You see, oil deposits can stretch for miles - but when a drill went straight down, the well was only tapping oil from the immediate vicinity.
你瞧，石油储备区可能延绵数英里，但是当钻头垂直钻入时，油井只能开采到附近区域的一点石油。
2
You see, oil deposits can stretch for miles - but when a drill went straight down, the well was only tapping oil from the immediate vicinity.
你瞧，石油储备区可能延绵数英里，但是当钻头直接垂直钻入时，油井只会利用到邻接区域的石油。
3
The use of the tapping chuck is particularly advantageous when working with the quick change system on drilling machines that allows to drill and tap in the same position without centring again.