The oil and gas mergers and acquisitions market, long known for its mega deals, is surviving at the moment on pockets of activity. But much like small discoveries of oil, bankers hope these smaller finds will eventually lead to the next big wave of mergers.

The world's largest companies, squeezed by rising costs and stable prices, have embarked on large divestiture programmes, fuelling dealmaking in the oil and gas sector after a slow 2013.