I remember something like this as well. Oil does not come from dinosaurs but is actually from tiny sea life like plankton. It settles on the sea floor and over millions of years of heat and pressure it changes to crude oil. I recently read an article that talks about samples being taken from various places around the world showing new oil forming. Logically we know that life in water has not stopped so there is a constant supply of new organic material being deposited that will eventually convert to oil. It just takes a very long time. Likely there are layers of organic material at various stages of conversion.