VictorJuiz/thesis huggingface dataset:
A Feasibility Study of In Situ Combustion for the C Zone of the Buracica Field, Brazil
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The Buracica Field is located in the Reconcavo Basin, 60 mi southwest of Salvador city, capital of Bahia state, in Brazil. It was discovered in 1960. The Buracica field is divided into four blocks (East Block, West Block, North Block, and Main Block) by tv;o geological faults as shown on the map on figure 1. It contains seven producing zones: A, I3, C, D, E, F, and G. Figure 2 presents a rough schematic of the oil zones of the field. Zones C, E, and G are the main oil producing zones. The other zones A, B, D, and F are shaly sands. Zones A and B are not producers, but zones D and F produce oil in a few wells or the Main Block. The well spacing is ten acres. The production wells are completed with pumping units and produce a dead oil from all producing zones, commingled. The original water saturation was 23 percent, p.v. Water flooding has been applied to the Main Block and Last Block since 1970. The North Block is small, 150 acres, and no secondary recovery technique has been used in it. The C zone is a friable sand., and it is considered the best producing zone of the field. Table 1 presents the properties of the C zone in the North Block of Buracica field, and Table 2 presents the sand size analysis of the C zone in the Main Block. The In Situ Combustion process is a well-known thermal oil recovery process. It is suitable for shallow reservoirs with porosities in the order of 20 percent or more, high permeabilities, and oil gravities a.s high as 40 %PI. An In Situ Combustion Pilot Field Test was proposed for the C zone of the North Block of the Buracica field for the following reasons: 1) The reservoir properties presented in Table 1 satisfy the conditions mentioned above. 2) It is a small field (150 acres), and no other secondary success, the of failure, recovery technique has been utilized in it. In case of process could be extended to the other Blocks. In case no damage would be done to the other blocks. 3) The expected. oil recovery using In Situ Comb1 be high ranging from 30% to 80% of the oil in place.
The Isothermal Compressibility of Natural Gases
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

During the use of a new correlation for the compressibility of sweet and sour natural gases, it was noticed that an alternate form was possible. This new form suggested a more compact and direct correlation than the one available from the earlier work of Trube, or the recent study by Mattar, et. al. For manual calculations of the coefficient of isothermal compressibility, a curve which represents the dimensionless number C P as a function of pseudo-reduced temperature and pressure was prepared. The results have been extended to reduced pressures of 30, and reduced temperatures as high as 3. Finally, the adjustment method of Wichert and Aziz, is included to adjust the pseudo-critical pressure and temperature to permit use of this correlation for sour natural gases.
The Real Gas Pseudo-Pressure for Geothermal Steam
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Physical properties o f geothermal steam mixtures were compiled as functions of pressure, temperature and composition. Specifically, these properties were ones which relate to isothermal fluid flow in porous media: viscosity, gas deviation factor, and compressibility. Using this information, the real gas pseudo-pressure function, m(p), was numerically evaluated for geothermal steam.Results are presented in the form of tables, graphs, and curve fit equations over the normal range of conditions found in geothermal reservoirs. Tables and equations are computed in both International and Engineering unit systems.At pressures below 130 psia (approximately), physical properties and the real gas pseudo-pressure exhibit behavior close to that which would be expected for an ideal gas, However,over the normal range of reservoir pressures, these values depart from ideal gas behavior. A substantial error might be incurred if reservoir pressure data is analyzed assuming the validity of the perfect gas law. As most reservoirs contain only small amounts of non-condensable gases, it is reasonable t o assume that geothermal steam behaves as pure steam. However, in cases of unusually high carbon dioxide concentration, it is necessary to adjust the physical properties and the real gas pseudo-pressure of the steam mixture.
An Evaluation of the Capacitance Probe as a Technique for Determining Liquid Saturations in Laboratory Flow Experiments
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Stanford Geothermal Program
Thesis

Of all the methods reported to date, the capacitance probe comes closest to meeting the constraints of measuring liquid saturations of cores at high temperatures and pressures (i.e. 250C and 500 psi). Changes in liquid saturation in the inner 4 inches of porous core are reflected in a one to four percent change in the resonant frequency of the probe. The higher the temperature at which the measurement takes place, the smaller the change for a given change in liquid saturation. The depth of penetration of the probe is only about one sixth the core thickness, and the properties of the core must be uniform throughout for the measurements to be meaningful.
A Study of Liquid Saturation Ahead of the Burning Front In Forward Combustion Oil Recovery
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

