"天然气逸出" can be translated as "natural gas leakage" or "escape of natural gas".
"Natural gas leakage" is a common and straightforward expression, emphasizing the unintended release of natural gas.
"Escape of natural gas" also accurately conveys the idea of gas escaping from its containment, though it's slightly less common in everyday usage compared to "leakage".
Both phrases are correct and can be used depending on the context and desired emphasis.