Transport operators face higher running costs this month after diesel prices jumped on Wednesday.
Coral South, operated by Eni, is the only project in operation, having come on stream in 2022.
Airspace restrictions during the G20 Summit will not disrupt commercial or cargo flights.
Transporters say a lower diesel price eases pressure on operating costs, but there is room for further price cuts.
The decrease in the price of crude oil and a stronger rand drove the significant decline in fuel prices.
Factors influencing the market include low stocks in the US, unplanned refinery shutdowns and EU refinery closures.
The block apparently contains reserves of up to 3.5 billion barrels of oil.
Double-digit price increases and a higher fuel levy will place financial pressure on households.
The ceasefire between Israel and Iran has offered some short-term relief for crude oil prices.
Adulterated fuel containing 68% paraffin has been detected during investigations.
The industry holds potential for at least US$300 billion in global exports over the next three decades.
