bluuebunny/crossref_metadata_2025 huggingface dataset:
Acting, Integrity, and Gender in Coriolanus
Authors: Lehnhof Kent R.
Published: September 2013

When Coriolanus's mother urges him to dissemble his disdain for the plebeians, the hero recoils, imagining that such a role would effeminate him. His response leaves little doubt as to the antifeminist assumptions underlying his antitheatrical commitments. However, these antifeminist assumptions are undermined by the play's presentation of gender, especially as it is expressed in the figure of the young boy and the virginal woman. By way of the boy, the play intimates that masculinity is neither un- nor antitheatrical but is actually a performative effect in its own right. By way of the virgin, the play implies that the "effeminate" or "unmanly" subject positions that Coriolanus scorns are not without virtue of their own, possessing a kind of antiperformative integrity that Coriolanus never achieves. As it aggressively theatricalizes masculinity and implicitly valorizes virginity, Shakespeare's play renders its hero's antitheatrical commitments less and less compelling, less and less coherent.
The Comic Structure of the Globe: History, Direct Address, and the Representation of Laughter in a Reconstructed Playhouse
Authors: Caldwell William Casey
Published: September 2013

This article argues that a comic tension is embedded in the experience of historical difference within a reconstructed playhouse like Shakespeare's Globe Theatre. Focusing on the visual experience of contemporary audience members of the disjunction between the image of "present-day" spectators versus the historical hue of the interior architecture, Caldwell suggests that this historical disjunction or tension is experienced as comic and released through laughter. He argues that the use of sunlight in the Globe theater is in fact harnessed to an attempt to ground the historical reality of the playhouse. Caldwell revises theories of the historicity of light to claim that the Globe playhouse cuts time out of daylight, splitting it between a sense of present-day-ness and the past. Furthermore, he argues the various forms of "direct address"-gestures from actor to audience-- catalyze the comic tension inherent in this disjunction into laughter, for an audience whose gaze is drawn from the stage to itself set against the reconstructed architecture. He concludes that these spaces solicit a mode of spectatorial surrogation for manifestly vacant early modern spectators. This position of standing in for audiences lost to a past the sun has left behind can offer a form of representation that loosens their narrow sense of historical identity, while enabling them to laugh in the face of historical absence both present-day and early modern audiences are implicated in.
The promise and the possibility: South Africa's contested industrial relations path
Authors: Webster Edward
Published: September 2013

A new vision of industrial relations emerged in the 1990s that grew out of a confident and militant labour movement which (unconsciously) drew on some of the key characteristics of a Coordinated Market Economy (CME). This outcome involved compromise which was contested from the beginning by all three social partners - labour, employers and government. Above all, the ability of the social partners to implement this fragile compromise was hampered by the complex legacy of South Africa's apartheid past. These tensions culminated in the Marikana massacre of 34 miners in August 2012.
Varieties of capitalism in emerging economies
Authors: Nölke Andreas , Claar Simone
Published: September 2013

Our contribution discusses the field of comparative capitalism research and it application to emerging economies. Based on criteria for a critical institutional analysis we review alternative models for the analysis of emerging market capitalisms. In doing so, we identify the model of state-permeated market economies (SMEs) as a suitable reference for emerging economies. Finally, the model of SMEs is discussed in the context of South African capitalism.
Capital structure of the South African automotive industry: historical perspectives and development implications
Authors: Barnes Justin
Published: September 2013

The capital structure of the South African automotive industry has undergone a pronounced transformation since 1994. After seven decades of Import Substituting Industrialisation and widespread MNC disinvestment from the late 1970s, the promulgation of the MIDP in 1995 and the associated re-engagement of MNCs in South Africa, has launched the industry on an entirely new development path. The industry is now locked into a global operating environment, albeit in a peripheral manner, that limits opportunities for national capital and major foreign direct investment.
A history of South African capitalism in national and global perspective
Authors: Hart Keith , Padayachee Vishnu
Published: September 2013

Keith Hart and Vishnu Padayachee locate the development of South African capitalism in the context of global developments in the long twentieth century, arguably the first time that such an analysis has been attempted. This paper grapples with multiple relationships, including that between the local and the global, the universal and the particular, and the historical and the present. The durable features of South African capitalism since its modern inception, it is argued, are mining, racial domination and an uneven relationship between the state, finance and industry. Although the national economy went through long swings between an external and internal orientation, each of the main periods highlighted in their analysis has been marked by both.
Corporate governance in South Africa: from 'Old Boys Club' to 'Ubuntu'?
Authors: Padayachee Vishnu
Published: September 2013

