Our funded research positions are curently full. Students holding major scholarships, e.g. NSERC or other national scholarships, are urged to apply at any time, and should indicate this in their communication.
Project 1.1 Thermal Multiphase Properties of Oilsands
PhD student will work with undisturbed bitumen free McMurray Formation Sand blocks - characterized by SEM and micrographs - triaxial cell with both axial and radial flow - testing under multiple stress paths to examine fundamental behaviour of absolute permeability. Tests to assess variations in multiple fluid effective permeability and absolute permeability on bitumen-saturated specimens at 5 to 250 °C will also be incorporated. The research will also advance technology by integrating thermal and resistivity measurements, and triaxial membrane designs with integrated measurement (deformation, permeability, Vp-Vs). Seismic frequency of dynamic properties of oil sands will be undertaken in Project 3.1.5.
Project 1.2 Reservoir Geomechanical Characterization of Shale Gas and Oil PhD student will correlate mechanical properties of shale to variations in lithology, sedimentology and mineralogy - measurement of anisotropy in properties such as strength, permeability and velocity - explore the stress related influences on desorption and diffusion mechanisms - advanced imaging will be explored to assess the pore-scale failure morphology for this class of materials to inform research conducted on upscaling of reservoir geomechanical processes in shale gas reservoirs – construct world’s smallest triaxial cell.
Project 1.3 Thermal-Hydro-Mechanical Properties of Intraformational/Caprock Shales PhD student will conduct literature review on the thermal-hydraulic-mechanical behaviour of shales - reconstitute highly overconsolidated shale and IHS specimens for use in the experimental program. Consolidated undrained and consolidated drained triaxial tests at ambient and elevated temperatures (up to 300 C?) will be conducted on both reconstituted and undisturbed in situshale and IHS specimens to better understand constitutive behaviour and establish a consistent framework for strength testing - research will use a triaxial cell to explore possible permeability enhancement mechanisms within IHS when subjected to SAGD thermal and pore pressure loadings. The PhD testing encompasses two programs: 1) the impact of pore pressure changes under isothermal conditions; and 2) the impact of temperature increase.
Project 1.4 Reservoir Geomechanical Characterization of Bitumen Carbonates PhD student will develop a carbonate discontinuum geomechanical model using PFC (2D and 3D) capable of handling heterogeneity, focusing on the effects of cavity size, quantity, shape and location as well as fracture distribution. Significant progress already being made in current MSc project. PFC3D models will be tested in virtual environments: triaxial tests; tension tests; Brazilian tests; and unconfined compression tests. This will enable a method in which void and fracture geometries can be used to quickly determine material strength reduction when moving from laboratory- to reservoir-scale behaviour, following the synthetic rock mass modelling approach. Given the high heterogeneity of the Grosmont reservoir, only small intact samples will likely be obtained for testing and calibration. Therefore, modified triaxial tests will be created to conduct experiments on smaller specimens. Digital fabrication will be used in this study.
Project 1.5 High Temperature Seismic Frequency Dynamic Properties PhD student - specialized servo-hydraulic load frame to dynamically load (forced oscillation) oil sands, shale and carbonate core specimens at seismic frequencies (30 to 100 Hz) rather than standard, conventional ultrasonic frequencies (MHz). The testing will use stresses, pore pressures and elevated temperatures (up to 300 °C) associated with unconventional resource in situ conditions. The results of this study will contribute to a better understanding of fundamental parameters of seismic-to-rock properties at in situconditions and high temperatures.
Project 1.6 Constitutive Behaviour of Thermal PhD student – Experimental Study (aligned with Project 4.1) Although both mechanical and chemical degradation result in degradation of mechanical properties, the mechanisms occur at significantly different temperature ranges. A number of studies have been published on the changes in the microstructure of hydrated Portland cement, range from changes in the mineralogy to changes in pore structure. In general, however, there has been limited information on the mechanical properties of cement paste at elevated temperatures.
Project 2.1 Upscaling for Reservoir Geomechanical Modeling PhD student will collect and study geomechanical laboratory test results obtained by previous researchers and investigate the effect of heterogeneous geomechanical properties on coupled geomechanical-flow simulation for SAGD. The aim is to build geological models to be used for numerical simulation and upscaling purposes in the second phase of this research. STARS (from CMG group) and FLAC (from Itasca) will be used for simulation of flow and geomechanical processes, respectively. Student will develop a local numerical upscaling technique to describe the macroscopic plastic behaviour of complex heterogeneous media. Progress has been made on the macroscopic elastic behaviour but the transition from elastic to elastic-plastic behaviour will present significant challenges. The geomechanical response of the coarse upscaled models will be compared to geomechanical responses of the fine-scale models such that responses obtained from the upscaled model appropriately match responses obtained from the baseline, fine-scale geological model.
Project 2.2 In Situ Stress Measurement: Techniques and Interpretation PhD student will review current interpretation techniques of minimum in situstress on hard soils-soft rocks when using the MDT tool. The student will collect and study field test results obtained from a case study. Data will be used to numerically evaluate the formation and MDT tool interaction by coupling ABAQUS (geomechanics) and CFX/Fluent (flow). Ultimately, the student will develop/modify the methodology for estimating minimum in situstress with the MDT tools for hard soils-soft rocks.
