SAGD Sand Control Performance Testing
We are performing laboratory testing using SAGD screen coupons to (1) verify and refine generic design criteria for slotted liners, (2) develop novel standard testing methods for custom design of slotted liners, and (3) perform a comprehensive performance analysis of slotted liners against other types of sand control completions. We are also setting up a laboratory testing facility for large-scale testing of SAGD sand control screens. The tests will utilize full-scale screens surrounded by large-scale oil sand under realistic rerservoir pressure and stress conditions.
Physical Model Testing of Sand Production
We are conducting sanding experiments by using a pressure vessel specially designed to enable complex loading and flow conditions, and to allow sand production. We designed the cell to hold samples up to 7 inches in diameter and 11 inches in height. We designed the cell to hold 10,000 psi operating confining pressure. The testing facility used in this research will allow a flow rate of up to 5.0 lit/min, ensuring most of detached fragments will be produced throughout the test. The primary outputs of the sanding experiments are the stress-deformation, fluid flow pressure and rate, and sand rate.
Laboratory Study of Breakout Evolution around Perforation Cavities
The primary objective of this research is to develop an understanding of failure initiation and growth around perforation cavities using physical model testing. We have built a laboratory set up that can simulate in situ conditions, resulting in the initiation and growth of breakouts. We are studying the effect of fluid flow on the breakout size and disaggregation mechanisms and the size of the fragments (e.g., sand grain or grain assembly). We have developed methods to capture the failure evolution in real time (real-time measurements) through the use of pseudo-identical samples in staged tests. We perform post-mortem analysis of breakout evolution using Computer Tomography (CT) scans and thin section studies. Another important observation during the testing is the degradation level in relation to the failure mechanism (tensile, shear, compactive or a combination of these).
Sand Production- Numerical Model Development with Validation against Laboratory and Field Data
This research is concerned with developing a sanding model for the prediction of sanding initiation and propagation in injector and producer wells. This model couples the rock mechanical response with fluid flow and can capture rock mechanical degradation using appropriate constitutive laws. The numerical model can calculate sanding volume using different types of sanding criteria.
Numerical Modeling of sand face-liner interface in SAGD wells
The aim of this project is to investigate the stability and deformation of the liner-sand face gap and the evolution of stress, porosity, and permeability in the vicinity of slotted liners in the life cycle of SAGD production wells.
Numerical Model Development for SAGD Caprock Integrity Assessment
We have developed a model by linking the Computer Modelling Group's thermal reservoir simulator code, STARS, and ITSACA's geomechanical software, FLAC. The linkage between these two software is by two-way iterative coupling. The cap shale is known to show significant anisotropic response to the loading. Nevertheless, to the best of our knowledge, anisotropic constitutive laws have not been attempted in caprock integrity assessments. We have implemented an anisotropic Mohr-Coulomb law combined with a nonlinear elastic model in our numerical tool that we have validated against lab testing. We are performing the SAGD caprock analysis using both isotropic and anisotropic assumptions to investigated the significance of the anisotropic response in the caprock integrity assessments.
Integrated Reservoir/Pipe Flow Model for SAGD wells
We are developing an integrated hydro-thermo-geomechanical model linked with wellbore flow analysis to optimize the placement and operation of inflow and outflow control devices in SAGD wells.
Development and Validation of Sand Erosion Criteria for Sand Production Prediction
We designed and constructed a laboratory set-up to perform erosion tests on unconsolidated sand samples. Bu performing these tests, we examine the effects of various parameters such as flow rate, permeability, porosity, grain size and capillary pressure on the rate of sand erosion. With the aid of these tests, we are improving and substantiating the existing constitutive erosion laws, which are currently mainly based on intuition.
Numerical Model Development for the Simulation of the Initiation and Growth of Hydraulic Fracture
We have developed a new smeared hydraulic fracture model which can simulate the initiation and growth of tensile fracture in un-predetermined directions. The model can capture phenomena such as shear fracture development, shear-enhanced permeability, and the interaction between shear and tensile fractures.
We advanced the smeared approach for the simulation of hydraulic fracture within the continuum mechanics framework. We considered both matrix and fracture flow, tensile and shear fracture development, and shear induced permeability enhancement. Shear fracturing of geomaterials involves intense localization of deformation and strain softening, which is a discontinuous phenomenon, resulting in mesh dependency of the results in the continuum model. We used the fracture energy regularization method to reduce the mesh size-dependency of the energy dissipated during fracture propagation. We validated the smeared fracture approach against laboratory hydraulic fracture experiments and field data with reasonable agreement. We found that shear fracturing and the shear-permeability evolution can be the most important mechanisms that influence and control the fracturing response.
Numerical Simulation of Fracpack
We are developing a proppant transport model and linking it to our smeared fracture model to enable the simulation of fracpacking process in petroleum wells. The model enables capturing shear fractures as well as tensile fractures for which there is no need to prescribe a predetermined direction.
Investigation of Liquefaction Potential around Injection Wells under Waterhammer Pressure Pulsing
The primary objective of this research is to determine the conditions that can lead to sand liquefaction in unconsolidated reservoirs. We are developing a numerical model that can predict the potential of sand liquefaction around injector wells under the dynamic effect of waterhammer waves. These waves are generated following a quick wellbore shut-in, which induces sudden changes in velocity of the flow. The magnitude of these waves depends on the magnitude of the injection pressure, and the shut-in rate. The code we are developing is capable of fluid dynamics analysis in porous media. This feature is combined with a solid dynamics analysis and a critical state constitutive model suitable for dynamics conditions.
A New Bounding Surface Constitutive Model for Cemented Sand under Cyclic Loading
We have developed a critical-state based constitutive model suitable for the simulation of rock degradation under cyclic loading conditions encountered in petroleum wellbores such as in injection, production, and CSS wells. The model captures the energy dissipation in cyclic loading (i.e. the hysteresis effect) that most constitutive models are incapable of. The application is in the numerical simulation of phenomena such as sand production, hydraulic fracturing, casing collapse, and reservoir deformation.
Micromechanical Study of Borehole Breakout Mechanism
This research numerically investigates the effect of the material micro and macro-parameters on the failure mechanism and the geometry of the wellbore breakout. We used a three-dimensional discrete element method in the simulations to investigate different types of breakouts such as uniform, dog-ear, and slit-type breakouts.
The results showed that the geometry of the breakout was affected by micro-parameters such as the particle contact modulus, the parallel bond normal and shear strengths, the particle crushing strength, and the particle size distribution. In addition, it was found that the macro Young’s modulus, friction and dilation angles, and the uniaxial compressive strength also affect the type of breakouts.
We also used the DEM approach to simulate triaxial testing, which showed that: (a) Young’s modulus is not just affected by the particle contact modulus, but also the friction coefficient between particles and the percentage of bonded contacts, (b) the dilation angle is a function of the particle contact modulus, percentage of bonded contacts and inter-particle friction, (c) the friction angle is not only affected by the friction coefficient between particles, but also by bond strengths, (d) cohesion is not just affected by bond strengths and the percentage of bonded contacts, but also by the friction coefficient between particles, and (e) the post-peak modulus is affected by the percentage of bonded contacts and inter-particle friction.
We have recently linked the DEM model with an in-house flow simulator to investigate sanding mechanisms at the particle level. The model incorporated several effects such as the role of particle rearrangement and sand production on permeability evolution. The DEM sanding tool is to be linked with a continuum based model to construct a hybrid model to enable the application of DEM model for large-scale sanding analysis.