Computer Modelling Group Ltd., abbreviated as CMG, is a software company that produces reservoir simulation software for the oil and gas industry. It is based in Calgary, Alberta, Canada with branch offices in Houston, Dubai, Bogota, Rio de Janeiro, London and Kuala Lumpur. The company is traded on the Toronto Stock Exchange under the symbol CMG.The company offers three reservoir simulation applications. IMEX, a conventional black oil simulator used for primary, secondary and enhanced or improved oil recovery processes; GEM, an advanced Equation-of-State (EoS) compositional and unconventional simulator; and STARS a k-value thermal and advanced processes simulator. CMG also offers CMOST, a reservoir engineering tool that conducts automated history matching, sensitivity analysis and optimization of reservoir models. In addition, CMG has developed CoFlow, which is a unique production engineering software for wellbore and facility analysis and allows for smart coupling with reservoir models.
Abstract Employing DLA methods, this paper explores the self-assembly of collagen fibers and resulting fibrosis at three scales up to the scale of regular lobule models. This allows a mechanistic exploration of the effects of collagen on drug transport (flow and diffusion) and metabolism. In addition, this method permits an analysis of fiber growth characteristics. First, variations of the DLA method of Parkinson et al (1994) will be used to generate multiple explicit collagen microfibril self-assembly using DLA particles in one dimension using cubic grid blocks of (4 mm) 3 in a 240 × 20 × 20 grid model. The second stage will be to assess the consequences of various densities of these fibers in three dimensions on flow reductions at a higher scale. Here we utilize DLA methods in cubic grid blocks of (80 nm) 3 to mimic 3D collagen self-assembly of fibrils. We then apply a pressure gradient or specified flow rates across a spatially gridded version of these models to quantify flow effects. This region represents a local zone of liver tissue affected by fibrosis. Analytic models of fibrotic effects on flow are employed for comparison. A third stage explores the implications of fibrosis in a liver lobule model using multiple grid blocks of size 3200 mm to represent the lobule tissue. Here, a continuum model of fiber density is employed, based on the previous two scales. The model also includes the effects of additional grid blocks representing sinusoidal flow paths found in the lobule. We contrast and quantify drug propagation and metabolism of molecular dissolved versus nanoparticle delivery vehicles in fibrotic media, achieved by upscaling explicit collagen distributions to appropriate average values.
Abstract Underground bio-methanation offers strong potential for large-scale renewable energy storage with simultaneous CO2 utilization. In this process, captured CO2 and green H2 are injected into a depleted gas reservoir, where methanogenic microbes convert them to CH4, which can later be produced through existing gas infrastructure. However, transport–reaction interactions in porous media are complex, and methane yield depends on microbial kinetics, flow behavior, and multiphase processes. The system is only low-carbon if the full operational chain remains energy and emissions efficient compared with alternative storage options. This study combines compositional reservoir simulation with a life-cycle exergy framework. A 3D homogeneous model evaluates kinetics-controlled conversion, gas composition, reaction-induced water generation, and grid sensitivity during cyclic injection–shut-in–production scheme. Two kinetic regimes—fast and slow—are represented using calibrated parameters. Simulation outputs feed into exergy analysis to determine exergetic efficiency and CO2 intensity, highlighting major energy penalties and emission sources. Results show near-complete conversion (99%) and methane-rich gas in the high-kinetic regime, but with increased water production due to rapid, localized reactions. The low-kinetic regime yields slower, more spatially distributed conversion with early CO2 and H2 breakthrough, while methane purity improves gradually over cycles. Grid sensitivity increases under slow kinetics. Despite differing reservoir behavior, system-level performance remains similar, with exergetic efficiency of 0.31-0.33 and CO2 intensity of 18–21 g-CO2/MJe.