Project 2.3 Reservoir Geomechanical Pressuremeter PhD student will continue the tool development stage, focusing on stress anisotropy and stress magnitudes. The potential for permeability measurements will also be explored - implement/perform the research plan to enhance the tool, and a field trial will be conducted at depths greater than 300 m. Work closely with the mechanical and electrical engineers engaged within the program. Field trials with industrial sponsors within the program will also be a key element of the research.
Project 2.4 Physical Modeling for Verification of DFNs PhD student (geomechanics) - physical modelling of discrete fracture networks in a beam centrifuge environment - literature of modelling and assessment techniques for micro-seismic events, fracture network and fracture permeability in reservoirs as well failure propagation of shale gas rock type - set the groundwork for creating techniques and protocols for building 3D fracture network block models with known fractures locations, focusing on novel 3D digital fabrication techniques that will be used to reproduce the DFN.
Project 2.4 Physical Modeling for Verification of DFNs PhD student (materials) - research into suitable substrate materials for both the sand and the bonding catalyst that surrounds the sand grains and provides the physical bonding necessary to create porous 3D geomodels with analog rock properties, such as unconfined compressive strength or tensile strength. This PhD student will work collaboratively with the geomechanics PhD student to evolve the techniques and protocols for building 3D fracture network block models with known fractures locations, focusing on novel 3D digital fabrication techniques that will be used to reproduce the DFN. This research will identify materials components that are cost-efficient and suitable for the construction of heterogeneous 3D geomodels.
Project 3.1 Adaptive Continuum/Discontinuum Modeling PhD student will continue the verification exercise of the SRM models with laboratory data. The students will develop a routine with a code to link each of the software packages (DFN, flow and continuum geomechanics).
Project 3.1 Adaptive Continuum/Discontinuum Modeling PhD student will develop a routine to link DFN and SRM. In parallel, the student will also incorporate the work of the previous PhD student. Creating and managing all of the links and data transfer will be a computer programming challenge with potential unforeseen conceptual challenges.
Project 3.2 Geomechanics/Geochemistry in Streamline Simulations PhD student will collect and compare results of streamline only simulations and streamline-geomechanical simulations. The student will evaluate the advantages and disadvantages of integrating geomechanics in streamline simulators. This initial series of studies will ultimately provide the basis for exploring how geomechanical-streamline simulation methodologies can be embedded within standard reservoir-geomechanical simulators as a means to achieve demonstrable increases in computational speed on large, reservoir-scale simulation models.
Project 4.1 Thermal Well Integrity Assurance Modeling PhD student - shared boundary modelling approaches (coupling two codes at different scales) to allow full field reservoir model results as a small wellbore model. The large-scale model would be a coupled reservoir geomechanics code using CMG’s STARS and Itasca’s FLAC. The small-scale wellbore code would take the inputs from the large-scale FLAC model and use them in a smaller-scale FLAC model. Laboratory testing on thermal-mechanical-hydraulic properties of cement specimens under simulated reservoir conditions generated by modelling results. This project will interface with Project 1.1, 1.4 and 1.6 since well integrity issues are potentially the result of unanticipated loading along the length of the wellbore due to deformations occurring within the oil sands formation. This will be equally true for bitumen carbonate deposits that are exploited using thermal recovery techniques.
Project 4.2 Re-Analysis of Joslyn Creek Steam Release Incident PhD student will use small and large-scale 3D coupled reservoir geomechanical simulations with continuum (Itasca’s FLAC3D) and discontinuum (Itasca’s 3DEC) modelling to explore the assumptions of the SAGD caprock acting as a fissured or non-fissured material. The ERCB and Total reports will be examined to extract model inputs including geology, operations pressures and temperatures. Laboratory testing on similar caprock specimens will be completed to obtain fissure/joint properties. Geostatistical models of the reservoir and potential fissure (DFN) networks will be generated to parametrically explore different scenarios and if this massive failure was a result of an alignment of unfavorable geological characteristics unique to the Joslyn setting or could be expected at other locations under similar operating conditions.
Project 4.4 Physical Modeling for SAGD Caprock Integrity (Centrifuge Studies) PhD student will modify the MSc modelling effort to explore the impact of horizontal or vertical discontinuities in caprock on failure process. The student will also conduct centrifuge tests by injecting an inert gas to dislocate/as-uplift mechanics in the caprock failure process and explore use of natural/in situClearwater Shale material as caprock (acquiring an undisturbed block sample from the field).
Project 5.1 Inclusion of Geomechanics in Reservoir Optimization PhD student - build upon the work of Azad (2012). The major outcome of this project is likely to be a methodology for co-optimization of SAGD reservoir flow physics and geomechanical responses of the reservoir and caprocks (shales) for different cases of reservoir characteristics and production objectives.
Accepting inquiries for PhD applications in September 2017.
If you would like more information on how to apply to the University of Alberta please contact Hope Walls