$课文13 探寻石油

187. The deepest holes of all made for oil, and they go down to as much as 25,0000 feet.

在所有洞穴中，为寻找石油所钻出的洞是最深的，这些洞可深达25,000英尺。

188. But we not need to send men down to get the oil our, as we must with other mineral deposits.

但是，我们不必像开采其他矿藏那样，把人送到地下去把石油取出。

189. The holes are only borings, less than a foot in diameter.

这些洞只不过是一些钻孔，直径不到1英尺。

190. My particular experience is largely in oil, and the search for oil has done more to improve deep drilling than any other mining activity.

我是专门搞石油的，寻找石油比其他任何采矿业对改进钻探作的贡献都要大。

191. When is has been decided where we are going to drill, we put up at the surface an oil derrick.

当确定钻孔地点后，我们就在那里竖起一个井架。

192. It has to be tall because it is like a giant block and tackle,

井架必须很高，因为它像一个巨型滑轮组。

193. 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.

我们必须把很长的钻杆一节节地钻入地下，然后再从地下拉出来。钻杆顶部安装的发动机带动钻杆旋转，它的底部装有钻头。