Oil & Gas Exploration
Tesorillo / Ruedalabola Concessions, Cadiz Province


Tesorillo and Ruedalabola, cover 38,000 ha (94,000 acres) in Cadiz Province in Southern Spain. The 1956 well Almarchal -1 was drilled by the Spanish firm Valdebro and intersected a thick section of gas pay which upon testing flowed gas to surface. The well is located 3km from the North African Maghreb gas trunkline providing ready access to high priced European gas markets.

Under a Share Purchase Agreement (“SPA”) entered into in December 2017 AIM listed Prospex Oil and Gas Plc (“Prospex”) will acquire up to a 49.9% of these concessions leaving Petrel witn a 50.1% interest. Prospex is an experienced European focused oil and gas player with a growing portfolio of interests and a presence in Spain, who have had success with smaller fore-deep plays elsewhere in Europe.

Sale proceeds of €2m will be used by SEI to fund its share of an agreed Tesorillo work programme (estimated at €3.8m) which includes a trial magnetotelluric programme, followed by a full magnetotelluric programme and if successful, a well to target the Almarchal-1 discovery drilled in 1956.

Gas Discovery

Almarchal-1 is the discovery well of what is likely a very large by-passed gas field. Drillstem tests and log analysis confirm 48m of proven gas pay from two Miocene Aljibe Formation sandstone intervals. A further 492m of probable gas pay is interpreted from logs but unconfirmed by testing.

The well is located on a seismically delineated thrust ramp anticline with closure area exceeding 70 km2. Multi-TCF gas-in-place is indicated. The 1957 Puerto de Ojen-1 well, located 15km to the east in Ruedalabola license, displayed similar gas shows to Almarchal-1 but could not be tested for mechanical reasons. It appears to be located on a separate large thrust feature.  

Resource Certification

Since November 2012 SEI have significantly improved the quality of data and resulting analysis from the Almarchal discovery well that forms the core of Tesorillo project in Spain. As a result, in May 2015, Netherland Sewell and Associates (“NSAI”) independently re-certified an unrisked Prospective Resource of up to 2,289 BCF* (2.3 TCF) (1,435 BCF net to Petrel) for the Tesorillo Project as outlined below.