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The optimal allocation of drainage areas and surface pads for SAGD development is challenging because of several surface and subsurface constraints. It becomes more complex due to uncertainty in reservoir properties. This Thesis presents a heuristic methodology to maximize the recovery of bitumen by optimal placement of drainage areas and surface pads. Multiple realizations of reservoir variables are used to quantify the uncertainty. The optimization problem can be seen as space packing and optimal allocation of well pairs. Space packing ensures the maximum access to available resource and optimal allocation of well pairs guarantees the maximum combined recovery over the field. A DASP (drainage area surface pad) software tool is developed and examples are presented to explain the optimization steps. Optimization considers the compact and non overlapping arrangements of drainage areas. Problem is converted into unconstrained optimization one by including penalties for different constraints. / Mining Engineering

Increasing energy consumption and continuous depletion of hydrocarbon reservoirs will result in a conventional oil production peak in the near future. Thus, the gap between the global conventional oil supplies and the required amount of fossil fuel energy will grow. Extensive attempts were made during the last three decades to fill this gap, especially using innovative emerging heavy oil and bitumen production technologies. Most of these recovery methods have been developed in Canada, considering the fact that Canada and Venezuela have the largest deposits of heavy oil and bitumen throughout the world. The horizontal well drilling technology opened a new horizon for the recovery of heavy oil and bitumen. Most of the in-situ recovery techniques, including Steam Assisted Gravity Drainage (SAGD) recovery method, take advantage of horizontal injection and production wells. The vacated pores in the reservoir are filled mainly either with steam or with a mixture of steam and solvent vapour in the case of the SAGD and Solvent Aided SAGD (SA-SAGD) recovery methods, respectively. The use of long horizontal wells combined with the reduced viscosity of the produced oil allows economic production with limited amount of bypassed residual oil in the invaded region. The macro-scale success of the SAGD recovery technique is greatly affected by its pore-scale performance. It is beneficial to understand the pore-level physics of the SAGD process in order to develop mathematical models for simulating field-scale performance. Available commercial reservoir simulators cannot describe pore-level mechanisms of the SAGD process including mechanisms related to the fluid-flow as well as heat-transfer aspects of the process. A systematic series of flow visualization experiments of the SAGD process using glass-etched micromodels was developed to capture the pore-level physics of the process using qualitative analysis. With the aid of image processing techniques, the pore-scale performance of the SAGD process was qualitatively and quantitatively investigated. The main objective of Chapter 2 of this thesis is to address the relevant pore-scale mechanisms responsible for the in-situ oil mobilization and drainage in a conventional SAGD process. Transport processes, occurred in a conventional SAGD process at the pore-level including fluid flow and heat transfer aspects, were mechanistically investigated and documented. The qualitative analysis of the results revealed that near a well-established oil-steam interface, gravity drainage takes place through a thick layer of pores, composed of about 1-6 pores in thickness, within the mobilized region. The drainage of the mobile oil takes place due to the interplay between gravity and capillarity forces near this mobilized region. In-situ mobilization of bitumen was found to be as a result of both conductive and convective elements of the local heat transfer process. Moreover, the phenomenon of water-in-oil emulsification at the interface was also demonstrated which is due to the local steam condensation and spreading characteristics of water droplets over the oil phase in the presence of a gas phase. Other pore-scale aspects of the process such as drainage displacement as well as film-flow drainage mechanisms of the mobile oil, localized entrapment of steam bubbles as well as condensate droplets within the mobile oil continuum due to capillarity phenomenon, sharp temperature gradient along the mobilized region, co-current and counter-current flow regimes at the chamber walls, condensate spontaneous imbibition followed by mobile oil drainage, and snap-off of liquid films are also illustrated using these pore-level studies. The second objective of Chapter 2 is to quantitatively analyze the production performance of the SAGD process based on the micro-scale measurements. Our pore-scale experiments revealed that the rate of pore-scale SAGD interface advancement depends directly on the pore-scale characteristics of the employed models and the pertaining operating conditions. The average sweep rate data were correlated using an analytical model proposed by Butler (1979, 1981, 1991) and a pore-scale performance parameter was defined for the SAGD process. The measured horizontal sweep rates of the SAGD process at the pore-scale are in good agreement with the theory predictions provided by the performance parameter. In addition, the effect of different system variables