Engine oil is critical to tractor engine performance. Engine designers recommend farmers change engine oil depending on recommendations by engine manufacturers. Engine manufacturers did not take into account different tasks often performed by tractors in fields, like tillage or seeding. Farmers do not have certain criteria to determine when engine oil must change. The only criteria to change engine oil is the physical /chemical method, which takes at least one week to obtain oil results. It is a waste of time to wait one week to get the results. There will be a lot of mechanical engine problems if oil is not changed. These engine oil problems cost farmers a lot of money. The aim of this research is to use new technology that could be contributed to solving these technical difficulties. Terahertz technology was used to determine engine oil characteristics by measuring refractive index and absorption coefficient on different conditions. Four experiments were performed to identify the ability of terahertz technology on various engine oil grades, engine oil types, and engine oil contaminants by using terahertz time-domain spectroscopy (THz-TDS). The first experiment was classifying gasoline engine oils of various viscosities by using THz-TDS. The range of 0.5–2.0 THz was evaluated for distinguishing among gasoline engine oils of three different grades (SAE 5W-20, 10W-40, and 20W-50) from the same manufacturer. ANOVA results confirmed a highly significant difference (p<0.0001) in refractive index among each of the three oils across the 0.5–2.0-THz range. Linear regression was applied to refractive index data at 0.25-THz intervals from 0.5 to 2.0 THz to predict kinematic viscosity. The refractive indices of these oil samples were promising for identification and distinction of oil grades. The second research identified three levels of water contaminants 0.0%, 0.1% and 0.2% inside diesel engine oils, grade SAE 15W-40, by utilizing THz-TDS in the range of 0.5 to 2.0 THz. The 0% water contamination level had the lowest absorption coefficient, while 0.2% water had the highest absorption coefficient. The refractive index of 0% water was the lowest and 0.2% water was the highest across the THz range. The refractive indices of these oil samples were promising for discrimination of water contamination. The third experiment demonstrated the possibility of identifying gasoline in engine oil (SAE 5W-20) which was contaminated with four rates (0%, 4%, 8% and 12%) of gasoline fuel and were measured by using THz-TDS. For both refractive index and absorption coefficient of the single cuvette method, ANOVA and Fisher results illustrated that there were highly significant differences (p < 0.0001) among each of the gasoline contaminant levels across the 0.5-2.5 THz range. The 2.5 THz frequency was the best to predict fuel contamination based on refractive index, and 0.5 THz was the best frequency for absorption coefficient. The fourth experiment illustrated the potential of THz-TDS to detect viscosity at 40 °C and TBN changes in gasoline engine oil (SAE 5W-20) due to thermal oxidation (TO). For refractive index, ANOVA and Fisher results showed that there were highly significant differences (p < 0.0001) among each of the TO times across the 0.51 - 2.48 THz range. Refractive index was used to predict TO time, and the 1.25 THz frequency was best to predict viscosity at 40°; for TBN, 2.25 THz was best.

No description available.

Typescript. Thesis (Ph. D.)--University of Hawaii, 1938. Bibliography: leaves 150-158.

