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  • Quantification of the vertical and lateral heterogeneity of distal submarine-lobe deposits, Wolfcamp formation, Delaware Basin, Texas: implications for subsurface lateral prediction

    Jobe, Zane R.; Aguada, Leonela; Desjardins, Patricio; French, Marsha (Colorado School of Mines. Arthur Lakes Library, 2023)
    Submarine-lobe deposits host important archives of paleo-environmental change and are major targets for exploring and producing hydrocarbons. Traditional conceptualizations of submarine-lobe architecture typically exhibit a systematic decrease in bed thickness, grain size, sand content, and amalgamation from proximal to distal and axis to fringe. However, contemporary interests in these submarine environments, driven by petroleum explorations and carbon sequestration endeavors, have unveiled complex lateral heterogeneities. This research presents a quantitative bed-scale analysis of core data from the Gas Technology Institute Hydraulic Fracturing Test Site 2 within the Wolfcamp A Formation, Delaware Basin. The study concentrates on correlating vertical and slant core datasets to delineate the vertical and lateral variability and event-bed architecture within a mixed carbonate-siliciclastic sea-floor fan. Data sets from two wells have been provided for this study: (1) A vertical well and (2) a slant well which include well log data, CT scans, core photos, and XRF data. They are situated 380.6 ft and 1007.2 ft apart for the studied interval, ideal for the quantification of lateral heterogeneity in a significantly short distance. Furthermore, this study investigates the correlation between CT-scan data and rock composition, assessing the utility of CT-scan technology in conjunction with XRF data and compositional proxies—Vcarb, Vsil, and Vclay—in heterogeneity analysis. Additionally, the potential of basic Machine Learning techniques for predicting rock composition is also explored (see Appendix). For the vertical heterogeneity quantification 20 distinct lithofacies were grouped into four Facies Associations (FA-1, FA-2, FA-3, FA-4). Our findings indicate a dominance of Facies FA-3, consisting mainly of pelagites and hemipelagites, followed by Facies FA-1, characterized by Hybrid Event Beds (HEBs), FA-4, composed of hemipelagites influenced by bottom currents and dilute turbidites, and FA-2, featuring turbidite deposits. Among the HEBs, the H3 deposits were the most prevalent, and are characterized by calcium-rich layers at the bottom that progressively transition to silica-dominant layers upwards. Regarding the lateral heterogeneity, this innovative approach highlights considerable differences in event-bed and background layer thickness and composition over relatively short distances. Trends revealed that background layers diminished in thickness approaching the slant well, whereas event-bed deposits became thinner closer to the vertical well. In addition, the interpreted intervals (A and B) were divided into seven depositional lobe elements, defined by compositional, thickness, and stacking pattern variances. These elements - Axis, Off-axis, frontal fringe, and distal fringe zones - demonstrated specific compositional trends. The distal fringes revealed a gradual shift towards silica-rich sediments, whereas the frontal fringes showed a transition to calcium-rich sediments. The central axis and off-axis regions were predominantly characterized by calcium-rich deposits, whereas the frontal fringes showed a transition from calcium-rich to mixed-deposits. The distal fringes revealed a shift from mixed-deposits towards silica-rich deposits. These findings underscore the complex dynamics of sedimentary deposition and its implications for petroleum exploration and developing strategies.
  • Investigating Li-ion battery species dynamics with operando FTIR spectroscopy

    Porter, Jason M.; Meyer, Lydia; Kee, R. J.; Wolden, Colin Andrew; DeCaluwe, Steven C. (Colorado School of Mines. Arthur Lakes Library, 2023)
    Lithium concentration polarization and slow ionic transport hinder fast charging of electric vehicle batteries and can cause cell degradation. Although pseudo-2D (P2D) models capture concentration polarization phenomena during fast charging, experimental measurements of Li-ion concentration have been limited. In this research, we collect operando optical measurements of Li-ion concentration in a graphite/NMC811 full cell with attenuated total reflection (ATR) and Fourier transform infrared spectroscopy (FTIR). To make these measurements, we have developed an optically accessible operando battery that enables real-time measurements of Li-ion concentration during cycling at fast charging rates. We measured significant Li-ion concentration changes during charging at 1C, 2C, and 3C, as well as discharging at C/2 and compared these results with a P2D model. Both the model and the experiments showed Li-ion depletion and rapid Li-ion concentration fluctuations that indicate non-ideal behavior during cycling. This research enables novel Li-ion concentration measurements with FTIR. This research also provides validation of P2D model physics for measuring and analyzing Li-ion concentration polarization at fast charging rates.
  • Production performance of Permian Basin wells and potential for improving oil recovery

