It's even better than a banana, in the sense that it has its own casing, except you can eat the casing as well.

它甚至比香蕉还好，因为它有自己的脆壳，只是脆壳也可以吃。

A specialized perforating gun is then lowered and fired, creating a series of small, inch-long holes that burst through the well's casing into the rock layer.

然后放下并发射专用射孔枪，形成一系列小的、一英寸长的孔，这些孔穿过井的套管进入岩层。