Insights on the Evolution of Oligocene-Miocene Carbonate Buildups from 3D Seismic Data, East Java Basin, Indonesia

Ruf, Amy S.¹, Toni Simo², Tina M. Hughes³, Kelley Steffen¹ (1) ExxonMobil Upstream Research, Houston, TX (2) University of Wisconsin, Madison, WI (3) ExxonMobil Upstream Research, Houston,

The High Density MC3D seismic survey, acquired by PGS in 2003 over the North Madura platform, is an excellent data set for quantitative interpretation of carbonate mound evolution. Detailed imaging of the growth histories of Oligocene-Miocene carbonate buildups provides insight into geometric parameters characteristic of platform initiation, development, and demise. Mound initiation occurs with development of small (<100m to 500m diameter), closely spaced, domal buildups, which become the nuclei for the formation of intermediate mounds (2km to 3km diameter). Nucleation mounds build concentrically to form intermediate mounds, which selectively coalesce into amalgamated platforms (>5km diameter), become isolated platforms of varying size (<5km diameter), or die off altogether.

The high quality seismic data enables visualization and quantitative analysis of geometry, orientation, and spatial distribution of nucleation and intermediate mounds, generating models of preferential morphology for development of isolated vs. amalgamated platforms. Flattened discontinuity time-slices from the 3D data provide clear images of mound size, distribution, and morphology at discrete growth steps, which record a complex history of initiation, aggradation, coalescence or isolation, progradation, potential exposure, and demise. Additional seismic attributes, including isochron and dip, reveal distinguishing characteristics of carbonate buildups that can be exploited by innovative volume interpretation tools for identifying, isolating, and extracting mound features. Once extracted, quantitative attributes (e.g., size, width: thickness ratio, orientation, etc.) are analyzed. The quantitative approach to the analysis of the geometric, spatial, and seismic facies characteristics of carbonate buildups enhances the understanding of Tertiary mound evolution, internal architecture, and growth history.