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Heavy oil recovery by combined solvent and hot water (CS-HW) injection: Experimental, numerical and data mining-based analysis
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Petroleum Systems Engineering, University of Regina. xxix, 244 p.In this study, a hybrid EOR process is developed and optimized in a two-well configuration
for heavy-oil recovery which combines solvent injection using different solvents such as
carbon dioxide (CO2), methane (CH4) and propane (C3H8) with a moderate reservoir
heating by hot-water flooding (HWF) as a solution to enhanced heavy oil recovery
(EHOR), reduce energy consumption, and improved solvent retrieval efficiency.
The combined injection of solvent and hot water offers several advantages including
reduction of energy consumption compared to steam-based thermal EOR methods, and
reduction of solvent volume required to reduce the viscosity of heavy oil. The proposed
hybrid EOR method of combined solvent and hot water (CS-HW) injection outperformed
the sole injection of solvent, conventional water flooding (WF) and hot-water flooding
(HWF) by sustaining the foamy oil flow and effectively delaying water and gas
breakthrough times.
A total of 21 laboratory tests including water flooding (WF), hot-water flooding (HWF),
solvent injection, combined solvent and hot water (CS-HW) injection in a two-well
configuration were designed and conducted. More specifically, the design parameters such
as injection rate (qinj) and temperature (Tinj), solvent composition and slug size were
optimized with the objective of maximizing heavy oil recovery. In order to study the
numerical simulation of CS-HW injection and other laboratory tests presented in this
research, CMG-STARS module was used. Sensitivity analysis was performed on the
effective parameters of CS-HW injection process to obtain the best history-match between
the experimental data and the simulation model.
Furthermore, a new computational approach for predicting the performance of hot-water
flooding (HWF) in unconsolidated heavy oil reservoirs was presented. The proposed model
predicts the changes in the oil–water viscosity ratio (μo/μw) by estimating the reservoir
temperature distribution through porous media. Then, the dimensionless and normalized
variables were redefined to forecast water fractional flow as a function of temperature and
water saturation. Moreover, the proposed approach predicts the cumulative heavy oil
production and recovery factor more accurately and with less required input data and
runtime compared to CMG-STARS (computer modeling group), etc. Estimated results
were validated using laboratory experimental data and numerical simulation outputs. The
relative errors between oil recovery factors obtained from computational approach and
experimental data were measured to be about 5.3%, 1.7% and 1.2% and 2.5% for injection
temperatures of 40, 60, 80 and 100 °C, respectively.
Finally, this thesis provides a novel data mining-based analysis by using artificial neural
network (ANN) methodology to develop a high-performance neural simulation tool for
predicting the efficiency of CS-HW injection process. In order to train, test and validate
the model the experimental and simulation data obtained in this study together with
available data in the literature were fed to the machine learning technique to develop a CSHW
recovery performance predictive model. The proposed intelligent predictive model is
expected to help petroleum engineers as an alternative model to predict the efficiency of
CS-HW injection process, where other models have limitations and their input parameters
are often not easily accessible.Studentye
Comparing resilience and coping among emerging, young, and middle-aged adults
No full textA Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts (Honours) in Psychology, University of Regina. vii, 62 p.Resilience and adaptive coping are two attributes that are essential to dealing with life’s perpetual stressors. Evidence supports that middle-aged adults are more resilient and better at coping with stressors than their younger counterparts. Nevertheless, some evidence also supports that young adults who use problem- and emotion-focused coping successfully cope with stressors. The present study was aimed at better understanding resilience and coping in emerging (i.e., 18 to 25 years), young (i.e., 26 to 44 years), and middle-aged (i.e., 45 to 64 years) adults in Saskatchewan by examining whether certain age groups demonstrated higher levels of coping and resilience and the factors (adverse events, coping style, social support, wisdom) that might be connected to these higher levels. A total of 297 Saskatchewan adults were included in the final sample, with 67 emerging, 164 young, and 66 middle-aged adults. Analyses of variance (ANOVAs) and simple linear regressions were performed. While no differences across age groups were identified for problem-focused coping, emerging and young adults reported higher levels of emotion-focused and avoidant coping compared to middle-aged adults. Social support and wisdom were found to significantly influence coping above and beyond age. These findings support existing literature on lifespan coping and point to the need to promote social support and wisdom expansion for well-being across adulthood.Studentn
Development of bio-composite filaments for drinking straw application
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Industrial Systems Engineering, University of Regina. xi, 107 p.Lifestyle shifts and the pursuit of comfort have led to an increased reliance on straws
for consuming beverages. This trend has contributed to the growing environmental concern
related to plastic waste. Plastic straws and stirrers accounted for ~7% of the debris found in the
ocean, with most being non-recyclable. This detrimental environmental impact has led to many
countries banning single use plastics, which includes straws, stirrers and cutlery. The bans on
single-use plastics have prompted initiatives to identify suitable alternatives, thereby creating
new market opportunities for the development of biodegradable materials.