A thesis Submitted to the School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2016 / Wettability of a porous reservoir rock is an important factor that affects oil recovery during waterflooding. It is recognized as being important for multiphase properties. Understanding the variation of these properties in the field, due to wettability trends and different pore structures, is very critical for designing efficient and reliable processes and projects for enhanced hydrocarbon recovery. After primary drainage the reservoir wettability changes: if it was oil-wet initially, it gradually changes to water-wet during waterflooding. This change in reservoir wettability towards water-wet will reduce the residual oil saturation and improve the oil displacement efficiency. However, knowledge of the constitutive relationship between the pore scale descriptors of transport in the porous system is required to adequately describe wettability trend and its impact on oil recovery, particularly during waterflooding. In this work, the petrophysical properties that define fluid flow in the Agbada, Nigeria sandstone reservoir were determined using conventional experimental and x-ray CT scanning methods. Experimentally measured average porosity is 0.28, average permeability is 1699 mD, while the initial and irreducible water saturation is 0.22. Permeability in the x, y and z directions, ranging from 50 to 200 mD, were calculated from the pore network extracted from the Agbada sandstone rock. Results obtained from the Amott-Harvey wettability measurement method indicate that the reservoir is strongly water-wet, with Amott-Harvey index of about 0.9. The cross-over between the water and oil relative permeabilities occurred at saturations of the samples above 0.5, giving an indication of strong water-wetness. The work summarizes the mechanism of wettability alteration and characterizes the performance of the reservoir during waterflooding from injecting water, and relates the residual oil saturation, relative permeability and volumes of water injected to wettability and its effects on oil recovery. Waterflood oil recovery is computed using the Buckley-Leverett method based on the reservoir rock and fluid properties. Computed waterflood oil recovery using this method was about 60% of the oil initially in place. Plots of spontaneous imbibition rate show that the injection rate for optimal oil recovery is 40 bbls of injected water per day. At this rate, both the mobility and shock front mobility ratios are less than 1, leading to a stable flood front and absence of viscous fingering. Waterflooding is by far the most widely applied method of improved oil recovery over the years with good results in conventional and unconventional (tight oil) reservoirs It is relatively simple and cost effective: abundance and availability of water. Waterflood oil recovery factor is affected by internal and external factors. The placement of the injection and production wells, for example, impacts on the effectiveness of the waterflooding process. I considered the placement of the wells in a five-spot pattern as elements of an unbounded double periodic array of wells and assumed the reservoir to be homogeneous, infinite and isotropic, with constant porosity and permeability. Both fluids are treated as having slight but constant compressibility and their flow governed by Darcy’s law. The average pressure in the reservoir satisfies quasi-static flow or diffusion equation. I then assumed piston-like displacement of oil by injected water that takes account of viscosity diffence between both fluids and proposed a model based on the theory of elliptic functions, in particular Weierstrass p-functions functions. Oil-water contact movement, dimensionless time for water breakthrough at the production well, areal sweep and average reservoir pressures were modeled. The model was tested using Wolfram Mathematica 10 software and the results are promising. The thesis has therefore established that the Agbada sandstone reservoir is strongly water-wet and that waterflooding is a viable option for enhanced oil recovery from the reservoir. / MT2016

Esta tese teve como objetivo analisar o processo de geração e apropriação da renda petrolífera nos modelos de organização adotados pela indústria brasileira de petróleo. O interesse pelas jazidas de petróleo tem sua origem nas altas rendas geradas na cadeia produtiva, principalmente na fase de exploração, as quais podem ser apropriadas por quem exerce a propriedade sobre o recurso. O entendimento da moderna indústria petrolífera brasileira em um contexto de altos preços de petróleo, de incremento da produção e da descoberta de grandes acumulações de petróleo no pré-sal, leva à discussão em torno da disputa da riqueza gerada, o modelo de organização da indústria e o papel da empresa estatal, PETROBRAS. Tais aspectos foram avaliados seguindo uma perspectiva histórica, baseada no estudo da renda marxista e na aplicação de categorias concretas de análise à indústria petrolífera, abrangendo no período de estudo o pré-monopólio do petróleo, a consolidação da indústria petrolífera com bases estatais, o modelo de concessão e o modelo misto para explorar o pré-sal. A indústria petrolífera mexicana e venezuelana foram estudadas como referencia. Realizada a análise, identificou-se - dada a disponibilidade de recursos petrolíferos orientados a atender o abastecimento interno - o predomínio de excedente econômico gerado no mercado nacional e em menor medida uma renda petrolífera, diferencial e absoluta conseguida no mercado internacional. Também se constatou que dentro do estado nacional moldou-se um processo de disputa do excedente econômico nas suas várias etapas históricas, já que, uma vez definida a hegemonia sobre o petróleo, a disputa pelos excedentes se dá no seio do próprio Estado, entre os estados e os municípios. Concluiu-se que o modelo de organização da indústria petrolífera brasileira é resultado da disputa pelas forças envolvidas na apropriação da renda petrolífera. / This thesis aims to analyze the process of generation and appropriation of oil rent in the organizational models adopted by the Brazilian oil industry. Interest in owning of petroleum fields has its origin in the high rents generated in the production chain, especially in the exploration phase, which may be appropriated by whoever has the property rights on the resource. The understanding of modern Brazilian oil industry in a context of high oil prices; the increase of production and the discovery of large accumulations of oil in pre-salt, leads to discussions around the dispute of the wealth generated, the organizational model of the industry and the role of state-owned company, PETROBRAS. These aspects were evaluated following a historical perspective, based on the study of Marxist rent theory and the application of concrete categories of analysis specific to the oil industry, covering in the period of the study the pre-monopoly, the consolidation of the oil industry with state basis, the concession model and the mixed model to explore the pre-salt. Given the availability of oil resources geared to meet domestic supply during the analysis it was identified the predominance of economic surplus generated in the domestic market and to a lesser extent, a differential and absolute rent achieved in the international market. On the other hand, also within the national state a process of dispute of that economic surplus was shaped, once defined hegemony over oil the dispute for economic surpluses occurs within the state itself, between the states and municipalities. It was concluded that the organizational model of Brazilian oil industry is a result of the dispute by the forces involved in the appropriation of oil rents.

