Publications

Research that advances theory and practice
GSERC publishes peer-reviewed research in computational poromechanics, reservoir simulation, and production forecasting. Our work challenges conventional assumptions and delivers validated frameworks for real-world African oil & gas operations.
PhD research papers
field-validated simulators
conference presentations
CCS case study (Porthos)

Peer-reviewed journal articles

  • Paper 1 — Discovery of the Critical Pressure State and Porosity-Induced Stiffening in Poroelastic Media
    Computational Poromechanics · Linear Superposition Method · Cubic Pore Arrangements
    Discovered the Critical Pressure State (PCRIT ≈ 104.5 MPa) and the porosity-induced stiffening phenomenon in poroelastic media using the Linear Superposition Method (LSM) on cubic pore arrangements. This work challenges the traditional assumption that increasing porosity always decreases bulk modulus — demonstrating that beyond a critical pressure, porous media actually stiffen as porosity increases. The findings establish a new theoretical framework for understanding pressure-dependent rock mechanics in reservoir conditions.
  • Paper 2 — Generalized Stiffening Theory and Incompatibility of Biot’s A Priori Upscaling
    Hexagonal Pore Lattices · Analytical Upscaling · Pressure-Dependent Coefficients
    Generalized the stiffening phenomenon to hexagonal pore lattices and proved mathematically that Biot’s a priori upscaling theory is incompatible with nonlinear stiffening behavior. Derived closed-form analytical upscaling equations with pressure-dependent coefficients A(F) and B(F) for direct engineering application. This provides the first rigorous theoretical alternative to classical Biot-Gassmann theory for pressure-sensitive porous rocks.
  • Paper 3 — Lateral Confinement Effects on Stiffening and CCS Validation (Porthos Case Study)
    Biaxial Loading · Hydraulic Diffusivity · CO₂ Injection · Reservoir Stiffening
    Applied biaxial far-field loading to demonstrate that lateral confinement accelerates stiffening — with PCRIT dropping to 80 MPa under equibiaxial conditions and 45 MPa under extreme anisotropy. Linked bulk modulus stiffening to hydraulic diffusivity increases, providing a coupled flow-mechanics framework. Validated the entire framework with the Porthos CCS (Carbon Capture and Storage) case study, showing approximately 20% reservoir stiffening during CO₂ injection — a critical insight for secure storage site characterization.
  • Paper 4 — Micro-Poromechanical Model for Pressure-Dependent Pore-Volume Compressibility
    Anisotropic Stresses · Pressure-Porosity Coupling · Nonlinear Elasticity · First Principles
    Developed a novel micro-poromechanical model for porosity and pressure-dependent pore-volume compressibility (c_p) that explicitly incorporates anisotropic far-field stresses (σH, σh, σv), pressure-porosity coupling, and nonlinear elastic stiffening. Unlike conventional hydrostatic laboratory correlations, this model is derived from first principles and applicable to real reservoir stress states — enabling more accurate compaction and subsidence predictions in producing fields.

Conference proceedings & presentations

  • Multi-Well Pressure Interference and Drainage Simulation in Heterogeneous Reservoirs — The Nechelik Field Study
    Reservoir Simulation · Finite-Difference Methods · Analytical Validation · MATLAB
    Presented the development and validation of a fully implicit 2D finite-difference reservoir simulator built in MATLAB for modeling transient pressure evolution and multi-well interference in heterogeneous clastic reservoirs. The study integrates real-field geostatistical data from the Nechelik field and validates numerical results against the exponential integral (Ei-function) analytical solution for radial flow.
  • Development of a Fully-Implicit 3D Waterflood Reservoir Simulator for Production Forecasting and Injection Optimization
    Multiphase Flow · Black-Oil Modeling · Newton-Raphson Methods · Python Scientific Computing
    Presented a fully implicit three-dimensional black-oil reservoir simulator developed from first principles in Python. The work covers finite-difference discretization, coupled oil-water flow equations, relative permeability and capillary pressure integration, Newton-Raphson Jacobian assembly, and scenario-based waterflood optimization across five injection cases. Demonstrated robust numerical performance through material-balance validation.
  • Advanced Multi-Functional Modeling of Unconventional Reservoir Characterization and Production Forecasting Using PTA/RTA/DCA
    Pressure Transient Analysis · Rate Transient Analysis · Decline Curve Analysis · Python Automation
    Presented automated workflows for unconventional reservoir characterization integrating Pressure Transient Analysis (PTA), Rate Transient Analysis (RTA) using Fetkovich-Arps, Blasingame and Agarwal-Gardner type-curves, and modern Decline Curve Analysis (DCA) methods including Duong, Logistic Growth Model (LGM), SEPD and T-model approaches. Demonstrated Python-based computational applications for automated reservoir engineering workflows and production forecasting.
  • Gravity- and Capillary-Driven Two-Phase Reservoir Simulation for Waterflood Optimization in Dipping Reservoirs
    IMPES Formulation · Brooks-Corey · Capillary Pressure · Buckley-Leverett · Adaptive Well Conversion
    Presented a 2D two-phase oil-water simulator for structurally complex dipping reservoirs using the IMPES formulation with Brooks-Corey relative permeability, capillary pressure integration, and gravity segregation. Validated against the Buckley-Leverett analytical solution. Demonstrated adaptive well conversion strategies achieving 46.27% recovery factor over 16.9 years of field life.
  • Indigenous 2D Reservoir Simulation Platform for Pressure Transient Analysis and Well Performance Forecasting in Anisotropic Reservoirs
    Fully Implicit · Non-Uniform Grid · Anisotropic Permeability · Peaceman Well Model · Mixed Constraints
    Presented a fully implicit 2D simulator for pressure transient analysis in heterogeneous anisotropic reservoirs with non-uniform grid discretization. Implemented harmonic transmissibility averaging, gravity-aware initialization, and Peaceman well modeling with mixed rate and BHP constraints. Demonstrated pressure evolution from hydrostatic conditions to stabilized distributions in reservoirs with k_y = 2k_x anisotropy.
  • Advanced Reservoir Simulation with Fault-Induced Compartmentalization: A 7×7 Grid Study with Custom Gaussian Elimination
    Fault Barrier · Zero Transmissibility · Custom Solver · Compartmentalized Flow · Pressure-Constrained Wells
    Presented a 7×7 Cartesian grid simulator incorporating a fault-induced zero-transmissibility barrier to model compartmentalized flow systems. Developed a custom Gaussian elimination solver in Python for full numerical transparency. Demonstrated pressure propagation, injector-producer communication, and steady-state convergence in structurally complex reservoirs with pressure-constrained well operations.

