This week the IMF forecast that extending full lockdowns well into the third quarter of 2020 would turn a 3% contraction of the world economy this year into a 6% one.

【翻译】国际货币基金组织在本周预测，将全面封锁延长至2020年第三季度，会使今年全球经济收缩3%变为收缩6%。

well 修饰后面的介词短语 into the third quarter of 2020 ，意思是“完全进入；彻底进入”。

well 用于介词短语之前，表示程度和强调。意为“十分地，完全地，彻底地，充分地” 等含义。仔细体会各句 well 的含义（红色的翻译）：

This tree is well above the other trees.  

这棵树远远高于别的树。

He is well on his way to recovery.  

他正在顺利恢复。

All that sort of thing is well over my head.  

那种事远不是我能明白的。

The standard of his work is well below the average of his class.  

他的成绩大大低于班上的平均成绩。

This idea is well worth considering.  

这个想法很值得考虑。

This is well within our capacity.  

现在我们完全有这个能力的。