Two years ago I read a book on oil exploration. The first part was on the geology of oil.
The book’s contention was that oil is the result of death of bazillions of microscopic sea creatures over millions of years, whose bodies sink to the bottom of the seas, are covered by sand & silt, slowly sinking beneath the ocean floors, heated & compressed underground, until it forms oil. Oil is not the remains of animals or dinosaurs. A similar process with decaying plants produces coal.
If this is true, & it seems a good explanation for the existence of oil, then the process continues now & for as long as the planet exists. This also implies than any area of the planet covered by the sea for long periods of time, including land that is currently above sea level, likely contains oil. Given that most areas of the planet were under water at on time or another, oil is virtually everywhere.
Another interesting theory about oil is that, being lighter & less dense that the surrounding earth & rock, oil tends to find its way to the surface. La Brea Tar pits in CA & the oils sands of Alberta are examples of this. So, whether we drill for it or not, it will still come to the surface sooner or later.
Oil may be the ultimate energy storage system for the energy sun light transmits to photosynthesizers, those organism that convert sunlight, carbon dioxide, and water into carbohydrates. It is these carbohydrates that become hydrocarbon fuels.