on the ultimate recovery factor of the SAGD experiments were investigated and it was found that higher permeability values and lower in-situ oil viscosities lead to higher ultimate recovery factor values for a particular SAGD trial. Moreover, the Cumulative Steam to Oil Ratio (CSOR) data were scaled and a reasonably good fit for the experimental data was achieved by defining a scaling parameter. Although the SAGD process offers several inherent advantages including high ultimate recovery, stable oil production rates, reasonable energy efficiency, and high stable sweep efficiency, there are some drawbacks associated with the SAGD process such as high energy consumption, high levels of CO2 emission, and usage of large quantities of fresh water which make this process uneconomical in reservoirs with thin net pay, low matrix porosity and thermal conductivity, and low initial pressure. The most promising route for improving the SAGD performance appears to be the co-injection of a light hydrocarbon solvent with steam in the context of the Solvent Aided SAGD (SA-SAGD) process. The pore-level aspects of the SA-SAGD process are not yet understood to the extent of incorporating the pore-scale physics into mathematical models. The main objective of Chapter 3 of my thesis is to mechanistically investigate the SA-SAGD process at the pore-level to enlighten the unrecognized pore-scale physics of the process. A methodical set of pore-scale SA-SAGD experiments were designed and carried out with the aid of glass micromodels. The methodology used in this set of the SA-SAGD trials was similar to that of the pore-scale SAGD experiments described in Chapter 2. Normal Pentane and Normal Hexane were used as the steam additives. The pore-level events were recorded on a real-time basis and then analyzed using the image processing techniques. According to the qualitative results, it was obtained that all the condensate and gaseous phases flow simultaneously in the mobilized region composed of about 1-4 pores in thickness. Heat transfer mechanisms at the pore-scale include conduction as well as convection. The mechanisms responsible for the mass transfer at the pore-level include molecular diffusion as well as convection. The mobile oil drains as a result of two active mechanisms of film flow as well as direct capillary drainage displacements at the pore-scale. Due to the near miscible nature of the displacement process, the residual oil left behind in the invaded portion of the micromodels was negligible and asphaltene precipitation and plugging was found to be a temporary phenomenon. The second objective of Chapter 3 is to quantify the pore-scale production performance of the SA-SAGD process using the flow visualization experiments. The horizontal SA-SAGD interface advancement velocity was chosen to be the indicator of the pore-scale performance of the process. It was found that addition of n-C6 as the steam additive was more effective than n-C5 in terms of enhanced pore-scale interface advancement as well as achieving higher ultimate recovery factor when all the other experimental variables are unchanged. The higher the solvent concentration in the injection mainstream is, the higher would be the pore-scale sweep rate as well as the ultimate recovery factor of the process. When oil type with lower in-situ viscosity was used, higher sweep rates as well as higher ultimate recovery factors values were achieved compared to the trials in which the more viscous bitumen was employed as the oil type. In addition, a scaling parameter composed of porous media properties was found by which the pore-scale interface advancement velocity and the ultimate recovery factor of the SA-SAGD trials were scaled when all other experimental variables remain unchanged. In Chapter 4 of this thesis, the production performance of the SAGD and SA-SAGD processes were demonstrated and compared at the macro-scale under controlled environmental conditions. A 2D physical model was designed and fabricated and Athabasca bitumen was used as the oil type. According to the experimental results, it was obtained that the average mobile oil as well as dead oil production rates are reasonably constant over the course of the SAGD and SA-SAGD trials. As far as the SAGD experiments are concerned, there is a linear correlation between the mobile oil production rates and the square root of the porous media permeability when all the other experimental variables remain unchanged. In addition, the Steam to Oil Ratio (SOR) values of the SAGD trials correlate reasonably well with the inverse of the square root of permeability when all the other experimental variables are fixed. By introducing the solvent additive to the injection mainstream of the SAGD process, it was found that enhancements of about 18% and 17% were observed in the mobile oil and dead oil production rates of the SAGD process respectively. In addition, the SOR values of the SA-SAGD process was reduced by about 35% compared to that of the SAGD process. Finally, an advanced photomicrography unit with an integrated image processing software was used in order to investigate size of the enclosed water condensate droplets in the continuum of the mobile oil produced during the course of the SAGD and SA-SAGD experiments. The captured microscopic snapshots were analyzed using the image processing techniques and some representative average values of the water condensate droplet sizes were reported for the corresponding SAGD and SA-SAGD trials.

