At $30.00 a barrel oil, a 1 billion barrel find is worth 30b.
Likwise, at 100.00 a barrel oil, a 300m barrel discovery is worth 30b.
Is this a fair comparison to say they are the same or would there be more that goes into it? It seems to me that with 100 oil you can extract the same amount of value from a field in a much shorter time, making it more valuable.