"无套管钻孔" can be translated as "uncased drilling" or "drilling without casing" in English.
* "Uncased drilling" emphasizes that the drilling is carried out without the use of a casing (a protective tube placed in the borehole), which is a key characteristic of this drilling method.
* "Drilling without casing" is a more straightforward and descriptive translation, clearly stating that no casing is used during the drilling process.
Both translations are accurate and can be used depending on the context and preference.