Increasing energy consumption and continuous depletion of hydrocarbon reservoirs will result in a conventional oil production peak in the near future. Thus, the gap between the global conventional oil supplies and the required amount of fossil fuel energy will grow. Extensive attempts were made during the last three decades to fill this gap, especially using innovative emerging heavy oil and bitumen production technologies. Most of these recovery methods have been developed in Canada, considering the fact that Canada and Venezuela have the largest deposits of heavy oil and bitumen throughout the world. The horizontal well drilling technology opened a new horizon for the recovery of heavy oil and bitumen. Most of the in-situ recovery techniques, including Steam Assisted Gravity Drainage (SAGD) recovery method, take advantage of horizontal injection and production wells. The vacated pores in the reservoir are filled mainly either with steam or with a mixture of steam and solvent vapour in the case of the SAGD and Solvent Aided SAGD (SA-SAGD) recovery methods, respectively. The use of long horizontal wells combined with the reduced viscosity of the produced oil allows economic production with limited amount of bypassed residual oil in the invaded region. The macro-scale success of the SAGD recovery technique is greatly affected by its pore-scale performance. It is beneficial to understand the pore-level physics of the SAGD process in order to develop mathematical models for simulating field-scale performance. Available commercial reservoir simulators cannot describe pore-level mechanisms of the SAGD process including mechanisms related to the fluid-flow as well as heat-transfer aspects of the process. A systematic series of flow visualization experiments of the SAGD process using glass-etched micromodels was developed to capture the pore-level physics of the process using qualitative analysis. With the aid of image processing techniques, the pore-scale performance of the SAGD process was qualitatively and quantitatively investigated. The main objective of Chapter 2 of this thesis is to address the relevant pore-scale mechanisms responsible for the in-situ oil mobilization and drainage in a conventional SAGD process. Transport processes, occurred in a conventional SAGD process at the pore-level including fluid flow and heat transfer aspects, were mechanistically investigated and documented. The qualitative analysis of the results revealed that near a well-established oil-steam interface, gravity drainage takes place through a thick layer of pores, composed of about 1-6 pores in thickness, within the mobilized region. The drainage of the mobile oil takes place due to the interplay between gravity and capillarity forces near this mobilized region. In-situ mobilization of bitumen was found to be as a result of both conductive and convective elements of the local heat transfer process. Moreover, the phenomenon of water-in-oil emulsification at the interface was also demonstrated which is due to the local steam condensation and spreading characteristics of water droplets over the oil phase in the presence of a gas phase. Other pore-scale aspects of the process such as drainage displacement as well as film-flow drainage mechanisms of the mobile oil, localized entrapment of steam bubbles as well as condensate droplets within the mobile oil continuum due to capillarity phenomenon, sharp temperature gradient along the mobilized region, co-current and counter-current flow regimes at the chamber walls, condensate spontaneous imbibition followed by mobile oil drainage, and snap-off of liquid films are also illustrated using these pore-level studies. The second objective of Chapter 2 is to quantitatively analyze the production performance of the SAGD process based on the micro-scale measurements. Our pore-scale experiments revealed that the rate of pore-scale SAGD interface advancement depends directly on the pore-scale characteristics of the employed models and the pertaining operating conditions. The average sweep rate data were correlated using an analytical model proposed by Butler (1979, 1981, 1991) and a pore-scale performance parameter was defined for the SAGD process. The measured horizontal sweep rates of the SAGD process at the pore-scale are in good agreement with the theory predictions provided by the performance parameter. In addition, the effect of different system variables on the ultimate recovery factor of the SAGD experiments were investigated and it was found that higher permeability values and lower in-situ oil viscosities lead to higher ultimate recovery factor values for a particular SAGD trial. Moreover, the Cumulative Steam to Oil Ratio (CSOR) data were scaled and a reasonably good fit for the experimental data was achieved by defining a scaling parameter. Although the SAGD process offers several inherent advantages including high ultimate recovery, stable oil production rates, reasonable