Stratigraphic trap fluida

Stratigraphic trap.

Just because you drill for oil or gas does not mean that you will find it! Oil and gas reservoirs all have edges. If you drill past the edge, you will miss it !

Your well may find a producing reservoir very near the surface. Or you might drill into a reservoir that has been depleted (all the oil and gas removed) by another well. There may ne a new infill reservoir between two wells that could be developed with a third well. Or one that was incompletely drained. Maybe if you drill a little deeper you might hit a deeper pool reservoir! You might be able to back up and produce a bypassed compartment. The Petroleum Geologist has to think of all these things when planning a new well.


Even though oil and gas are not easy to find, they are found in commercial quantities in many areas of the United States. This map shows most of these areas. It's really a crummy map, and not very accurate, and I need to replace it sometime. But for now, this is the map.




Finally, structures in the earth can give the PG many challenges. Look at the diagram to theFaulting_Causes_Problems.gif (6460 bytes) right. Imagine you first drilled the hole on the left into the green layer which represents a nice oil and gas-bearing rock. YES! You have a great well, producing lots of oil and gas!

Then you drilled your second hole to the east (right) of the first one. What happened to that hole?

Answer below.