Improved Resolution of a Subtle Stratigraphic Play in a Mature Basin: Integration of Traditional Geological Techniques and Seismic Geo-modeling Technology

Abstract

Exploration for hydrocarbons in mature basins is increasingly challenging and potential prospects have a greater degree of complexity and uncertainty associated with them, compared to historical finds. The case study area has been explored for hydrocarbons for more than 25 years during which time there has been a notable degree of success in drilling reservoirs in structural closures. As a result, there is a need to explore for the difficult hydrocarbons, which are possibly sitting in stratigraphic traps and other complex settings unlike conventional structural traps. A potentially large turbidite system was identified from seismic data using conventional interpretation methods and attribute extractions that proved to be seismically anomalous. Regional well-based geological work established gross depositional environments across the region that indicated a sand prone provenance area to the north of the area of interest. However, the geological context of these isolated sand deposits has been limited due to the uncertainty associated with the seismic interpretation in a structurally complex geological setting. Conventional interpretation techniques limit the ability to interpret and analyze these stratigraphic levels of interest across an inversion structure to an inferred sand provenance area. In this paper, we demonstrate and evaluate the possibility of discovering more subtle hydrocarbon reservoirs within the prospective interval of interest, using an integrated interpretation strategy exploiting geological and geophysical data and using innovative interpretation approaches. An innovative geo-modeling technology has been exploited to develop a methodology that helps to reduce the uncertainty of the seismic interpretation process and improves our understanding of the stratigraphy. In addition, data from seismic inversion was also integrated for interpretation purposes. The approach to interpretation demonstrated in this paper has helped to impose strong constraints to guide the seismic interpretation and reduce uncertainty. The techniques used to construct a reliable geo-model eventually made it possible to correlate horizons across the inversion structure, which revealed amplitude anomalies suggesting a channel system across a shelfal area down to the anomalies in the deeper basin thereby completing the geological model.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014