energy efficiency, and high stable sweep efficiency, there are some drawbacks associated with the SAGD process such as high energy consumption, high levels of CO2 emission, and usage of large quantities of fresh water which make this process uneconomical in reservoirs with thin net pay, low matrix porosity and thermal conductivity, and low initial pressure. The most promising route for improving the SAGD performance appears to be the co-injection of a light hydrocarbon solvent with steam in the context of the Solvent Aided SAGD (SA-SAGD) process. The pore-level aspects of the SA-SAGD process are not yet understood to the extent of incorporating the pore-scale physics into mathematical models. The main objective of Chapter 3 of my thesis is to mechanistically investigate the SA-SAGD process at the pore-level to enlighten the unrecognized pore-scale physics of the process. A methodical set of pore-scale SA-SAGD experiments were designed and carried out with the aid of glass micromodels. The methodology used in this set of the SA-SAGD trials was similar to that of the pore-scale SAGD experiments described in Chapter 2. Normal Pentane and Normal Hexane were used as the steam additives. The pore-level events were recorded on a real-time basis and then analyzed using the image processing techniques. According to the qualitative results, it was obtained that all the condensate and gaseous phases flow simultaneously in the mobilized region composed of about 1-4 pores in thickness. Heat transfer mechanisms at the pore-scale include conduction as well as convection. The mechanisms responsible for the mass transfer at the pore-level include molecular diffusion as well as convection. The mobile oil drains as a result of two active mechanisms of film flow as well as direct capillary drainage displacements at the pore-scale. Due to the near miscible nature of the displacement process, the residual oil left behind in the invaded portion of the micromodels was negligible and asphaltene precipitation and plugging was found to be a temporary phenomenon. The second objective of Chapter 3 is to quantify the pore-scale production performance of the SA-SAGD process using the flow visualization experiments. The horizontal SA-SAGD interface advancement velocity was chosen to be the indicator of the pore-scale performance of the process. It was found that addition of n-C6 as the steam additive was more effective than n-C5 in terms of enhanced pore-scale interface advancement as well as achieving higher ultimate recovery factor when all the other experimental variables are unchanged. The higher the solvent concentration in the injection mainstream is, the higher would be the pore-scale sweep rate as well as the ultimate recovery factor of the process. When oil type with lower in-situ viscosity was used, higher sweep rates as well as higher ultimate recovery factors values were achieved compared to the trials in which the more viscous bitumen was employed as the oil type. In addition, a scaling parameter composed of porous media properties was found by which the pore-scale interface advancement velocity and the ultimate recovery factor of the SA-SAGD trials were scaled when all other experimental variables remain unchanged. In Chapter 4 of this thesis, the production performance of the SAGD and SA-SAGD processes were demonstrated and compared at the macro-scale under controlled environmental conditions. A 2D physical model was designed and fabricated and Athabasca bitumen was used as the oil type. According to the experimental results, it was obtained that the average mobile oil as well as dead oil production rates are reasonably constant over the course of the SAGD and SA-SAGD trials. As far as the SAGD experiments are concerned, there is a linear correlation between the mobile oil production rates and the square root of the porous media permeability when all the other experimental variables remain unchanged. In addition, the Steam to Oil Ratio (SOR) values of the SAGD trials correlate reasonably well with the inverse of the square root of permeability when all the other experimental variables are fixed. By introducing the solvent additive to the injection mainstream of the SAGD process, it was found that enhancements of about 18% and 17% were observed in the mobile oil and dead oil production rates of the SAGD process respectively. In addition, the SOR values of the SA-SAGD process was reduced by about 35% compared to that of the SAGD process. Finally, an advanced photomicrography unit with an integrated image processing software was used in order to investigate size of the enclosed water condensate droplets in the continuum of the mobile oil produced during the course of the SAGD and SA-SAGD experiments. The captured microscopic snapshots were analyzed using the image processing techniques and some representative average values of the water condensate droplet sizes were reported for the corresponding SAGD and SA-SAGD trials.

