It's actually easy to extract if you can find it in pockets.
Look at Utah...Bush's dipshit friends passed over a section because they thought it was too tough to drill in. Wolverine Gas picked up the claim and found 1 Billion barrels worth of oil in one field.
the problem with Jurassic shale is that it is pushed up and fragments over centuries. That forces the oil into pockets here and there. You'll have to literally drill and redrill and the pockets are tough to identify with seismic technology. Those shale stacks are like cafeteria trays stuck on a conveyor belt. They overlap. Those folds and thrust faults make finding oil tricky.