Development of new asphalt technologies to reduce both energy consumption and CO2 production has attracted great interest in recent years. The use of foam bitumen, as one of them, is attractive due to the low investment and production cost. Formation and decay of foam bitumen is a highly dynamic temperature dependent process which makes characterization difficult. In this thesis, new experimental tools were developed and applied for characterizing the foam bitumen during the hot foaming process.  One of the main goals of this study was to improve understanding and characterization of the foam bitumen formation and decay. X-ray radiography was used to study the formation and decay of foam bitumen in 2D representation. The results demonstrate that the morphology of bubble formation depends on the types of bitumen used. Moreover, theoretical investigation based on the 3D X-ray computed tomography scan dataset of bubble merging showed that the disjoining pressure increased as the gap between the bubbles in the surface layer (foam film) decreased with time and finally was ruptured.   Examining the foam bitumen stream right at the nozzle revealed that foam bitumen at a very early stage contains fragmented pieces of irregular size rather resembling a liquid than foam. The result from thermogravimetric analysis demonstrated that residual water content depends on the initial water content, and was found to be between 38 wt% and 48 wt% of the initial water content of 4 wt% to 6 wt%. Moreover the influence of viscosity and surface tension on bubble shape and rise velocity of the bubbles using level-set method was implemented in finite element method. The modeling results were compared with bubble shape correlation map from literature. The results indicated that the bubble shapes are more dependent on the surface tension parameters than to the viscosity of the bitumen, whereas the bitumen viscosity is dominant for bubble rising velocity. / <p>QC 20160303</p>

Thesis (PhD (Civil Engineering))--Stellenbosch University, 2008. / The cold bituminous mixtures, which are the subject of this study, are obtained by mixing mineral aggregate with either bitumen emulsion or foamed bitumen at ambient temperatures. These techniques are frequently used in Cold In-Place Recycling whereby typically the top 150 – 250 mm of the existing pavement is reworked, as a rehabilitation measure when structural maintenance is required. To differentiate from the cold mixes for surfacing layers the term Bitumen Stabilised Materials (BSM’s) is adopted here. The increased use of BSM’s, shortcomings in the existing design guidelines and manuals and ongoing developments in the concepts and understanding of these materials require further research into the fundamental properties and behaviour of BSM’s. Achieving a better understanding of the fundamental performance properties of BSM’s is the main objective of this study, with a view to using the extended knowledge for improvements to current mix design and structural design practices. The state-of-the-art of bitumen emulsion and foamed bitumen techniques is reviewed in a literature study. Current best practices in the design of BSM’s and pavements incorporating such materials is also included in this literature study. Shortcomings and areas for further improvement of the design practice have been identified. With new environmental legislation that recently came into effect in South Africa, the importance of BSM technology as an environmentally-friendlier and more sustainable construction technique is set to increase in the coming years. A laboratory testing programme was set-up to study the properties and behaviour of BSM’s and to establish links with the compositional factors, i.e. the type of binder used, the percentage of Reclaimed Asphalt Pavement (RAP) in the mix and the addition of a small dosage of cement as active filler. The mineral aggregates used were sourced in the USA and consisted of crushed limestone rock and RAP millings. These were blended in two different proportions of crushed rock : RAP, i.e. 3:1 (with 3.6 % residual binder) and 1:3 (with 2.4 % residual binder). Tri-axial testing (150 mm diamter) was carried out to determine shear parameters, resilient modulus and permanent deformation behaviour, while