Steam Assisted Gravity Drainage (SAGD) is a commonly used EOR/IOR method for improving recovery in heavy oil reservoirs. However, continued research for a more energy efficient method has led to the development of an improved version called Expanding Solvent (ES)-SAGD, which has the potential to replace conventional SAGD method for production from some heavy oil reservoirs. This thesis provides some insights into determination of the reservoir performance of ES-SAGD process using an improved semi-analytical method. This model is then used for optimizing the solvent requirement while minimizing the steam injected. The semi-analytical model is determined by combining Butler’s oil drainage analytical model and solvent dilution effect of VAPEX process. The predictive ability of this model was improved by accounting for concentration and viscosity dependent solvent diffusion process. Results from this extended model in terms of solvent injection, oil production and Cumulative Steam to Oil Ratio (cSOR) were compared with that of reservoir simulation at various levels of grid resolution. Furthermore, the results from simulation were analyzed using response surface methodology including gradient based optimization technique to determine optimum operating conditions, which was then compared with more robust multi-objective optimization based on Non-dominated Sorting Genetic Algorithm II (NSGA-II) and Pareto-optimality. Both the optimization techniques were used within the improved semi-analytical formulation to come up with optimized operational parameters. Modeling solvent diffusivity as a function of solvent concentration gives better results than those obtained using a constant value for diffusivity. Moreover, results for some key performance factors are in good agreement between the semi-analytical model and the numerical simulation, rendering this model suitable for performing solvents-screening studies. The multi-objective optimization framework within the semi-analytical model is demonstrated to be a feasible option for determining optimum ranges of key operating parameters that would result in success of the project. Intermediate values of solvent fraction ranging 0.1 to 0.2 for almost the entire range of injection pressures result in high bitumen recoveries and relatively low cSOR. The results indicate that higher values of solvent fraction at low operating pressures and lower values of solvent fraction at high operating pressures lead to optimized oil recovery rate and lower steam-oil-ratio. The multi-objective optimization process results in several combinations of control parameters that yield solutions along the Pareto-optimum front. These combinations are all viable solutions to the optimization problem. / text

This thesis presents different methods that improve the ability to relate the flow properties of heterogeneous reservoirs to equivalent anisotropic flow properties in order to predict the performance of the Steam Assisted Gravity Drainage (SAGD) process. Process simulation using full scale heterogeneous reservoirs are inefficient and so the need arises to develop equivalent anisotropic reservoirs that can capture the effect of reservoir heterogeneity. Since SAGD is highly governed by permeability in the reservoir, effective permeability values were determined using different upscaling techniques. First, a flow-based upscaling technique was employed and a semi-analytical model, derived by Azom and Srinivasan, was used to determine the accuracy of the upscaling. The results indicated inadequacy of flow-based upscaling schemes to derive effective direction permeabilities consistent with the unique flow geometry during the SAGD process. Subsequently, statistical upscaling was employed using full 3D models to determine relationships between the heterogeneity variables: k[subscript italic v]⁄k[subscript italic h] , correlation