Browsing by Subject "Qatar"
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Item A Systems-Integration Approach to the Optimal Design and Operation of Macroscopic Water Desalination and Supply Networks(2012-02-14) Atilhan, SelmaWith the escalating levels of water demand, there is a need for expansion in the capacity of water desalination infrastructure and for better management and distribution of water resources. This dissertation introduces a systems approach to the optimization of macroscopic water desalination and distribution networks to tackle three problems: 1. Optimal design of desalination and allocation networks for a given demand, 2. Optimal operation of an existing infrastructure of water desalination, distribution, and storage, 3.Optimal planning for expanding the capacity of desalination plants to meet an increasing water demand over a time horizon. A source-interception-sink representation was developed to embed potential configurations of interest. Mathematical programming was used to model the problem by studying different objective functions while accounting for constraints the supply, demand, mass conservation, technical performance, and economic aspects. Such approach determines the type of technologies to be selected, the location and capacity of the desalination plants, and the distribution of the desalinated water from sources to destinations. For the operation and planning problems, the planning horizon was discretized into periods and a multi-period optimization approach was adopted with decisions made for each period. Short- and long-term water storage options (e.g., in storage tanks, aquifers) were included in the optimization approach. Water recycle/reuse was enhanced via the use of treated water and its utilization was improved by minimizing the losses observed in discharged water resulting from the linkage of power plants and thermal desalination plants and the lack of integration between water production and consumption. Several case studies were solved to demonstrate the applicability of the devised approaches.Item Altering Wettability in Gas Condensate Sandstone Reservoirs for Gas Mobillity Improvement(2012-07-16) Fernandez Martinez, Ruth GabrielaIn gas-condensate reservoirs, production rate starts to decrease when retrograde condensation occurs. As the bottomhole pressure drops below the dewpoint, gascondensate and water buildup impede flow of gas to the surface. To stop the impairment of the well, many publications suggest wettability alteration to gas-wetting as a permanent solution to the problem. Previous simulation work suggests an "optimum wetting state" to exist where maximum gas condensate well productivity is reached. This work has direct application in gas-condensate reservoirs, especially in identifying the most effective stimulation treatment which can be designed to provide the optimum wetting conditions in the near-wellbore region. This thesis presents an extensive experimental study on Berea sandstone rocks treated with a fluorinated polymer. Various concentrations of the polymer are investigated to obtain the optimum alteration in wettability to intermediate gas-wet. This wetting condition is achieved with an 8% polymer solution treatment, which yields maximum gas mobility, ultimately increasing the relative permeability curves and allowing enhanced recovery from gas-condensate wells. The treatments are performed mainly at room conditions, and also under high pressure and high temperature, simulating the natural environment of a reservoir. Several experimental techniques are implemented to examine the effect of treatments on wettability. These include flow displacement tests and oil imbibitions. The experimental work took place in the Wettability Research Lab in Texas A&M University at Qatar in Doha, Qatar. The studies in this area are important to improve the productivity of gas-condensate reservoirs where liquid accumulates, decreasing production of the well. Efficiency in the extraction of natural gas is important for the economic and environmental considerations of the oil and gas industry. Wettability alteration is one of the newest stimulation methods proposed by researchers, and shows great potential for future research and field applications.Item The Arab street : a photographic exploration(2009-12) Cheney, Clifford Sidney; Darling, Dennis Carlyle; Reed, EllisJournalists use the term Arab Street to describe what they often imply is a volatile Arabic public opinion. This photo story travels through four Arab areas or Jordan, Qatar, Israel/Palestine and Egypt in order to show the diversity and complexity of each. The media’s tendency to lump all Arabs into one political block is detrimental to a true sense of cultural understanding that is required for peace.Item From trucial states to nation state : decolonization and the formation of the United Arab Emirates, 1952-1971(2011-08) Barnwell, Kristi Nichole; Louis, William Roger, 1936-; Hopkins, Antony G.; Henry, Clement; Marcus, Abraham; Aghaie, Kamran S.Harold Wilson, the British Prime Minister, announced in January 1968 that the British government would withdraw from the Persian