Interpretation value of diffractions and sub-specular reflections – applications on the Zhao Dong field

The recent glut of giant oil and gas hydrocarbon discoveries on the North West African coast (Figure 1) began in 2014 with the SNE-1 discovery by Cairn in Senegal. This play-making well targeted Albian sandstones and Aptian carbonates in a structural trap, at the eroded edge of the Early Cretaceous platform margin.There are a number of interesting play elements at work in this play that require definition so that a model can be extracted and reused elsewhere along the margin in the chase for analogue traps. Where we will end up is Guinea Bissau, Senegal’s southern neighbour, where the plays is as yet unexplored yet appears to have an even more promising potential, but first – SNE.The SNE discovery has been presented to the industry by operator and partners several times over the last few years, including a presentation at the recent HGS PESGB African conference by Wytze de Boer et al. of Cairn Energy (Geophysics of the SNE Field, Senegal, HGS PESGB 16th African Conference, 2017). It is hardly surprising that industry is interested in this discovery as, with current resource estimates exceeding 500mmbbls, this was the biggest discovery in the world in 2014 and a truly ground-breaking, basin opening innovation. Most remarkable was that the discovery was oil – bucking the global trend of discoveries that was otherwise suggesting we have fine tools to explore for big gas resources but struggle to find big oil. The Liza-1 (u003e2bn bbls oil) discovery in Guyana in 2016 put this concept firmly to bed, yet the SNE discovery is still one of the few giant oil resource additions drilled this century.