BHP Billiton (BHP) reacted swiftly to the collapse in oil price by increasing capital efficiency, accelerating asset high-grading and making cuts across the business. It is using the down-cycle to address weaknesses in its portfolio, in particular a lack of greenfield deepwater and international development opportunities. Strategic priorities include marketing its unconventionals portfolio for sale, high-grading the conventional portfolio, and delivering on a bold counter-cyclical exploration strategy.BHP has two heartland conventional E&P regions – the NW Shelf of Australia and the deepwater US Gulf of Mexico. BHP's conventional exploration has underperformed, but the company is committed to turning this around, securing new acreage and rigs, and maintaining spend. This counter-cyclical acceleration of its drilling programme contrasts with the average fall of 48% in exploration spend between 2014 and 2016 for the other companies in our coverage.