新概念英語第四冊
Lesson 13 The search for oil
1 . so every so often a sample is obtained with a coring bit.因此時常要用取芯鑽頭取樣。
2 . Once we get down to the oil, it usually flows to the surface because great pressure,一旦到達油層，石油就會由於地下巨大的壓力流到地面上來，
3 . and we have to lower into the ground and haul out of the ground great lengths of drill pipe which are rotated by an engine at the top and are fitted with a cutting bit at the bottom.我們必須把很長的鑽桿一節節地鑽入地下，然後再從地下拉出來。鑽桿頂部安裝的發動機帶動鑽桿旋轉，它的底部裝有鑽頭。
4 . When it has been decided where we are going to drill, we put up at the surface an oil derrick.當確定鑽孔地點後，我們就在那裡豎起一個井架。
5 . But we do not need to send men down to get the oil out, as we must with other mineral deposits.但是，我們不必像開採其他礦藏那樣，把人送到地下去把石油取出。
6 . either from gas or water, is pushing it.這種巨大的壓力來自地下天然氣或水。
7 . It has to be tall because it is like a giant block and tackle,井架必須很高，因為它像一個巨型滑輪組。
8 . from which can be seen the strata the drill has been cutting through.從中能看出鑽頭所鑽透的地層。
9 . We want it to stay down the hole until we can lead it off in a controlled manner.我們要讓石油留在井下，直到我們能用一種有控制的方法把它引上來為止。
10 . The geologist needs to know what rocks the drill has reached,地質學家需要知道鑽頭已經到達什麼樣的岩層，
11 . and we control it by means of the mud which we circulate down the drill pipe.我們讓泥漿順著鑽桿向下循環，用這種方法來控制壓力。
12 . My particular experience is largely in oil,我是專門搞石油的，
13 . The deepest holes of all are made for oil, and they go down to as much as 25,000 feet.在所有洞穴中，為尋找石油所鑽的洞是最深的，這些洞可深達25，000英尺。
14 . and the search for oil has done more to improve deep drilling than any other mining activity.尋找石油比其他任何採礦業對改進深孔鑽探作的貢獻都要大。
15 . This pressure must be under control,這種壓力必須加以控制，
16 . It cuts a clean cylinder of rock,這種鑽頭能切割一段光滑的圓柱形岩石，
17 . We endeavour to avoid the old, romantic idea of a gusher, which wastes oil and gas.我們盡量避免使用陳舊天真的噴井方法，那樣會浪費石油和天然氣。
18 . The holes are only borings, less than a foot in diameter.這些洞只不過是一些鑽孔，直徑不到1英尺。