An Overview of 3D Broadband Seismic Acquisition and Processing Challenges in Foz Do Amazonas Basin in Brazil

Abstract

Foz Do Amazonas (FDA) Basin is located in the northwest of the Brazilian Equatorial Margin, encompassing the continental platform, slope and deepwater. A 3D Broadband seismic survey of 11330 km² was acquired in the area , covering all the 7 blocks awarded in the 11th licensing round(2013) . The Narrow Azimuth survey, was acquired by Oceanic Endeavour for Spectrum/CGG as a Multi Client survey, starting in January 2014 with a duration of 9 months using a slanted BroadSeis profile. A quick look “Very Fast Track” Post Stack Time Migrated product was generated ( 3 weeks after last shot point) with a Fast Track (PSTM, TTI PSDM) delivered 3-4 months later by CGG Rio. The FOZ area is quite challenging for acquisition due to strong eddy and rip currents, rough weather conditions with swell, fresh water from the Amazon with large debris flow of seaweed and logs, resulting in loss of streamer control, collapsed towing spread and high noise level. This basin is an abrupt margin with deep channels and canyons posing issues for demultiple and PSDM Model Building. This paper will give an overview of the acquisition issues and processing solutions during the course of the project.