1,720,960 research outputs found
A Systematic Evaluation of Fault Seal Integrity in the southern Pletmos Basin, offshore South Africa: A 3D Multidisciplinary Modelling Approach
Get PDFMagister Scientiae - MSc (Earth Science)The syn-rift succession encompasses the primary exploration target in the southern
Pletmos Basin. Several fault-bounded structural traps that contain gas accumulations
have been discovered within this succession. Likewise, ubiquitous residual gas shows have
been encountered in most drilled wells. Yet, the impact of faults on fluid flow is poorly
understood. Therefore, this study aspires to predict, and where possible, quantify fault seal
integrity and sealing capacities of some of the major prospect-bounding faults.
A multi-disciplinary research strategy was employed in order to fulfil the study
objectives. Fault mapping and geo-cellular modelling using geostatistical algorithms were
undertaken to provide the basic geometric and structural input for more advanced fault seal
analysis applications. Juxtaposition analysis was carried out to identify zones with a high
probability to seal (or leak) and as the first-order tool for predicting fault seal potential.
Threshold pressures, hydrocarbon column heights, cross-fault permeability and transmissibility
were used to estimate the sealing capacities of the faults. In addition to juxtaposition and
customary fault-rock properties, the study also analysed parameters that can be deemed to be
representative of cross-fault fluid flow (i.e. effective cross-fault permeability and
transmissibility; ECFP and ECFT). Finally, modelling of the geo-history facilitated the
validation of the properties that underpinned fault seal analysis studies.
The Ga-Q and proposed Ga-K prospects along with their main bounding faults formed
the foci of the fault seal analysis results. The analysed faults showed excellent initial sealing
potential due to either favourable juxtaposition or shale gouge development. Nonetheless,
predicted hydrocarbon column heights and threshold pressures were low suggesting that the
seal integrity of the analysed faults is predisposed to failure. In addition, high predicted fault
permeability and transmissibility values signify the presence of open and permeable fracture
networks within the fault zones. Thus, it is proposed that the faults are very likely to have
leaked during hydrocarbon migration and filling of traps resulting in empty or under-filled
hydrocarbon reservoirs
Source Rock Analysis, Thermal Maturation and Hydrocarbon Generation Modelling within the Southern Pletmos Basin, Offshore of South Africa
Get PDFMagister Scientiae - MSc (Earth Science)This study is a first attempt that integrates source rock geochemical evaluation, with
analytic and numerical basin-modelling techniques to identify and ascertain the present-day
configuration, spatial distributions, characteristics and hydrocarbon generative potentials of
existing source rocks within the southern depocenter of the relatively frontier Pletmos sub-basin.
Petroleum charge within the basin is proposed to have occurred during most of the Cenozoic Era.
The investigation employed a forward modelling approach whereby models were calibrated
through a combination of geological and geophysical datasets from 6 wells, and constrained by
vitrinite reflectance and kinetic parameters
An investigation of key seismic attribute analysis of the Whitehill Formation in the Karoo Basin
Get PDFMagister Scientiae - MSc (Earth Science)The object of this study is to determine the thickness of the Whitehill formation based on historic seismic data
provided by the Council for Geoscience (CGS). The thickness of the Whitehill was determined through the
development of a velocity model and extraction of velocities at each picked location for the horizon in question.
Amplitudes data was also extracted to determine if the data could be used to establish possible anomalies that
could represent hydrocarbon prospects in the Whitehill formation.
Ninety nine seismic lines were selected for the purpose of this study in the south western part of the Karoo Basin. It
has been noted that due to the lack of velocity logs and sonic logs that a velocity model was created to determine
depth conversion.
This has been used to create depth and time variation maps, amplitude variation maps and isopach maps across
the Whitehill formation.
Essentially the data proved acceptable in establishing the topographical shape and depth of the Whitehill but
lacked in estimating the thickness, due to the base of the Whitehill being difficult to discern.
It was concluded that the results produced acceptable results for estimating the depth of the Whitehill and in some
areas the thickness of the Whitehill but due to the poor quality of the data it could not produce accurate results
from the HVA and the amplitude variation maps
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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