Gulf by the end of 1971. For Britain, the decision indicated a re-prioritization of British global defense obligations. For the rulers of the Arab emirates of the Persian Gulf, Wilson‘s announcement signaled an end of British military protection, and the beginning of a process of negotiations that culminated in the establishment of the United Arab Emirates on December 3, 1971. An examination of the process by which the individual Persian Gulf states became a sovereign federation presents an opportunity to examine the roles of nationalism and anti-imperialism played in the establishment of the Union. This work demonstrates that Arab rulers in the Persian Gulf strove to establish their new state with close ties to Great Britain, which provided technical, military, and administrative assistance to the emirates, while also publicly embracing the popular ideologies of anti-imperialism and Arab socialism, which dominated the political discourse in the Arab world through most of the twentieth century. viii This dissertation draws on primary source materials from British and American government archives, speeches and government publications from the Arab Emirates, memoirs and a wide variety of secondary sources. These materials provide the basis for understanding the state-building process of the United Arab Emirates in the areas of pre-withdrawal development, the decision to withdraw, the problems of establishing a federal constitution, and the problems posed by the need for security in the post-withdrawal Persian Gulf.Item Increasing Well Productivity in Gas Condensate Wells in Qatar's North Field(2010-07-14) Miller, NathanCondensate blockage negatively impacts large natural gas condensate reservoirs all over the world; examples include Arun Field in Indonesia, Karachaganak Field in Kazakhstan, Cupiagua Field in Colombia,Shtokmanovskoye Field in Russian Barents Sea, and North Field in Qatar. The main focus of this thesis is to evaluate condensate blockage problems in the North Field, Qatar, and then propose solutions to increase well productivity in these gas condensate wells. The first step of the study involved gathering North Field reservoir data from previously published papers. A commercial simulator was then used to carry out numerical reservoir simulation of fluid flow in the North Field. Once an accurate model was obtained, the following three solutions to increasing productivity in the North Field are presented; namely wettability alteration, horizontal wells, and reduced Non Darcy flow. Results of this study show that wettability alteration can increase well productivity in the North Field by adding significant value to a single well. Horizontal wells can successfully increase well productivity in the North Field because they have a smaller pressure drawdown (compared to vertical wells). Horizontal wells delay condensate formation, and increase the well productivity index by reducing condensate blockage in the near wellbore region. Non Darcy flow effects were found to be negligible in multilateral wells due to a decrease in fluid velocity. Therefore, drilling multilateral wells decreases gas velocity around the wellbore, decreases Non Darcy flow effects to a negligible level, and increases well productivity in the North Field.Item A look at engagement strategies that promote persistence and retention of entering students at the Community College of Qatar(2011-08) Tamimi, Abdulnassir; Cantú, Norma V., 1954-; Bumphus, Walter G.; Roueche, John E.; Tyler, Arthur Q.; Silva, RitoAccording to Tinto (2000a), institutions have fewer retention and persistence problems when their students are not only academically prepared, but are also engaged on campus as well as satisfied with the resources and support provided by the college. A student that has a positive first semester experience is more likely to achieve academic success and re-enroll the following term. The purpose of this study was to explore the differences in experiences, perceptions, expectations, and engagement levels of entering male versus female students and returning male versus returning female students at the gender-segregated Community College of Qatar during the first three to six weeks at the college. The study also attempted to determine if any student support services such as advising, tutoring, counseling, new student orientation program, and participation in student activities were useful and had any influence in promoting student engagement. Data were analyzed using descriptive statistics. For entering male and female students survey responses were classified using questions from five Survey of Entering Student Engagement (SENSE) benchmarks: (1) Engaged Learning (2) Early Connections (3) Clear Academic Plan and Pathway (4) Academic and Social Support Network and (5) Effective Track to College Readiness. While questions from four Community College Survey of Student Engagement (CCSSE) benchmarks: (1) Active and Collaborative Learning (2) Student Effort (3) Support for Learners (4) Student-Faculty Interaction were used for returning male and female students. One-Sample t-tests were run to determine if significant differences