第13课

旁白 neutral

The deepest holes of all are made for oil, and they go down to as much as 25,000 feet.

所有最深的孔都是为石油而钻的，它们深达25,000英尺。

旁白 neutral

But we do not need to send man down to get the oil out, as we must with other mineral deposits.

但我们不需要像开采其他矿藏那样派人下去取油。

旁白 neutral

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

这些孔只是钻孔，直径不到一英尺。

旁白 neutral

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

我尤其在石油方面经验丰富，而寻找石油对深层钻探的改进作用，比任何其他采矿活动都要大。

旁白 neutral

When it has been decided where we are going to drill,

当我们决定了钻探地点之后，

旁白 neutral

we put up at the surface an oil derrick.

我们就会在地面上架设一个采油井架。

旁白 neutral

It has to be tall because it is like a giant block and tackle and we have to lower into the ground

它必须很高，因为它就像一个巨大的滑轮组，我们必须把巨大的钻杆放下去，

旁白 neutral

and haul out of the ground great lengths of drill pipe which are rotated by an engine at the top

并把巨大的钻杆从地下拉上来，这些钻杆由顶部的发动机带动旋转，

旁白 neutral

and are fitted with a cutting bit at the bottom.

底部装有钻头。

旁白 neutral

The geologist needs to know what rocks the drill has reached,

地质学家需要知道钻头钻到了什么岩石，

旁白 neutral

so every so often a sample is obtained with a coring bit.

因此，每隔一段时间就会用取心钻头取一个样本。

旁白 neutral

It cuts a clean cylinder of rock, from which can be seen the strata the drill has been cutting through.

它能切下一段干净的圆柱形岩石，从中可以看到钻头穿过的地层。

旁白 neutral

Once we get down to the oil, it usually flows to the surface because great pressure either from gas or water, is pushing it.

一旦我们钻到石油，它通常会流到地表，因为巨大的压力，无论是来自天然气还是水，都在推动它。

旁白 neutral

This pressure must be under control, and we control it by means of the mud which we circulate down the drill pipe.

这种压力必须得到控制，我们通过循环注入钻杆的泥浆来控制它。

旁白 neutral

We endeavour to avoid the old, romantic idea of a gusher, which wastes oil and gas.

我们努力避免那种老式的、浪漫的喷油井，那只会浪费石油和天然气。

旁白 neutral

We want it to stay down the hole until we can lead it off in a controlled manner.

我们希望它留在井下，直到我们能以受控的方式将其引出。