A snapshot of the geotectonics and petroleum geology of the Durban and Zululand Basins, offshore South Africa

Abstract

The offshore Durban and Zululand Basins have recently become of interest to the oil and gas industry as a result of large discoveries made along the eastern margin of Africa, most notably in Tanzania and Mozambique. In South Africa, exploration over the last three decades has focused on near-shore trends of rotated fault blocks and a combination of structural-stratigraphic traps. This has resulted in the drilling of four wells north-east of the city of Durban. Although no wells have been drilled in the deepwater acreage yet, the area is considered to have petroleum potential. As a result of the growing industry interest and with collaboration from Spectrum and the Petroleum Agency of South Africa (PASA), CGG acquired a new multi-client broadband 2D seismic survey (CDZ13-14) in the Durban and Zululand Basins (Figure 1). The data were processed with Kirchhoff pre-stack time migration (PreSTM). The survey was shot and processed in two phases (2013-2014) using BroadSeis, a proprietary broadband solution using variable-depth streamers and advanced imaging technologies, and consisted of 6920 km of 2D lines over held acreage. The survey is made up of 42 lines widely spaced over the Durban and Zululand Basins and includes 17 strike lines and 25 dip lines. Water depths within the area of interest range from 400 m to 3200 m. The results of this broadband 2D survey have shed new light on the interpretation of the geology in the area.