four-point beam testing was carried out to determine strain-at-break, flexural stiffness and fatigue behaviour. It was found that the process of bitumen stabilisation improves the shear strength of the material, particularly in case 1 % of cement is added as active filler. This increase in shear strength is entirely the result of increased cohesion. There is a good correlation between the shear strength and the resilient modulus of BSM’s. The resilient modulus of BSM is stress-dependent and the Mr-θ model is adequate to model the resilient modulus of the blends with a low percentage of RAP. For the blends with a higher percentage of RAP this model cannot be applied and the resilient modulus reduces in stiffness at higher deviator stress ratios. A considerable part of the efforts of this study were dedicated to characterise and model the permanent deformation behaviour. The General Permanent Deformation Law as originally developed by Francken applies also to BSM’s. An improved nonlinear method to converge at a solution for the model parameters that describe the tertiary flow part of this deformation law was developed as part of this study. Parameters that can be derived from the first stage of the permanent deformation test, i.e. initial strain and initial strain rate as defined in this study, were found that correlate well with the model parameters that describe the first linear part of the deformation law. Critical deviator stress ratios for the several mixes tested were determined. When BSM’s are subjected to loading below these ratios, tertiary flow is unlikely to occur. A high variability was generally found in the four-point beam test results, especially for the strain-at-break. Specimen preparation protocols and the quality of the beam specimens are of utmost importance when performing four-point beam tests on BSM’s. This limits the practical applications of the strain-at-break test. Trends observed in the strain-at-break were also inconsistent and sometimes not in line with the other type of tests. BSM’s exhibit a visco-elastic behaviour, which was determined by flexural stiffness testing, however, to a lesser extent than HMA. Phase angles and Black Diagrams were developed for the BSM’s tested, which also made it possible to determine the parameters of the Burgers Model, which is a mechanical model describing viscoelastic behaviour. Fatigue relationships were also developed for the BSM’s tested. The fatigue performance of these mixes is lower than for selected HMA mixes. The foamed BSM generally showed better fatigue life than emulsion BSM, however, the lower initial stiffness of the foamed BSM’s may contribute to a perceived longer fatigue life. For the mixes tested, the flexural stiffness of foamed BSM’s is generally also lower than that of emulsion BSM’s It is recommended that the mix design of BSM’s be split into two phases. During the first phase the usually large number of variables could be reduced to a selected few by means of UCS and ITS indicator testing. Subsequently, more fundamental parameters should be determined during the second phase, such as shear strength and resilient modulus, as well as permanent deformation behaviour. The fact that commercial laboratories in South Africa do not have tri-axial testing facilities is currently a practical limiting factor. Initiatives currently underway to develop “simple” shear tests are welcomed in this regard. It is proposed that classification of BSM is based on shear strength. There are indications that shear failure in BSM is more critical than failure as a result of fatigue. The effect of curing resulting in an increase in BSM stiffness in the period after construction, i.e. typically 6 to 18 months, is currently ignored in structural design models. The rapid stiffness reduction of BSM’s during the first period after construction in the current structural design models and also found during Accelerated Pavement Testing is not being observed in Long-Term Pavement Performance (LTPP). On the contrary, an increase in stiffness is observed in LTPP. This would indicate that stiffness reduction as a result of fatigue does not occur or is overshadowed by the effect of curing and that fatigue as a failure mechanism of BSM’s is currently over-emphasized.

