Uncertainties in Modeling Deepwater Basins From a Petroleum Systems Perspective – A Tale From Frontier to Prolific Petroliferous Basins of the Brazilian Margin

Abstract

The offshore Brazilian margin covers more than 1,550,000 square kilometers providing an opportunity to explore more than sixteen sedimentary basins. Each basin contains a wide range of opportunities and play types, from clastic to marine and lacustrine carbonate reservoirs with cretaceous to tertiary source prone intervals. With the advancement of seismic imaging and drilling technology, the industry has moved into deeper water plays de‐risking world class source and reservoir systems in multiple basins. Recently significant exploration and appraisal efforts were focused on the world class Santos and Campos basins. However, a big swath of the offshore acreage remains untested or poorly tested. Here we explore some key petroleum systems uncertainty parameters that may impact future exploration campaigns and development concepts for both the frontier and the prolific petroliferous basins of the Brazilian margin. Multivariate elements of the Brazilian petroleum systems were investigated in detail to understand the influence on future prospectivity for the offshore basins. This includes the source presence/potential, maturity, as well as kitchen sizes, migration pathways, reservoir distributions and seal presence of which source richness and maturity plays a key role in the economic evaluation. Source rock presence is fundamental for proving a working petroleum systems concept in a basin. A multitude of datasets and models were incorporated to de‐risk source presence, richness and organofacies along the margin. Significant uncertainty exists for these parameters across the margin, so multiple geological models were explored by integrating available datasets. Even in proven plays significant uncertainty exists in maturity and phase. Here we present some of the fundamental uncertainties around thermal perturbation and its impact on maturity.

AAPG Datapages/Search and Discovery Article #90349 © 2019 AAPG Hedberg Conference, The Evolution of Petroleum Systems Analysis: Changing of the Guard from Late Mature Experts to Peak Generating Staff, Houston, Texas, March 4-6, 2019