I used to work in the industry and was talking to one of the...

I used to work in the industry and was talking to one of the exploration/drilling blokes once about success rates. He said the industry average @ that time was 10% hit rate for a commercially viable prospect. They were averaging 20% so he was happy with himself. Anyway that's the statistics you are playing with when investing in O&G. The likes PSI81 input here could be of value.