensitive techniques, stratigraphy, thermal maturity data, and isotopic geochemistry to address the structural development of sedimentary basins/domes, hydrocarbon generation, and magmatic CO 2 emplacement and subsequent evolution.Item Effects of tax credits on carbon capture and sequestration in a multi-phased model(Montana State University - Bozeman, College of Engineering, 2021) Strahan, Cooper Davis; Chairperson, Graduate Committee: Sean YawStudies have consistently shown that the increase of CO 2 in the atmosphere is correlated to rising temperatures. In order to stop the rise in global temperatures, climate change mitigation strategies will need to be deployed at scale. All of the plans that meet the goal of staying below 2 °C include CO 2 capture and storage (CCS) as one of those strategies. CCS is a climate change mitigation strategy aimed at reducing the amount of CO 2 vented into the atmosphere by capturing CO 2 emissions from industrial sources, transporting the CO 2 via a dedicated pipeline network, and injecting it into geologic reservoirs. Designing CCS infrastructure is a complex problem requiring concurrent optimization of source selection, reservoir selection, and pipeline routing decisions. Current CCS infrastructure design methods assume that project parameters including costs, capacities, and availability, remain constant throughout the project's lifespan. In this research, we introduce a novel, multi-phased, CCS infrastructure design model that allows for analysis of more complex scenarios that allow for variations in project parameters across distinct phases. We also apply this new model to a study exploring the impacts of modifying CCS tax credits on the economic viability of CCS projects.Item Scalable solutions to the carbon capture infrastructure problem(Montana State University - Bozeman, College of Engineering, 2020) Whitman, Caleb; Chairperson, Graduate Committee: Sean YawCO 2 capture and storage (CCS) is a climate change mitigation strategy that aims to reduce the amount of CO 2 vented into the atmosphere from industrial processes. Designing cost-effective CCS infrastructure is critical to meeting CO 2 emission reduction targets and is a computationally challenging problem. CCS infrastructure design is a generalization of the capacitated fixed charge network flow problem, CFCNF. CFCNF is NP-hard with no known approximation algorithms. In our work, we design three novel heuristics to solve CCS. We evaluate all heuristics on real life CCS infrastructure design data and find that they quickly generate solutions close to optimal. Decreasing the time it takes to determine CCS infrastructure designs will support national-level scenarios, undertaking risk and sensitivity assessments, and understanding the impact of government policies (e.g. 45Q tax credits for CCS).Item A study of bio-mineralization for the application of reducing leakage potential of geologically stored CO 2(Montana State University - Bozeman, College of Engineering, 2019) Daily, Ryanne Leigh; Chairperson, Graduate Committee: Adrienne PhillipsA primary concern of carbon capture and storage (CCS) is leakage of the stored carbon dioxide (CO 2) from the subsurface back to the surface. To ensure long term storage of the CO 2, mitigation strategies are being developed to seal high permeability regions, such as fractures present in the caprock or the near wellbore environment. Ureolysis induced calcium carbonate precipitation (UICP) is a widely investigated technology utilizing the enzymatically driven process of ureolysis to alter the properties of porous media. The advantage of this technology over traditional fracture sealing methods, such as well cement, is the use of low-viscosity aqueous fluids enabling access to smaller fractures. However, CCS reservoirs provide a problematic environment for microbial activity due to the acidity of dissolved CO 2, high pressures, and elevated temperatures. A flow-through pressurized reactor experiment and batch high-pressure ureolysis rate experiments were conducted to investigate the application of UICP technology to mitigate CO 2 migration. First, UICP was induced in two composite rock cores in an environment simulating a CCS reservoir, using a high-pressure axial flow reactor, with an initial and final exposure of the rock cores to a carbonated brine. As a result of UICP, the apparent permeability of the rock cores were reduced by 5-orders of magnitude. The CO 2 challenge increased apparent permeability by 4-orders of magnitude, likely due to a preferential flow path created through the calcium carbonate (CaCO 3) seal, which was found with X-ray microcomputed tomography (micro-CT) imaging. The porosity of the composite rock cores was assessed throughout the experiment with two non-invasive technologies, micro-CT and nuclear magnetic resonance (NMR), both reported a significant