With discovery rates for new reserves dropping steadily, and demand for crude oil continuing to grow, it seems that the greatest need is for improved oil-recovery methods to produce the large reserves of so-called "unrecoverable" oil whose location is already known . There are some technical factors that control the rate and ultimate amount of oil recovery. The two primary ones are the permeability of the reservoir rock and the nature of the displacement mechanism. The operating examples relating to the former are fracturing and acidizing, while the latter category includes water flooding, gas repressuring, miscible flooding, and thermal recovery.
An Investigation of Oil Recovery in Underground Combustion
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The purpose of this experiment was to obtain laboratory data to investigate oil recovery in underground combustion. Underground, or In Situ combustion, is a secondary oil recovery process which consists of igniting the oil in a porous rock by means of an ignitor, and driving a combustion zone through a reservoir rock by means of air and/or combustion gases. The heat generated serves to increase the mobility of the oil, permitting its displacement to producing wells.There are two types of combustion processes: (1) forward combustion, in which the burning front moves from the injection well toward the production well(s). (2) reverse combustion, in which the burning front moves from the producing well towards the injection well, countercurrent to the injected air.A considerable amount of work has been done on the forward combustion oil recovery process, and numerous investigators have reported the results of laboratory combustion-tube studies, as well as experimental results from field tests. As a result, the engineering parameters of the combustion process are reasonably well known. Engineering data needed to evaluate the process include the amount of air required per barrel of oil recovered, minimum injection rates which will support combustion, total air requirement, produced fluid gas-oil ratios, oil produced, fuel requirements, and saturation distributions. The present laboratory experiment also provides these data.Details concerning the design, construction, and operation of the combustion tubes are rare. The experiments done by Mandel and Gringarten were followed closely in this report. Actually, portions of the same equipment were used.Combustion tubes used by various investigators vary in size, length, and mode of operation. Therefore, one purpose of this experiment is to present considerations important to construction and operation of a combustion tube.
Contact Metamorphism and Decarbonation in the Gangdese Arc: A Petrological, Geochemical, and Phase Equilibria Study
Keywords: Carbon flux
Contact metamorphism
Decarbonation
Metacarbonate
Phase equilibria
Southern Tibet

The potential correlation between long-term climate changes on Earth and the intensity of continental arcs, particularly their considerable CO2 emissions, implies considerable climatic impacts from these petro-tectonic processes. Contact metamorphism of sedimentary carbonates converts the country rocks into calcsilicate and releases substantial CO2. The widespread carbonate sequences deposited on major continental margins where arc activities culminated in the Cretaceous to Paleogene give rise to a hypothetical causal relationship between the magma-carbonate interaction and the Cretaceous Thermal Maximum. While isotopic and modeling evidence supports this hypothesis, direct field-based studies constraining the extents and rates of decarbonation would help assess aureole-scale CO2 fluxes. A wide range of lithology within contact aureoles, from calcsilicates to marble, in the Cretaceous Gangdese Arc in southern Tibet reveals distinctive behaviors of contact metamorphism. The first step to approach the question is the understanding of phase relations. Current phase diagrams detailing metacarbonate systems can be further refined to include additional components and minerals at lesser pressures. Metamorphic conditions such as pressure, temperature and the fluid composition can be estimated from the phase diagrams provided in this thesis. This thesis then presents comprehensive data obtained from the study of two exemplary endmember cases from the Lhasa terrane in southern Tibet. In the case of calcsilicate aureole, diffusion modeling across compositional zones within garnet and diopside suggests brief metamorphic alteration. As these calcsilicate samples demonstrate a large fraction of carbon loss, the corresponding carbon fluxes could be enormous, comparable to fluxes from other contemporary tectonic units. In contrast, studies on marble aureoles suggest fluid behaviors can vary according to rock rheology, thereby affecting the extent of carbon release. Thermobarometric and isotopic measurements from veins surrounded by recrystallized marble suggest that brittle carbonate country rock adjacent to short-lived intrusions facilitates rapid fluid migration and minimal decarbonation reactions. We speculate that, in comparison, ductile country rocks in the vicinity of long-lived intrusions seem to promote extensive fluid-rock interactions, leading to the creation of calcsilicate aureoles. Collectively, this thesis adds to our understanding of decarbonation processes through contact metamorphism from various perspectives, such as the duration and degree of decarbonation, fluid-rock interactions, and phase relations in metacarbonate rocks.
The Cosmopolitans: International Students’ Identity Negotiations, Past and Present, at an Ontario University
Keywords: cosmopolitanism
early study abroad
hybrid identity
identity negotiation
international students
superdiversity

