3D QUANTITATIVE SEISMIC STRATIGRAPHY OF JURASSIC CARBONATE STRATA ON THE ARABIAN PLATFORM

Abstract

Quantitative seismic stratigraphy of a 3D seismic volume of the Arabian platform provides critical information on the heterogeneity of reservoir quality of a productive Jurassic carbonate grainstone. The Vail method of sequence stratigraphy allowed the delineation of thirteen sequence boundaries from the Permian to the Cenozoic. Integrating the Galloway petrophysical methods of sequence stratigraphy from well constraints, four third-order cycles of HST, RST, TST, and LST parasequence sets are identified. As these are regionally correlated on the seismic they appear to be allocyclically controlled. The 3D porosity prediction via neural network application successfully predicted the continuity of HST high porosities, suggesting the porosities were caused by fresh-water vadose/phreatic diagenesis of these Hothouse mineralogies during sea level falls of the ensuing RST’s. Unfortunately, while discernible in the wells, these parasequence sets are below seismic resolution for interpretation. The LST’s have good mudstone deposition with accompanying enriched organic matter content for potential self-sourcing of the overlying HST’s. The TST’s which followed, much like the RST’s, are below seismic resolution for mapping. Combined with post-depositional structural, this parasequence porosity centralization in these stacked cycles of carbonates provides an ideal assemblage of reservoir criticals for hydrocarbon accumulation and suggests quantitative seismic stratigraphy is a powerful tool for Arabian platform Jurassic carbonate exploration and exploitation.