Operationalizing Reservoir Architectural Element Re-Definition as a Decision-Control Mechanism in Mature Deltaic and Turbidite Fields (Published)
Mature deltaic and turbidite reservoirs represent critical hydrocarbon assets globally, yet their management is persistently challenged by declining production efficiency, rising subsurface uncertainty, and static geological models that progressively diverge from observed dynamic behavior. Conventional reservoir characterization workflows, including those structured within the Reservoir Management Maturity Model (RM3) framework, typically treat architectural element definitions—the fundamental building blocks of geocellular models—as fixed inputs established during field appraisal and preserved through subsequent model updates. This practice results in “frozen” geological frameworks that lose epistemic flexibility, leading to systematic static-dynamic mismatch, uncontrolled volumetric uncertainty, and suboptimal infill well placement decisions. The chronic failure to operationalize architectural reinterpretation as an active decision variable represents a critical gap in mature field value optimization methodology.This study presents and validates a novel, structured workflow that operationalizes reservoir architectural element re-definition as a formal decision-control mechanism within mature field static modeling practice. The methodology comprises five integrated stages: (1) baseline model audit identifying systematic performance anomalies symptomatic of architectural misconception; (2) data-driven reinterpretation integrating seismic geomorphology, sedimentological reanalysis, and production diagnostics to propose revised element boundaries; (3) static model re-population implementing revised architectural frameworks within geocellular constructs; (4) dynamic calibration discriminating between competing interpretations through history matching; and (5) decision-control formalism translating narrowed uncertainty into quantified infill well rankings and investment sanction criteria. The workflow is demonstrated through application to two anonymized offshore assets: a wave-influenced deltaic reservoir (Asset D, Niger Delta analogue) and a confined turbidite channel-lobe system (Asset T, deepwater Gulf of Mexico analogue), both characterized by 15–28 years production history and legacy static models constructed under initial appraisal-phase data constraints. Application of the workflow to Asset D achieved 60% reduction in Original Oil in Place uncertainty span (P90-P10 range narrowed from 91% to 36% relative to P50), 74% reduction in Connected Static Volume uncertainty for candidate infill locations, and 46% improvement in history match quality without geologically implausible parameter adjustments. Critically, architectural reinterpretation—distinguishing distributary channel from mouth bar elements using integrated seismic-core-dynamic evidence—directly enabled sanction of Well D-44, which was ranked 9th under legacy interpretation but elevated to 2nd rank under revised framework. Well D-44 delivered 3.21 MMstb cumulative production over 66 months, tracking within 6% of revised model forecasts and generating $18.2 million incremental net present value. Across both study assets, the workflow identified seven previously unrecognized infill opportunities, collectively representing 12.4 MMstb incremental accessible resources, with four wells drilled to date achieving average forecast accuracy within ±12%. This study demonstrates that systematic architectural element re-definition, conducted through disciplined integration of existing datasets rather than new data acquisition, functions as a powerful decision-control mechanism that narrows uncertainty, improves model predictiveness, and directly governs capital allocation confidence in mature clastic reservoirs. The methodology transforms static geological models from passive knowledge repositories into active decision-control systems, providing transferable value to hydrocarbon portfolio optimization and emerging subsurface energy transition applications including CO₂ storage site characterization and geothermal resource assessment.
Keywords: decision-control mechanism, mature field revitalization, reservoir architectural elements, seismic geomorphology, static-dynamic model integration