A successful cement job results in complete zonal isolation while saving time and money. To achieve these goals, various factors such as well security, casing centralization, effective mud removal, and gas migration must be considered in the design. In the event that high-pressure and high-temperature (HPHT) conditions are encountered, we must attempt to achieve permeability in the set cement to prevent gas migration and to prevent any other fluid passing through to collapse the entire structure. Therefore, the design of the cement must be such that it prevents: Micro-annuli formation Stress cracking Corrosive fluid invasion Fluid migration Annular gas pressure In HPHT cases, we need more flexible cement than in conventional wells. This cement expands more at least 2 to 3 times more in some special cases. The stress in the cement is strongly connected with temperature and pressure, as well as lithology and in-situ stress. If we can define a method which connects the higher temperature to the lower stress field, we would have the solution for one side of the equation, and then we could model the pressure (stress principles) at the designated depth and lithology. Since the stress is so dependent on temperature, the temperature variation must be accurately predicted to properly design the fluid and eliminate excessive time spent waiting on cement. In addition, a post-job analysis is necessary to ascertain zonal isolation and avoid unnecessary remedial work. By increasing the flexibility of the set cement (lowering the Young's modulus), we can reduce the tensile stress in the cement sheath during thermal expansion. This could be a solution to the problem of cement stability in high temperature cases. Here we report the use of the finite-element method (FEM) to investigate the stress fields around and inside the cement, and to forecast the time of failure and its affect on cement integrity. This method is more powerful than conventional stability methods since complex boundary conditions are involved as initial conditions and are investigated simultaneously to more accurately predict cement failure. The results of this study show the relevant dependency of stress principles with temperature and pressure. These results clarify the deformation caused by any disturbance in the system and the behavior of under-stress locations based on their relative solid properties.

A successful cement job results in complete zonal isolation while saving time and money. To achieve these goals, various factors such as well security, casing centralization, effective mud removal, and gas migration must be considered in the design. In the event that high-pressure and high-temperature (HPHT) conditions are encountered, we must attempt to achieve permeability in the set cement to prevent gas migration and to prevent any other fluid passing through to collapse the entire structure. Therefore, the design of the cement must be such that it prevents: Micro-annuli formation Stress cracking Corrosive fluid invasion Fluid migration Annular gas pressure In HPHT cases, we need more flexible cement than in conventional wells. This cement expands more at least 2 to 3 times more in some special cases. The stress in the cement is strongly connected with temperature and pressure, as well as lithology and in-situ stress. If we can define a method which connects the higher temperature to the lower stress field, we would have the solution for one side of the equation, and then we could model the pressure (stress principles) at the designated depth and lithology. Since the stress is so dependent on temperature, the temperature variation must be accurately predicted to properly design the fluid and eliminate excessive time spent waiting on cement. In addition, a post-job analysis is necessary to ascertain zonal isolation and avoid unnecessary remedial work. By increasing the flexibility of the set cement (lowering the Young's modulus), we can reduce the tensile stress in the cement sheath during thermal expansion. This could be a solution to the problem of cement stability in high temperature cases. Here we report the use of the finite-element method (FEM) to investigate the stress fields around and inside the cement, and to forecast the time of failure and its affect on cement integrity. This method is more powerful than conventional stability methods since complex boundary conditions are involved as initial conditions and are investigated simultaneously to more accurately predict cement failure. The results of this study show the relevant dependency of stress principles with temperature and pressure. These results clarify the deformation caused by any disturbance in the system and the behavior of under-stress locations based on their relative solid properties.

Thesis (M. Eng. Sc.)--University of Queensland, 2002. / Includes bibliographical references (p. 99-104).

Reduction of CO2 Emissions from Cement Plants Governments around the world have been pressured by society to discuss environmental issues, and global warming is one of the most controversial debates. The Kyoto Protocol is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC). Under Kyoto protocol some countries committed to reduce their Greenhouse Gas (GHG) emissions. The Intergovernmental Panel on Climate Change (IPCC) has predicted global rise in temperature and carbon dioxide is a major greenhouse gas responsible for global warming. The cement industry contributes approximately five per cent of the total CO2 emitted worldwide. Currently Canada sustains a very aggressive objective to reduce GHG emissions to support the Kyoto Protocol. It is clear that international affairs and global polices will affect different sectors and even though cement production and distribution is constrained by location and natural resource availability, the major cement producers around the globe will be required to meet more stringent environmental regulations. Kyoto presents a ???cap and trade??? mechanism that requires countries to reduce, on average, 5.2 per cent below their 1990 baseline. This reduction must take place between 2008 and 2012. Although these caps are country specific, most countries are requiring industries to have particular objectives for reduction. This can be seen especially in European countries. The credit trade opportunity increases the possibility for an economical justification of new and environmentally friendly solution for GHG emissions abatement. St Marys Plant, located in St Marys, Ontario, was used as a case study to evaluate the results of various modifications on cement plants operation that can impact on the plant CO2 emissions. An economic model which objective is to highlight the best selection strategy to reduce CO2 emissions with the least cost was developed using St Marys Plant data as part of this thesis. St Marys Plant achieved a significant result of 23.6 per cent reduction in CO2 emissions per tonne of cement produced. The results were achieved mainly by applying a progressive approach prioritising project implementation effort and feasibility. St Marys main steps were 1) implementation of a more robust maintenance system, 2) plant optimization and Kiln expert system; 3) alternative fuels and 4) major equipment modifications.

Thesis (Ph.D.)--University of Tulsa, 1987. / Bibliography: leaves 222-226.

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1898. / Herman C. Cowen determined to be Herman Cyril Cowen from "Thirtieth Annual Catalogue of the School of Mines and Metallurgy". The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed November 14, 2008)

Thesis (Master)--İzmir Institute of Technology, İzmir, 2006. / Keywords: Modeling, optimization, process monitoring. Includes bibliographical references (leaves 77-78).

Akademisk avhandlung--Stockholms tekniska högskolan. / Estra t.p., with thesis note, inserted. "[Based on] investigations [which] were carried out at the laboratory of Skånska cementakitiebolaget in Limhamn on the chemistry of cements 1938"--Foreword. Bibliography: p. [148]-150.

Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 62-64).

Thesis (Ph.D.)--Aberdeen University, 2007. / Includes bibliographical references.