Dear Jasim... Regarding the extraction of porphyrins from crude oils, It has been proved that vanadium porphyrins represent only part of the metal content of the oil. You may refer to one of my publications on the subject
Separation and spectrophotometric investigations of the distribution on nickel and vanadium in heavy crude oils. Fuel, 68 (1989) 84 – 87.
However, porphyrins posses a structure that is very close to the chlorophyll, the basic component of plants. I shift more to the plant origin of crude oil. Regards