    Kazemi, Hossein; Sonnenberg, Stephen A.; Uzun, Ilker Ozan; Düzgün, H. Sebnem; Miskimins, Jennifer L.; Wu, Yu-Shu; Sarg, J. F. (J. Frederick) (Colorado School of Mines. Arthur Lakes Library, 2023)
    The Permian Basin is one of the most prolific oil and gas-producing geologic basins in the United States. The Permian Basin is located in West Texas and Southeastern New Mexico. It has supplied more than 33.4 billion barrels of oil and 118 Tcf of natural gas during a 100-year period (EIA 2022). The ever-increasing water production and usage (e.g., hydraulic fracture stimulation) in the Permian Basin requires produced water management by the operators. Oil recovery from shale reservoirs is a very slow process because of the extremely low permeability of oil-containing pores, with the ultimate oil recovery of around 3 to 8%. Classical waterflooding or gas flooding in unconventional reservoirs is not plausible because of the small pore size and low permeability of the shale matrices. Therefore, creative approaches are needed to increase oil production without relying on large quantities of water injection to enhance oil production, which became the motivation for my research with the objective to integrate geology, fluid flow theory, experimental data, and reservoir modeling to assess production performance and enhance hydrocarbon recovery in the Permian basin. Injecting rich gas or CO2 in such formations in a cyclic fashion (the huff-n-puff process) increases oil recovery substantially but is expensive because of gas compression and injection equipment. Another alternative is to use solvent-containing water in a cyclic fashion (e.g., solutions of ketones and ethoxylated alcohols). Using brine-containing 3-pentanone or surfactant-based solutions results in much additional oil recoveries by cleaning the micro- and macro-fracture flow paths in the stimulated reservoir volume. In this study, the efficacy of injecting a brine solution containing a very small amount of 3-pentanone or a non-ionic surfactant (0.5 to 1.5 percent) determined to enhance oil recovery (EOR). The aqueous EOR huff-n-puff method is more cost-effective and easier to apply than the gas injection huff-n-puff process for the Wolfcamp formation in the Permian Basin. As an initial review of Wolfcamp formation, the production data for wells drilled into the Wolfcamp Formation of the Delaware Basin between 2012 and 2021 was reviewed and organized. A set of bubble maps to identify and visualize cumulative oil, gas, and water production changes was created. The maps showed the maturity of the basin where gas-prone wells are the majority in the northern and northwestern parts, and the southern area is more oil-prone. The wells drilled in Lea, Loving, and East-Reeves counties show the most oil production in one year of production. The gas production is highest in Culberson, North Reeves, and Loving counties. Furthermore, water production is significant throughout the region regardless of the produced hydrocarbon type. Wettability measurements (i.e., contact angles and wettability indices) and the associated water-rock capillary pressures reflect the interactions between the reservoir rock and the pore fluids, which, in turn, strongly affects the distribution of fluids in the reservoir pores. Consequently, I conducted contact angle experiments on five different unconventional reservoir formations across the US and measured interfacial tension (IFT) between oil and brine from the associated formations. Furthermore, I conducted contact angle experiments on the Wolfcamp formation rock samples using ketone and surfactant solutions. For engineering analysis, first, a static geologic model utilizing well-logs and core data was built on Petrel. Subsequently, the aforementioned static model was used to construct a compositional dual-porosity reservoir model using the CMG-GEM commercial reservoir modeling software in conjunction with the experiments. Second, Rate Transient Analysis (RTA) to determine the stimulated permeabilities associated with the hydraulic fracture stimulation was conducted. Next, Wolfcamp PVT report were evaluated and used to build a reservoir fluid model with CMG’s Winprop module. Finally, the compositional reservoir model was history match the field production data to validate the model. After the numerical model was ascertained by history matching, three distinct enhanced oil recovery (EOR) techniques, the huff-n-puff gas injection, ketone solution injection, and surfactant solution injection were implemented for the selected well. Afterward, a sensitivity analysis was conducted to determine the characteristics that had the most significant influence on the reservoir performance of the well in the three enhanced oil recovery (EOR) scenarios. A broad conclusion is that the use of ketone solutions resulted in a significant increase in oil production, while injection rate magnitude and period, soaking period, and solvent concentration affected the magnitude of the incremental oil recovery outcome.
  • Enhancing energy system design and dispatch optimization models for improved climate resilience considerations

