Oil majors are highlighting continued frugality in their 2018 exploration plans. But they all plan to increase output over the coming years with a return to deepwater exploration and development the key driver.

Senior Gulf Opec ministers Khalid al-Falih of Saudi Arabia and Suhail al-Mazrouei of the UAE have repeatedly warned over the past year that they see global upstream investment as dangerously low. Their stated aim is to hasten a drawdown of global inventories, with the resultant price...