Oil explorer Rockhopper will know in 10-15 days exactly how big its discovery in the North Falkland Basin is.The firm drilled well 14/10-2 on the Sea Lion prospect down 2,744m during the 35 days it had hired the rig for. It's now been suspended for future testing."Based on that timetable, the company anticipates making a further update within the next 10-15 days at which point it expects to be able to provide initial estimates of the potential size of the discovery," it said in a statement Wednesday.It's been an exciting month so far for Rockhopper whose shares were trading below 50p before news of its find broke. The stock now changes hands for 193p, valuing the business at £340m.