length and shale proportion. An iterative procedure coupled with an optimization algorithm was deployed to determine optimal k[subscript italic v] and k[subscript italic k] values. Further regression analysis was performed to explore the relationship between the variables of shale heterogeneity in a reservoir and the corresponding effective properties. It was observed that increased correlation lengths and shale proportions both decrease the dimensionless flow rates at given dimensionless times and that the semi-analytical model was more accurate for cases that contained lower shale proportions. Upscaled heterogeneous values inputted into the semi-analytical model resulted in underestimation of oil flow rate due to the inability to fully account for the impact of reservoir barriers and the configuration of flow streamlines during the SAGD process. Statistical upscaling using geometric averaging as the initial guess was used as the basis for developing a relationship between correlation length, shale proportion and k[subscript italic v]⁄k[subscript italic h]. The initial regression models did not accurately predict the anisotropic ratio because of insufficient data points along the regression surface. Subsequently a non-linear regression model that was 2nd order in both length and shale proportion was calibrated by executing more cases with varying levels of heterogeneity and the regression model revealed excellent matches to heterogeneous models for the prediction cases. / text

Steam Assisted Gravity Drainage (SAGD) is used widely as a thermal recovery technique in Canada to produce a very viscous bitumen formation. The main research objectives of this simulation and experimental study are to investigate oil recovery mechanisms under SAGD process with different injection fluids, including steam, solvent or steam with solvent. 2D simulation studies based on typical Athabasca reservoir properties have been performed. Results show that a successful solvent co-injection design can utilize the advantages of solvent and steam. There is an optimal solvent type and concentration ratio range for a particular reservoir and operating condition. Long, continuous shale barriers located vertically above or near the wellbore delay production performance significantly. Co-injecting a multi-component solvent can flush out the oil in different areas with different drainage mechanisms from vaporized and liquid components. Placing an additional injector at the top of the reservoir results only in marginal improvement. The pure high-temperature diluent injection appears feasible, although further technical and economic evaluation of the process is required. A 2D scaled physical model was fabricated that represented in cross-section a half symmetry element of a typical SAGD drainage volume in Athabasca. The experimental results show co-injecting a solvent mixture of C7 and xylene with steam gives better production performance than the injection of pure steam or steam with C7 at the study condition. Compared to pure steam injection runs ( Run 0 and 1), coinjecting C7 (Run 2) with steam increases the ultimate recovery factor of oil inside the cell from 25 percent to 29 percent and decreases the ultimate CSOR from 2.2 to 1.9 and the ultimate CEOR from 4892 J/cm 3 to 4326 J/cm 3 ; coinjecting C7 and Xylene (Run 3) increases the ultimate recovery factor of oil from 25 percent to 34 percent, and decreases the ultimate CSOR 2.2 to 1.6 and the ultimate CEOR from 4892 J/cm 3 to 3629 J/cm 3 . Analyses of the experimental results indicate that partial pressure and the near wellbore flow play important roles in production performance. In conclusion, a successful solvent injection design can effectively improve the production performance of SAGD. Further research on evaluating the performance of various hydrocarbon types as steam additives is desirable and recommended.

