On Thursday, the 7th February, 2019, Total issued a press release stating that the Brulpadda 1Ax well, situated to the south east of Mossel Bay, 175 km offshore, had intersected a total of 57m of reservoir interval in the Albian section of the southern Outeniqua Basin. They also announced the discovery of a large gas condensate resource.
This discovery is the culmination of many years of work. In 2001, Canadian Natural Resources (CNR), who had just acquired the block through the buy-out of Ranger Oil, acquired 3700 line km of 2D data in the block. This survey allowed the confirmation of numerous large domal structures within the synrift succession along the edge of the basin, but the most interesting revelation was the presence of a large basin floor fan complex in the western section of the southern Outeniqua Basin (Roux, van der Spuy and Singh, 2004), first identified through mapping of the new data by Jacques Roux of Petroleum Agency SA. This prospective play was recognised as analogous to the oil-producing complexes of the Bredasdorp sub-basin, but to be orders of magnitude greater in size. The play was characterised by mounding, amplitude anomalies and a flat spot. The Agency immediately presented their findings to CNR and the Paddavissie play (so termed due to its resemblance to a tadpole in mapped view) became the major focus of their exploration efforts. Further work on the play included AVO analysis and the acquisition of electromagnetic resonance profiles, leading to the delineation of drillable prospects within the play.
However, the play lies in water depths of between 1100m and 1900m, directly in the path of the Agulhas current. It would be many years before an attempt was made to drill it. In 2013 CNR successfully farmed out 50% of their interest in the block to Total, who took over operatorship of the block.
A first attempt to drill the Brulpadda (bull frog) prospect in the extreme west of the Paddavissie play was made in June 2014, but after making only 500m progress below mudline, the well had to be abandoned. This was due to the extremely challenging drilling conditions caused by the current in the area. Total then spent over 3 years planning their return and developing an approach that would allow the safe drilling of the prospect. They contracted Odfjell’s Deepsea Stavanger rig, and the well was re-entered on Christmas Eve in 2018. By January, the well had encountered the primary target, and drilling was continued to intersect a deeper, secondary target.
Petroleum Agency SA would like to take this opportunity to congratulate Total and their partners Qatar Petroleum, CNR and Main Street on a world-class engineering feat, and of course, on the discovery. This successful deepwater well, drilled in the most challenging conditions off South Africa’s shores, has opened up the greater Outeniqua Basin for further exploration and discovery.