Print this pageGeochemical Identification of Paleo-Oil Zones in Present Gas Zones: Definition of Oil Water Contacts and Geochemical Reservoir Screening used to Identify Intra-Reservoir Migration Avenues "Filling Conduits" and Tar-Mats using Microextraction and Iatroscan TLC-FID
BHULLAR, ABID G., DAG A. KARLSEN, KRISTIAN BACKER-OWE, and KHANH Le TRAN
The ability to screen geochemically large numbers of reservoir core samples to produce pseudo-three-dimensional representations of the amount of bitumen vertically and laterally in the Elf operated Froy and Lille Froy oil reservoirs on the Norwegian Continental Shelf is exemplified using microextraction and the Iatroscan TLC-FID method.
Examples will show how this method is used routinely to screen 600 core samples for determination of bitumen content, amount of saturated hydrocarbons, aromatic hydrocarbons and polars (resins and asphaltenes), and calibration of these data with log determined oil saturations.
These data have a yet not realized potential for systemizing varying wettability characteristics and oil saturation, elements which could have great importance for ROS estimates.
The data on bitumen amounts and composition from different reservoir units is used to define oil water contacts and also, using an empirical approach on bitumen content and composition to be expected from oil zones, "condensate zones" and gas zones respectively, to determine if a present "condensate zone" held oil earlier. In this way the Iatroscan TLC-FID data are used to reconstruct the filling history for the reservoirs.
The presentation will also show examples of how the quantitative output from so called microextraction, that is extraction of reservoirs sands and shales in closed vials, preceding Iatroscan TLC-FID, was calibrated against conventional solvent extracted bitumen, and how these data compare with Rock-Eval S[1] and S[2] hydrocarbon and pyrolysis data.