The Steam-Assisted Gravity Drainage (SAGD) Process involves the injection of steam through a horizontal well and the production of heavy oil through a lower horizontal well. Several authors have tried to model this process using analytical, semi-analytical and fully numerical means. In this dissertation, we improve the predictive ability of previous models by accounting for the effect of anisotropy, the effect of heat transfer on capillarity and the effect of water-in-oil (W/O) emulsion formation and transport which serves to enhance heat transfer during SAGD. We account for the effect of anisotropy during SAGD by performing elliptical transformation of the resultant gravity head and resultant oil drainage vectors on to a space described by the vertical and horizontal permeabilities. Our results, show that unlike for the isotropic case, the effect of anisotropy is time dependent and there exists a given time beyond which it ceases to have any effect on SAGD rates. This result will impact well spacing design and optimization during SAGD. Butler et al. (1981) derived their classical SAGD model by solving a 1-D heat conservation equation for single phase flow. This model has excellent predictive capability at experimental scales but performs poorly at field scales. By assuming a linear saturation -- temperature relationship, Sharma and Gates (2010b) developed a model that accounts for multiphase flow ahead of the steam chamber interface. In this work, by decomposing capillary pressure into its saturation and temperature components, we coupled the mass and energy conservation equations and showed that the multi-scale, multiphase flow phenomenon occurring during SAGD is the classical Marangoni (or thermo-capillary) effect which can be characterized by the Marangoni number. At low Marangoni numbers (typical of experimental scales) we get the Butler solution while at high Marangoni numbers (typical of field scales), we approximate the Sharma and Gates solution. The Marangoni flow concept was extended to the Expanding Solvent SAGD (ES-SAGD) process and our results show that there exists a given Marangoni number threshold below which the ES-SAGD process will not fare better than the SAGD process. Experimental results presented in Sasaki et al. (2002) demonstrate the existence of water-in-oil emulsions adjacent to the steam chamber wall during SAGD. In this work we show that these emulsions enhanced heat transfer at the chamber wall and hence oil recovery. We postulate that these W/O emulsions are principally hot water droplets that carry convective heat energy. We perform calculations to show that their presence can practically double the effective heat transfer coefficient across the steam chamber interface which overcomes the effect of reduced oil rates due to the increased emulsified phase viscosity. Our results also compared well with published experimental data. The SAGD (and ES-SAGD) process is a short length-scaled process and hence, short length-scaled phenomena (typically ignored in other EOR or conventional processes) such as thermo-capillarity and in-situ emulsification should not be ignored in predicting SAGD recoveries. This work will find unique application in predictive models used as fast proxies for predicting SAGD recovery and for history matching purposes. / text

L'injection de vapeur lors de la production des bruts lourds par SAGD soumet les roches réservoirs (sables bitumineux non consolidés ou faiblement consolidés) à une élévation de température (jusqu'à 280°C). L'apport de fluide chaud augmente la pression de pore, dilate le squelette rocheux et le fluide interstitiel, ce qui modifie le champ de contrainte in situ. Le travail de thèse, à forte connotation expérimentale, vise à contribuer à la caractérisation mécanique et acoustique des réservoirs bitumineux sous différentes conditions de température, de contrainte et de saturation. Les travaux ont été effectués sur des échantillons de sables bitumineux Canadiens, mais également sur un matériau modèle, un sable reconstitué artificiellement cimenté. Plusieurs techniques expérimentales ont été mises en œuvre pour caractériser les matériaux utilisés : tomographie RX, microtomographie RX, cryomicroscopie, RMN, etc. Des essais ont ensuite été effectués dans une cellule oedométrique, une cellule pétroacoustique et également dans une cellule triaxiale dite haute température qui a été développée dans le cadre de cette thèse.Les divers essais de chargement mécanique et thermique dans cette thèse ont permis d'enrichir les connaissances sur le comportement thermo-hydro-mécanique des sables bitumineux ainsi que celui des sables reconstitués. Les paramètres investigués ont été la dilatation thermique, la compressibilité sous chargement oedométrique et triaxial isotrope et la résistance au cisaillement. Les différentes mesures des propriétés acoustiques (vitesses Vp et Vs, atténuations et modules dynamiques) effectués sur les sables naturels et reconstitués ont montré l'importance des propriétés des fluides saturants, principalement de leur viscosité. Le bitume est un fluide viscoélastique avec une viscosité