Thesis (MScEng (Civil Engineering))--Stellenbosch University, 2008. / There are currently well established compaction methods being used in laboratories globally to prepare specimens for material testing. None of these methods provides the repeatability and reproducibility, ease of execution or simulation and correlation to field compaction desired by engineers. The research presented in this report was aimed at the development of a new or adapted compaction method for bituminous stabilized materials (BSM) that would address the aforementioned factors, by making use of a vibratory hammer. Along with this, a new protocol was to be established. The initial vibratory hammer that was tested was the Kango 637®. This specific vibratory hammer suffered irreparable damage to the gearbox during the research. A replacement Kango hammer could not be purchased, therefore a substitute hammer was purchased i.e. a Bosch GSH 11E®, for which back-up service and replacement parts are readily available throughout South Africa. Significant progress had been made with the development of a laboratory compaction protocol for BSM using the Kango Hammer. The specifications of the Bosch® hammer showed it was superior in terms of power, weight and other technical features. Comparative testing was therefore carried out. This allowed for the adaptation of the results achieved to that point. Extensive experimentation was then carried out using two types of BSM i.e. foamed bitumen (80/100 bitumen) and bitumen emulsion (60/40 Anionic Stable Grade) stabilized material. The initial material used for the experimentation was a G2 quality graded crushed stone. Additional material was also obtained from a recycling project taking place along the N7 near Cape Town. The N7 material was used to perform correlation experiments so as to determine how representative the laboratory compacted specimens were to field compacted material. Results showed that the vibratory hammer is capable of producing specimens for testing in the laboratory as well as providing a possible benchmark method for accurately controlling the quality of work on site i.e. field density control. This was done by identifying the time to and level of refusal density compaction. The level of refusal density compaction was expressed as a percentage of Mod AASHTO compaction and using current specifications, a potentially new site compaction level specification was determined. In order to asses the material applicability of the vibratory hammer compaction method, tests regarding moisture sensitivity analysis were carried out on a G5 material. The vibratory compaction protocol includes a specification for the type of hammer, guide-frame, surcharge weight, compaction moisture and number of layers. Vibratory compaction can be used to prepare two types of specimens: • Specimens for triaxial testing with a diameter of 150mm and a height of 300mm • Specimens for laboratory testing with a diameter of 150mm and a height of 125mm. Tests showed that the material properties prove to have an influence on the compactability of the material. Material from the N7 recycling project had been milled out thus altering the grading and including some RAP. This in turn influenced compaction. The vibratory hammer moisture curve was found to shift slightly to the left when compared to the Mod AASHTO moisture curve. The variability of the vibratory hammer was found to be well below the specified variability of 15%. Repeatability experiments on G5 material indicate that vibratory hammer compaction may be used on lesser quality granular materials. A recommended procedure for the compaction of BSM was developed following the experimentation results.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009. / The need for a more reliable testing procedure for the characterisation and Quality Assurance/ Control of Bitumen Stabilised Materials (BSMs), besides UCS and ITS testing, has long been recognised by the roads industry. In fact, at CAPSA 2004 and CAPSA 2007, discussions of improved test methods for granular materials, i.e. possible replacement tests for CBR procedures, were conducted in workshops. Triaxial testing for the evaluation of shear parameters is widely recognised as a reliable method of measuring these critical performance properties of granular and Bitumen Stabilised Materials (BSMs). However, the triaxial test in its current state as a research test has little chance of extensive use by practitioners and commercial laboratories, because of complexity, cost and time issues. Major adaptations to the research triaxial test are necessary, before this useful test can have a chance of being accepted by road practitioners. The main aim of this study is to investigate possibilities of developing a simple, affordable, reliable and robust test for characterizing granular and bitumen stabilized materials thus linking test outcome with in-situ performance. This is achieved through the innovative design and manufacture of a prototype triaxial cell capable of accommodating 150 mm diameter by 300 mm deep specimens. The cell is simpler than the research (geotechnical) triaxial cell and the operational protocols have been streamlined, thereby reducing the time and steps required in assembling specimens and testing them. In order to ensure the development of an appropriate triaxial cell for industry, a survey was conducted aimed at investigating currently available