Finally, on 10 August 1910, the first oil drilling operation was started. A rig (nicknamed the "Grand Old Lady") made up of wooden derricks and cable tool drilling was used in the operation by Royal Dutch Shell. On 22 December 1910, oil was struck after of drilling at the well. Royal Dutch Shell also founded a subsidiary company named Sarawak Oil Field Ltd, which now operated as Sarawak Shell Berhad. Since then, another 624 land wells have been drilled around Miri until 1972 which are collectively known as the "Miri field". The Miri field is the only onshore field in Sarawak, because oil production has shifted offshore since the late 1950s. The first oil well on Canada Hill (Miri Well No. 1) produced a total of for the next 60 years until its closure on 31 October 1972. The first oil refinery and submarine pipeline was built in Miri in 1914. The oil refinery has since been relocated to Lutong, to the north of Miri, in 1916.