Fracture diagnostics is a key technology for well performance prediction of a horizontal well in a shale reservoir. The combination of multiple fracture diagnostic techniques gives reliable results, and temperature data has potential to provide more reliability on the results. In this work, we show an application of a temperature prediction model for a horizontal well with multiple hydraulic fractures in order to investigate the possibility of evaluating reservoir and hydraulic fracture parameters using temperature data. The model consists of wellbore model and reservoir model. The wellbore model was formulated based on mass, momentum and energy balance. The reservoir flow model was solved by a numerical reservoir simulation, and the reservoir thermal model was formulated by transient energy balance equation considering viscous dissipation heating and temperature variation caused by fluid expansion besides heat conduction and convection. The reservoir flow and reservoir thermal model were coupled with the wellbore model to predict temperature distribution in a horizontal well considering boundary conditions at the contact of reservoir and wellbore. In the reservoir system, primary hydraulic fractures which are transverse to the horizontal well were modeled with thin grid cells explicitly, and the hydraulically-induced fracture network around the horizontal well was modeled as higher permeable zone to unstimulated matrix zone. The reservoir grids between two primary fractures were logarithmically spaced in order to capture transient flow behavior. We applied the model to synthetic examples: horizontal well with identical five fractures and with different five fractures. The results show two fundamental mechanisms: heat conduction between formation and wellbore fluid at non-perforated zone, and wellbore fluid mixing effect at each fracture. The synthetic example with identical fractures shows that fracture locations affect wellbore temperature distribution because of fluid mixing effect between reservoir inflow and wellbore fluid. And also, the synthetic example with different fractures shows that the fracture heterogeneity causes different magnitude of temperature change due to inflow variation per fracture. In addition, the model was applied to synthetic examples without network fracture region in order to find the effects by the network. It reveals that under constant rate condition, network fracture masks large temperature change due to small pressure change at the contact between fracture and formation, and that under constant BHP condition, network fracture augments temperature change with the increase of flow rate in wellbore and inflow rate from reservoir. Sensitivity studies were performed on temperature distribution to identify influential parameters out of the reservoir and hydraulic fracture parameters including reservoir porosity, reservoir permeability, fracture half-length, fracture height, fracture permeability, fracture porosity, fracture network parameters, and fracture interference between multiple clusters. In this work, in order to find contributions by a target fracture, temperature change sensitivity is evaluated. Single fracture case reveals that fracture permeability, network fracture parameters and fracture geometries are primary influential parameters on temperature change at the fracture location. And also, multiple fractures case shows that temperature change is augmented with the increase of fracture geometry and is decreased with the increase of fracture permeability. These results show the possibility of using temperature to determine these sensitive parameters, and also the quantified parameter sensitivities provide better understandings of the temperature behavior of horizontal well with multiple fractures.

In this study, the optimum conditions for wormhole propagation in horizontal well carbonate acidizing was investigated numerically using a horizontal well acidizing simulator. The factors that affect the optimum conditions are rock mineralogy, acid concentration, temperature and acid flux in the formation. The work concentrated on the investigation of the acid flux. Analytical equations for injection rate schedule for different wormhole models. In carbonate acidizing, the existence of the optimum injection rate for wormhole propagation has been confirmed by many researchers for highly reactive acid/rock systems in linear core-flood experiments. There is, however, no reliable technique to translate the laboratory results to the field applications. It has also been observed that for radial flow regime in field acidizing treatments, there is no single value of acid injection rate for the optimum wormhole propagation. In addition, the optimum conditions are more difficult to achieve in matrix acidizing long horizontal wells. Therefore, the most efficient acid stimulation is only achieved with continuously increasing acid injection rates to always maintain the wormhole generation at the tip of the wormhole at its optimum conditions. Examples of acid treatments with the increasing rate schedules were compared to those of the single optimum injection rate and the maximum allowable rate. The comparison study showed that the increasing rate treatments had the longest wormhole penetration and, therefore, the least negative skin factor for the same amount of acid injected into the formations. A parametric study was conducted for the parameters that have the most significant effects on the wormhole propagation conditions such as injected acid volume, horizontal well length, acid concentration, and reservoir heterogeneity. The results showed that the optimum injection rate per unit length increases with increasing injected acid volume. And it was constant for scenarios with different lateral lengths for a given system of rock/ acid and injected volume. The study also indicated that for higher acid concentration the optimum injection rate was lower. It does exist for heterogeneous permeability formations. Field treatment data for horizontal wells in Middle East carbonate reservoirs were also analyzed for the validation of the numerical acidizing simulator.

