OIL INITIALLY IN PLACE - OIIP

Oil initially is the amount of crude initially estimated to be in the reservoir. Oil initially and oil reserves are different though, because OIIP pertains to the total amount of oil that is possibly in the reservoir, and not the volume that can be recovered. It requires engineers to determine how absorbent the rock surrounding the oil is, how high water saturation may be and the net rock volume of the reservoir.