Padayachee examines developments in the culture and practice of corporate governance largely within the private sector in South Africa. His analysis reveals the dominance of powerful individuals, family trusts and groups sharing common social, cultural, and linguistic norms, bound together outside the boardrooms thorough old school, club, societal, political, church, sports and other such networks. A sound corporate governance culture based on transparency and disclosure hardly existed before and during the apartheid era. Since 1994 and as South Africa opened up to global economic circuits and institutional rules and practices, there has been a much stronger commitment, at least nominally, to compliance with developments in global corporate governance. The King codes of corporate governance (now into version 3) are the strongest indication of this. South African companies have over the last 18 years shifted from an initial state (a management controlled, 'social club' approach to corporate governance) towards an Anglo-American corporate governance model, practising what is widely referred to as 'shareholder wealth maximization'. But Padayachee argues that the practice of this approach remains uneven, as large family networks (both old and new) still exercise significant influences in boardrooms.
A ghost from the past: the South African developmental state of the 1940s
Authors: Freund Bill
Published: September 2013

Bill Freund offers an account of the development of South African capitalism through the lens of the 'development state' model. This model is a label used in the variety of capitalism literature to describe state-business relations in some Asian economies, including Japan, in the post war era. Though focusing on the 1940s, Freund examines the early signs of such a model in the period immediately after the South African (Boer) war, associated with Alfred, Lord Milner, which has come to be known as the 'reconstruction' period. While conventional wisdom associates the policy initiatives of the 1924 Pact government around industrial and labour policy to the need to accommodate 'poor whites', Freund, following Christie, Clark and others, also argues that these and related policies also incorporated strong elements of industrialization (arguably though cautiously), even 'developmentalism'
Social policy, social citizenship and the historical idea of a social democratic welfare state in South Africa
Authors: van Niekerk Robert
Published: September 2013

This paper continues the development state theme in historical context, but with a greater focus on very recent developments. The developmental state as a strategic objective is largely taken as a given with policy discussion reduced to how the current state form could be reformed to achieve the outcomes posited for a developmental state. This paper argues that this is an a-historical approach that fails to engage with the history of ideas and the policy frameworks which emerged within the liberation movement to inform the type and nature of the democratic state which could overcome the legacies of colonialism, segregation and apartheid. These ideas were articulated in the 1940s by the ANC in seminal policy documents such as 'Africans' Claims'. The argument is made, significant from the perspective of the mainstream VOC approach, that the business sector in the 1940s did not present an organised force in the debate on social policy reform. Organised business largely employed a laisser-faire approach to the health, education and welfare of urbanising Africans, contingently supporting government commissions established during the 'war years', where it served their interests. In the post-apartheid era the Reconstruction and Development Programme (RDP) base document reflected this historical trajectory and gave further impetus to the idea of a social democratic welfare state. The advent of GEAR and ASGISA represented a shift in emphasis - giving greater primacy to economic growth as a condition for meeting social imperatives. Yet the role of business, both progressive and conservative, and its impact on social policy debates, in this period was more apparent than in the 1940s.
Neo-liberalism, varieties of capitalism, and the shifting contours of South Africa's financial system
Authors: Ashman Sam , Fine Ben
Published: September 2013

This article focuses on the role played by both national and global finance in comparative economic performance. It critically examines financial economics, arguing that both the Efficient Markets Hypothesis and the New Financial Economics, with its emphasis on market imperfections, information asymmetries and financial systems, fail fully to explain theoretically the specific role played by finance in the economy and the emergence of specific financial systems. It cannot provide, therefore, an adequate account of variety in capitalism. Neither, however, can the Varieties of Capitalism literature which rejects excessively homogenising visions of institutional convergence but which foregrounds institutional variety without providing an adequate theory of institutions or a deeper theory of capital and capitalism. The argument is demonstrated through an examination of the changing nature of South Africa's financial system from the apartheid to the post-apartheid periods and its insertion in both national and global economies. Financialisation, it is argued, incorporates a global dynamic into the economic and social formation of class interests and national economies which is seen clearly in the South African case. The argument therefore provides a critique of both mainstream financial economics and the Varieties of Capitalism literature and sheds light on the relationship between finance and the real economy and the nature of contemporary capitalism.
Historical varieties of space, scale and speculation in South Africa: the uneven and combined geographical development of financialised capitalism
Authors: Bond Patrick
Published: September 2013

The central problem of Varieties of Capitalism analysis is its failure to assess dynamics of capital accumulation associated with finance and uneven and combined development. This is an especially critical shortcoming in what is probably the capitalist world's most extreme example of these phenomena, dating back at least two centuries. In reviewing the stylised history of financialised South African capitalism, a great many insights are provided about the ebb and flow of capital across space, scale and speculative outlets. These insights should lead policy makers into a much different understanding of the costs/benefits of financial liberalisation in the contemporary world. Yet central to this article's thesis is that with financialised economic activity comes banker power, and hence it is unrealistic to assume the a neoliberal Treasury and Reserve Bank will make the changes required to lessen the adverse effects of South Africa's extreme uneven and combined development.
Introducing varieties of capitalism into the South African debate: uses and limits
Authors: Padayachee Vishnu
Published: September 2013