qui varie avec l'élévation de la température. Aux températures in situ, il se comporte comme un solide avec un module de cisaillement. L'approche théorique de Ciz et Shapiro (2007), permet de prendre en compte ce module de cisaillement du fluide visqueux et généralise l'équation de Biot Gassmann. Son utilisation a été validée sur nos essais. La modélisation prend en compte les aspect dispersifs et permet d'extrapoler aux fréquences sismiques des résultats acquis en laboratoire avec des fréquences ultrasonores. Les vitesses Vp et Vs diminuent avec le passage de la chambre de vapeur. Les variations sont faibles mais peuvent être identifiées par la sismique 4D / The steam assisted gravity drainage (SAGD) has been successfully used to enhance the recovery of heavy oil in Western Canada and Eastern Venezuela basins. Temperature, pressure and pore fluid variations during SAGD operations induce complex changes in the. properties of the heavy oil sand reservoir. This dissertation focuses on the geomechanical and acoustic behaviours of oil sand and how they change under various temperature, pressure and pore fluid conditions. Both natural oil sands samples and reconstituted samples were tested in this research program. Several experimental techniques have been used to characterize the materials including X-Ray tomography, X-ray microtomography, cryomicroscopy, NMR. Natural oil sands samples, characterized by high permeability, high porosity and an interlocked structure have been extracted from the estuarine McMurray Formation in Athabasca (Alberta, Canada). Reconstituted samples, made up of slightly cemented Fontainebleau sand, have been considered as possible analogues of the natural oil sands. Tests have been carried out in high pressure oedometer cells, in an isotropic pressure cell and in a new high temperature triaxial cell. The various geomechanical and thermal tests have been carried out to better understand the thermo-hydro-mechanical behaviour of natural oil sands and of reconstituted samples. The parameters investigated were the thermal dilatation, the bulk compressibility (under oedometric and isotropic loading) and the shear strength. The acoustic measurements (P and S-wave velocities, attenuations and dynamic modules, etc.) performed on natural oil sands and reconstituted samples showed the importance of the saturating fluids properties, mainly through viscosity. Bitumen has a viscoelastic behaviour with a non-negligible shear modulus that depends strongly on temperature and frequency and that allows shear wave propagation. The theoretical approach of Ciz and Shapiro (2007), that accounts for the effects of the shear modulus of the viscous fluid and generalizes the Biot – Gassmann equation, has been validated by our tests. The model takes into account the dispersive aspects and allows the results obtained in the laboratory with ultrasonic frequencies to be extrapolated to seismic frequencies. Velocities Vp and Vs decrease with the steam invasion. Changes are small but can be detected by 4D seismic

Ranking of multiple realizations is an important step when the processing time for a realization is large. This is the case in reservoir flow simulation and in other areas of geology, environmental and even medical applications. Significant uncertainty exists in all reservoirs especially at unsampled locations where the geological heterogeneity and connectivity are impossible to exactly predict between wells. Geostatistical techniques are used to construct models of static properties such as lithofacies, porosity, permeability and residual fluid saturations and provide multiple equally probable realizations of these properties. The number of realizations that is required for modeling the uncertainty may be large; usually 100 realizations are considered enough to quantify uncertainty. However, this number of realizations is still too high for processing by a flow simulator. This thesis aims at developing a robust and reliable ranking methodology to rank the realizations using a static ranking measure. The outcome is the identification of the high, low, and intermediate ranking realizations for further detailed simulations. The methodology was developed for the steam assisted gravity drainage (SAGD) reservoir application. This thesis will consider the cumulative oil produced (COPrate) and cumulative steam-oil-ratio (CSOR) as the ranking parameters in the flow simulations, hereafter called performance parameter. Connected hydrocarbon volume (CHV) was the parameter that was used in the ranking methodology as the static ranking measure. High calibration between the performance parameters and the CHV would indicate the success of the proposed ranking methodology. The ranking methodology was validated against the results of the flow simulations. The results indicate a mediocre correlation between the SAGD performance parameters and CHV. The ranking methodology was modified by incorporating the average reservoir permeability. Significant improvement in the correlation between the static ranking measure and the SAGD performance parameters resulted. / Petroleum Engineering