Geology 101
Oil is not found everywhere. And there are some places that you can look all you want and you will never find a drop. Oil is found in specific types of formations and no where else. These formations are found in certain parts of the world. Coal is found the same way. You will not find coal in igneous rocks so don't look. Right now we are looking for oil that is recoverable with good profit to be had. As the price of oil climbs you will find that some reservoirs will come back into production because they can economically recover it, NOT that the oil is growing in the earth.
BTW "we will never run out of oil but it will become unaffordable for most to buy" I heard that statement from a president of a mining company last month.