The essays in this edited special issue aims to probe the nature and 'varieties' of capitalism that emerged and evolved in South Africa following the diamond and gold discoveries of the second half of the 19th century. Is there anything about the origins, evolution and structure of South African capitalism that is distinct or special? What are the continuities, and what the disjunctures, between the character of capitalism in South Africa before and since democratic change? Can one indeed talk about a model or models of South Africa capitalism? Are the rhythms of South Africa's capitalist development, its cycles and crises, determined by and form an inseparable part of capitalist accumulation trajectories on a global scale? Or can one argue that while some components of any national economy today will be inextricably driven by global imperatives, this exists alongside (in either mutually supportive or antagonistic ways) a set of institutions and a history that is essentially national in character. Finally, how similar or how different is contemporary South African capitalism from other models of capitalism - viewed either as stylised, theoretical constructions or in relation to comparable middle-income developing or emerging market economies. These and related themes are set out in this first essay.
Periodic and Solitary Wave Solutions of Complex Nonlinear Evolution Equations by Using First Integral Method
Authors: Taşcan Filiz , Bekir Ahmet
Published: September 2013

In this paper, we utilize the first integral method with symbolic computation to constructing periodic and solitary wave solutions of complex nonlinear evolution equations. With the aid of Maple, new exact solutions of two nonlinear evolution equations in physics, namely, generalized Zakharov equations (GZ) and higher-order nonlinear Schrodinger equation (HONLS) describing propagation of ultrashort pulses in nonlinear optical fibers are obtained.
Sylvester-tridiagonal Matrix with Alternating Main Diagonal Entries and its Spectra
Authors: Kılıç Emrah
Published: September 2013

Recently some generalizations of Sylvester type tridiagonal matrices have been considered with their spectra. We introduce a new kind generalization of Sylvester type tridiagonal matrix by considering its main diagonal entries. Then we compute its spectra and determinant.
Information Experience: Informationen zum Erlebnis machen / Information Experience: Designing information for experience / Information Experience: faire des informations une expérience vécue
Authors: Burmester Michael , Mangold Mangold , Tille Ralph
Published: September 2013

Information Experience baut auf den emotions- und motivationspsychologischen sowie handlungstheoretischen Grundlagen des Konzeptes der User Experience auf und fokussiert auf statische, dynamische und interaktive Informationsmedien. Die Information Experience and Design Research Group an der Hochschule der Medien erforscht die erlebnisorientierte Nutzung von Informationsmedien, um fundierte Gestaltungsprozesse und -methoden zu entwickeln, die Gestaltung für freudvolle und bedeutungsvolle Informationserlebnisse unterstützen. In diesem Rahmen wurde die Valenzmethode entwickelt, um erlebnisorientierte Gestaltung von Informationsmedien zu beforschen und formativ evaluieren zu können. In einer Reihe von Studien wurde dieses Verfahren sowohl für interaktive als auch dynamische Informationsmedien eingesetzt und ermöglichte tiefe und detaillierte Einblicke in die emotionale Wirkung von Gestaltungseigenschaften und deren motivationale Grundlage im Rahmen von Nutzererlebnissen.
Parallel processing and the human mind: Re-understanding consciousness with James Joyce's Ulysses
Authors: Hogan Patrick Colm
Published: September 2013

Research on neural models for cognition suggests that thought is far from a simply serial process. Nonetheless, there has been relatively little work on which parameters govern just what aspects of thought are parallel and what are serial. Clearly, speech as such is serial. In consequence, interior monologue (understood as subvocalised speech) is serial. Moreover, stream of consciousness – mental experience not confined to subvocalised speech – must be articulated in serial form in a novel. Due to this constraint on representation, it seems that novelists commonly imagine that stream of consciousness itself really is serial. Joyce, however, developed a sense of parallel cognitive processing in the course of Ulysses. Specifically, in the “Wandering Rocks” episode, he explored spatiotemporally parallel events in complex social systems. In the following chapter, “Sirens,” he in effect transferred this treatment of external parallelism to the human mind, systematically developing cognitive parallelism in his representation of Leopold Bloom. This development was perhaps reinforced by ideas of harmony and counterpoint associated with the episode's musical model. Understanding Joyce's exploration of parallel and serial processes in thought is important not only for what it tells us about Ulysses. It is also important for what it contributes to our understanding of cognitive parallelism.
Affect and artifice in cognitive literary theory
Authors: Polvinen Merja
Published: September 2013

