bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Three-Dimensional Three-Phase Fully Coupled Numerical Simulator for Modeling Hydraulic Fracture Propagation in Tight Gas Reservoirs
Authors: Jahromi Mohamad Zeini , Wang John Yilin , Ertekin Turgay 
Published: February 2013

Abstract
Conventional fracture propagation models predict fracture geometry based on fracture fluid mechanics, rock mechanics, petrophysical properties, and analytical leak-off models. Reservoir flow simulators are then used to evaluate post-fracture well performances. This approach is called de-coupled modeling. It is a major challenge to couple these two processes, particularly when dealing with large amount of input data. Furthermore decoupled modeling is a time-intensive job that requires a coordinated effort from stimulation and reservoir engineers. This approach may not work in low-permeability reservoirs because the hydraulic fracture propagation is complex, fracture fluid leak-off is pressure/reservoir/fracture dependent, and there are changes in in-situ stress and permeability during and after fracturing. Therefore, a new model is needed to include all of these influences.
This paper describes a three-dimensional, three-phase coupled numerical model which takes into consideration the mutual influence between dynamic fracture propagation and reservoir flow. The model is capable of fully simulating reservoir flow, fluid leak off, fracture propagation and resulted stress change through a stationary reservoir/stress grid system.
The model uses a three-dimensional, three-phase finite difference reservoir flow simulator coupled with finite difference geomechanics model where both are applied on the same grid system. Using an iterative procedure, changes in pressure, in-situ stress and fracture propagation boundaries are determined during and after the fracture treatment.
The model has been validated with the most recent available data. The results show that the model predicts fracture parameters accurately and match the history of injections and change in fracture /matrix area pressure/stress. This model could help one optimize completion and fracture design and evaluate pre-fracture and post fracture well performances.
Evolution of Horizontal Well Hydraulic Fracturing in the Granite Wash – Understanding Well Performance Drivers of a Liquids-Rich Anadarko Basin Formation
Authors: Srinivasan K. , Dean B. , Belobraydic M. , Azmi Z. 
Published: February 2013

Abstract
The multi-zone Granite Wash is a mature vertical well play extending across 6 counties in the Texas Panhandle and Western Oklahoma. The laterally and vertically extensive formations were developed with close spaced vertical wells for several decades. In the last five years, almost all development has been horizontal, initially adapting drilling and completion technologies from shale gas development. With over 200 million barrels of proven Granite Wash reserves and low US natural gas prices, Anadarko basin E & P efforts are migrating towards higher rates of return from Granite Wash light oil, gas condensate and natural gas liquids. Driven by horizontal drilling and modern completion and fracturing techniques, horizontal well count and hydrocarbon liquid production have more than tripled over the last 4 years in this active U.S. mid-continent play.
Unlike typical sandstone reservoirs, the Granite Wash has complex mineralogy including quartz, potassium and sodium feldspars, illite, chlorite, dolomite and calcite. Depositional environments range from near shoreline to continental slope events to deep marine. Many of the targets consist of compartmentalized sub-marine fan deposition. Due to high level of reservoir heterogeneity and GOR, it is difficult to characterize reservoir property changes between fields and horizons. Prior production driver studies on vertical wells in the Granite Wash did focus on both reservoir and completion parameters. The bulk of horizontal studies are limited to completions and stimulation without rigorous investigation of stratigraphic and reservoir quality variation. This paper correlates well performance with completion and fracturing practices in well samples of similar geographic and stratigraphic position, determined from public domain well, completion and well and log data.
Using the large enormous public database of vertical wells, a three-dimensional sub-surface model of the reservoir is built for three geographic areas with multiple stratigraphic benches to reduce sample variation of reservoir quality. Reservoir quality is defined from petrophysical properties that affect the productivity of the well including but not limited to porosity, permeability, saturations and rock mineralogy, and accordingly, property distribution models are built for each property across study areas. Stimulation parameters investigated include, but are not limited to lateral length, number of fracturing stages, and normalized fluid and proppant volumes. Reservoir quality from the three dimensional model and parameters from the stimulation database are then correlated with well production to identify both stimulation and reservoir production drivers. The result sought is improved conclusions and recommendations for completion and stimulation in specific geographic areas and stratigraphic benches.
Revisiting the Before Closure Analysis Formulations in Diagnostic Fracturing Injection Test
Authors: Lamei H. , Soliman M. Y. , Shahri M. 
Published: February 2013

