Discoveries of new oil reserves have dropped to their lowest level for more than 60 years, pointing to potential supply shortages in the next decade. Oil explorers found 2.8bn barrels of crude and related liquids last year, according to IHS, a consultancy. This is the lowest annual volume recorded since 1954, reflecting a slowdown in exploration activity as hard-pressed oil companies seek to conserve cash. Most of the new reserves that have been found are offshore in deep water, where oilfields take an of average seven years to bring into production, so the declining rate of exploration success points to reduced supplies from the mid-2020s. The dwindling rate of discoveries does not mean that the world is running out of oil; in recent years most of the increase in global production has come from existing fields, not new finds, according to Wood Mackenzie, another consultancy. Additionally, there has been a predominance of gas, rather than oil, in recent finds. But if the rate of oil discoveries does not improve, it will create a shortfall in global supplies of about 4.5m barrels per day by 2035, Wood Mackenzie said. That could mean higher oil prices, and make the world more reliant on onshore oilfields where the resource base is already known, such as US shale. Paal Kibsgaard, chief executive of Schlumberger, the world’s largest oil services company, told analysts last month: “The magnitude of the E&P [exploration and production] investment cuts are now so severe that it can only accelerate production decline and the consequent upward movement in [the] oil price.”