This essay suggests that separating emotionally immersed and reflectively rational ways of experiencing fiction on the basis of ontological structures and spatio-temporal metaphors is hampering our understanding of the experience of fiction. Beginning in a rhetorical approach, I argue for a model where engagement with fiction is seen in terms of joint attention. Using joint attention rather than knowledge of ontological realms as a reference point has two distinct benefits: it refocuses attention on literature as a rhetorical mode, and it takes mental action to be a system of parallel processes, thus giving an alternative to the back-and-forth movement between the interior and exterior of imagined worlds. My focus is on Dave Eggers's A Heartbreaking Work of Staggering Genius (2000), a memoir that embeds an autobiographical narrative within self-reflective commentary, and which explicitly calls attention to the issues of emotional sincerity and rational distance.
Preserving Facebook Records: Subscriber Expectations and Behavior
Authors: Blaha Craig
Published: September 2013

The number of social networking services and the number of subscribers to those services have grown at an exponential rate over the last decade. This study examines how long Facebook subscribers expect their records to persist and how these expectations affect subscriber’s use of Facebook. I use an online survey (n = 144) and a focus group (n = 6) to determine Facebook subscribers’ preservation expectations and to what extent these expectations affect the type of information subscribers choose to share. I found that respondents expect records to persist for less than ten years, and that respondents alter their sharing behavior based on their preservation expectations. A better understanding of subscribers’ attitudes toward preservation, and the effect of these attitudes on the information subscribers choose to share, is an important step in developing a workable preservation strategy for these records.
Soluble guanylate cyclase in NO signaling transduction
Authors: Pan Jie , Zhong Fangfang , Tan Xiangshi
Published: September 2013

Nitric oxide (NO), a signaling molecule in the cardiovascular system, has been receiving increasing attention since Furchgott, Ignarro, and Murad were awarded the Nobel Prize in Physiology and Medicine for the discovery in 1998. Soluble guanylate cyclase (sGC), as an NO receptor, is a key metalloprotein in mediating NO signaling transduction. sGC is activated by NO to catalyze the conversion of guanosine 5′-triphosphate (GTP) to cyclic guanylate monophosphate (cGMP). The dysfunction of NO signaling results in many pathological disorders, including several cardiovascular diseases, such as arterial hypertension, pulmonary hypertension, heart failure and so on. Significant advances in its structure, function, mechanism, and physiological and pathological roles have been made throughout the past 15 years. We herein review the progress of sGC on structural, functional investigations, as well as the proposed activation/deactivation mechanism. The heme-dependent sGC stimulators and heme-independent sGC activators have also been summarized briefly.
Diagnostic value of a ghrelin test for the diagnosis of GH deficiency after subarachnoid hemorrhage
Authors: Blijdorp K , Khajeh L , Ribbers G M , Sneekes E M , Heijenbrok-Kal M H , van den Berg-Emons H J G , van der Lely A J , van Kooten F , Neggers S J C M M
Published: September 2013

Objective

To determine the diagnostic value of a ghrelin test in the diagnosis of GH deficiency (GHD) shortly after aneurysmal subarachnoid hemorrhage (SAH).

Design

Prospective single-center observational cohort study.

Methods

A ghrelin test was assessed after the acute phase of SAH and a GH-releasing hormone (GHRH)–arginine test 6 months post SAH. Primary outcome was the diagnostic value of a ghrelin test compared with the GHRH–arginine test in the diagnosis of GHD. The secondary outcome was to assess the safety of the ghrelin test, including patients' comfort, adverse events, and idiosyncratic reactions.

Results

Forty-three survivors of SAH were included (15 males, 35%, mean age 56.6±11.7). Six out of 43 (14%) SAH survivors were diagnosed with GHD by GHRH–arginine test. In GHD subjects, median GH peak during ghrelin test was significantly lower than that of non-GHD subjects (5.4 vs 16.6,P=0.002). Receiver operating characteristics analysis showed an area under the curve of 0.869. A cutoff limit of a GH peak of 15 μg/l corresponded with a sensitivity of 100% and a false-positive rate of 40%. No adverse events or idiosyncratic reactions were observed in subjects undergoing a ghrelin test, except for one subject who reported flushing shortly after ghrelin infusion.

