The three US oil supermajors have followed their European compatriots into the green in their financial results for Q1 2021. With the price of crude oil rallying hard through the quarter and as demand creeps back towards pre-pandemic levels, the cost-cutting measures of the past 12-months have facilitated a new tide of cash. The coming months of spending will be key to defining the role that these behemoths manage to cling onto in the future of the energy sector. ExxonMobil – the captain of US big oil – reported its first quarterly profit in since 2019, with net earnings of $2.7 billion for Q1 2021. This marks a huge increase from the $610 million loss seen in the same quarter…