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E-363 - Core Analysis for Reservoir Characterization

  • Reservoir engineers an experienced technicians willing to deepen their knowledge in core analysis; young scientists, geoscientists and production engineers moving towards reservoir engineering
  • To provide comprehensive information on core analysis and the importance of rock properties for reservoir description and fluid-flow dynamics
Learning Objectives
  • To know and understand rock properties used in reservoir modeling and reservoir simulation models
  • To know how to interpret and validate a SCAL report and review a quality control process
  • To know how to design a SCAL program with regard to given objectives
Ways and means
  • Interactive lectures and exercises
  • Interpreting a two-phase flow experiment
  • Hands-on practices using dedicated software for SCAL data interpretation

  • Reservoir characterization: seismic, core analysis, well testing, logs, cuttings, PVT… Role of core analysis
  • Method for coring - Core preservation, cleaning and analysis - Conventional and special core analysis (CCA and SCAL)
Generalities on two-phase flow properties
  • Darcy's law for two-phase flows in reservoir simulations and core analysis
  • Relative permeabilities - Capillarity, Capillary pressure - Wettability
  • Effect of petrophysical properties on fluid displacements, importance of wettability in water flooding
  • Modeling miscible displacements
Conventional core analysis
  • Porosity: definition and measurements - Pore size distribution by NMR and Mercury Injection
  • Use of mercury to determine reservoir initial saturation and transition zones
  • Permeability: definition, measurements, indirect estimations, limits
  • Porosity/permeability correlations - Use of Core Analysis for Rock Typing
Design of SCAL program
  • SCAL program to obtain dynamic properties for reservoir simulations
  • Plug selection and preparation (Rock typing, CT scan, plugging…) - Additional measurements on trimends (Mercury, XRD, Thin section)
  • Choice of a method for placing oil into the plug (Swi state) - Choice of a wettability restoration procedure
  • Choice of operating conditions for relative permeabilities, reservoir conditions, live oil, dead oil, calculation or confining pressure
Measurements of scal properties
  • Dispersion tests to quantify plug heterogeneities - Measurement of wettability: Amott index, USBM, use of NMR
  • Relative permeabilities: steady-state, unsteady-state, in-situ saturation monitoring, interpretations
  • Capillary pressures: porous plates, centrifuge, semi-dynamic method - Formation factor and Resistivity index RI
Quality control of available data
  • Old and new data, contents of reports
  • Porosity, comparisons with logs when available (effective and total porosity)
  • Permeability, various methods, liquid and gas permeability, Klinkenberg corrections, effect of confining pressure
  • Wettability: Amott compared to USBM, effect of wettability on Pc, Kr and RI, check consistency of the results
  • Validity of Kr measurements, existence of wettability restoration, interpretation with capillary pressure
  • Validity of centrifuge interpretation, existence of calculation of local saturation
  • Final verification of the plug selection in the various rock types (mineralogy, porosity/permeability correlation, pore size distribution, Kr, Pc, RI)
Averaging petrophysical properties
  • Need for averaging rock types for reservoir simulations
  • Effect of heterogeneities, description of heterogeneities
  • Averaging for grid block properties - Averaging porosities and permeabilities - Averaging capillary pressures
  • Static averaging of end-points Kr
  • Dynamic averaging of Kr: pseudoization (Kyte and Berry)