Exploration in the Tunisian Illizi-Ghadames Basin has previously presented a good investment opportunity, stimulated by a string of small but profitable discoveries. But only 66 mmboe of reserves was discovered over the last ten years. Developments have been characterised by rapid start-ups, achieved by recompleting discovery wells as producers and tapping into the well-established infrastructure. However the average discovery size is small and in decline, reflecting the increasing maturity of the basin. The basin still offers niche explorers the opportunity to create good returns based on modest investment, but prospective resource estimates and potential prospect sizes are much smaller than elsewhere in North Africa. The resulting value creation is marginal. In this report Wood Mackenzie examines the key issues impacting exploration in the Silurian oil play, and provides the cost and returns metrics from historical and forecast exploration activity in this play.