The Predictive Power of Depositional Paradigms When Chasing Deep Water Sand-rich Turbidites
Ph.D., Vice President Exploration, Barra Energia
A systematic petroleum exploration of deep water turbidites was triggered as part of a larger process during the worldwide spreading of seismic surveys since the 80's, and seasoned by increasing quantity and quality. A great number of published papers and case histories have emphasized successful campaigns in Tertiary and Cretaceous sand-rich turbidites in deep waters of sedimentary basins like Gulf of Mexico, Campos, Congo, Niger Delta, Mozambique, to mention a few.
On the other hand, failures of years and even decades in exploratory campaigns revealed a much more sad history in other basins. It can be justified by claiming the poor sand nature of certain basins or the erratic behavior of sand-rich turbidite sedimentation. Part of the disappointing results are due to the failure in recognizing or utilizing the most basic set of depositional paradigms related to turbidite sedimentation. They have a fundamental importance in the identification of turbidites, especially in seismic sections.
Paradigms imprint attributes on seismic sections as evidence of turbidites and serve to calibrate and constrain our search. Especially when looking in open and vast deep-water regions. Depositional paradigms were comprehensibly relegated to the background due to the tremendous success of the binomial amplitude anomalies-DHI's and turbidites. The identification and mapping of such attributes, produced by depositional paradigms, provides the predictive stratigraphic framework for sand rich turbidites in deep water, mitigating the exploratory risk. Such paradigms are flexible enough to accommodate the intrinsic difficulties in various basins at different levels of knowledge and exploration.
It will be discussed some of the depositional paradigms and associated attributes to recognize deep water sand-rich turbidite deposits in seismic surveys.
AAPG Search and Discovery Article #90204 © AAPG Geoscience Technology Workshop, Stratigraphic Traps and Play Concepts in Deepwater Settings, May 14-15, 2014, Rio de Janeiro, Brazil