Browsing by Subject "Eagle Ford Shale"
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Item An experimental investigation of oil recovery in EOR processes in tight rocks(2021-07-26) Quintanilla, Zach Tyler; Sharma, Mukul M.Unconventional oil production has become the largest source of oil production in the United States and is expected to continue for the foreseeable future. However, total oil recovery in these types of reservoirs is generally less than 10% of original oil in place. EOR treatments in the field have had mixed success and require further understanding for optimization at the field scale. Identifying the optimal treatment for these types of wells is difficult due to the low porosity (<5%) and nano-Darcy permeability which makes conventional methods of EOR and lab testing not feasible. In this study we will propose a new method for testing and comparing EOR treatments in tight rocks. By observing the oil in place from NMR before and after treatment, we can determine the most effective treatment method. In this study we analyzed three different formations: the Austin Chalk, Buda Limestone, and Eagle Ford Shale. Additionally, we tested different combination of treatment gases (nitrogen and carbon dioxide) and treatment fluids (brine, nano-activated, and nano-activated + surfactant). From the results of this work, we were able to identify the optimal treatment for each formation from the treatments that were tested. The experimental results were shown to be fast and repeatable. Additionally, the oil recovery results from each of the tested treatments were able to be easily compared (oil recovery ranged from 1% to 98%). By using a combination of treatment fluid and gas, the total incremental oil recovery increased when compared to gas only treatments. Lastly, we were able to identify the optimal treatment for each rock type by referring to the treatment with the greatest oil recovery.Item Anisotropic seismic characterization of the Eagle Ford Shale: rock-physics modeling, stochastic seismic inversion, and geostatistics(2016-05) Ren, Qi; Sen, Mrinal K.; Spikes, Kyle; Srinivasan, Sanjay; Fomel, SergeyQuantitative reservoir characterization using integrated seismic data and well log data is important in sweet spot identification, well planning, and reservoir development. The process includes building up the relations between rock properties and elastic properties through rock physics modeling, inverting for elastic properties from seismic data, and inverting for rock properties from both seismic data and rock physics models. Many quantitative reservoir characterization techniques have been developed for conventional reservoirs. However, challenges remain when extending these methods to unconventional reservoirs because of their complexity, such as anisotropy, micro-scale fabric, and thin beds issues. This dissertation focuses on developing anisotropic rock physics modeling method and seismic inversion method that are appliable for unconventional reservoir characterization. The micro-scale fabric, including the complex composition, shape and alignment of clay minerals, pore space, and kerogen, significantly influences the anisotropic elastic properties. I developed a comprehensive three-step rock-physics approach to model the anisotropic elastic properties, accounting for the micro-scale fabric. In addition, my method accounts for the different pressure-dependent behaviors of P-waves and S-waves. The modeling provides anisotropic stiffnesses and pseudo logs of anisotropy parameters. The application of this method on the Upper Eagle Ford Shale shows that the clay content kerogen content and porosity decrease the rock stiffness. The anisotropy increases with kerogen content, but the influence of clay content is more complex. Comparing the anisotropy parameter pseudo logs with clay content shows that clay content increases the anisotropy at small concentrations; however, the anisotropy stays constant, or even slightly decreases, as clay content continues to increase. Thin beds and anisotropy are two important limitation of the application of seismic characterization on unconventional reservoirs. I introduced the geostatistics into stochastic seismic inversion. The geostatistical models, based on well log data, simulate small-scale vertical variations that are beyond seismic resolution. This additional information compensates the seismic data for its band-limited nature. I applied this method on the Eagle Ford Shale, using greedy annealing importance sampling as inversion algorithm. The thin Lower Eagle Ford Formation, which cannot be resolved by conventional inversion method, is clearly resolved in the inverted impedance volume using my method. In addition, because anisotropy is accounted for in the forward modeling, the accuracy of inverted S-impedance is significantly improved.Item The Eagle Ford formation of Travis County, Texas(1925-06) Green, Guy EmmettItem Oil and gas in the great state of Tejas : centering land tenure histories of fracking geographies within the Texas-Mexico border landscape(2020-04-23) Wirsching, Andrea Christina; Sletto, Bjørn; Mueller, Elizabeth; Paterson, Robert; Guidotti-Hernández, Nicole; Webber, MichaelThis dissertation examines the Texas-Mexico border oil and gas landscape and the unequitable distributions of impacts and benefits these extractive activities produce. I situate my work within critical, interdisciplinary literature on the relationship between the exploitation of natural resources and wealth distribution, and the explicit problematization of inherent uniqueness of border spaces. I utilized a critical, multi-disciplinary framework drawing from political ecology, planning, and border studies, to critique and inform more nuanced vulnerability assessments and literatures across temporal and spatial scales. I argue consideration of the role of who owns what and how they obtained it in policy and planning, not just land use, is key to understanding the reproduction of oppressive and exclusive political structures and land rights regimes along the border. Using a mixed method approach to examine this exemplary case study, I integrated spatial, quantitative methods with qualitative interviews and archival document analysis to trace the historical land tenure patterns of property ownership in Webb County, as well as conduct vulnerability and risk assessments. Using governance geographies as a spatial and conceptual lens for analyses, I demonstrate how land tenure and ownership illuminate the important role of the gradations of informality, and by extension the state, is in producing social vulnerabilities in borderlands. The following themes emerged from analysis of my case study: relationship between land wealth and political power and vulnerability; tensions between land control, stewardship, and exploitation; and the value in learning from histories of land tenure and borderlands in reconceptualizing, identifying, and developing policies that aim to address vulnerability. My research suggests the confluence of physical and regulatory remnants of past colonial powers along the border region continue to be visible and influence the balance and power and distribution of public resources. Furthermore, their corresponding land rights regimes, dispossession via subsequent sovereign land grants, and generational wealth accumulation and political power from these activities, are significant in shaping this particular oil and gas producing landscape. As one of the least regulated, pro-property rights and pro-oil-and-gas states in the country, this study serves as an example of what happens when wealth and political power continues to fortify the structural mechanisms that, in the absence of regulatory controls and avenues for redistribution and remediation, effectively rendering moot a government meant to serve and protect everyone else.Item Weathering the Price Storm: The Importance of Reducing Oil and Gas Production Costs in Texas(2016-03-30) Webb, Romany