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Advanced Carbonate Rock Typing and Property Distribution in an Upper Jurassic Reservoir: Getting the Geology Right
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Eighth EAGE Arabian Plate Core Workshop, Nov 2022, Volume 2022, p.1 - 6
Abstract
Carbonate rock typing methodologies are essentially an attempt to identify reliable statistical relationships between geological parameters, mostly from core when available, and the log domain and distribute the resulting categories in the reservoir using spatial trends and relationships embedded in the geological domain, mostly based on depositional and textural concepts. The reality, unfortunately, is that the log domain relationship with geological parameters from core is generally weak (below statistically acceptable thresholds) and therefore obscures petrophysical distributions in resulting models. On the one hand, diagenetic modification may explain part of this lack of correlation, but our knowledge of diagenetic body trends and juxtaposition are poor due to the absence of reliable analogs. On the other, we may question the reliability and grounding of depositional facies models used. Finally, the common carbonate rock typing approach is not tailored to test and handle such uncertainties. By focusing on the statistical predictability of petrophysical rock categories first and understanding kriged distributions in reservoir space we attempt to resolve this conundrum. This paper uses a Middle East example to highlight such pitfalls and, at the same time, to integrate sedimentary characteristics in rock typing practices and reservoir characterization.