Technical white papers & reports

  • White Paper: Computational Reservoir Simulation for African Independent Operators — A License-Free Approach
    Technology Strategy · Local Content · Open-Source Simulation
    A strategic white paper arguing for the adoption of open-source and academic-license simulation tools (Python, MATLAB) by African independent operators and national oil companies. Compares total cost of ownership against commercial simulators (ECLIPSE, CMG, tNavigator) and presents validated case studies demonstrating equivalent accuracy for standard reservoir engineering workflows.
  • Technical Report: Porosity-Induced Stiffening — Implications for Reservoir Compaction and Subsidence Prediction
    Poromechanics · Compaction Modeling · Subsidence Risk
    Translates the PhD theoretical framework on critical pressure states and stiffening into practical guidance for reservoir compaction and subsidence prediction. Discusses implications for geomechanical modeling in high-pressure, high-porosity reservoirs common in African basins.
  • Technical Report: Waterflood Performance Evaluation Framework for Heterogeneous Clastic Reservoirs
    Enhanced Oil Recovery · Waterflood Design · Scenario Analysis
    Documents the five-case scenario analysis methodology developed for the Python waterflood simulator. Provides decision matrices for injection rate selection, water breakthrough prediction, and recovery optimization in heterogeneous oil reservoirs — directly applicable to mature field redevelopment in African producing assets.

