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Commercial accumulation of petroleum requires several essential elements and processes which should occur in a certain sequence. Any departure from this sequence will be against petroleum accumulation. Therefore, the timing of oil migration and its emplacement in a reservoir is very important for petroleum geologists.
In the present work, a sequence of diagenetic events has been established for the Tirrawarra Sandstone utilizing petrographic studies, scanning electron microscopy, stable isotope, fluid inclusion microthermometry, electron microprobe analysis, cathodoluminescence observations and X-Ray diffraction.
Based on an integrated study, the timing of oil migration has been constrained with relation to other diagenetic events. Entrapment of hydrocarbon between quartz and siderite cement phases has indicated that migration of hydrocarbon has occurred at temperature range between 80°C and 102°C.
This paper discusses the diagenetic history of the Tirrawarra Sandstone reservoirs in detail and then correlates diagenetic events and the timing of hydrocarbon migration.