facilities, testing capacity and resources within civil engineering laboratories in South Africa. Findings of the survey (Appendix 4) have provided guidance with regard to the nature and sophistication of any new tests to be developed. The survey highlighted some of the limitations and lack of sophistication of the current loading frames used for CBR and UCS testing such as lack of electronic LVDTs, limited overhead space, limited loading capacity and others. Most laboratories would need to invest in new loading facilities to carry out triaxial tests. A review of the test procedure for monotonic triaxial test showed that two main factors contribute to the complexity of the research (geotechnical) triaxial cell namely, time taken to assemble the specimen accurately in the cell and secondly the inherent design of the cell which makes it water and/or air tight at relatively high pressures. The design of the Simple Triaxial Test, therefore, was aimed at overcoming the drawbacks of research triaxial test e.g. fitting a membrane to each specimen to be tested, through considerable simplification by means of a new structure design and procedure of assembly of specimen into the cell. The advantage of addressing these issues would be reduction in the number of steps required in the test procedure and therefore reduction in testing time. The design of the cell particularly was preceded by a conceptualization process that involved investigation of numerous options. Concepts such as the bottle, encapsulated-tube, bottle and sandwich concepts were considered and given reality checks. In addition, available triaxial procedures of a similar nature e.g. Texas Triaxial, were evaluated and analyzed. Ultimately, with some trials and innovation, a design was developed for a simple triaxial cell comprising a steel casing with a latex tube which is then introduced around the specimen sitting on a base plate. It is based on the ‘tube concept’ in which the specimen acts like a ‘rim’ and the cell acts like a ‘tyre’ providing confinement to the triaxial specimens for testing, within the tube. This approach eliminates the use of O-rings and membranes for the specimen and tie-rods for the triaxial cell, thus reducing testing time considerably. The overall dimensions of the cell are 244 mm diameter by 372 mm height (Appendix 5). The cell was manufactured at Stellenbosch University Civil Engineering workshop and preliminary tests were conducted under this study. Parallel tests were also conducted with the Research Triaxial Test setup at Stellenbosch University in order to determine if preliminary results obtained with the Simple Triaxial Test setup were comparable therefore providing a means of validating the data. Results of analysis of variance (ANOVA) show that variability between Simple Triaxial Test (STT) and Research Triaxial Test (RTT) results is less significant whilst that within samples of STT and RTT results is quite significant. Comparisons also show that good correlation were obtained from Reclaimed Asphalt Pavement (RAP) Hornfels + 3.3 % Emulsion + 0 % Cement mix and mixes with the G2 base course aggregate whilst completely different correlation was obtained from RAP + 3.3 % Emulsion + 1% Cement. It is evident however that the differences observed stem from material variability i.e. random variability to one degree or the other and not to the STT apparatus. It is recommended for future research that more STT versus RTT testing be done especially on a mix with known mechanical properties when compacted to a specified dry density, e.g. graded crushed stone (G1) compacted to 100% mod. AASHTO. In summary, a locally made, low cost, relatively durable triaxial cell with relatively easy and quick specimen assembly procedures has been developed. It is now possible to perform triaxial tests on 150 mm diameter by 300 mm high specimen relatively easily and quickly. However, the challenge of validating results obtained, as well as improving the manufacture process of its main component, the tube, still remains.

Despite applications of foamed bitumen technology in pavement construction in various places around the world, there are still several aspects about this technology that are not clear. In addition, knowledge on foamed bitumen technology is mainly empirical and lacks scientific basis. This study addresses some of the aspects for foamed bitumen technology such as: Investigation of any effects in binder composition during the production process for foamed bitumen; assessment of the effect of bitumen source on foamed bitumen characteristics; development of a rational method to optimise foamed bitumen characteristics and conditions; evaluation of aggregate particle coating within foamed bitumen mixes; further improvements in the mix design procedure specifically the method of compaction and optimum bitumen content determination stages are suggested.  