Conclusion

Owing to its convenience, validity, and safety, the ghrelin test might be a valuable GH provocative test, especially in the early phase of SAH.
Drought induces spruce beetle (Dendroctonus rufipennis) outbreaks across northwestern Colorado
Authors: Hart Sarah J. , Veblen Thomas T. , Eisenhart Karen S. , Jarvis Daniel , Kulakowski Dominik
Published: September 2013

This study examines influences of climate variability on spruce beetle (Dendroctonus rufipennis) outbreak across northwestern Colorado during the period 1650–2011 CE. Periods of broad‐scale outbreak reconstructed using documentary records and tree rings were dated to 1843−1860, 1882–1889, 1931–1957, and 2004–2010. Periods of outbreak were compared with seasonal temperature, precipitation, vapor pressure deficit (VPD), the Palmer Drought Severity Index (PDSI), and indices of ocean–atmosphere oscillation that include the El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). Classification trees showed that outbreaks can be predicted most successfully from above average annual AMO values and above average summer VPD values, indicators of drought across Colorado. Notably, we find that spruce beetle outbreaks appear to be predicted best by interannual to multidecadal variability in drought, not by temperature alone. This finding may imply that spruce beetle outbreaks are triggered by decreases in host tree defenses, which are hypothesized to occur with drought stress. Given the persistence of the AMO, the shift to a positive AMO phase in the late 1990s is likely to promote continued spruce beetle disturbance.
A Practical Approach for Enhancing Model Accuracy Using Pressure and Permeability Function
Authors: Al-Zahrani Tariq , Al-Hoti Saud
Published: September 2013

In a typical reservoir simulation model, varying details of its geological and petrophysical properties need to be captured accurately. There are single-phase regions, where a considerable savings in costs may be realized if large blocks are used, while there are regions, particularly near well-bores, where fine grids are required to adequately capture high and low permeability streaks. The main goal of reservoir characterization is to get a reservoir model that accurately describes and predicts dynamic fluid flow paths and production/injection performances of the wells. This implies a correct description of extreme values of connections of petrophysical properties, mainly permeability and porosity.

The fine scale model can handle most structural and geological complexity with few compromises. Such a model will allow us to quantify uncertainties and also to run risk analysis. This ensures a realistic and consistent model that honors and maintains the latest field information. In case of updating or adjustment to the simulation model, this can be updated in the geological model as well.

Moreover, history matching, by nature, is a very complex inverse problem that can be computationally intensive and practically difficult for very large multimillion cell reservoir models. Therefore, the use of an optimal parameterization and refinement grid is crucial to get fast and valid history matching results.

This paper shows that fine models provide much more accurate results than the up scaled coarse model. A new method will be introduced to enhance history match quality by conditioning a second version of the permeability model to a relation found between errors in pressure and KH from well test data. A comparison of results including core permeability and saturation from both models are presented. The positive impact of this new method on the history match process is discussed in details.
Computational Fluid Dynamics (CFD) Study and Investigation of Proppant Transport and Distribution in Multistage Fractured Horizontal Wells
Authors: Bokane Atul , Jain Siddharth , Deshpande Yogesh , Crespo Freddy
Published: September 2013

Multistage hydraulic fracturing has become the key technology for completing horizontal and many vertical wells. In horizontal wells, the perf-and-plug method is the most commonly used staging method; in each stage, multiple perforation clusters are used to create separate transverse fractures at each cluster. How these clusters are placed can significantly affect a well's short- and long-term production performance. The simultaneous creation of multiple fractures is a cost effective and time saving method for stimulating both vertical and horizontal wells. Multistage fracturing is an effective method from the perspective of production, but the challenge of achieving even proppant distribution to each cluster is an intricate task for the industry.

Numerical simulations predict uneven proppant distribution for the fluid streams entering different perforation clusters. Field data indicates that, in many cases, some of the clusters do not contribute to production. This led to hypothesizing that actual proppant and fluid distribution along the stimulated clusters might be different from the assumed uniform distribution. However, in limited entry fracture design concept, the proppant distribution among the different perforations is assumed to be the same as the fluid distribution. Until recently, this assumption remained unchallenged.

This paper presents an extensive study and investigation of proppant transport in different perforation clusters within a single stage by using computational fluid dynamics (CFD) techniques. The effects of varied fluid and proppant specific gravity, viscosities, proppant sizes, and slurry flow rates were analyzed while keeping outside-casing parameters constant. Validation of empirical proppant transport CFD simulation results are compared to experimental test data. This is helpful to better understand fluid and proppant behaviors in multicluster fracturing processes to help achieve maximum efficiency.

The results of the study indicate that proppant transport can be accurately modeled when the effects of single particle settling, density driven flow, particle velocity profiles, and slurry rheology are all considered. The investigation shows CFD is an effective tool for optimizing proppant distribution among perforation clusters and enhancing production.
Effect of Some Parameters Influencing Enhanced Oil Recovery Process using Silica Nanoparticles: An Experimental Investigation
Authors: Hendraningrat Luky , Li Shidong , Torsæter Ole
Published: September 2013

Align with current dynamic technology development, waterflooding techniques have been improved and optimized to have better oil recovery performance. In addition the latest worldwide industries innovation trends are miniaturization and nanotechnology materials such as nanoparticles. Hence one of the ideas is using nanoparticles to assist waterflood performance. However it is crucial to have a clear depiction of some parameters that may influences displacement process.