This research highlights the superdiversity (Blommaert, 2013; Vertovec, 2007) of undergraduate students in a university located within a large urban area in Ontario. Almost one-quarter of the total student body comprises international students, primarily from Asia. This superdiversity has created the cosmopolitans, a by-product of globally mobile students who are in pursuit of an Inner Circle English (Kachru, 1985) education. To theoretically frame the second-language socialization experiences of mobile students in English-speaking contexts, scholars have positioned cosmopolitanism at the junction of identity, language, culture, capital, and ideology (Darvin & Norton, 2016). Cosmopolitanism is a philosophy and a disposition that emphasizes openness and recognizes diversity while respectfully engaging in critical dialogue about difference (Appiah, 2006; Delanty, 2009). This study seeks to examine the role of cosmopolitanism in international students’ identity negotiations, past and present, as reflected in their dispositions and experiences while studying at a university in Ontario as well as in their recollections of their high school experiences. Elements of ethnographic and phenomenological approaches are blended with a case study method, and data have been collected and analyzed using qualitative, interpretivist methodologies. Data were collected through semi-structured interviews with 12 university students (focal participants) and two of their peers (non-focal participants), during which a Venn Diagram was used as a heuristic to discuss hybrid identity negotiations (Bhabha, 1994). Some students also completed journals. In addition, interviews were conducted with seven educational professionals to gain multiple perspectives. The research findings highlight the ways in which early study abroad experiences shape students’ identities and future choices. This study also expands the use of a tool that can be used to collect data about participants’ identities, specifically by using the Venn diagram. This dissertation provides educators with a deeper understanding of international students’ experiences. It has the potential to promote third space (Bhabha, 1994) for international students to negotiate their identities in the classroom and beyond, including those students who participate in early study abroad as adolescents.
Understanding Modern Machine Learning Models through the Llens of High-dimensional Statistics
Keywords: Deep learning theory
High-dimensional statistics

Deep neural networks have become an indispensable component of artificial intelligence as seen in a wide range of impressive applications, yet many of their properties remain mysterious. For instance, the non-convex loss landscape may conflict with efficient optimization by standard gradient-based methods, and the common practice of overparameterization (i.e., large number of trainable parameters) seemingly goes against good generalization performance. The empirical success of deep learning has motivated the following important theoretical questions: 1. How does overparameterization interact with the selection of hyperparameters, such as L2 regularization? 2. How does the implicit bias of optimization algorithms (e.g., gradient descent) lead to favorable generalization properties? 3. How does neural network benefit from representation learning, and outperform classical machine learning models such as kernel methods? In this thesis, we study the above questions from a high-dimensional viewpoint, that is, we consider the regime where the data and model size tend to infinity. As we will see, when the problem dimensionality becomes large, certain “macroscopic” statistics of the studied system admit a deterministic limit and can be exactly solved using mathematical tools such as random matrix theory, which is the study of large-dimensional matrices with certain random structures. This thesis is divided into three chapters, addressing questions 1-3 respectively. 1. In Chapter 2 we consider the generalized ridge regression estimator in the overparameterized regime. We derive the precise formulae of the asymptotic generalization error, and study the optimal choice of (weighted) L2 regularization. Our analysis leads to surprising findings including: (i) the optimal ridge penalty can be negative, but only in the overparameterized setting, (ii) regularization can suppress “multiple descent” in the risk curve. 2. In Chapter 3 we study the implicit bias of preconditioned gradient methods in the interpolation setting. The asymptotic formulae allow us to precisely compare the generalization performance of first- and second-order optimizers, and identify factors that affect this comparison. Our results challenge the common perception that second-order methods does not generalize, and demonstrate that the benefit of implicit bias heavily depends on structures of learning problem. 3. In Chapter 4 we go beyond linear estimators and characterize the benefit of representation (feature) learning via gradient descent in a (nonlinear) two-layer neural network. By studying the precise performance of ridge regression on the optimized neural network features, we prove that representation learning results in a considerable advantage over the initial random features model (and a wide range of kernel models); our analysis also highlights the role of large learning rate scaling in the initial phase of gradient descent.
Conservation Properties of Finite-Difference Time-Domain Methods for the Maxwell and Schrödinger Equations With Application to the Development of New Schemes with Guaranteed Stability
Keywords: dissipative systems
energy conservation
finite-difference time-domain
probability conservation
stability

