• List of Articles Reservoir.

      • Open Access Article

        1 - Geochemical evaluation of the Sarvak and Fahliyan reservoirs crude oils by biomarker data in one of the Abadan Plain oilfields
        Seyed Ali Moallemi Mahnaz Amir hosyeni Azizolah Habibi
        In this study, 8 crude oil samples of the Sarvak (5 samples) and Fahliyan (3 samples) reservoirs from one of the main oilfields of the Abadan Plain was assessed geochemically by Liquid Chromatography, Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GC- More
        In this study, 8 crude oil samples of the Sarvak (5 samples) and Fahliyan (3 samples) reservoirs from one of the main oilfields of the Abadan Plain was assessed geochemically by Liquid Chromatography, Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GC-MS) techniques. Types of crude oils of the Sarvak reservoir are Paraffinic Naphtenic and Aromatic Intermediate and are Paraffinic type for the Fahliyan reservoir crude oils. Biomarker ratios of saturate fractions such as variation of Pr/nC17 and Ph/nC18 ratios and Pr/Ph versus C27/C29 (20R) Sterane diagram indicate formation of source rock in reducing marine environment for both oil reservoirs. Furthermore, high amount of C29 Sterane in compare to C27 and C28 Steranes show that organic matter of source rock was formed in marine environment with terrestrial kerogen input. High amount C29 Hopane versus C30 Hopane, variation C27 (Dia/Dia+Reg) Steranes versus Pr/(Pr+Ph), low amount of Diasteranes versus Steranes and variation Sterane/Hopane versus C27/C29 Steranes show carbonate- shale lithology for source rock of studied oils. Depending on high amount of resin, scattering of normal alkanes, high values of Pr/nC17 and Ph/nC18 and higher UCM in compare to other samples, K11 and K15 samples of the Fahliyan reservoir and B5 sample of the Sarvak reservoir demonstrate slight to moderate biodegradation while B19 sample show very slight biodegradation. According to variation of Pr/nC17 vs. Ph/nC18, C29 Sterane 20S/(20S+20R) vs. C32 Hopane 22S/(22S+22R), C29 Sterane 20S/(20S+20R) vs. C29 Sterane αββ/(αββ+ααα) samples from both reservoirs denote early oil window formation. Samples from the Fahliyan reservoir have high thermal maturity in compare to the Sarvak reservoir samples. Manuscript profile
      • Open Access Article

        2 - The history of deposition and post-deposition and their effects on the reservoir quality of Asmari Formation in Ahvaz oilfield
        Akbar Heidari Milad Faraji Narges Shokri
        The carbonate interval of the Asmari formation along with sandstone deposits were deposited in most areas of the Zagros sedimentary Basin, including the Ahvaz area, in Oligo-Miocene. In this study, the effects of depositional and post-depositional environments on the re More
        The carbonate interval of the Asmari formation along with sandstone deposits were deposited in most areas of the Zagros sedimentary Basin, including the Ahvaz area, in Oligo-Miocene. In this study, the effects of depositional and post-depositional environments on the reservoir quality of zone A7 of the Asmari Formation in well No. 4 in Ahvaz oil field were studied. The study of the sequences of the Asmari Formation in this section led to the identification of 11 carbonate facies, one evaporite facies, one mixed carbonate-siliciclastic facies, and one siliciclastic facies. Sedimentary environments of tidal zone, lagoon, coral reef and open sea were introduced for the depositional environment of identified facies. Due to the absence of sudden changes, it seems that the studied deposits were deposited in a ramp-type carbonate platform that was influenced by siliciclastic sediments from the Zagros river systems. The immature sedimentary texture of the sandstone facies indicates the proximity of the origin of the quartz sources to the carbonate basin. Among the diagenetic processes that have affected the examined sequences, the following processes can be mentioned: micritization, cementation, neomorphism, physical and chemical compaction, dissolution, fracture development and filling, dolomitization, and anhydritization. These diagenetic processes occurred in post-depositional marine, meteoric and burial diagenetic environments. Many fractures were filled with petroleum, which indicates that fractures, along with dolomitization, chemical compaction, and fenestral pores, are among the most important post-sedimentation complications to increase reservoir quality. While cementation and anhydritization resulted in reducing the reservoir quality by closing the pore spaces . Manuscript profile