Crude oil plays an important role for the global energy system. As there is ample evidence that conventional oil production will have peaked by 2020, unconventional oil has attained a stronger focus. In particular, oil derived from bitumen from Canadian oilsands has been proposed as a possible remedy to global oil depletion. This study aims to test the hypothesis that forecasts on the Canadian oil sands published between about 2000 and 2010 have been overestimating production significantly. A large compilation of oil sands projects, prognoses and production data has been established using openly available databases and reports. Conversion, standardization and analysis of the data was done using the statistical programming language R. The resulting programming code and databases have been compiled into a package available free and open-source online. The statistical analysis shows a significant bias of the prognoses towards an overestimation of oil sands production. The compilation shows that most authors tend to overestimate the rate of expansion of the industry. Therefore, any prognosis on the expansion of the industry should be examined thoroughly before use.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 63-64).

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 18, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering, Department of Chemical & Materials Engineering, University of Alberta. Includes bibliographical references.

Operators can improve a reservoir’s value by optimizing it in a more holistic manner, or over its entire life cycle. This thesis developed approaches to life cycle optimization, with emphasis on accessible technical and economic modeling techniques for production. The challenges of life cycle optimization are properly scheduling the times at which the operator should switch from one recovery phase to the next, along with determining other field design parameters such as well spacing and injection pressures for waterflooding and enhanced oil recovery processes. To deliver the most value, the operator needs to produce from a reservoir the greatest quantity of oil, at a relatively low cost, reasonably soon, and ideally at a time when the oil price is high. This is quite a tall order, as these goals are often in conflict. This thesis extended existing research regarding lifecycle optimization, first modeling production from a reservoir using an exponential decline model and assuming the oil price’s behavior can be approximated with mean-reverting processes. Implications of operating and capital costs potentially being correlated with the oil price were also examined. Finally, a mean-reverting price model that forecasts the mean oil price as increasing and described by a logistic model was proposed to accommodate both recent price forecasts and economic reality. As exponential decline models are more appropriate for characterizing existing production history rather than making a priori predictions, a geologic-parameter-based model was developed using a tank model for primary recovery and a model based on Koval theory and parameterizing a reservoir in terms of flow capacity and storage capacity for waterflooding and CO2 flooding. This model was adapted from existing theory to account for situations where a waterflood has incompletely swept a reservoir at the start of CO2 flooding. Analytical expressions were also derived for estimating injection rates into a formation parameterized by flow capacity and storage capacity. The geologic-parameter-based model was combined with economic assumptions and optimized using a genetic algorithm. This optimization suggested an operator should switch from primary recovery to a CO2 flood with a large WAG ratio relatively early in the reservoir’s life. / text

Thesis (Ph. D.)--University of Wyoming, 2005. / Title from PDF title page (viewed on Nov. 1, 2007). Includes bibliographical references (p. 179-192).