- Service Description Audit-Ready Petrophysical Modeling provides a transparent, documented, and reproducible petrophysical interpretation framework that ensures reservoir properties used in static models and reserves estimates can withstand technical review, partner scrutiny, and regulatory audits . The service focuses on traceability, validation, and uncertainty quantification in petrophysical workflows. Key objectives • Ensure petrophysical interpretations are fully reproducible • Align logs, core, and SCAL data in a traceable modeling workflow • Provide audit documentation for reserves certification • Quantify uncertainties impacting volumetrics and reserves 2. Scope of Work A. Data Audit & Quality Control Comprehensive review of: • Well logs and environmental corrections • Core analysis (Routine Core Analysis – RCA) • Special Core Analysis (SCAL) data • Formation test and pressure data • Mud log and lithology information Typical checks include: • Log calibration consistency • Depth matching core vs logs • Outlier identification • Missing or suspect intervals B. Petrophysical Modeling Framework Development of a fully documented interpretation workflow, including: Lithology and mineral model definition Porosity modeling (multi-log integration) Shale volume estimation Formation water resistivity (Rw) calibration Saturation model selection (Archie / Dual-Water / Simandoux, etc.) Each step includes: • Model assumptions • Parameter sources • Calibration datasets C. Core & SCAL Integration Calibration of log-derived properties using laboratory data: • Porosity calibration with RCA • Permeability relationships • Capillary pressure interpretation • Relative permeability implications Outputs include: • Rock typing • Saturation height functions • Reservoir quality classification D. Uncertainty & Sensitivity Analysis Critical step for reserves auditing . Sensitivity testing performed on: • Archie parameters (a, m, n) • Formation water resistivity (Rw) • Clay corrections • Net-to-gross cutoffs Deliverables: • P10 / P50 / P90 petrophysical scenarios • Impact on STOIIP / GIIP • Risk assessment for development decisions E. Documentation for Audit Final deliverables prepared in audit-ready format . Includes: • Methodology report • Interpretation assumptions • Input parameter tables • QC checks and validation results • Uncertainty summary The result is a transparent interpretation that can be reviewed by partners, regulators, or reserves auditors . 3. Deliverables Typical deliverables include: Technical Documentation • Petrophysical interpretation report • Methodology workflow documentation • Calibration with core and SCAL data Digital Deliverables • Interpretation project files (Techlog / IP / Interactive Petrophysics) • Petrophysical calculation spreadsheets • Sensitivity analysis models Visual Outputs • Multi-well log interpretation panels • Rock typing plots • Saturation-height relationships • Uncertainty charts 4. Value for Operators Audit-ready modeling provides: ✔ Confidence in reserves estimates ✔ Transparency for technical partners ✔ Faster field development decisions ✔ Reduced interpretation risk ✔ Improved integration with reservoir models This is especially important for: • Reserves certification (SPE-PRMS) • Farm-out evaluations • Asset acquisitions • Regulatory reporting