Model for Fracturing Fluid Flowback and Characterization of Flowback Mechanisms

A large volume of fracturing fluid that may include slick water and various sorts of additives is injected into shale formations along with proppant to create hydraulic fractures which define a stimulated shale volume a shale gas well will actually drain. While in hydraulic fractures in conventional reservoirs most of the injected fracturing fluid flows back quickly, field observations have reported that load recovery from shale gas wells occurs over a long period, and in some shale formations only a small fraction of total injected fluid is recovered. An unresolved question is whether unrecovered injected fluids are detrimental to well performance. This study emphasizes three main aspects: the location of injected water after fracturing treatment; the mechanisms of water retention underground; and the mechanisms behind the observed flowback behavior. To locate the injected fracturing fluid we cataloged the possible fracture types including the main propped fracture and secondary fractures that may or may not be filled with injected fluid or proppant or even hydraulically connected. The investigation of factors impacting water retention will consider formation properties and fracture configurations of the cataloged locations for injected water and will evaluate the degree to which each factor plays. Finally, we will model long term flowback and formation flow behavior and mechanisms in order to quantify fundamental implications of retained water on well performance and expected ultimate recovery. The significance of this research work lies on understanding how flowback behavior impacts the gas production performance of shale gas wells in both short term and long term view. Whether the unrecovered water blocks the gas flow path to the well or behaves as proppant to keep the fractures open and enhance the conductivity of an induced fracture system should be understood before the fracturing treatment design and flowback scheme determination. More specifically, an aggressive flowback schedule might reduce the effective stimulated shale volume and/or the gas production rate. Therefore, understanding where the injected water is located, how water is distributed underground, how water flows with gas and what controls water flowback are critical to understand the beneficial or detrimental effects of flowback and load recovery on shale gas well production

The relationships between school belonging and students' motivational, social-emotional, behavioural, and academic outcomes in secondary education:a meta-analytic review

This meta-analytic review examines the relationships between students' sense of school belonging and students' motivational, social-emotional, behavioural, and academic functioning in secondary education. Moreover, it examines to what extent these relationships differ between different student groups (grade level, SES), measurement instruments, and region. The meta-analysis included 82 correlational studies, published in peer-reviewed journals between 2000 and 2018. Results revealed, on average, a small positive correlation with academic achievement, and small to moderate positive correlations with motivational outcomes such as mastery goal orientations; with social-emotional outcomes such as self-concept and self-efficacy; and with behavioural outcomes such as behavioural, cognitive, and agentic engagement. A small negative correlation is observed with absence and dropout rates. Similar results are found across different student groups (grade level, SES). Although the results vary to some extent across measurement instruments and region, generally, the results reveal that school belonging plays an important role in students' school life

How contextual factors influence teachers' pedagogical practices

Background Primary teachers' pedagogical practices (TPP) are strongly focused on supporting pupils' psychological needs, creating a safe learning climate, and encouraging pupils' developmental and learning processes. As a core motivation for teachers is the desire to interact constructively with children, pedagogical practices can be understood as central to teachers' work. A familiar problem in many international contexts is that TPP can come under pressure, typically as the result of interplay between personal and contextual factors. However, which contextual factors influence TPP, and how they do so, remains unclear. Purpose In this study, we aimed to better understand how context influences primary school teachers' pedagogical practices, within the setting of primary education in the Netherlands. We were particularly interested in which contextual factors were perceived as important and how they influenced TPP. Methods Data were collected through open questions in a survey among 215 primary school teachers in the northern part of the Netherlands. Focus group interviews were then held with 11 of the survey participants. The data were analysed qualitatively, using a framework approach with five stages of familiarisation: identifying themes, indexing, charting, and mapping and interpretation. Findings The analysis identified nine contextual factors that, according to participants, both positively and negatively affected TPP. The most frequently mentioned threats to TPP were educational accountability and standards, and organisation of work in the classroom, whilst school improvement and pupils' educational needs were regarded as the most important stimulating factors. We clustered the factors into four patterns which reflected the way that teachers appraised them: organisation of daily classroom practices, school culture, educational improvement, and contribution to pupils' development. Conclusions According to the teachers, the interplay between TPP and the context can cause pressure, frustration, and feelings of incompetence because there is insufficient time for achieving pedagogical goals. Our study draws attention to the complex challenges that teachers face in terms of balancing pedagogical practices and other educational tasks, and draws out implications for policy and practice

The Factors Influencing Teaching (FIT)-Choice scale in a Dutch Teacher Education Programme

This study examined the suitability of the FIT-Choice scale in a Dutch educational context among two cohorts of preservice teachers (Ns = 62, 89), surveyed at the end and the beginning of their one-year program respectively. The relationships between the motivations for becoming a teacher and concurrent commitment were examined, as well as the differences between the two cohorts. The factor analyses were consistent with the original FIT-Choice structure. The main motivation for becoming a teacher was the self-perception of teaching-related ability. Affective commitment was predicted by the motivations of teaching ability, working with children, prior teaching and learning experiences, and time for family, as well as satisfaction with the choice of teaching and perceived task demand. Lastly, preservice teachers at the end of their teacher education considered social influences and teaching ability to be more important motivations for becoming a teacher