Libya’s largest oil concession, the Sharara fields in the southwest, suffered a security breach on 4 November, according to state oil firm NOC. But notwithstanding this latest challenge to Sharara’s smooth running, production from the blocks has climbed every quarter this year, according to figures published by operator, Spain’s Repsol.

The 4 November security breach, on block NC-186, is the latest of several incursions against infrastructure related to Sharara operations....