LONDON: Shell and its partners have made what the oil major described as an “ encouraging ” discovery in a closely-watched exploration well off the coast of Namibia, which could spark a wave of investment in the south African country. Shell said in a statement that results from the deep water Graff-1 well revealed “ the presence of a working petroleum system with light oil ” and that Shell and its partners would continue to assess how much oil could be recovered. Shell holds a 45% stake in the o