Currently, I've started working on a geophysics project. More specifically, I'm trying to find gas and oil reservoirs in SEGY files using deep learning. I've been reading about seismic reflection methods and watched a series of lessons at IRIS Youtube channel, but something isn't very clear to me yet, and this leads to my question. Is there some kind of relationship between two different rock layers? I mean, something along the lines "after a layer of shale it's more likely that I find an oil reservoir than after a layer of limestones". In summary, what I'd like to know is whether or not there is some kind of "common layer ordering", or pattern, in the subsurface, even though if it's not 100% deterministic.