Technical reports & field studies

  • Probabilistic Reserves Estimation & Economic Risk Assessment: Field KK Case Study
    Monte Carlo Simulation · Triangular & Uniform Distributions · PSC Fiscal Modeling · 10-Year NPV Forecasting
    Probabilistic estimation of OOIP and economic risk evaluation for a Mediterranean offshore oil reservoir. P50 OOIP = 2.095 Billion barrels under triangular distribution. NPV analysis confirms high commercial viability across exploration and production phases.
  • Modern Decline Curve Analysis for Shale Gas: Cross-Model Validation & EUR Forecasting
    Duong · LGM · SEPD · T-Model · Excel VBA Automation · 20-Year Forecast
    Cross-validation of four modern DCA models against 20 years of historical shale gas production. LGM achieves 4.44% flow-rate error; Duong/T-Model achieve 0.49% cumulative error. 20-year EUR: 2.758 Bcf.
  • Well Deliverability Optimization & ESP Design: EL AIN Field, Tunisia
    Nodal Analysis · Vogel IPR · Hagedorn-Brown VLP · Python WD_APK · ESP Sizing · Economic Evaluation
    Nodal analysis and ESP design for mature wells experiencing severe production decline. ESP installation restored production from 0 to 8,000 bbl/d with +37.9% and +40.6% gains. 10-year net income validates multi-billion-dollar returns.
  • Integrated PTA/RTA/DCA Workflow for Unconventional Tight-Gas Reservoirs
    Pressure Transient Analysis · Rate Transient Analysis · Modern DCA · Python Platform · Multi-Method Validation
    All-in-one Python application integrating PTA, RTA, and Modern DCA for hydraulically fractured tight-gas wells. Cross-validated permeability (0.01–0.05 mD), skin (-3.68 to -5.02), fracture half-length (~80–101 ft), and Gas Initially In Place (~2.1–8.98 Bcf).
  • Stochastic Material Balance & Economic Modeling: MODEC Petroleum Framework
    Generalized Material Balance · Havlena-Odeh · Monte Carlo · Polynomial Regression · PSC Economics
    Python-based integrated framework combining GMBE with 10,000-scenario Monte Carlo simulation, dynamic GOC/OWC tracking, and ML performance prediction. Deployed on anonymous offshore field: P50 STOOIP 346.72 MMstb, NPV10 $231.54M, 5.78-year payback.
  • Machine Learning for Automated Facies Prediction: Rio Del Rey Basin
    Random Forest · XGBoost · Decision Tree · KNN · SVM · Scikit-Learn · ENY apps
    Automated well log facies classification using ensemble ML models. Trained on 8,264 points from offshore Cameroon. Achieves 99.95% accuracy with 0.8-second execution — replacing days of manual interpretation with objective, reproducible results.
  • Artificial Lift Selection & Economic Optimization: Gas Lift vs. ESP Analysis
    PROSPER · PIPESIM · Nodal Analysis · ESP Design · Gas Lift Design · 10-Year Economics
    Comparative evaluation of Gas Lift versus ESP for dead wells in the EL AIN field. EMC App automated bottomhole pressure traverse calculations. ESP outperformed Gas Lift by 4× in high water-cut wells, generating +$211M gross profit over 10 years.
  • Computational Production Forecasting for Unconventional Gas: Well NF-1
    YM-SEPD · Duong · LGM · Excel VBA · History Matching · 1,400-Day Forecast
    Benchmarking modern DCA models for a Tunisian shale gas well. SEPD selected as best overall model, projecting bounded EUR of 762.25 MMscf. LGM delivered best cumulative production match (3.5% error). Duong excelled at daily rate trend prediction.
  • Gas Lift Design & CAD Validation: GALDAP Software Development
    Python · PROSPER · PIPESIM · Continuous Gas Lift · Unloading Valve Design · Wax Deposition Prediction
    Custom Python CAD application (GALDAP) for continuous gas lift design, validated against commercial PROSPER/PIPESIM with ~3% average discrepancy. Includes Zimmerman temperature gradient model for Wax Appearance Temperature (WAT) prediction. Restored production to 118–543 STB/d.
  • Advanced Gas Lift Valve Optimization with Integrated Flow Assurance
    Variable Position Control · Scale Inhibitor · Coridos 98P15 · Wax Thermodynamics · Excel VBA · 10-Year Economics
    Variable Position Control (VPC) gas lift valve design for high water-cut wells. Increased oil rates by 4–50% over conventional On/Off valves. Integrated scale inhibitor dosing expanded safe operating windows. Converted -$32.9M loss into +$33.2M profit for EL AIN-1.
  • Hybrid Gas Lift-ESP System Design for Enhanced Mature Well Production
    Hybrid Artificial Lift · Dual-Packer Architecture · Multiphase Hydraulics · Economic Evaluation · 5-Year Forecast
    Novel Hybrid GL-ESP architecture for well ELAIN-1 combining mechanical pumping with gas lift aeration. Reduced ESP Total Dynamic Head by 34% (4,858 ft → 3,224 ft). 5-year economics: standalone ESP generates +$111.3M gross profit; hybrid generates +$104.6M with superior technical performance.

Software documentation & technical notes

  • User Manual: Nechelik Field Reservoir Simulator (MATLAB)
    Documentation · Grid Setup · Well Configuration · Validation Protocol
    Comprehensive user manual covering grid generation, geostatistical data import, well model configuration, timestep selection, solver settings, and analytical validation procedures. Includes worked examples and troubleshooting guides for common numerical issues.
  • Developer Guide: Multiphase Waterflood Simulator (Python)
    API Documentation · Jacobian Assembly · PVT Configuration · Scenario Setup
    Technical documentation for developers extending or modifying the Python waterflood simulator. Covers the Newton-Raphson loop structure, Jacobian matrix sparsity pattern, PVT model parameterization, relative permeability table formats, and scenario file syntax for batch optimization studies.
  • Technical Note: Comparison of Implicit vs. Explicit Formulations for Reservoir Simulation Stability
    Numerical Analysis · Stability Criteria · Timestep Selection
    A concise technical note deriving the stability criteria for explicit and implicit finite-difference formulations in reservoir simulation. Demonstrates why implicit methods are essential for practical field-scale simulation with realistic timestep sizes, supported by numerical experiments from both the Nechelik and Waterflood simulators.
Research Themes
Computational poromechanics
Critical pressure states, porosity-induced stiffening, nonlinear upscaling, anisotropic stress coupling, and micro-mechanical modeling of pore-volume compressibility.
Reservoir simulation
Implicit finite-difference methods, sparse matrix solvers, Peaceman well models, Newton-Raphson Jacobian assembly, and multiphase black-oil formulations.
Production forecasting
PTA/RTA type-curve methods, modern decline curve analysis (Duong, LGM, SEPD, T-model), waterflood optimization, and scenario-based recovery evaluation.
CCUS & energy transition
CO₂ injection modeling, reservoir stiffening during carbon storage, coupled flow-geomechanics, and transition pathway analysis for African petroleum assets.
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