“It takes all the running you can do to keep in the same place. If you want to get somewhere else, you must run at least twice as fast,” the Red Queen told Alice in Lewis Carroll’s novel “Through the Looking-Glass”. Oil companies have to invest heavily simply to offset the impact of natural decline rates on their existing fields, and even more if they want actually to increase production. The need for continued investment and drilling to maintain output as a result of the rapid decline rates on shale wells has been widely discussed. But decline rates on conventional oil fields are even more important because they account for more than 90 percent of global production. Decline rates on conventional fields will play a critical part rebalancing the oil market […]