Field evidence consistently shows that hydraulic fractures initiated from newly drilled “child” wells preferentially propagate toward existing “parent” wells. This asymmetric behavior arises from depletion-induced pore pressure sinks and stress redistribution around the parent well, which locally reduces the reservoir stresses and creates stress anisotropy. The resulting attraction of child fractures toward depleted zones often manifests as “frac-hits” - mechanical interference and pressure communication events that can compromise parent well integrity, alter fluid distribution, and reduce overall recovery efficiency. This study presents a fully integrated modeling workflow that couples three-dimensional hydraulic fracturing simulation with geomechanical stress evolution and reservoir flow modeling, augmented by Sealed Wellbore Pressure Monitoring (SWPM) diagnostics. The framework enables dynamic calibration of fracture propagation by correlating simulated fracture growth with observed pressure responses in nearby monitoring wells. SWPM provides precise identification of fracture arrivals through real-time pressure change monitoring, facilitating quantification of cluster efficiency, and stage-to-stage fluid distribution. The integrated workflow captures the complete life cycle of parent and child well simulation - from initial fracture creation and depletion-induced stress change to subsequent stress shadowing-controlled propagation. Simulation results demonstrate that reservoir depletion in the parent well leads to anisotropic stress redistribution, reducing local stresses and creating preferential reduced stress zones that attract fracture growth from the adjacent “child” well. This depletion-induced stress relaxation results in asymmetric fracture propagation and elevated risk of inter-well hydraulic communication. By coupling the 3D hydraulic fracturing simulator with SWPM diagnostics, the study quantitatively constrains fracture half-lengths, height containment, and cluster efficiency, allowing for dynamic calibration of the geomechanical model. Benchmarking of model predictions against SWPM derived Volume to First Response (VFR) and fracture growth signatures demonstrate strong agreement with field observations, confirming the model’s capability to capture asymmetric propagation and vertical containment behavior, multi-stage fracture growth, inter-well interactions, and staggered well configurations. SWPM-calibrated simulations further confirm that parent-well re-pressurization, optimized landing depths, and staggered well configurations effectively restore local stress balance, limit fracture coalescence, and enhance vertical containment.
Carbon Capture and Storage (CCS) has emerged as a pivotal technology in mitigating greenhouse gas emissions and combating climate change. In this study, we explore the feasibility of CO2 storage in saline aquifers through a robust two-way coupling approach between dynamic reservoir simulation and geomechanical modeling. This integrated methodology enables a comprehensive understanding of the interactions between fluid flow dynamics and mechanical responses of subsurface formations. By iteratively exchanging data between reservoir and geomechanical models, we capture the evolution of porosity, permeability, and stress-strain behavior over time, thereby enhancing the accuracy of CO2 plume prediction and risk assessment. The workflow and results presented herein offer valuable insights for optimizing CCS operations and ensuring long-term storage integrity. In this study a dual grid system is adopted for two-way coupling between reservoir and geomechanical models. Reservoir grids are fine and represent the area of CO2 injection, whereas Geomechanical grids are coarser and cover ground surface, overburden, caprock, reservoir, side burdens, and under burden. It is an iterative coupled model where pressure and temperature from reservoir simulator is passed on to geomechanical module to compute stress/strain and displacement changes, which in turn will update porosity, permeability and compressibility for next time step in the reservoir simulator where fluid flow calculations involving pressure and saturation changes are performed. Two-way coupled simulations are run for 25-years of CO2 injection followed by 45-years of observation. Results from two-way coupled models are analyzed for CO2 plume modeling and geomechanical risk assessment. Ground surface deformations (heave) and reservoir deformations are also predicted. Reservoir properties changes due to CO2 injection are also modeled and updated at every time-step. Geomechanical risk assessment e.g. fault stability and caprock integrity analysis can also be performed using the results of two-way coupled models. Two-way coupled reservoir & geomechanical models helped us to model interaction between reservoir and geomechanical parameters, thereby accurately predicting reservoir storage parameters and geomechanical risk assessment. Two-way Coupling workflow developed in this study can be applicable to other CCS projects for integrated risk assessment.
