nterests in the Aitken Creek and Alberta Hub natural gas storage facilities, which have aggregate total capacity of approximately 100 billion cubic feet. These facilities are located in western Canada near the Duvernay, Horn River, Liard and Montney shale gas plays. Greenland: In December 2012, the company relinquished its 29.2 percent non operated working interest in Exploration License 2007/26, which includes Block 4 offshore West Greenland. Argentina: The company holds operated interests in four concessions in the Neuquen Basin. Working interests range from 18.8 percent to 100 percent. During 2012, two exploratory wells targeting shale gas and tight oil resources were drilled in the Vaca Muerta formation in the El Trapial concession. The El Trapial concession expires in 2032. Brazil: The company holds working interests in three deepwater fields in the Campos Basin: Frade (51.7 percent-owned and operated), Papa-Terra and Maromba (37.5 percent and 30 percent non operated working interests, respectively). During 2012, construction activities and development drilling continued for the Papa-Terra project. The project includes a floating production, storage and offloading vessel and a tension leg wellhead platform, with a design capacity of 140,000 barrels of crude oil per day. Colombia: The company operates the offshore Chuchupa and the onshore Ballena and Riohacha natural gas fields as part of the Guajira Association contract. Chevron receives 43 percent of the production for the remaining life of each field and a variable production volume based on prior Chuchupa capital contributions. Suriname: In 2012, the company acquired a 50 percent non operated working interest in Blocks 42 and 45 offshore Suriname. Trinidad and Tobago: The company has a 50 percent non operated working interest in three blocks in the East Coast Marine Area offshore Trinidad, which includes the Dolphin and Dolphin Deep producing natural gas fields and the Starfish development. Venezuela: The company holds interests in two producing affiliates located in western Venezuela and one producing affiliate in the Orinoco Belt. Chevron has a 30 percent interest in the Petropiar affiliate that operates the Hamaca heavy-oil production and upgrading project located in Venezuela’s Orinoco Belt, a 39.2 percent interest in the Petroboscan affiliate that operates the Boscan Field in the western part of the country, and a 25.2 percent interest in the Petroindependiente affiliate that operates the LL-652 Field in Lake Maracaibo. The company holds a 34 percent interest in the Petroindependencia affiliate that is working toward commercialization of Carabobo 3, a heavy-oil project located within the Carabobo Area of the Orinoco Belt. The company operates and has a working interest of 60 percent in Block 2 in the Plataforma Deltana area offshore eastern Venezuela, which includes the Loran Field. AFRICA In Africa, the company engages in upstream activities in Angola, Chad, Democratic Republic of the Congo, Liberia, Morocco, Nigeria, Republic of the Congo, Sierra Leone and South Africa. Angola: The company holds company-operated working interests in offshore Blocks 0 and 14 and non operated working interests in offshore Block 2 and the onshore Fina Sonangol Texaco (FST) area. The company operates the 39.2 percent-owned Block 0, which averaged 98,000 barrels per day of net liquids production in 2012. The Block 0 concession extends through 2030. A project to develop the Greater Vanza/Longui Area of Block 0 is scheduled to enter front-end engineering and design (FEED) in second-half 2013. In addition to the exploration and production activities in Angola, the company has a 36.4 percent interest in Angola LNG Limited, which would operate an onshore natural gas liquefaction plant in Soyo, Angola. The plant is designed to process 1.1 billion cubic feet of natural gas per day, with expected average total daily sales of 670 million cubic feet of natural gas and up to 63,000 barrels of natural gas liquids. The company also holds a 38.1 percent interest in a pipeline project that is designed to transport approximately 250 million cubic fee