This is the 9806th most frequent Japanese word.
製油
"製油" means "oil production" or "oil refining."
Here, '製油' refers to the process of refining oil. It is used as part of the term '製油工場' (oil refinery), indicating a facility where oil is processed.
製油工場で新しい技術が導入されました。
New technology was introduced at the oil refinery.
In this sentence, '製油' refers directly to the process of oil refining, describing its complexity.
その製油の工程は非常に複雑です。
The process of refining oil is extremely complex.
Here, '製油' is used to denote the field or industry of oil refining, indicating a professional involvement in this area.