Oil shale in Morocco

Oil-shale deposits in Morocco.

Morocco's total oil shale resources are estimated to contain 53.381 billion barrels (8.4869×10^⁹ m³) of shale oil.[1] According to the United States Department of Energy, the oil shale deposits in Morocco constitute about 3.5% of the world's known oil shale resources.[2] There are ten known oil shale deposits in Morocco.[3] Most of the local deposits were laid down during the Upper Cretaceous era and are marinites. The most important of these are located at Tarfaya (in the south-westernmost part of Morocco) and Timahdit (in the Middle Atlas Mountains).[4]

The largest known oil shale deposit in Morocco is located at Tarfaya. The deposit is estimated to consist of 80 billion tons of oil shale, containing 22.7 billion barrels (3.61×10^⁹ m³) of shale oil.[1] The deposit is divided into two flanks on each side of Tazrha sabkha. The volume of the west flank area is over 200 square kilometres (77 sq mi); the east flank area's volume is over 140 square kilometres (54 sq mi).[5] The average thickness of the formation is 22 metres (72 ft). Its moisture content is about 20% and its sulfur content is about 2%. It yields about 62 litres (14 imp gal; 16 US gal) of shale oil per one ton of oil shale.[6]

The second largest deposit is located at Timahdit, about 250 kilometres (160 mi) southeast of Rabat.[1] Geologically, it comprises two basins: El koubbat and Angueur synclines.[5] The oil shale formation is about 70 kilometres (43 mi) long and 4 to 10 kilometres (2.5 to 6.2 mi) wide. The volume of the El koubbat syncline formation is about 250 square kilometres (97 sq mi); the Angueur syncline area is about 100 square kilometres (39 sq mi).[5][6] The deposit is estimated to consist of 42 billion tons of oil shale, containing 16.1 billion barrels (2.56×10^⁹ m³) of shale oil.[1] The oil shale formation's thickness varies from 80 to 250 metres (260 to 820 ft).[5][6] Its moisture content is 6–11% and sulfur content is about 2%. On average it yields 70 litres (15 imp gal; 18 US gal) of shale oil per one ton of oil shale.[6] As the Timahdit deposit is located near Ifrane National Park and Haut-Atlas Oriental National Park, oil extraction is an environmentally sensitive issue.[7]

The third largest deposit, consisting of 2,000 square kilometres (770 sq mi), is located near Tanger. The deposit is estimated to contain 2 billion barrels (320×10^⁶ m³) of shale oil. The oil shale formation's maximum thickness is 8 metres (26 ft). It yields 30–85 litres (6.6–18.7 imp gal; 7.9–22.5 US gal) of shale oil per one ton of oil shale.[5]

The Moroccan oil shale industry began with research during the 1930s.[5] Tanger was the first discovered oil shale deposit.[8] An 80-tonne-per-day pilot plant extracted shale oil from the formation between 1939 and 1945.[1] The pilot plant was operated by Société des Schistes Bitumineux de Tanger.[5]

The Timahdit and Tarfaya deposits were discovered during the 1960s.[8] These deposits were researched and tested during the 1970s and 1980s.[1] Over 2,200 tons of Timahdit and Tarfaya oil shales were processed in pilot plants in Europe, the United States, Canada, and Japan.[8] Following these tests, in 1984–1986 the Moroccan Office of Hydrocarbons and Mining (ONHYM) developed and tested a shale oil extraction process called T³. T³ was a surface retorting process, which used two semi-continuous identical retorts. While one retort operated, another retorted cooled after retorting process.[1] The resulting oil yield was 70% of that given by a Fischer Assay, the benchmark test of shale oil extraction potential. Approximately 400 tons of shale oil were produced at Timahdit.[9]

In 1981–1986, Royal Dutch Shell tested the Tarfaya deposit. Shell mined the shale using open pits and extracted its oil in an above-ground retort.[10]

A new strategy and legal framework for oil shale activities was adopted in 2005.[9] Since 2008, Petrobras and Total S.A. have been evaluating the Timahdit deposit.[1][7] In May 2009, San Leon Energy signed a three-year agreement with ONHYM for development of the Tarfaya deposit. San Leon Energy concluded an exclusive agreement with Mountain West Energy to use the Mountain West Energy-patented In-Situ Vapor Extraction technology for a three-year pilot project at Tarfaya.[8][10] In August 2012, San Leon commissioned Enefit Outotec Technology, a joint venture of Eesti Energia and Outotec, to study a feasibility of an Enefit 280 production plant.[11][12]

Another agreement on Tarfaya deposit was signed with Xtract Energy (Oil Shale) Morocco SA, a joint venture of Global Oil Shale Group Limited (70%) and Alraed Limited Investment Holding Company which is controlled by Bandar bin Mohammed bin Abdulrahman al-Saud.[1][11][7][13] Eesti Energia had signed an agreement on evaluation of the Aghbala and Errachidia deposits but found these deposits not suitable for commercial production.[1][14][15]