Abstract
The before closure analysis (BCA) method describes the unsteady flow of fracturing fluid into a formation considering time-dependent fracture face resistance. It provides a methodology for calculating the permeability and fracture face resistance instead of calculating the conventional leakoff coefficient. The original BCA model developed by Mayerhofer et al. (1995) has been simplified by different authors, including Valkó and Economides (1999). It is found that their proposed simplified formulation has some inconsistencies, which results in erroneous analysis of data and interpretation of permeability.
In this paper, the inconsistencies in the formulation have been addressed and resolved. The formulation of the corrected model is presented in a complete fashion. A discussion on sensitivity of the analysis, effect of pressure-dependent permeability, height recession, tip extension, and the effect of the reservoir fluid type is also provided. To validate the approach, two field examples of conventional oil reservoirs are presented as well. In the second case, the results are compared to the after closure analysis (ACA), and the effect of normal leakoff and pressure- dependent leakoff (PDL) on the BCA plot is discussed. The importance of considering correct data points in a normal leakoff portion is shown and illustrated on a BCA plot.
Thermal Reactivation of Microfractures and its Potential Impact on Hydraulic Fractures Efficiency
Authors: Dahi Taleghani A. , Olson J. E. , Wang W. 
Published: February 2013

Abstract
Core studies have proven the presence of abundant cemented micro-fractures in many tight formations. Furthermore, these studies have revealed the opening of some of these microfractures on the wall surface of main hydraulic fractures. Additionally, early-production well-testing analysis in some of these cases provides estimates for hydraulically induced fracture surface area which is much larger than fracture dimensions estimated in fracturing design or provided by the location of microseismic events. Existence of open small-size fractures could be a possible cause behind this discrepancy. In this paper, we show in what extent thermal stresses induced by temperature difference between fracturing fluid and formation fluid could provide the driving force to open a portion of these small cemented natural fractures laying on the surface of hydraulic fractures. Moreover, through combination of stress analysis and empirical fracture distribution models obtained from outcrops, we calculate the increase of total reservoir/fractures contact surface under the condition of microfractures activation. Our thermoelasticity analysis reveals the effect of the pump rate and temperature of the fracturing fluid on the number of activated microfractures. The results show that the volume of the micro-fractures varies depending on the length of the microfracture, rock properties and time. At the end, through an example, we show that activation of only a small portion of these microfractures can increase the total formation contact surface considerably and consequently initial production. Reservoir pressure changes due to production might partially close or re -open these micro-cracks during production. Hence, the role of these microfractures is mainly restricted to the early life of the reservoirs.
Utilization of Microseismic Event Source Parameters for the Calibration of Complex Hydraulic Fracture Models
Authors: Downie Robert , Xu Jian , Grant Dee , Malpani Raj , Viswanathan Anup 
Published: February 2013

Abstract
Observations of microseismic events detected during hydraulic fracturing treatments have provided an incentive to develop complex fracture models. Calibration of these models can be difficult when only the locations and times of the microseismic events are used. Incorporating the microseismic event source parameters into the model calibration workflow reveals changes in fracture behavior that are not easily visualized and provides additional guidance to the selection of modeling parameters.
Microseismic events occur when deformation of the reservoir and surrounding formations produces seismic waveforms. Travel-time and hodogram analysis of the recorded waveforms are used to locate the microseismic event sources while the amplitudes and polarities of the waveforms provide information about the deformation that has occurred. The geophysical property that is derived from the wave amplitudes is known as the seismic moment and is related to the area and displacement of the failure.
The relationship between seismic moment values and the deformations that produced microseismic events can be applied to engineering evaluations to identify variations in microseismic response. Use of this source parameter supplements commonly used visualizations of microseismic response where microseismic activity has been mapped. An example from a field case is included.
Mapping of the seismic moment distributions in a 3-dimensional viewer provides insights into fracture behavior that can be used to calibrate complex hydraulic fracture models. This is done through an integrated software package that facilitates comparisons of the microseismic evaluation and complex fracture modeling outputs seamlessly. Changes to the complex fracture model inputs can be evaluated quickly and easily to determine if the fracture modeling correlates well with the measured microseismic responses. Production evaluation, history-matching, and forward-modeling to test different completion and stimulation design scenarios can be undertaken with improved confidence using the calibrated complex fracture model.
The Role of Accounting Conservatism in the Equity Market: Evidence from Seasoned Equity Offerings
Authors: Kim Yongtae , Li Siqi , Pan Carrie , Zuo Luo 
Published: February 2013

ABSTRACT
Using seasoned equity offerings (SEOs) from 1989 to 2008, we examine the role of accounting conservatism in the equity market. We find that issuers with a greater degree of conservatism experience fewer negative market reactions to SEO announcements. We further show that an important mechanism through which conservatism affects SEO announcement returns is by mitigating the negative impact of information asymmetry. Additional analyses suggest that our results are not driven by the effects of other forms of corporate governance. We also find evidence that conservative issuers continue to use conservative accounting after the equity offerings. Taken together, our findings are consistent with the argument that accounting conservatism reduces financing costs in SEOs.
Data Availability: Data used in this study are available from public sources identified in the study.
Hypofractionated stereotactic radiotherapy for large or involving critical organs cerebral arteriovenous malformations
Authors: Blamek Sławomir , Larysz Dawid , Miszczyk Leszek , Idasiak Adam , Rudnik Adam , Tarnawski Rafał 
Published: February 2013