The focus of this study is to investigate the effects of some parameters influencing oil recovery process due to nanoparticles such as particle size, rock permeability, initial rock wettability, injection rate and temperature. This study is part of our ongoing research in developing nanofluids for future or alternative enhanced oil recovery (Nano-EOR) method.

Three different sizes of hydrophilic silica nanoparticles with single particle diameter range from 7 to 40 nm were employed and have been characterized under scanning electron microscope (SEM). Nanofluids were synthesized using 0.05 wt.% nanoparticles that dispersed into synthetic brine (NaCl 3 wt.% ~ 30,000 ppm). The contact angle variation due to nanoparticles size was also measured at room condition. Coreflood experiment has been conducted using 26 Berea sandstone cores to evaluate the effect of those parameters above on oil recovery due to Nano-EOR. The cores permeability was in range from 5 to 450 mD. To study the effect of initial rock wettability on oil recovery due to Nano-EOR, original core wettability has been changed with aging process from water-wet to intermediate and oil-wet respectively. Temperature was also studied in range 25-80 °C to fulfill the possibility of applying Nano-EOR at reservoir temperature.

The coreflood testing was repeated for each case to have consistency result. The processes and results are outlined and also further detailed in the paper to bring knowledge about nanoparticles flooding as a future promising EOR method.
Reservoir Model History-Matching and Uncertainty Quantification in Reservoir Performance Forecast Using Bayesian Framework
Authors: Okano H.
Published: September 2013

Reservoir performance forecasts are essentially uncertain due to the lack of data. The unknown parameters are calibrated so that the simulated profile can match the observed data. However the history-matching is ill-posed and may have non-unique solutions. The aim of our study is to quantify uncertainty of reservoir connectivity in a Turbidite sandstone reservoir where the wells have been stimulated by hydraulic fracturing. The reservoir properties were calibrated using a stochastic sampling algorithm called Differential Evolution (DE). Then a Bayesian framework along with Markov Chain Monte Carlo and Neighbourhood Approximation in parameter space is used to calculate the posterior probability.

A Bayesian framework and DE have been applied to the evaluation of CO2 injection test in the tight oil reservoir. The in-place volumes and connectivity between the wells have been calibrated in a simple model. The calibrated parameters include the length of a hydraulic fracture around the injector well and net-to-gross ratios. The observed data used for history-matching include the bottom-hole flowing pressure at the injector well and the gas composition at the wellhead of the producer wells.

We showed the best fit model for the gas breakthrough and the P10-90 envelopes in the reservoir performance forecast. Assuming an on-going injection after the actual pilot test, the uncertainty envelopes in the CO2 mole fraction in the produced gas were estimated to see a gas breakthrough at each of the producer wells. Our results contribute to the evaluation of the pilot test for a continuous CO2 injection in the tight oil reservoir.

The key is starting with a simple model, because it is much quicker to adjust large-scale heterogeneity in a simple model than in a detailed model. The simple model calibration with DE and the forecast of Bayesian inference have been successfully applied to the field test evaluation.
Multiscale Lattice Boltzmann Method for Flow Simulations in Highly Heterogenous Porous Media
Authors: Li Jun , Brown Donald , Calo Victor M. , Efendiev Yalchin , Iliev Oleg
Published: September 2013

A lattice Boltzmann method (LBM) for flow simulations in highly heterogeneous porous media at both pore and Darcy scales is proposed in the paper. In the pore scale simulations, flow of two phases (e.g., oil and gas) or two immiscible fluids (e.g., water and oil) are modeled using cohesive or repulsive forces, respectively. The relative permeability can be computed using pore-scale simulations and seamlessly applied for intermediate and Darcy-scale simulations. A multiscale LBM that can reduce the computational complexity of existing LBM and transfer the information between different scales is implemented. The results of coarse-grid, reduced-order, simulations agree very well with the averaged results obtained using fine grid.
Pore-Scale Simulation of Viscoelastic Polymer Flow using a Stabilised Finite Element Method
Authors: Qi Meishan , Wegner Jonas , Falco Lisa , Ganzer Leonhard
Published: September 2013

The paper deals with the numerical investigation and simulation of viscoelastic effects during polymer flooding. A possible pore structure is derived from high-resolution micro-CT images of a typical sandstone suitable for EOR applications. The simulation results achieved will allow for better understanding of micro-scale displacement efficiency and will help to optimize polymer flooding designs for enhanced oil recovery (EOR) projects.