    Bazilian, Morgan; Zolan, Alexander J.; Macmillan, Madeline R.; Tabares-Velasco, Paulo Cesar; Newman, Alexandra M.; Lange, Ian; Flamand, Tulay (Colorado School of Mines. Arthur Lakes Library, 2023)
    Energy system planning models have been commonly used for design and dispatch decisions with the goal of cost minimization. Due to the threat climate change poses to energy system operations, however, these models have been gaining popularity for their ability to obtain optimal design and dispatch decisions with resilience considerations. In order to provide informed resilient planning decisions, there is a gap in how current energy system models address long-term uncertainties with respect to climate change. This research explores this gap and how augmentations to existing methods can improve resilient planning in the face of climate change. In this novel body of work, we first conduct a literature review of qualitative and quantitative resilience definitions and, based on our synthesis and observations, propose a working definition and metric to guide the remainder of this work. We then develop a novel scenario generation method combined with a two-stage stochastic program to account for long-term uncertainties including the effects of population and electrification trends on load growth and the impacts of climate change load growth and variable renewable energy availability. From this, we are able to analyze the implications of our novel approach to develop optimal design and dispatch recommendations that account for system resilience. We then broaden the application of our novel methodology to include heating and cooling loads and to evaluate the impacts of long-term uncertainty-informed resilience planning on system design and operations across different climates and building types. Through this body of work, we aim to improve existing energy system planning models by enabling more uncertainty-informed planning decisions that will, in turn, increase the resilience of future energy systems against climate change.
  • Physical beneficiation of the Iron Creek cobalt deposit via flotation

    Anderson, Corby G.; Brevig, Mason; Spiller, D. Erik; Taylor, Patrick R.; Puvvada, George (Colorado School of Mines. Arthur Lakes Library, 2023)
    Cobalt is a critical material as designated by the United States Department of Energy. It is used in electric vehicles as a cathode material and in high strength steels as an alloying addition. The United States currently relies nearly 100% on imports and secondary scrap materials for refined cobalt consumption. Because of this, efforts to establish a domestic supply for cobalt are being pursued. This thesis describes research into sortation and flotation to improve one such effort by Electra Battery Materials through the Iron Creek, ID deposit. Coarse material sortation was tested in order to determine its viability, specifically the viability of XRT sensor-based sorting on Iron Creek material. The sortation testing was successful as low-grade material was able to be separated from rocks that had higher cobalt and copper grades. Rougher flotation testing was used to ascertain the most appropriate conditions for particle size, collector type, and collector dosage. A cobalt grade of approximately 1.8% was achieved with a recovery of nearly 92.0% using rougher flotation. Differential flotation testing was undergone to obtain separate copper and cobalt concentrates by depressing the pyrite at a PH of 11.5. Separate cobalt and copper concentrates were obtained with the copper concentrate having a cobalt recovery of 3.98% and a copper recovery of nearly 20%. Cleaner flotation at high PH was undergone to further recovery cobalt from the differential flotation copper concentrate. Re-grinding to a particle size P80=80 microns aided in the recovery of cobalt to the cobalt concentrate as the final copper concentrate from cleaner flotation had only 0.27% cobalt recovery. Locked cycle testing was also conducted to simulate an industrial flotation operation with results supporting the implementation of an industrial flotation circuit for the recovery of cobalt and copper as separate products. An overall economic analysis incorporating sortation, flotation, thermal degradation, and magnetic separation was constructed. The economic analysis showed that the process was economical and a positive NPV of $35.2 million (+ or – 35%) indicated that the project should be pursued at the industrial level.

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