Oil. In an upper horizon. And actually, the more shallow of the...

Oil. In an upper horizon. And actually, the more shallow of the two intersected so far? None in the lower horizon. Well, they did not mention it, but the wording is a bit unclear... not specific.
So. Yes, there was an oil kitchen somewhere. Yes, the oil did migrate to a sand from where it may be recoverable. Note, a thin sand in the target - thin to me means a metre or less. There is a likelihood that it will have migrated into the lower targeted sands. Still trapped there? And is the lower target interbedded sands and shales?
That's all for holders to worry about.
And no, you are not interested in hitting the source system.. that will be a muddy, fine grained set of thin sands and mostly shales into which the marine biologic debris was accumulated, layer by thin layer over tens of thousands of years. You don't produce from such.