The finite-difference time-domain (FDTD) method is a popular technique for solving the Maxwell equations. The method works by updating unknowns in a leap-frog manner, starting with initial conditions. The update equations are explicit, and hence have relatively low computational requirements. However, the explicit nature comes at the cost of conditional stability, which makes it substantially harder to create new FDTD-based methods, compared to implicit or frequency-domain methods. Methodologies for stability analysis exist, but can lead to lengthy derivations when applied to complex problems. FDTD has also been applied to solving the Schrödinger equation. Research related to this scheme, along with other numerical methods for quantum mechanical problems, is becoming increasingly important. Another type of FDTD methods that were recently inspired by quantum applications are schemes that use potentials as unknowns in order to facilitate modelling of light-matter interaction. Much like in the conventional FDTD, the difficulty of stability analysis poses a significant challenge in advancing these schemes. This thesis draws inspiration from results in control theory in order to facilitate stability analysis of these FDTD methods based on the concepts of energy conservation and dissipation, as well as probability conservation in the case of FDTD for the Schrödinger equation. For the fields-based FDTD, expressions are proposed to quantify the energy stored in a region and the energy entering the region through the boundary. Based on these expressions, we formulate rigorous conditions under which the region is unable to generate spurious energy. These results provide a way to create new schemes by coupling the FDTD equations for the region to other dissipative or energy conserving models. As an example we develop a subgridding scheme by coupling two FDTD grids of different resolution in an energy-conserving manner. The theory is extended to FDTD for the Maxwell equations written in terms of potentials and a subgridding scheme with potentials is developed as a demonstration of application. Furthermore, this thesis extends the approach to propose a similar framework for FDTD for the Schrödinger equation, based on the concept of probability conservation. Conditions for the energy conservation of the scheme are also derived, motivated by the possibility of extending the results to the coupled Maxwell-Schrödinger system of equations in the future.
Expressivist Pedagogy: Re-conceptualizing Writing through Narratives of Self in a Postsecondary Writing Classroom
Keywords: Decolonizing Writing Pedagogy
Expressive Writing
Holistic Education
Language of Love
Pedagogy of Love
Re-conceptualizing Writing

What magic transpires when we give our academic experiences a personal tongue? This research sought to unravel the alternative knowledges spawned through heretical texts when students begin to trust their own experiences to lead them to meaning. To understand this, I taught and observed an Expressive Writing classroom at an Arts College in Lahore, Pakistan. I specifically wanted to explore: 1) How do students re-conceptualize writing after taking a course built on expressivist principles? 2) How does student writing change over the course using a rhetorical analysis as a guiding framework? and 3) How do student writers respond to an expressivist pedagogy? Using a narrative action oriented case study design, I collected data through semi-structured interviews with two participants, student writings, classroom observations, reflexive diary and exit tickets gathered from all students enrolled in the course. The study showed that students re-conceptualized writing as dialectical, relational, communal, situated, liberating, intuitive and transformative. Students took control of their narratives, wrote for a real audience in conversations with one another, started to understand life through the stories they chose to tell, developed their own voice/s in the midst of others, and saw their own lives as sources of meaning. Knowledge was no longer conceptualized as some elusive entity “over there,” external from them. Overall, the writing workshop model of the course was a palatable experience for the majority of students while some found that writing in discourse communities felt disconcerting. Student writing displayed a preliminary understanding of rhetorical conventions (discrepancy between defining good writing and writing good writing) and contained resonant passages (writings with added presence) of gendered rhetoric typifying Shock Expressive Writing—deeply visceral writing which shocks the reader into revisionism, meta-transcendence and/or alternative thinking through authentic expression. Based on the findings of this action research, implications include recommendations for teachers who want to teach expressive writing which centers indigeneity, decolonizes writing pedagogy, and is rooted in holistic education and a pedagogy of love (bridging the gap between the academic and the heart). Concomitantly, this study also makes a case for the language of love—a novelty—to permeate academia.