Oil & Gas Journal, Vol.111, No.10, 46-46, 2013
A modern approach to build 3D sequence stratigraphic framework
The conventional approach of performing sequence stratigraphy on 3D seismic data is comprised of a limited set of seismic horizons. This practice can be changed with the help of a semiautomated solution that maps all stratigraphically consistent seismic reflectors in 3D. Modern computer-aided semiautomated workflows are changing these trends. One such approach is utilized in this article. The approach is applied in gas-bearing Pliocene deltaic sands of the Netherlands North Sea. Using the data-driven approach, three third-order stratigraphic sequences are identified and further classified into systems tracts. The subdivision is performed by integrating the seismic results with the available well data and also by covisualizing the structural and Wheeler (chronostratigraphic) domains in 3D. This article also introduces several new ideas that add further value to understand sequence stratigraphy. It includes: new stratigraphic attributes, statistical curves, data-driven stratal slicing, and integration of Wheeler diagrams with well data. Some of these ideas are also applied on the presented case study. It is concluded that the studied interval contains two distinct stratigraphic traps. Sand ridges are elongated downslope traps and are under high risk in the study area because of limited gas charge, whereas several detached shoreface sand bodies are favorable plays in the southern North Sea. This study also documents that the utilized method and workflows are applicable to search for shallow gas stratigraphic plays in the adjoining regions.