摘要
The Mid Continent Oilfield region is the greatest of the world’s developed oil territories. During the past three years, 1917-1919, the annual yield(140-180 million barrels), has been nearly one-third of the world’s production and already almost one-sixth of all the oil yet taken out of the earth has been supplied by these fields(1, 266 million barrels out of 8, 057 million barrels).