Discoveries of new oil and gasfields have dropped to a fresh 60-year low, as companies put a brake on exploration and large fields have become harder to find. There were only 174 oil and gas discoveries worldwide last year, compared to an average of 400-500 per year up until 2013, according to IHS Markit, the research group. The slowdown in exploration success shows that the world is likely to become increasingly reliant on “unconventional” resources such as US shale oil and gas to meet demand for energy in future decades. The typical time from discovery to production is five to seven years, so a shortfall in oil and gas discoveries now implies tighter supplies in the next decade. However, there are signs of a tentative upturn in conventional exploration this year, with some companies including Statoil of Norway planning to step up drilling activity. Discoveries hit a six-decade low in 2015, and then dropped again last year to about 8.2bn barrels equivalent of oil and gas. The slowdown reflects both the cyclical cuts in exploration made by companies struggling to stay afloat after the drop in oil and gas prices since 2014, and the structural shift in the industry towards onshore shale and similar reserves, especially in North America.