Abstract
Oil fingerprinting is a common name for techniques based on geochemical analysis of hydrocarbon fluids composition which could provide valuable and unique information for well and reservoir management. Hydrocarbons in oil and gas deposits are affected by different processes, such as: biodegradation, gas flushing, water washing and evaporation. The degree of change depends on many factors: temperature, reservoir compartmentalization, tectonics, aquifer activity etc. Consequently, hydrocarbons initially migrated from one source rock become different in different reservoirs and compartments. Evaluation of changes in composition allows identification of hydrocarbons from different reservoirs, in other words to identify unique "fingerprints" of hydrocarbons. This information can be very valuable for production allocation between reservoirs and for needs of well and reservoir management. This article summarizes the results of a pilot oil fingerprinting project on Astokh oil field based on High Resolution Gas Chromatography (HRGC). The primary objective of this work was to develop a methodology for production allocation in comingled oil producers based on HRGC as applied for the Astokh area. In the course of work some more opportunities were identified, for instance monitoring of reservoir dynamics which could turn out to be more powerful than the primary objective.