Fourier transform infrared spectroscopy techniques were used to investigate any changes in bitumen composition after the production process of foamed bitumen. Fourier transform infrared tests were done on foamed bitumen and neat bitumen specimens for two bitumens with similar penetration grades. Foamed bitumen characteristics of three bitumens were established by producing foamed bitumen at temperatures of 150ºC up to 180ºC and foamant water contents of 1, 2, 3, 4 and 5%. From the analysis of variation of foamed bitumen characteristics (maximum expansion ratio and half-life) at different temperatures a new method based on the equi-viscous bitumen temperature to optimize foamed bitumen conditions and characteristics was proposed. Rice density and surface energy concepts were used to evaluate aggregate particle coating with foamed bitumen. A granite aggregate divided into three different size fractions and three sets of foamed bitumen produced from three bitumen penetration grades were used. A gyratory laboratory compaction procedure for laterite gravels treated with foamed bitumen was established using the modified locking concept. Three laterite gravels with different chemical composition were mixed with foamed bitumen produced from one penetration bitumen grade. The resulting mixes were compacted up to 200 gyrations and the corresponding compaction curve defined in terms of height versus number of gyrations noted. In addition, the optimum moisture content requirements at the modified locking point were determined. 3D packing theory concepts, primary aggregate structure porosity and an indirect tensile strength criteria were employed to determine optimum bitumen content for foamed bitumen mixes.  Fourier infrared techniques revealed that foaming did not cause any changes in the bitumen chemistry, implying that the foamed bitumen production process may possibly be a physical process. Characterisation of foamed bitumen produced from three bitumen penetration grades showed that foamed bitumen characteristics (maximum expansion ratio and half-life) were mainly influenced by binder viscosity rather than the source. The equi-viscous temperature seemed to provide a suitable criterion at which foamed bitumen with optimum characteristics could be produced. Rice density results showed that aggregate size fraction, binder expansion ratio and viscosity influenced aggregate particle coating. For the coarser aggregate fraction, results revealed that binder coating seemed to be mainly influenced by temperature. Whilst for fine aggregate fraction the coating was mainly influenced by surface area. Surface energy results revealed that foamed bitumen exhibited better coating attributes than neat bitumen. A new laboratory compaction procedure for laterite gravels treated with foamed bitumen based on the modified locking point was developed. The modified locking point represents the state at which maximum aggregate particle interlock occurs when mixes are compacted in the field. It is based on the iii analysis of the rate of change for the gyratory compaction curve. The compaction curve in this case is defined in terms of compaction height versus number of gyrations. Gradation analysis beyond the modified locking point showed that aggregate particle breakdown occurred. Analysis of the optimum moisture at the modified locking point revealed that the moisture conditions were less than the aggregate optimum moisture conditions. It is recommended that this point be used to determine the optimal compaction characteristics of foamed bitumen mixes.  Aggregate structure porosity and an indirect tensile strength criteria can be used to determine the bitumen content that could be used in design of foamed bitumen mixes. This would reduce the amount of resources required since the bitumen content could be estimated prior to carrying out the actual laboratory work given that the aggregate grading is known. The aggregate structure can be divided (based on 3D packing theory) into oversize, primary, and secondary structures. The primary structure is mostly responsible for carrying loads whilst the secondary structure fills the voids within the primary structure and provides support to the primary structure. The aggregate size particles constituting the primary structure are deduced as a function of standard sieve sizes using the packing theory concepts. The minimum sieve size for the primary structure is proposed as 1 mm. The oversize structure consists of aggregate particles whose size is greater than the maximum size for the primary structure. The secondary structure consists of aggregate particles whose size is below the minimum size for the primary structure. The primary aggregate structure porosity can be used to establish the starting bitumen content; the bitumen content at which this porosity is 50% is chosen as the initial bitumen content. Indirect tensile strength values corresponding to 50% primary porosity are determined as well as the bitumen contents and compared against the recommended minimum values. / <p>QC 20161012</p>

Cette étude porte sur l'émulsification en continu du bitume à l'aide de mélangeurs statiques de type SMX, dans le domaine des émulsions concentrées, voire très concentrées. Ce travail suit une approche intégrant trois types de paramètres : procédé, formulation physico-chimique et composition, avec pour objectif ultime la maîtrise de la taille de gouttes. Il a été montré qu'une combinaison de fortes teneurs en bitume et de hautes températures d'émulsification favorisent l'obtention de très petites tailles de gouttes (diamètre médian inférieur ou égal à 1 µm). Cette observation contraste avec l'émulsification à forte teneur en phase dispersée en procédé discontinu. Ces résultats mettent en évidence une compétition entre les aspects énergétiques de l'émulsification et la formulation physico-chimique. Il a été mis en évidence, que lors de l'émulsification en continu à des fractions massiques en bitume supérieures à 90 %, la