We perform an empirical analysis of the extent to which ongoing technological change through research and development activity has offset the effect of ongoing depletion on the cost of finding and developing additional reserves of oil in eight global regions. We introduce a finding cost function which, among other factors, depends on the cumulative number of past R&D expenses and cumulative past production, measuring technological change and depletion, respectively. For all our regions we find significant effects of both depletion and technological change on oil finding costs from 1981 to 2009, while we take into consideration cyclical variations in finding costs that could come from changes in factor prices. For almost all regions, technology more than mitigated depletion until around the mid-nineties. However, we find that depletion generally outweighed technological progress over the last decade. (C) 2015 Elsevier Ltd. All rights reserved.