As global oil firms make ever-bigger bets on Brazil’s massive deepwater fields in its ‘subsalt’ area, a swarm of small and mid-sized companies has sprung up to specialize in lower-profile fields that still produce over a third of the country’s crude.  The proliferation of niche players, ranging from private equity firms to domestic and international oil companies, is adding to the dynamism of an oil industry long ruled by state oil firm Petroleo Brasileiro SA, or Petrobras. In recent years, Petrobras has shed billions of dollars of onshore and shallow-water fields, as well as some less prolific deepwater blocks, to pay down debts and focus on hugely promising subsalt areas, where billions of barrels of oil are trapped beneath a layer of salt under the sea […]