ExplorationYellowtail-2 spurs ExxonMobil to seek deeper riches in GuyanaUS supermajor and partners see potential of deeper horizons after latest Stabroek appraisalDeep play: the drillship Stena Carron has been a key component in the drilling campaign that ExxonMobil has carried out off GuyanaPhoto: STENA DRILLINGGareth ChetwyndLondon