Seismic Recognition and Evaluation of Mixed Turbidite Contourite Systems

Spectrum’s Karyna Rodriguez originally produced this abstract for EAGE 2019.

2018 saw a series of major discoveries in what is conventionally classified as deep water, including Ranger and Longtail (part of the Liza complex) in Guyana, Guanxuma in Brazil and Calypso in Cyprus. These discoveries accounted for the biggest proportion of resources discovered in 2018. Exploration efforts should clearly be heading in this direction, targeting significant remaining potential. Most of the deep water environment is considered as frontier exploration ground where long offset 2D seismic data is proving to form an integral part of taking the first steps in identifying both proven and new play fairways.

In this deep water setting, drift (or coast parallel bottom currents) and turbidite (or gravity) processes are common along continental margins. The interaction of these processes can build large mixed / hybrid (turbiditic-contouritic) depositional systems. These have only been recently recognized and are only now being studied in more detail. One of the leading research groups is part of a joint industry project (JIP) led by Royal Holloway under Javier Hernandez Molina and supported by a group of major oil companies. This initiative has led to the start of widespread recognition of these systems at a global scale by integrating outcrop, well and seismic data and should make an important contribution in our understanding of contourite-influenced areas.

Several prolific discoveries have been associated with hybrid turbidite-contourite systems, of which the most notable is in the Rovuma Basin offshore Mozambique (Maba Complex 85 TCF) (Palermo et al., 2014). Another significant hydrocarbon accumulation associated with a mixed system, though not published as this type of depositional system but with clear seismic indications, is the deep water confined channel Barra complex (3 BBOIP) in the Sergipe Basin, Brazil. This study focuses on recognizing and evaluating these mixed systems on seismic data using several examples from a comprehensive global long offset 2D seismic dataset (Figure 1). The work aims to contribute to the understanding of these depositional systems which have already proven to contain significant potential and as indicated by this study, have clear signs of being associated with huge hydrocarbon potential.

 

Click to read the full abstract here:
Seismic Recognition and Evaluation of Mixed Turbidite Contourite Systems