Mehran Moradpour | Ferdowsi University of Mashhad (original) (raw)

Papers by Mehran Moradpour

Carbonates and Evaporites, Mar 5, 2018

The Shahbazan Formation at Kialu section in the Zagros Basin, southwest of Iran, is composed main... more The Shahbazan Formation at Kialu section in the Zagros Basin, southwest of Iran, is composed mainly of carbonates with the age of middle Eocene. This formation, with a thickness of 240 m, consists of thick carbonates which pervasively dolomitized. On the basis of petrographic and geochemical features, four different replacive and cement dolomite phases have been recognized. Cathodoluminescence and scanning electron microscope were used to study time of cementation and diagenetic feature as well as to illustrate fine dolomite crystals which are not visible under common microscope. Cathodoluminescence figures show growth zonation and a rimmed bright green luminescence of syntaxial overgrown dolomite as a diagenetic cement as well as some kinds of lattice defects in some cement crystals. Inside-out dolomites seen by applying scanning electron microscope have been interpreted as a result of meteoric diagenesis, caused dissolution of dolomites during exposure. Geochemical analysis of major elements including Mg 2+ and Ca 2+ and trace elements such as Sr, Na, Mn 2+ and Fe 2+ with a trend of decreasing in Sr and increasing in Na, Mn 2+ and Fe 2+ during burial diagenesis, along with the cement zonation, visible under cathodoluminescence microscope, indicate dolomite purification and recrystallization under reducing condition.

فصلنامه علمی-پژوهشی علوم زمین, Nov 22, 2010

Proceedings, 2009

This contribution refines the diagenetic evolution of the Asmari Formation (Oligocene – Early Mio... more This contribution refines the diagenetic evolution of the Asmari Formation (Oligocene – Early Miocene) in southwest Iran. It presents diagenetic maps providing invaluable data for assessing reservoir heterogeneities and optimising rock-typing. The major results of this work bridge the gap between classical geological study (which includes conceptual dolomitisation models, burial history and paragenesis) and the actual reservoir heterogeneity encountered in the investigated field and demonstrated by the production distribution. Diagenetic maps (Limestone %, Dolomite %, Anhydrite %, Total Porosity %, Dissolution Porosity %, Cementation %) covering six stratigraphic intervals that are bounded by key sequence stratigraphic surfaces reveal spatial and vertical distribution characteristics in the investigated oil field. Integrating these diagenetic maps shows dolomite, anhydrite, porosity and dissolution relative distribution across the study area and per stratigraphic interval, resulting in better understanding of the diagenetic processes and their products. Thus, a comprehensive, generalized diagenesis model explaining the reservoir properties evolution prior to oil charging was succeeded.

GeoArabia, Oct 1, 2007

The late Oligocene-early Miocene Qom Formation in the Central Iran Basin contains oil and gas in ... more The late Oligocene-early Miocene Qom Formation in the Central Iran Basin contains oil and gas in the Alborz and Sarajeh fields. Organic geochemical analyses in previous studies indicated that the hydrocarbons migrated from deeper source rocks, likely of Jurassic age. In the Central Iran Basin, the Qom Formation is 1,200 m thick and is bounded by the Oligocene Lower Red Formation and the middle Miocene Upper Red Formation. In previous studies, the Qom Formation was divided into nine members designated from oldest to youngest: a, b, c 1 to c 4 , d, e and f, of which "e" is 300 m thick and constitutes the main reservoir. Our study focused on a Qom section located in the Gooreh Berenji region of central Iran which is 294 m thick. The lower part of the formation was not deposited, and only the following four members of early Miocene age (Aquitanian and Burdigalian) were identified between the Lower and Upper Red formations: "c 2 "? (mainly greyish to greenish gypsiferous marls); "d" (thin-to thick-bedded anhydrite with intercalation of thin-bedded sandstone); "e" (argillaceous or sandy limestone); and "f" (fine-grained coral and bryozoan boundstone). In contrast to the Central Iran Basin, the "e" member in Gooreh Berenji is only 15 m thick and does not have a good reservoir potential. A detailed petrographic analysis of the Gooreh Berenji section resulted in the identification of 13 microfacies (MF) that were interpreted in terms of their depositional environments according to the following categories: MF1 (sabkha), MF2 (intertidal river channel), MF3 (lower intertidal), MF4 (peritidal), MF5 (supratidal), MF6 and MF7 (shallow restricted lagoon), MF8 and MF10 (proximal open-marine), MF9 (leeward lagoon), MF11 (shoal), MF12 (reef and patch reef formed within lagoon), and MF13 (open-marine). The Qom Formation constitutes a regional transgressive-regressive sequence that is bounded by two continental units (Lower and Upper Red formations). The transgression started from the south in the late Oligocene and by the early Miocene the sea covered all of central Iran. In the Gooreh Berenji area, carbonate deposition occurred on a shallow-marine ramp. The presence of a wide range of lagoonal facies indicates that reefal facies ("f") developed in a narrow elongated strip away from the shoreline.