Abstract
Background. The treatment of large arteriovenous malformations (AVMs) or AVMs involving eloquent regions of the brain remains a challenge. For inoperable lesions, observation, volume-staged radiosurgery or hypofractionated stereotactic radiotherapy (HFSRT) are proposed. The aim of our study was to assess the safety and efficiency of HFSRT for large AVMs located in eloquent areas of the brain.
Materials and methods. An analysis of records of 49 patients irradiated for cerebral AVMs with a mean dose of 19.9 Gy (12-28 Gy) delivered in 2-4 fractions with planned gap (at least one week) between fractions. Actuarial obliteration rates and annual bleeding hazard were calculated using Kaplan-Meier survival analysis and life tables. Results. Annual bleeding hazard rates were 4.5% and 1.6% after one and two years of the follow-up, respectively. Actuarial total obliteration rates were 7%, 11%, and 21% and total response rate (total and partial obliterations) 22%, 41%, and 55% after one, two and three years of the follow-up, respectively. There was a trend towards larger total obliteration rate in patients irradiated with fraction dose ≥ 8 Gy and total dose > 21 Gy for lesions of volume ≤ 8.18 cm3 which was not observed in case of partial obliterations.
Conclusions. HFSRT results with relatively low obliteration rate but is not associated with a significant risk of permanent neurological deficits if both total and fraction doses are adjusted to size and location of the lesion. Predictive factors for total and partial obliterations can be different; this observation, however, is not firmly supported and requires further studies.
Dangerous disciplines: Understanding pedagogies of punishment in the neoliberal states of America
Authors: Robbins Christopher G. , Kovalchuk Serhiy 
Published: February 2013

Abstract
Public schools deploy a range of processes and practices that help constitute the formation and legitimation of certain knowledges, relationships, skills, values and, ultimately, subjectivities. School discipline regimes are one of these practices. Exercising their power through pedagogical modes of address, these regimes are currently organizing relationships throughout school cultures that reflect the values and encourage role performances associated with neoliberal capitalism. This research paper describes and analyzes two widely used discipline regimes-zero tolerance/hyper-criminalization and positive behavior interventions and support (PBIS) -through Foucault’s theories of governmentality and biopolitics. These two regimes provide mirror images of the primary modes of punishing and disciplining under neoliberalism: criminalization and individualization. The paper will also explore how neoliberalism subjects schools to processes of enclosure, but also how schools themselves have become sites productive of neoliberal subjects through the content, values and interests embedded in the curricula of PBIS and criminalization which students must master.
Post-Social politics, employability, and the security effects of higher education
Authors: Frauley Jon 
Published: February 2013

Abstract
Trends within Western capitalist societies toward the individualizing of social problems, the responsibilizing of individuals for such problems, the treating of social problems as problems of control, ongoing attempts to shift the burden for safety and security from the state to the market, and changing conceptions of citizenship, have produced a context within which economic insecurity appears as a governable problem for higher education. Canada’s most populous province, Ontario, experienced radical education reforms during the “common sense revolution” of the Progressive Conservative government from 1995 to 2003. The paper examines government documents, committee and task force reports, and legislative debates and hearings pertaining to these restructuring efforts and draws on the work of Michel Foucault and political sociology to explore the ‘security effects’ of higher education and the latter’s conceptual relationship to employability. Higher education policy and restructuring, shaped as it is by human capital theory, takes employability to be an outcome of restructuring. However, as the paper shows, in an attempt to produce ‘security effects’, employability operated as a central and constitutive category of governance around which education policies as regulatory strategies were crafted. In the recent emergence of a ‘next step’ in the production of the security effects of education employability is displaced by innovation.
Being different and the same? The paradoxes of ‘tailoring’ in education quasi - markets
Authors: Savage Glenn C. 
Published: February 2013

