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Rocks: Integrated Approach of Rock-Typing from Core Scale to Log Scale—Example
Rebelle, Michel1, Mohamed Al Nuaimi1,
Maria Teresa Ribeiro1, Stephanie GottlibZeh2, Bertrand
Valsardieu2, Brian Moss2 (1) ADCO,
Rock-Typing is an important issue for the Geological Model and Dynamic simulation. In many Abu Dhabi onshore carbonate reservoirs studies, Rock-Typing is not supported by a High Resolution Sequence Stratigraphy and is essentially borne by arbitrary cut-offs of poro-perm values. Relationships between Lithofacies and Petrophysics should be defined using objective and quantified statistical approach. Distribution of petrophysics properties should rely on detailed sedimentological and diagenesis studies, supporting a “back to the rocks” philosophy.
Such an approach has been used to define static Rock-Types for an
A detailed core description and petrographic analysis leads to identification of 11 Lithofacies. A High Resolution Sequence Stratigraphy framework could be defined, evidencing 5 High Frequency Sequences (HFS) within a 3rd order sequence.
A quantitative statistical approach incorporating available core
petrophysical data (Phi, K,
After log data QC and normalization, an unsupervised log data partitioning was indexed against depth-by-depth core descriptions to apply physical meaning to log clusters. This indexation strategy permits robust prediction of lithofacies from log data. Permeability modelling was also performed. Similarly, propagation of PGc in uncored wells was achieved through indexation of log data partitions to establish 6 Petrophysical Groups (Rock Types) at log scale (PGL). Correspondence between PGC and PGL was quantified.