国立情報学研究科で電子化したコンテンツを使用している。

[Abstract]Research within clinical, organisational and community contexts, generally equates an individual’s sense of well-being with the absence of adverse psychological states.More recently, proponents of ‘positive psychology’ have drawn attention to positive affective states, like happiness and joy. The focus on affective states relates to a Subjective Well-Being (SWB) approach to well-being. In contrast, a Psychological Well-Being (PWB) approach considers the role of mastery and efficacy beliefs, asense of autonomy and positive relatedness with others, as separate dimensions that are related to SWB. Two studies tested the hypothesis that two affect dimensions ofSWB, Positive (PA) and Negative (NA) Affect, were independently related to PWB.In both studies, factor analysis differentiated between items from two SWB and PWB measures, whilst correlations between the well-being factors were moderate. Apreliminary study reported PWB to be a significant predictor of SWB after controlling for Demographics and Negative Life Events. A lack of association between Negative Life Events and PA suggests independent effects for two broad SWB dimensions. Using an Organisational Health Research Framework (OHRF), a study of high-school teachers further controlled for a five-factor model of personality and both Positive and Negative Organisational Climate. PWB was still identified as a significant predictor of SWB after controlling for demographic, organisational climate and personality variables. Independent effects on positive and negative SWBdimensions were also identified. Assessing change of both dependent and independent variables with two waves of data supported the independence of SWB outcomes and the strong effect of PWB on SWB across time. Higher levels of PWBwere mostly related to better SWB outcomes (lower negative and higher positive SWB states). Although the OHRF proposes reciprocal effects of employee wellbeingand personality on perceptions of climate, the strongest effects were those reported whereby organisational climate and individual characteristics, being mostly independent of each other, strongly predicted employee SWB within and across waves. Implications for future employee well-being research are that organisational interventions need to address reducing negative and improving positive facets of the organisation. Individual interventions which promote PWB components would appear to be a most important avenue by which to improve employee SWB, by reducing NA and improving PA states.

The restrictions of micro-scale systems are approaching rapidly. In anticipation of this development, nano-scale electronics has become the focus of many researchers and engineers in academia and industry since early 1990s. The basic building blocks of modern integrated circuits have been diodes and transistors with their current-voltage I-V characteristics being of prime significance for the design of complex signal processing and shaping devices and systems. Classical and semi-classical physical principles are no longer powerful enough or even valid to describe the phenomena involved. The application of rich and powerful concepts in quantum theory has become indispensable. These facts have been influential in undertaking this research project. This research is built upon the determination of the Eigenpairs of one and two dimensional positive differential operators with periodic boundary conditions. The Schrödinger equation was solved for positive operators in both one and two dimensions. Fourier series were used to express the derivatives as the summation of Fourier terms. This led to a novel approach for the calculation of the eigenmodels of a perturbed potential well. The perturbation can be done via an electric field applied to the potential well. The research in this thesis includes a thorough understanding of quantum mechanics fundamentals, mastering of different approximation techniques such as the variational technique and results that have been generated and published using the novel techniques.

Influenced by the global phenomenon of the third way paradigm, the reform of the New Zealand Local Government Act 2002 (LGA 2002) marked significant changes for local authorities. Under this Act, local authorities were required to consult with their communities to develop long term plans identifying social, economic, environmental and cultural outcomes and progress indicators within a sustainable development framework. Since 2002, local authorities have developed at least one long term plan with a full consultation process. This thesis explored the interpretation of cultural wellbeing based on ethnicity and cultural identity, identifying factors that may influence indicator development using Hamilton City Council’s Long Term Council Community Plan (LTCCP) 2006 as a case study. The qualitative and secondary quantitative research has shown tensions exist, between the application of a western definition of cultural wellbeing and the cultural worldview within a governance model. Subsequent findings relate to the dearth of literature exploring the relationship between principles of citizenship, cultural diversity and cultural wellbeing within a New Zealand setting. Through the reflexive research process it has been identified that any further work in this area draws on community participatory research design and indigenous methodology. Cultural wellbeing is a live process moving beyond the manifestation of tradition and custom that traditionally has been associated with indicator development. The generic nature of cultural wellbeing indicators could be related to the need for more research into the epistemology of culture as a knowledge tradition in itself and how it is incorporated into development of wellbeing measures and indicators. By drawing on central, local and regional monitoring programmes, local authorities, such as Hamilton City Council have demonstrated an evolution in the type of cultural wellbeing indicators and outcomes used; however the full intent of broadening the role of local government to include cultural wellbeing is still to be realised.

Thesis (MSpor)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (M.A.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 126-134). Also available via Humboldt Digital Scholar.

Thesis (D. Phil.(Biokinetics, Sport and Leisure Sciences))--University of Pretoria, 2007. / Summary in English and Afrikaans. Includes bibliographical references.

Thesis (D.Psych.) - James Cook University, 2005. / Typescript (photocopy) Bibliography: leaves 203-223.