decrease in porosity due to UICP and a slight increase after the CO 2 exposure. Second, ureolysis kinetics were assessed in the presence of a pressurized carbonated brine at pressures between 0 and 4 MPa. The kinetic studies were performed in a high-pressure batch reactor connected to high-pressure pH and conductivity probes. Samples could not be taken from the batch reactor without losing pressure; thus, conductivity was used as a surrogate measurement for urea concentration. It was found that, for the pressures tested, JBM urease was capable of hydrolyzing urea in the presence of a pressurized carbonated brine. It was also hypothesized that the rate observed at each experimental pressure may have been dependent on the buffered pH of the system. The combination of these studies suggests that, if the challenge of dissolution could be overcome, bio-mineralization may be used to enhance CCS by reducing the permeability of CO 2 leakage pathways.Item An inventory of carbon stocks under native vegetation and farm fields in south-central Montana(Montana State University - Bozeman, College of Agriculture, 2015) Kisch, Hailey Rose; Chairperson, Graduate Committee: Clayton B. MarlowAnnually, carbon dioxide (CO 2) is emitted from the burning of fossil fuels, creating a CO 2 emission source. Vegetation and soils capture and store these emissions, however not nearly in the quantity being emitted. Disparity between sources and sinks of CO 2 emissions requires actions focused on reducing CO 2 emissions (CCSP, 2007). Cabin Creek Ranch, near Shepherd, MT offers a rich opportunity to understand the current carbon balance within various land cover types, and to determine the effect that cropping, grazing and concentrated feeding has on the potential for ranch soils to sequester additional carbon. Samples were collected from 30 soil and 16 vegetation locations, which were randomly chosen in a variety of cover types. Soil samples were taken every 15 cm throughout the soil profile (down to 100 cm, if possible). Four .25 m 2 frames were used to collect herbaceous material 25 meters in each cardinal direction from soil pit center. Clay and land cover type were found to have a significant interaction on the organic carbon content in the soils (p=0.021). Additionally, dryland crop was found to be significantly different in organic carbon content compared to other cover types (p<0.0001). Therefore, management towards a specific land cover type could help mitigate CO 2 emissions. For example, revegetating dryland crop fields to a native grassland, sagebrush or forest, the landscape would be able to store 230%, 232% and 256% more organic carbon, respectively. Understanding the carbon balance on the landscape scale contributes to understanding the global carbon balance to help mitigate burning of fossil fuels.Item A fiber optic array for the detection of sub-surface carbon dioxide at carbon sequestration sites(Montana State University - Bozeman, College of Engineering, 2014) Soukup, Benjamin John; Chairperson, Graduate Committee: Kevin S. RepaskyA fiber sensor array for sub-surface CO 2 concentrations measurements was developed for monitoring geologic carbon sequestration sites. The fiber sensor array uses a temperature-tunable distributed feedback (DFB) laser outputting a nominal wavelength of 2.004 microns. Light from this DFB laser is directed to one of the four probes via an in-line 1x4 fiber optic switch. Each of the probes is placed underground and utilizes filters that allow only soil gas to enter the probe. Light from the DFB laser interacts with CO 2 within the probe before being directed back through the switch. The DFB laser is tuned across two CO 2 absorption features where a transmission measurement is made, allowing the CO 2 concentration to be retrieved. This process is repeated for each probe, allowing CO 2 concentration measurements to be made as a function of time for each probe. The fiber sensor array was deployed for fifty-eight days at the Zero Emission Research Technology (ZERT) field site and for a twenty-eight day period at the Kevin Dome geologic carbon sequestration site. Background measurements indicate the instrument can monitor background levels as low as 1,000 parts per million (ppm). During a thirty-four day sub-surface CO 2 release, elevated CO 2 concentrations were readily detected by each of the four probes with values ranging to over 60,000 ppm.Item An investigation of the reactions of supercritical CO 2 and brine with the Berea sandstone, muscovite, and iron bearing minerals(Montana State University - Bozeman, College of Letters & Science, 2015) Mangini, Seth Alexander; Chairperson, Graduate Committee: Mark L. SkidmoreThe reduction of anthropogenic CO 2 emissions while still generating energy is a challenge that society faces. Most current energy production comes from fossil fuels that