text: The earliest known gas wells were drilled in China in AD 347 or earlier. They had depths of up to about  and were drilled using bits attached to bamboo poles. The gas was burned to evaporate brine and produce salt. By the 10th century, extensive bamboo pipelines connected gas wells with salt springs. The ancient records of China and Japan are said to contain many allusions to the use of natural gas for lighting and heating.  Petroleum was known as burning water in Japan in the 7th century. In his book Dream Pool Essays written in 1088, the scientist and statesman Shen Kuo of the Song Dynasty coined the word 石油 (Shíyóu, literally "rock oil") for petroleum, which remains the term used in contemporary Chinese and Japanese (Sekiyu).
  The first streets of Baghdad were paved with tar, derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in the area around modern Baku, Azerbaijan. These fields were described by the Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. Through Islamic Spain, distillation became available in Western Europe by the 12th century. It has also been present in Romania since the 13th century, being recorded as păcură.