taille des gouttes n'est pas une fonction de l'énergie fournie mais que ce sont les paramètres de formulation qui contrôlent l'émulsification. Le suivi de la cinétique de l'émulsification et de la morphologie de l'émulsion au cours du processus d'émulsification a montré que le mécanisme d'émulsification à très fortes concentrations en bitume (90 % massique) passe par une étape d'inversion de phases catastrophique, suivie d'un affinage de l'émulsion dû aux effets de cisaillement et d'élongation lors de la phase finale de mélange. Une méthodologie basée sur une analogie de Poiseulle pour la mesure en ligne de la viscosité de procédé a été développée, permettant l'évaluation in-line du comportement rhéologique d'un fluide à travers des mesures de débit et de perte de charge / This work focuses on the continuous emulsification process (using SMX static mixers) of bitumen for concentrated and highly concentrated emulsions. This work uses an approach that integrates the process, the physic-chemical formulation and composition parameters, with the main objective of controlling the drop size of the emulsions. It was shown that the emulsification carried out at high bitumen concentrations and high temperatures favours the production of emulsions with very small droplets sizes (mean diameter ? 1 mm). This is in contrast with emulsification process in batch mode, in the same concentration and temperature conditions. These results demonstrate the competition between energy and physic-chemical formulation aspects. It was also revealed that when continuous emulsification is carried out at 90 % wt. of bitumen, droplet sizes are not a function of the energy provided and, hence, the emulsification process is controlled by the formulation parameters. Morphological analyzes, coupled with kinetics of emulsification obtained by in-situ monitoring of the viscosity, allowed the description of the mechanisms occurring during the emulsification at high internal phase ratio. It was possible to identify two principal steps in the mechanism: a catastrophic phase inversion followed by a droplet reduction by agitation, the largest size reduction being achieved thanks to the effects of shear and elongation in the static mixer. An inline process viscosity measurement methodology was developed. This methodology, based on a Poiseuille analogy, allows the evaluation of the rheological behavior of a fluid through flow rate and pressure drop measurements

Microbial biodegradation is the primary mechanism by which petrogenic hydrocarbons (PHCs) are removed from the environment. Though hydrocarbon biodegradation is widely studied in marine systems, knowledge of how it occurs in freshwater systems is still lacking. The Peace-Athabasca Delta (PAD), located in northeastern Alberta, is an ideal location to study microbial hydrocarbon degradation since it has a long history of exposure to PHCs. What’s more, these PHCs are predominately sourced from bituminous deposits and are therefore relevant to the Canadian Oil Sands Industry. This thesis investigated the genetic potential for hydrocarbon degradation of PHCs via metagenomic reconstruction of microbial communities in lakes of the Peace and Athabasca Deltas, as well as reference lakes in the nearby boreal uplands. In order to properly evaluate the microbial community and its potential for hydrocarbon degradation, a comprehensive analysis of PHCs (including n-alkanes, polycyclic aromatic compounds (PACs), and petroleum biomarkers of terpanes, hopanes, and steranes) was performed. PHC analysis showed that n-alkanes in lake sediments from all three regions were highly similar and predominately biogenic, while PAC composition was significantly different in each region. Restricted-drainage lakes of the Athabasca Delta had the highest concentrations of PACs from petrogenic sources. Closed-drainage lakes in the Peace Delta had lower concentrations of PACs that likely originated from a mixture of pyrogenic and petrogenic sources. Closed-drainage lakes in the boreal upland region had the lowest concentrations of PACs likely sourced from pyrogenic wood combustion with traces of petrogenic PACs, possibly from atmospheric deposition of dust. Petroleum biomarkers of terpanes, hopanes, and steranes were successfully used to identify the long-range fluvial, and possibly atmospheric, transport of bituminous compounds more than one hundred kilometers from their potential source. This validates the future use of these biomarkers in environmental forensics. Microbial communities in all three regions under study were highly diverse, and their composition was significantly different in both sediment and water. Targeted gene analysis identified a total of 3885 genes involved in the degradation of n-alkanes and PACs in sediment and water. The results show that organic carbon, nitrogen, and sulfur content, as well as PAC and short-chain alkane concentrations were important chemical predictors of change in degradation gene composition. Furthermore, genes for anaerobic degradation of PHCs were identified in syntrophic bacteria, methanogens, nitrate and sulfate reducers, demonstrating the potential for syntrophic hydrocarbon degradation in PAD lakes. Though this thesis confirms the genetic potential for hydrocarbon degradation in PAD and boreal upland lakes, further research is necessary to determine whether these microbial communities can actively degrade the PHCs present in these lakes.