This study investigates creating bio-composite material from locally available flax fibre
and PLA as a filament and analyzing the properties for future manufacturing of drinking straws.
Specifically, this proof-of-concept research focuses on manufacturing different bio-composite
filaments and characterizing properties related to drinking straw’s functionality of strength and
moisture absorption according to standardized material testing protocols. By deriving the
mathematical models of these properties as a function of fibre composition, future optimization
for production of value-added products will be possible.
Various blends of PLA powder and flax fibre were extruded using a WellzoomTM
filament extruder. Their moisture absorption, tensile properties, and flexural properties, based
on ASTM D570, ASTM D638 and ASTM D790 protocols, were studied. Transfer of the rodlike
filament analysis to hollow cylindrical drinking straws is possible.
Moisture absorption on four specimens of each composition was completed in both
distilled water and a carbonated beverage. During the initial 45 minutes, the highest rate of
moisture absorption occurred ranging from 0.0006 g/min to 0.001 g/min. Minimal absorption
occurred for the remaining 24hrs with distilled water, whereas the amount of absorption
doubled for the carbonated beverage. The observed trends showed moisture absorption
increased with increasing fibre content. No visible change in geometry or surface of the
specimen occurred during the 24hrs. The tensile properties were analysed using six specimens
from each composition. The filaments with 10% flax content sample exhibited superior tensile
properties, and retained 63% and 82% of PLA’s tensile strength and Young’s Modulus,
respectively. Samples with higher fibre content recorded lower tensile properties. Flexural
properties were analysed using 5 specimens; the filaments with 7.5% fibre content had the
highest flexural property and exhibited 87% of the flexural strength of PLA filament. The
filament composted of 12.5% fibre (87.5P12.5F) had the lowest flexural properties. The
trendline (third order polynomial) for the 8 data points had a correlation factor (R2) ranging
from 0.73 to 0.9 for predicting composite material properties.
By examining the manufacturing parameters and properties like water absorption,
tensile and flexural, valuable insights have been gained into the behaviour and performance of
these composites. Others have shown that PLA degrades at higher temperatures below PLA
melting point in industrial biodigesters at rates that are in hours compared to years at
temperatures near 60°C; the increase in flax fibre is expected to further increase the
biodegradability. Using these results, future drinking straws may be manufactured by 3D
printing or by extruding PLA-flax fibre blends. The latter requires developing an extrusion
nozzle to form tubes. This could benefit many sectors, such as food and beverage, hospitality,
and healthcare, which rely on straws for convenience and accessibility.Studentye
Associations of dispositional mindfulness
No full textA Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts (Honours) in Psychology, University of Regina. 70 p.Background: Psychological disorder symptoms impact a large portion of the Canadian population, and while effective treatments are available, few people seek them out. This can be partly attributed to low mental health literacy: lack of knowledge about where to seek help or poor recognition of psychological disorder symptoms when present. Dispositional mindfulness (DM) is the capacity to pay non-judgmental attention to present-moment experiences. This construct is typified by acceptance and non-reactivity toward inner experiences, including negative emotions and psychological distress. This suggests higher DM may facilitate the recognition of psychological symptoms and may be associated with higher MHL.
