ADCO, the largest crude oil producer in the southern Arabian Gulf, undertakes exploration, drilling, production and export activities in Abu Dhabi's onshore areas, and the shallow coastal waters. The original concession agreement was signed in January 1939 with Petroleum Development (Trucial Coast). In 1962 the company became known as the Abu Dhabi Petroleum Company Ltd. (ADPC), and later became the Abu Dhabi Company for Onshore Oil Operations (ADCO) in 1978.The company operates on behalf of ADNOC and six industry shareholders and produces oil mainly from five fields: Asab, Bab, Bu Hasa, Sahil and Shah. These fields are linked by more than 450 kilometers of pipeline network to the storage and shipping facilities located at Jabel Dhanna, where tankers load crude oil for export to markets in many parts of the world. Oil production comes also from four other oil fields: Jarn Yaphore, Al Dabb iya, Rumaitha and Shanayel but as early production phase.