As part of that process they had to replace the dense drilling mud, which was used to keep the well under pressure while it was drilled, with sea-water.

在封井过程中，他们必须把用于在钻探过程里，保持钻井与海水压力相当的高密钻井泥更换掉：因为上方的海水的压力低于底下油气的压力。

youdao

The waters of the Arctic are particularly perilous for drilling because of the extreme cold, long periods of darkness, dense fogs and hurricane-strength winds.

对于海上钻探，北极的水域特别危险，因为极端寒冷，长时间的黑暗，密雾，以及飓风强度的大风。

youdao

Rigs form a dense ring around the tribe’s borders; only recently has drilling begun within.

钻井机密密麻麻地在部落边境上围成一个圈，直到最近才开钻。

youdao