Potiguar Basin, Brazil - New 3D Seismic Elevates Exploration Opportunities from Leads to Prospects

Authors: Randall Etherington (presenter); Eric Newman, TGS

The Potiguar Basin is the largest oil-producing region in equatorial Brazil along the onshore and near offshore areas of the basin. The petroleum system of the basin contains lacustrine to marine prolific source rocks of rift to post-rift spanning in age from Barremian through Turonian. Proven reservoir rocks range in age from Barremian to Eocene times. Seal rocks are observed throughout the entire stratigraphic column and are represented by intra-formational lacustrine shales, fine-grained argillaceous sandstones and shales, and thick deep marine pelitic rocks. The Pitu well, announced in December of 2013 became the first deep water oil discovery of the Potiguar Basin. The Pitu well found a 188 meter hydrocarbon column in Upper Aptian sands of the Pescada Formation in a rift structure at depths of 4,300 meters, thus confirming that the proven petroleum system extends into the deep water. Two main play types have been identified. The confirmed ‘Rift’ play which follows the Potiguar oil basin off the shelf is the same play as Pitu and extends across all of the basin. The well-defined horst blocks at Pescada Formation level show several thickened intervals. The greatly anticipated ‘Drift’ Late Cretaceous-Tertiary play is a turbidite sand play of channel sands and toe of slope fans, many with amplitude anomalies. Broadband, long offset 2D seismic clearly shows the Aptian ‘Rift’ play and evidence of the ‘Drift’ Late Cretaceous-Tertiary turbidite channel complex and basin floor fans. The most recent 3D data takes the seismic image and detail of the Cretaceous turbidite channel/fan complexes and Aptian ‘Rift’ structures to an all-new level.

Bio:

Randall Etherington, TGS-NOPEC Geophysical Company

Randall earned a bachelor’s degree in Engineering from Utah State University, and a MSc in Geology from Brigham Young University.

His more than 40 years of experience in the industry include several positions in companies as ExxonMobil, Chevron, Shell, Phillips, Devon, YPF-Regsol, Pennzoil, Cobalt, Murphy; Maersk, among others. Currently, he is Exploration Advisor at TGS-NOPEC Geophysical Company, where is responsible for geophysical interpretation and basin analysis.

Randall is a member of AAPG and SEG.