Canadian Journal of Earth Sciences

This study presents a long-term, multi-proxy reconstruction of the Asian southwest monsoon during... more This study presents a long-term, multi-proxy reconstruction of the Asian southwest monsoon during the Tortonian to Piacenzian, based on a 4.78 Ma record from Coastal Makran, northwestern Gulf of Oman, southeast Iran. The integration of humidity proxies (clay minerals, Th/K, volume magnetic susceptibility, and grain size analysis), marine redox sensitivity (Th/U), total organic matter, carbonate content, 87Sr/86Sr ratio, and spectral gamma-ray data conducted here provide valuable information that fill the existing gap in marine palaeoclimate records. The results show that a strong winter monsoon condition associated with relatively low precipitation and subsequently low physical and chemical weathering dominated the region during late Tortonian – late Messinian (7.65–5.83 Ma). However, a few episodes of intense physical and chemical weathering related to high precipitation are observed during this period (6.23–6.01 Ma), which is consistent with increased organic matter input from con...

Ui Journals System, Sep 15, 2013

AIP Conference Proceedings, 2009

Istanbul 2012 - International Geophysical Conference and Oil & Gas Exhibition, 2012

Journal of Geophysics and Engineering, 2014

ABSTRACT This study has been conducted on Mansuri onshore oilfield located in Dezful Embayment, s... more ABSTRACT This study has been conducted on Mansuri onshore oilfield located in Dezful Embayment, south-west Iran. One of the hydrocarbon-bearing formations is a Oligo-Miocene Asmari formation—the most prolific Iranian reservoir rock. Like many other oilfields in the area, the trap in this field is deemed structural (anticline), formed during the collision of the Arabian plate with the Iranian plate and the folding of Neotethys deposits with a NW–SE trend. This study integrates three different quantitative studies from geology, geophysics and petrophysics disciplines to quantitate 'the qualitative study of seismic facies analysis based on trace shapes and 3D multi-attribute clustering'. First, stratigraphic sequences and seismic detectable facies were derived at one well location using the available high resolution core facies analysis and depositional environment assessment reports. Paleo and petrophysical logs from other wells were subsequently used for the extrapolation of stratigraphic sequences interpreted at the first well. Utilizing lithology discrimination obtained by wire-line log interpretation, facies were extrapolated to all wells in the area. Seismic 3D attribute analysis and seismic facies classification established a 3D facies volume accordingly, which was finally calibrated to geological facies at well locations. The ultimate extracted facies-guided geobody shows that good reservoir-quality channel sands have accumulated with NW/SE elongation at the ridge of the structure. As a result, this type of geometry has created a stratigraphic/structural hydrocarbon trap in this oilfield. Moreover, seismic facies analysis shows that buried channels do not parallel the predominant Arabian plate-originated channels (with SW–NE trends) in SW Zagros and are locally swerved in this area.

CL images provide insights, not available by other research techniques, into diagenetic changes, ... more CL images provide insights, not available by other research techniques, into diagenetic changes, such as cementation and porosity loss, which take place in sandstones, shales, and carbonate rocks during burial. In this study perform some cathodoluminescence photos of Lower Cretaceous (Aptian-Albian) Limestones, which are called Dariyan Formation located in Fars area, SW of Iran are presented. Petrographic and cathodoluminescence observations suggest diagenetic alteration of Dariyan Formation occurs in a burial setting. Different generations of spary calcite cement were recognized in the Dariyan limestone mainly in burial setting. Minescus cement with bright luminescent, indicating meteoric vadose diagenesis. The origin of equant cement is shallow burial, syntaxial cements are burial, too. Drusy cements are meteoric and reveal bright luminescence with zoning. Trace elements (Sr, Na, Mn, Fe) bivariates plots and δ18O-δ13C isotop plot confirm these conclusions.

Journal of Petroleum Geology, 2008

The Lower Triassic Kangan Formation together with the underlying Upper Permian Dalan Formation fo... more The Lower Triassic Kangan Formation together with the underlying Upper Permian Dalan Formation forms one of the most important reservoirs for natural gas in the Middle East. The carbonate-dominated Kangan Formation was studied at a gasfield in the southern Persian Gulf and some 100 m of core were examined at micro-and macro scales. Twelve microfacies were identified. Previous studies have divided the Kangan Formation reservoir into Lower (K2) and Upper (K1) Units. The Lower Kangan can divided into two subunits (K2b and K2a), while three subunits (K1c, K1b and K1a) are recognised in the Upper Kangan. Diagenetic processes have affected reservoir quality in the Kangan Formation in different ways. Processes improving reservoir quality include dissolution, dolomitization and fracturing, while reservoir quality was decreased by cementation, and chemical and mechanical compaction. Micritization and neomorphism have had both positive and negative effects. Fracture development has improved reservoir quality, particularly in dolomitic intervals.