The main area of research delineated in this thesis provides instances when Computer vision based technology has shown tremendous productivity gains in the Oil sands industry in Fort McMurray, Alberta, Canada. Specifically, the interface between Bitumen-froth (crude oil) and the Middlings (Sand) in separation cells (during the extraction process) is estimated in real time from camera video and used for automatic control of the interface level. Two original algorithms have been developed which solve the interface estimation problem using techniques ranging from image analysis, estimation theory (Particle filters) and probabilistic reasoning. These ideas are discussed in chapters three and four. The first chapter of this thesis discusses the broad area of Computer vision research as a knowledge basis for the current work. Computer vision (automatic image analysis) has been presented starting from the basics and culminating in advanced algorithms that are used frequently. The methods described in this chapter form the foundation of the work that follows in the subsequent chapters. After the introduction to automatic image analysis, a set of Monte Carlo simulation based methods called Particle filters are introduced in the second chapter. These Monte Carlo filters assume importance in the current work as they are used to derive one of the main results of this thesis. A large part of this chapter though is devoted to the introduction of the concept of measure theoretic probability which is used in proving the convergence of Particle filters. Another application of Computer vision techniques is also developed in this thesis (in chapter five) to treat the problem of automatic interface and boundary detection in X-ray view cell images. These images are typically used to observe liquid-liquid and liquid-vapour phase behaviour of heavy oils such as Bitumen in chemical equilibrium investigations. The equilibrium data would then be used to enhance Bitumen separation technologies. Manual tracking of the interfaces between these phases for different mixtures and conditions is time consuming when a large set of such images are to be analysed. A novel algorithm is developed that is based on state-of-the-art in Computer vision techniques and automates the entire task. / Process Control

A laboratory experiment and a numerical simulation of a dual well pair SAGD process with live bitumen were conducted to examine operating strategies on the recovery performance of a multiple well pair SAGD process. The experiment was successfully carried out under such operation strategies as injecting steam into one well pair while producing from both producers after chambers mergence to sweep the oil between the two well pairs. The experimental results showed high oil recovery from the transition region between the two well pairs with these operation strategies. Numerical simulation matched reasonably well experimental results, which indicated that the numerical model captured the key mechanisms of the dual well pairs experiment. The improved SAGD process behaviour and performance was demonstrated in terms of faster oil production, enhanced solution gas production, and accelerated adjacent chambers communication in the experimental and numerical studies. These operation strategies could be applied in the multiple well pairs SAGD and enhance SAGD performance after steam chambers merge between adjacent well pairs. / Petroleum Engineering

The effect of slurry conditioning on bitumen recovery and bitumen froth quality has been studied by using three oil sands ores tested with a laboratory hydrotransport extraction system (LHES) and a Denver flotation cell. Tests with the LHES show that an increase in slurry conditioning time yielded a lowered bitumen recovery for a long flotation time (30 min). Longer slurry conditioning time led to a better bitumen froth quality regardless of flotation time. However the over conditioning could be compensated by higher conditioning temperatures and higher slurry flow velocities. Tests with the Denver flotation cell show that the increase in slurry conditioning time resulted in a higher bitumen recovery and a better bitumen froth quality for both good and poor processing ores for a shorter flotation time of 5 min. For a longer flotation time of 20 min, increasing slurry conditioning time had little impact on bitumen recovery but led to a slightly better bitumen froth quality for the good processing ore whereas no effect on bitumen froth quality of the poor processing ore. Results also show that higher slurry temperatures and stronger mechanical energy input were beneficial to both bitumen recovery and bitumen froth quality for all three oil sands ores tested on both devices. / Chemical Engineering