Kwanza Basin — Geological Overview

Basin Overview

The Kwanza Basin is a sedimentary basin offshore Angola that has emerged as one of the most significant frontier petroleum provinces in West Africa. Located south of the prolific Lower Congo Basin (which hosts Angola's existing deepwater production from Blocks 17, 32, 15/06, and others), the Kwanza Basin extends along the central Angolan coast with deepwater sections in 1,500-2,000+ meters of water depth. The Kaminho project represents the first large-scale deepwater development in this basin.

The Kwanza Basin is geologically significant because its pre-salt section is directly analogous to the pre-salt formations of Brazil's Santos and Campos basins — which have yielded some of the world's largest oil discoveries in the 21st century (Tupi/Lula, Búzios, etc.). Before the opening of the South Atlantic, the Kwanza and Santos basins were conjugate — part of the same geological system before continental drift separated South America and Africa. This geological relationship was the primary driver of exploration interest in the Kwanza pre-salt beginning in the late 1990s.

Structural Geology

The Kwanza Basin's petroleum system is dominated by Aptian carbonate reservoirs located below a thick salt layer (the pre-salt section). These carbonates formed over basement highs during the late rift stage (Apto-Barremian), creating a distinctive "string of pearls" fairway along structural ridges. The carbonate mounds are 4-way dip closures — structural traps formed by the geometry of the basement and overlying salt.

The salt layer provides an excellent seal, trapping hydrocarbons in the underlying carbonates. However, the thick and deformed salt also creates significant challenges for seismic imaging — one of the historical barriers to exploration success in the basin. Advances in seismic acquisition and processing technology (broadband, full-waveform inversion) have progressively improved sub-salt imaging, enabling more confident well placement.

Exploration History

Early exploration in the Kwanza Basin deepwater began in the late 1990s when companies like BHP acquired large 3D seismic datasets, attempting to tie the geological success of Brazil's pre-salt to the conjugate African margin. BHP and ExxonMobil drilled two dry wells in Block 22 in 2001-2002, after which activity receded. The breakthrough came with Cobalt International Energy's exploration campaign (2012-2016), detailed on our Discoveries and Block 20/11 pages.

For the broader context of Angola's petroleum sector, licensing opportunities, and the future potential of the Kwanza Basin, see our dedicated pages.