Purpose: The objective of the present study is to examine whether DM scores were meaningfully associated with psychological disorder symptom recognition and mental help-seeking attitudes (MHSAS).
Method: A total of n = 299 participants (Mage = 41.04; 49.5% cis women) were recruited via Amazon’s Mechanical Turk and completed measures of depression (PHQ-9), anxiety (GAD-7), DM (FFMQ-24), and MHSAS (MHSAS-9). Further, participants read eight vignettes of fictitious patients (developed according to ICD-10 criteria) suffering from various psychological disorder symptoms, and the accuracy of their recognition of symptoms was tallied (PDR-V).
Results: Correlation analyses revealed DM scores were positively associated with MHSAS (r = 0.25, p <.001), and PDR-V scores (r = 0.18, p <.001). Hierarchical regressions revealed that DM predicted variance in symptom recognition (1.3%) and MHSAS scores (6%) over and above demographic variables.
Implication: DM shows an association with MHL components, and if an intervention effectively cultivates mindfulness, it may also enhance aspects of MHL.Studentn
Parenting and social media: Exploring parental understanding of adolescent social media use
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Social Work, University of Regina. v, 77 p.Social media (SM) has become an integral part of adolescent socialization. SM is widely
accessible through advanced technology with resulting demands for constant connection.
Existing research has focused on the negative aspects of SM while highlighting the need for an
understanding of how to mitigate risk factors associated with adolescent SM use. Parental
mediation strategies have been noted in existing research as an important factor in lessening risks
or negative outcomes related to adolescent SM use. Using interpretive phenomenology analysis
(IPA), parental understanding of adolescent SM use was explored to gain insight into how
parents understand and experience mediation strategies related to adolescents’ involvement in
the virtual world. Findings indicate parents do understand mediation strategies and have
employed varying strategies inclusive of monitoring, restrictions, and open communication.
Further, findings suggest parents accept SM and embrace the associated challenges of
adolescents’ involvement in the online world, adapting to changes and adjusting mediation
strategies to meet the needs of their adolescent and family. This thesis asserts parents are creating
a parenting philosophy that focuses on relationships, with potential for SM to provide important
teaching opportunities and improved communication with their young people. Improving
understanding of parental experiences regarding adolescent SM use and how parents navigate
this socio-cultural shift can provide helpful information for social work practice to support
parents and families navigating this foreign world.Studentye
Ranking Canadian waste management system efficiencies using three waste performance indicators
No full textThis version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s11356-023-25866-0Three waste management system (WMS) efficiency indicators are adopted to systematically assess WMSs efficiency in Canada from 1998 to 2016. The study objectives are to examine the temporal changes in waste diversion activities and rank the performance of the jurisdictions using a qualitative analytical framework. Increasing Waste-Management-Output-Index trends (WMOI) were identified in all jurisdictions, and more government subsidiaries and incentive packages are recommended. With the exception of Nova Scotia, statistically significant decreasing Diversion-Gross-Domestic-Product-ratio (DGDP) trends are observed. It appears that the increases in GDP from Sector 562 were not contributing to waste diversion. On average, Canada spent about $225/tonne of waste handled during the study period. Current-Spending-per-Tonne-Handled (CuPT) trends are decreasing, with S ranged from +5.15 to +7.67. It appears that WMSs in Saskatchewan and Alberta are more efficient. The results suggest that the use of diversion rate alone to evaluate WMS may be misleading. The findings help the waste community to better understand the trade-offs between various waste management alternatives. The proposed qualitative framework utilizing comparative rankings is applicable elsewhere, and can be a useful decision support tool for policy-makers.The research reported in this paper was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (RGPIN-2019-06154) to the corresponding author, using computing equipment funded by FEROF at the University of Regina
Do trauma cue exposure and/or PTSD symptom severity intensify selective approach bias toward cannabis cues in regular cannabis users with trauma histories?