in engagement levels existed between the four independent groups for each of the benchmark categories. Cohen’s d calculations were used to measure the effect size and the standardized differences between the means of the variables. For the purpose of this study, Cohen’s d effect size of 0.35 or higher was used as the criteria for interpreting statistically significance. The results of this study revealed entering and returning female students reported statistically higher engagement levels than entering and returning male students in most of the variables indicating that they are more likely to utilize student support services at higher frequencies and have a more positive first semester experience than their counterparts.Item Modeling Density Effects in CO2 Injection in Oil Reservoirs and A Case Study of CO2 Sequestration in a Qatari Saline Aquifer(2012-10-19) Ahmed, TausifCO2 injection has been used to improve oil recovery for several decades. In recent years, CO2 injection has become even more attractive because of a dual effect; injection in the subsurface 1) allows reduction of CO2 concentration in the atmosphere to reduce global warming, and 2) improves the oil recovery. In this study, the density effect from CO2 dissolution in modeling of CO2 injection is examined. A method to model the increase in oil density with CO2 dissolution using the Peng-Robinson equation of state and the Pedersen viscosity correlation is presented. This method is applied to model the observed increase in oil density with CO2 dissolution in a West Texas crude oil. Compositional simulation of CO2 injection was performed in a 2D vertical cross section and a 3D reservoir with the density effect. The results show that the density increase from CO2 dissolution may have a drastic effect on CO2 flow path and recovery performance. One main conclusion from this work is that there is a need to have accurate density data for CO2/oil mixtures at different CO2 concentrations to ensure successful CO2 injection projects. While CO2 enhanced oil recovery (EOR) is part of the solution, saline aquifers have the largest potential for CO2 sequestration. A literature review of the CO2 sequestration in saline aquifers is performed. The dominant trapping mechanisms and transport processes and the methods used to model them are discussed in detail. The Aruma aquifer, a shallow saline aquifer in southwest Qatar is used as a case study for CO2 sequestration. A compositional simulation model is prepared for the Aruma aquifer using the available log data and flow test data. It was found that the grid size is a key parameter in modeling CO2 sequestration accurately. It affects the propagation of the CO2 plume and amount of CO2 dissolved in brine.Item Mothers' Perceptions of Community Integration Opportunities for Children with Disabilities in Qatar(2009-12-14) Abbs, Alyn KThis study analyzed the perceptions of mothers of children with disabilities in Qatar. This interpretive work included components of the methodology of both cultural study and translation study. Mothers' responses in Arabic and Farsi, were translated, separated, and analyzed through inductive analysis of data from translated interviews according to 22 thematic categories. Translators were questioned after each interview, and the personal interactions with mothers, both verbally and non-verbally, provided added substance to the delicate process of naturalistic inquiry. Forty mothers of one or more children with moderate to severe disabilities from age four to 19 participated in the interviews. Their children attended the same education center for children with disabilities in Doha, Qatar. Mothers shared about their daily routines with their children, activities within the home, activities in the community, and needs they saw within the community to remove social and physical barriers that hindered access to the community for those with disabilities. Due to a high prevalence rate of disability and social issues that limited access to service provisions, many individuals with disabilities had not received services in Qatar. The pervasive need for community resources, such as genetic counseling, appropriate medical facilities and care, and appropriate and inclusive schooling opportunities were reported. At the most basic levels of the education system, children with disabilities need to be present to foster greater awareness and acceptance of persons with disabilities. The education reform in Qatar has instituted change on a small scale level for a few children with mild disabilities, but this effort must be further expanded. The data showed various impacts of disability on families. Results indicated that disability changed the way daily life was carried out and the activities that families participated in together within the home. Disability also readjusted the way families participated in the community. Community integration or lack thereof, affected the family life of those with children with disabilities in Qatar. These data reflected a lack of resources in a community where mothers expressed a desire for a more inclusive atmosphere for individuals with disabilities.