Numerical modelling of viscoelastic fluids is notoriously difficult. Standard Galerkin finite element method tends to have numerical oscillations. Therefore, a stabilised finite element method was used in this work, which contains stabilization terms for the constitutive equation. The model was validated using existing literature results. The viscoelasticity effect of polymer was simulated using the Oldroyd-B model. After validation this method was applied to several pore structures (contraction, expansion and expansion-contraction structure) and one real pore geometry based on SEM (Scanning Electron Microscopy). Flow effects and recovery effects were studied by changing the Reynolds number (Re) and Weissenberg number (We). Correspondingly, the streamline plots of the polymer solution flowing through the pore structures are shown. The plot of the first normal stress difference at the re-entrant profile of a contraction structure shows the cause of vortex enhancement.

The fluid invades deeper into dead pores with higher elasticity. With a high Reynolds number, the fluid reaches into the dead pore even much deeper. The simulation results indicate the contribution of the viscoelasticity of polymer solutions to the micro-scale sweep efficiency. The non-dimensional model of simplified pore structures will contribute to the selection of suitable rheological parameters for polymer flooding processes.
Nested Karst Simulations and Uncertainty Quantification - Application Case Study from a Kazakhstan Field
Authors: Labourdette R. , Glass L. W. , Lapointe P. A.
Published: September 2013

In carbonate reservoirs, heterogeneity is usually driven by both depositional and diagenetic patterns, which influence the final static and dynamic reservoir properties. Karstification is one of the most crucial diagenetic phases because of the way in which it constrains the permeability behaviour of the field. Defining static rock-type can therefore be problematic due to the highly imbricate karstic phases and their various distributions and extensions. A further major difficulty is the spatial distribution of rock-types in reservoir models, each linked to different sedimentological and karstic processes and each with their own, but interdependent, geometrical characteristics.

This paper presents a modeling workflow applied to a large carbonate mound in Kazakhstan, affected by hydrothermal karstification. This new approach is based on nested stochastic simulations, geologically-driven and derived from the relationships between karst, depositional facies, and proximity to fault/fracture zones. In addition to the initial depositional model, three diagenetic phases and bitumen deposits are modeled successively in order to restore the complex spatial relationship existing between described alterations. The overall workflow is designed to quantify uncertainties at each step of the nested chain, including structural and filling uncertainties.

The results of this study are quantification of uncertainties and volumetric estimations. They underline the importance of karst distribution and density on reservoir volumes ans especially on static recovery factors. They introduce high permeability drain increasing connectivity between injector and producer wells.

This workflow provides new perspectives for reservoir modeling, including the appropriate effective porosities and permeabilities affected by karst features. It leads to multiples realization scheme allowing uncertainty quantification, either in mature or appraisal field development. The outcome of this modeling workflow, after a stage of up-scaling and dynamic simulation, allows a better assessment the potential impact on field behavior.
Developing a Methodology To Detect Non Drained Sandbodies Using Geology Techniques in Mature reservoirs To Increase Recovery Factor
Authors: Sablit R. Ch.
Published: September 2013

A mature area in an advanced state of depletion can be reassessed as to either maintain the current production or to increase it at least in a minimum amount. Most important of all is to be able to increase the recovery factor. The variables that are related to the oil production are correlated to the sedimentology-stratigrahy model as to give us the most appropriate arrangements of wells and to relocate locations which could have given less production than expected. The facies for each of the environment of deposition identified in every producing reservoir of the formation are described based on which we locate the present wells and compare to the future locations. This is a heavy oil field producing since 1930. The crude ranges between 10–14 °API, the viscosity is in the range of 1000 to 25000 cp. The method of production is cyclic steam stimulation (CSS) which after three cycles becomes less efficient. The steam to oil ratio (SOR) is less than five from initial values of 30–40. Having a huge reserve in the area, however the recovery factor is only 23%. Since several of the sandbodies have not been yet drained out, this gives a new challenge by which a new approach will be used as to produce these bodies. Using sedimentology concepts we can determine the paleodeposition based on the existing facies in this way we locate new locations to optimize well production. Once we locate the new wells, we will be able to screen out the most appropriate way of production by applying thermal methods. Cyclic Steam Stimulation (CSS), steamflood, SAGD, Electromagnetism or Combustion, all together will increase the recovery factor an accumulated 80% of the reserves. The non-drained sandbodies could be stimulated with Cyclic Steam Stimulation (CSS) followed by steamflood in areas of the model with good thermal communication. Finally the very depleted reservoirs with low pressure and clean sands are the best for dry or wet combustion.
Improving the Estimation of Porosity and Permeability Distribution by Linking Basin Modelling to Diagenetic Evolution of Carbonate Reservoirs
Authors: Mangione Alessandro , Lewis Helen , Geiger Sebastian , van der Land Cees
Published: September 2013