increase atmospheric CO 2 concentrations. Pending a breakthrough in clean energy production, technological solutions that increase efficiency and sequester CO 2 are required. Carbon Capture and Storage (CCS) or carbon sequestration technology can provide part of the solution by providing disposal of point source CO 2 emissions. The research described in this thesis aims to aid development of CCS technology. There are three parts to the thesis. First, is an experimental study of the Berea sandstone to determine the reactivity of its minerals, as these could impact its potential as a reservoir for CO 2 storage. Cores of Berea were placed in a "flow-through reactor" that pumped a continuous stream of supercritical CO 2 (scCO 2) mixed with simulated groundwater through the rock. Chemical and physical changes to the solid, liquid and gas phases were monitored. Second, batch experiments were conducted to study the behavior of pyrite, magnetite, hematite, and muscovite when subjected to simulated groundwater and scCO 2. Third, is an outcrop study of the Devonian Jefferson Formation, a carbonate formation to serve as an analog to the same formation in the subsurface where it is the target of a Department of Energy CCS pilot project. The field study provided analysis of the mineralogy, sedimentology, and stratigraphy so as to better understand its potential as a reservoir for CO 2 storage. The flow-through experiments on the Berea sandstone demonstrated that carbonate cement and iron oxides were reactive phases. It was equivocal as to whether muscovite was reactive. The batch experiments quantified the reactivity of iron oxides and pyrite and demonstrated significant dissolution of the scCO 2, such that supercritical conditions were not maintained for the duration of the experiment. The batch experiments also showed that muscovite was not reactive within the time frame of the Berea flow-through experiments (72 hours), but was reactive over longer time periods (500+ hours). The field study indicated that the best potential reservoir zones of the Jefferson Formation are altered reef complexes composed mostly of dolomite.Item NMR studies of supercritical CO 2 in carbon sequestration and immiscible two phase flow in porous media(Montana State University - Bozeman, College of Engineering, 2015) Prather, Cody Allen; Chairperson, Graduate Committee: Sarah L. CoddNuclear magnetic resonance (NMR) was used to research mechanisms related to two-phase flow in porous media. Experiments were conducted to further understand; 1) the capillary trapping mechanism that occurs during sequestration of CO 2 in deep underground sandstone reservoirs, 2) the viscous fingering phenomena that occurs when scCO 2 convectively dissolves in brine under reservoir conditions, and 3) flow patterns and fluid mechanisms in immiscible two-phase flow in porous media for the two pressure gradient regimes formed under different capillary numbers. Capillary trapping is a prominent mechanism for initially trapping CO 2 in pore structures of deep underground rock formations during the sequestration process. Because of its significant role in securing CO 2 underground, it is important to characterize and understand the residual saturation and distribution of CO 2 within the pore structure. A setup was developed in which drainage and imbibition of a Berea Sandstone core takes place within an NMR spectrometer under reservoir conditions. NMR results provide comparisons between the different nonwetting fluids used and help characterize the capillary trapping of each nonwetting fluid. In conclusion, scCO 2 is trapped 13% less efficiently than air or CO 2, and the nonwetting fluid is preferentially trapped in larger pores. Viscous fingering is a significant long-term trapping mechanism that further increases storage security by enhancing mass transfer through convective dissolution. A setup was developed in which scCO 2 could dissolve into a water saturated bead pack, under reservoir conditions, within the NMR spectrometer. NMR results track spatial changes in T 2 relaxation time and signal intensity. The results are inconclusive and the phenomena could not be directly observed but results do suggest dissolution is occurring during the experiment. Immiscible two-phase flow in porous media is unpredictable and existent in many industries. Therefore, determining flow patterns and understanding the fluid mechanisms from a capillary number/pressure gradient relationship could prove valuable. A setup was developed in which an immiscible two-phase flow through a bead pack was monitored, for different capillary numbers, with NMR techniques. NMR results provide snapshots of the water saturation distribution within the bead pack. The results suggest there's a consistent slug-type flow pattern during the steady state.
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