AIM-listed hydrocarbon explorer Borders & Southern (B&S) says that the exploration well 61/17-1, south of the Falklands, was spudded yesterday.The well, which is the first of a two-well exploration programme on licence PL018, is designed to test the Darwin East prospect, "a fault / dip closed structure with a Lower Cretaceous sandstone reservoir target"."The well will investigate geophysical attributes that include a flat spot, amplitude conformance to structure and an AVO anomaly," B&S said.Operations are expected to take around 45 days and the group says it will make a further announcement once the well has reached total depth and the interpretation of wireline logs has been completed.Shares rose 2.95% to 69.75p in early trading.BC