Carbonate reservoirs have petrophysical property distributions largely controlled by a combination of the depositional, diagenetic, and structural (burial/uplift) histories of the reservoir itself and also of the basins that contain them. Carbonates are very prone to diagenetic alteration; porosity and permeability can be strongly affected by the thermal state, fluid-pressure and pore fluid chemistry through their geological history. We use a novel workflow, adapted from basin modelling, to investigate how the burial/uplift history of an offshore carbonate reservoir and its basin, taken as a system, can have controlled the fluid and heat movement within, into and out of the reservoir. The reservoir rock properties and diagenetic history are assessed, as is the local and regional geological evolution for potential contributory factors to the diagenesis. A model of the potential basin system is developed, observed reservoir diagenetic history being added to the normal basin modelling constraints. This model provides good estimates of geometry and property evolution, and of fluid transport, through geological time. Since fluid and heat fluxes are important in the diagenetic evolution of the carbonate pore system, these results are complemented by simulating the movement of heat and brine in the reservoir using finite element-finite volume simulations. These simulations capture the complex geological structures, especially fault-fracture systems, and better represent the flow physics and chemistry that control reservoir diagenesis. Results from these simulations will later be returned to the basin model to improve the calibration of the timing, depth, and rates of diagenetic events.

This new workflow is applied to a Lower Eocene offshore carbonate reservoir with a complex diagenetic history which seems to have a strong basin evolution influence. Importantly this workflow is generic and can be applied to any carbonate reservoir to enhance the link between geological models at the basin scale and reservoir scale models.
History Match of a DST Using a Turbidite Elementary Channels Modelling Technique, Deep Offshore Congo
Authors: Labourdette Richard , Devilliers M C. , Bui T.
Published: September 2013

In turbidite deposits, production history analysis indicates that fluid flow behavior is often more complex than expected. The cause is commonly linked to the presence of fine-scale sedimentary heterogeneities within the reservoir particularly in the case of turbiditic submarine channel complexes with final channel-filling stages composed of lateral migration deposits usually below seismic resolution.

Depositional patterns recognized as channel migration and aggradation packages from Oligocene and Miocene series in the Congo Basin, offshore Congo, exhibit different dynamic responses when modeled in a reservoir simulator.

They are related to the various preservation rates of bank collapse sediments within isolated channel bodies. The proposed workflow comprises 3D sedimentary simulations –, based on geometrical modeling that allow a realistic distribution of elementary channels in the final fairway reservoir model. The individual channel borders, below reservoir grid resolution, are identified as the main heterogeneity, and are used to position transmissibility multipliers.

These elementary channels are used as guides for facies and petrophysical modeling. The proportions and distributions of the different parameters are controlled by well data and sedimentary concepts and architectures. The channels, localized in the main fairway, are grouped per sequence. The main dynamic heterogeneities can be addressed either by the sequence boundaries or by elementary channels borders.

Channel sequences and elementary channels were integrated in Eclipse simulations to history match the DST, with transmissibility reduction between sequences, and between elementary channels.

Multipliers that were used to match the DST are extended along the fairway and lead to a conceptual model, where the variation of channel "skin" is a function of its sinuosity and migration type. Transmissibilities are either reduced in meander zones dominated by lateral channel stacking or preserved in "linear zones" dominated by vertical channel stacking.
Accounting for Regional Aquifer Data in a Simulation Model of the Burgan Minagish Reservoir - A Novel Approach
Authors: Al-Faresi F. A. , Bond D. J. , Wang J. T.
Published: September 2013

The Minagish reservoir in the Burgan Field has been produced intermittently at relatively low rates since the 1960's. Full development has been delayed because of the relatively high H2S content of the reservoir fluid. A sour service production facility is now being planned. Reservoir pressure has declined over time and it has been recognized that a component of this decline is due to offset production from several other reservoirs in the area sharing an extensive common aquifer. Reservoir simulation has been used in two phases for the reservoir to assess development options as follows:

The first phase of this work, the "fast loop", involved building models of the regional aquifer and producing reservoirs, developing multiple history matched models and using these models to assess the required volume of injection needed to prevent further reservoir decline. The field level history match was highly non-unique. This work identified the need to have water injection available prior to a new sour service production facility being available and to inject at above voidage rates.

A more detailed "slow loop" simulation model has been developed for the Burgan Minagish reservoir following further geological, geophysical and petrophysical studies. This model has been used to perform development planning studies and, in particular, to plan water injection in the period up to the new production facilities being available. The simulation model has been used as one of the inputs to planning for reservoir management and data acquisition in this period.

The integration between these two models uses a novel methodology. This paper describes how the "fast loop" and "slow loop" studies are linked so as to include the effect of the regional aquifer in conditioning the "slow loop" model to historical data, and using it for predicting future development scenarios performances.