Yes, I am aware and a majority of the time you will find both other. In this case and this shallow he found a large NG field.
Yes, I know it is sedimentary. Trying to go through igneous or metaphoric rock would be rather difficult to do.
Sedimentary rock composes about five percent of the Earth’s crust and basically like a veneer on it. I just don’t know how far it extends down. Do you by any chance?