No full textTrauma cue-elicited activation of automatic cannabis-related cognitive biases are theorized to contribute to comorbid posttraumatic stress disorder and cannabis use disorder. This phenomenon can be studied experimentally by combining the trauma cue reactivity paradigm (CRP) with cannabis-related cognitive processing tasks. In this study, we used a computerized cannabis approach-avoidance task (AAT) to assess automatic cannabis (vs. neutral) approach bias following personalized trauma (vs. neutral) CRP exposure. We hypothesized that selective cannabis (vs. neutral) approach biases on the AAT would be larger among participants with higher PTSD symptom severity, particularly following trauma (vs. neutral) cue exposure. We used a within-subjects experimental design with a continuous between-subjects moderator (PTSD symptom severity). Participants were exposed to both a trauma and neutral CRP in random order, completing a cannabis AAT (cannabis vs. neutral stimuli) following each cue exposure. Current cannabis users with histories of psychological trauma (n = 50; 34% male; mean age = 37.8 years) described their most traumatic lifetime event, and a similarly-detailed neutral event, according to an established interview protocol that served as the CRP. As hypothesized, an AAT stimulus type x PTSD symptom severity interaction emerged (p = .042) with approach bias greater to cannabis than neutral stimuli for participants with higher (p = .006), but not lower (p = 0.36), PTSD symptom severity. Contrasting expectations, the stimulus type x PTSD symptoms effect was not intensified by trauma cue exposure (p = 0.19). Selective cannabis approach bias may be chronically activated in cannabis users with higher PTSD symptom severity and may serve as an automatic cognitive mechanism to help explain PTSD-CUD co-morbidity.PTSD-Cannabis Use Disorder Comorbidity: Associative Memory Mechanisms : Canadian Institutes of Health Researc
Novel synthesized transition metals liquid catalysts for heavy oil recovery
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Petroleum Systems Engineering, University of Regina. xv, 168 p.The effectiveness of oil recovery operations can be increased through the use of chemical-assisted enhanced oil recovery (EOR), which has recently attracted a lot of interest. Due to the high viscosity and high asphaltene concentration of heavy oil, which makes production technically difficult, new recovery techniques are frequently tested and used on a lab scale. This dissertation contributes to general progress in this area by synthesizing three metallic liquid catalysts (LCs) in the lab and applying it to enhance heavy oil recovery for the first time. A number of sand-pack flooding experiments, data collection on viscosity, density, interfacial tension (IFT), Fourier-Transform Infrared Spectroscopy (FTIR), saturate, aromatic, resin, and asphaltene (SARA) fractions, and numerous modeling runs were all used in this work to assess the LC-EOR. The main objective is to develop and synthesize non-corrosive LCs that can be used as upgrading agents as well as displacing fluids. The first series of tests looked at the effectiveness of acidic Ni-Mo-based LC in enhancing heavy oil recovery from sand-pack columns in order to achieve this goal. The second experiment of the research was performed to study the effect of Co-Mo LC in improving heavy oil recovery. The third set of experiments looked at the use of an Organobimetallic LC as a heavy oil upgrading agent.
According to the findings, heavy oil quality can be improved at low temperatures and pressure, and oil recovery can be boosted by injecting various LCs into sand-pack columns. One mild pollutant that is moderately removed as a result of LC treatment is the sulfur component, which is unquestionably a benefit of LC treatment. The findings additionally demonstrated that LCs lower the IFT of oil-brine systems, which helps improve the sweep efficiency and, consequently, enhance the oil recovery. Moreover, the oil's density andviscosity both decreased after treatment with LCs, increasing its mobility and boosting oil recovery. In order to determine the ideal production conditions for the LCs flooding approach for heavy oil recovery, simulation studies were carried out using the CMG-STARS software and integrated with the findings of the first and second sets of experiments. Sand-pack flooding experiments (water flooding and liquid catalyst flooding in tertiary recovery mode) were selected in order to obtain the historical matching of the laboratory scale findings of cumulatively produced oil and water cut utilizing CMG-STARS and CMOST modules. Additionally, a sensitivity analysis was conducted to test a wide range of hypotheses in order to identify the best process regulating factors. The best operational parameters are then chosen to optimize oil production using a genetic algorithm (particle swarm optimization).
The findings of this research would be useful in deciding which EOR schemes to pursue, as well as opening up new avenues for developing existing procedures and introducing strategies that were not previously considered.Studentye
