Enefit’s proprietary oil shale extraction technology has been used successfully by Eesti Energia in Estonia, so San Leon is keen to see if it works on ­recently awarded acreage close to its Tarfaya asset.

A study by Shell in 1985 of an open pit mining project located on a site next to San Leon’s blocks established that mineable reserves could underpin a 50,000 barrel-per-day operation for 30 years.

San