Oil field services companies facing the worst downturn in decades will have to reshape the way they do business to meet the evolving needs of oil companies clamoring for cheaper and more efficient tools and services, according to a new analysis by Bain & Company. "It's a pivotal moment," said Ethan Phillips, a Bain partner who co-authored the report examining the services industry's response to the oil slump. "The industry that comes back is going to look quite different than it did a few years ago."