Closed System Evaporative Fractionation as a tool to Reservoir Alteration

Evaporative fractionation of petroleum by gas injection over oil was established by Thompson. In this process he could fractionate reservoir petroleum to paraffin rich condensate in the shallow reservoir and aromatic rich residual oil in the original reservoir. In the present work attempt has been made to test fractionation by heating crude oil in a closed system to build up adequate vapour pressure necessary for fractionation in the vapour phase condition. The technique has been tested using Sabah oil of East Malaysia and Dulang oil of Peninsular Malaysia. Results of present experiment indicate aromatic rich condensate in the shallower reservoir and paraffin rich residual oil in the original reservoir. It is therefore concluded that evaporative fractionation can alter the nature of reservoir oil to paraffin rich or aromatic rich depending on the process of fractionation.