Abstract
In Australia, market-based education policies promote the notion that government schools should flexibly tailor secondary education to the needs of young people and their local communities. Far from offering a “one size fits all” system, policies seek to enable clients (parents, students) to exercise freedom of choice in quasi-markets that offer different educational products to different individuals. The intended effect is a kind of bespoke education tailoring, whereby schools operate as flexible service providers, adapting to the needs and desires of local markets. In this paper, I analyse the policy turn towards market tailoring as part of broader shifts towards advanced liberal governance in education. Following this, I feature interviews with educators in two socially disparate government secondary schools in the Australian city of Melbourne. In doing so, I analyse the extent to which each school tailors its marketing practices to its local community. These interviews suggest inherent contradictions emerge when tailoring is attempted in a hierarchical market with normative and rigid indicators of ‘brand value’. Schools are caught, I argue, between paradoxical demands, requiring them to be simultaneously different and the same.
Physical Culture in the Tradition and Rites of the Tatar Population Inhabiting Polish Territory
Authors: Szum Ernest , Cieoeliński Ryszard 
Published: February 2013

Abstract
This report presents the findings of a qualitative study on the physical culture of the Tatar community inhabiting Polish territory. Historical elements of the physical culture of the Tatar community have been presented against the background of general characteristics of this ethnic group and the history of the presence of Tatars on Polish soil. The article shows particular aspects of the Tatar tradition of physical culture and its place in Tatar national culture. This is the first known report on the physical culture of this ethnic group on the ground of ethnology or cultural anthropology.
Time Series Approach To Athletes Motor Potential
Authors: Maszczyk Adam , Roczniok Robert , Pietraszewski Przemysław , Stanula Arkadiusz , Zając Adam , Gołaś Artur 
Published: February 2013

Abstract

Introduction
. The aim of this study was to determine the dynamics of changes in selected motor abilities of javelin throwers and to determine predictors of javelin throw distances.
Material and methods
. Research material included the results obtained from a group of 60 competitors from the Silesia Region of Poland, aged 14 - 15 years. In order to answer the research question, the following statistical analysis were employed: Pearson's linear correlation coefficients, vectors R0 and R1, time series analysis, distributed lag analysis and Almon distributed lag analysis and coefficient of concordance φ2

Results
. The correlation analyzes allowed for a selection of two variables for further analyses: specific strength of arms and trunk (SSAT) and specific strength of shoulders girdle and trunk (SSGT). Calculated indexes revealed that the level of SSAT showed a constant upward tendency (+15%). The highest rise in SSAT level was recorded in the 4th and 5th quarter (+9%). The level of SSGT showed an upward tendency nearly (+6%). In this case, the highest rise was observed in the 7th and 8th quarter (+4.5%).
Conclusions
. The standardized regression analysis revealed that the variable of specific power of arms and trunk (SOBT) is the most important predictor for javelin throw distance with a full approach run.
It Will/Must/May Be a Modal Auxiliary
Authors: Ilc Gašper 
Published: February 2013

Abstract
The English modal verb system has proved to be a difficult linguistic concept even for advanced EFL students. Their comprehension/usage problems may be of purely morpho-syntactic and semantic nature or may also involve sociolinguistic dimensions. The paper examines the question of polysemy, sociolinguistic factors and the role of ELT models.
Alienation in Caryl Churchill’s a Number
Authors: Anghel Florentina 
Published: February 2013

Abstract
Caryl Churchill’s play A Number echoes the author’s attitude towards scientific evolution, having as a result cloning, and its impact on social and moral values and relationships. The paper will focus on identitary problems raised by cloning, on the clash between uniqueness and seriality, on the confusion arising from opportunities and unexpected effects.
Daniel Martin’s Multiple Journeys
Authors: Coser Cornelia 
Published: February 2013

Abstract
Modern literature modifies the pattern on which most western narration was founded. The hero’s adventures come to exhibit the same dependence on initial conditions as dynamical systems do. In John Fowles’s novel, Daniel Martin, both character and author benefit from multiple journeys, the fractal characteristics of the novel standing in contrast with the wholeness of the vision.
Off the Beaten Path: Ella D'arcy's Yellow Book Stories
Authors: Doroholschi Claudia Ioana 
Published: February 2013

Abstract
The small body of work produced by Ella D’Arcy in the 1890s is noteworthy for its experimentation with narrative instability, its unsympathetic treatment of character and its oppressive, claustrophobic fictional world. The paper looks at how D’Arcy’s fiction makes use of shifts in focalisation, melodramatic plot twists and closure to build up a sense of irresoluteness and moral de-centering.
Reconstructing a Life: Charles ‘Buddy’ Bolden
Authors: Dumescu Patricia-Dorli 
Published: February 2013

Abstract
Michael Ondaatje’s novel Coming through Slaughter is a fascinating attempt to bring literature and oral history together in order to recreate Charles ‘Buddy’ Bolden’s mysterious life. Daily routines and gestures, inner thoughts and high musical notes form a puzzle to which the citizens of the flamboyant New Orleans keep adding pieces. With the help of his only existing photograph, the present paper focuses on the unquestionable father of jazz, who kept “away from recorded history”.