Sentence:  The dawn of the oil age was fairly recent. Although the stuff was used to waterproof boats in the Middle East 6,000 years ago, <WSD>extracting</WSD> it in earnest began only in 1859 after an oil strike in Pennsylvania. The first barrels of crude fetched $18 (around $450 at today's prices). 
Meaning of the word marked with <WSD> tags:  To draw out; to pull out; to remove forcibly from a fixed position, as by traction or suction, etc.