Abstract
The Yamama Formation is characterized by a wide geographic extension of southern Iraq. Microfacies analysis of this formation was studied in six wells distributed in six fields: Fayhaa, Sindbad, Siba, Zubair, Ratawi and West Qurna. This research aims to determine paleoenvironments by diagnosing biofacies and lithofacies. Miscellaneous marine fauna of foraminifera and calcareous algae, mainly green algae (dasycladacean.) and skeletal bioclasts from gastropods, pelecypods, bryozoans, sponge spicules, and echinoderms were found. Petrographic studies and well logs interpretations led to the identification of five main Microfacies ( Mudstone, Wackestone, Packestone, Grainestone and Rudstone and twelve submicrofacies (Foraminiferal-Lime mudstone submicrofacies, Argillaceous Lime Mudstone submicrofacies, Planktonic foraminiferal – Lime Wackestone submicrofacies, piculites/ Calcisphers – Lime Wackstone submicrofacies, Benthonic Foraminiferal -Lime wackestone/packestone submicrofacies, Algal (desycladecan) Lime wackestone submicrofacies, Algal-Lime packestone submicrofacies, Bioclastic/ Algal-Lime packestone submicrofacies, Algal/ Foraminiferal- Algal -Lime packstone submicrofacies, Peloidal poorly sorted grainstone with bioclasts submicrofacies, Intraclastic grainstone submicrofacies, Pesudo oolitic-Lithocodium aggregatum grainstone submicrofacies and finally Peloidal-intraclastic, and bioclastic grainstone submicrofacies). Microfacies are deposited in the lagoon, shoal, rudist biostrome and open marine gradient to middle and outer ramp environments. Vertical changes in microfacies with depth were reflected by lateral changes in marine depositional systems and the thickness of the formation. Shoal environments' microfacies are characterized by high thickness, while low thickness characterizes the open marine microfacies. The Yamama Formation was deposited on the low-angle homoclinic carbonate ramp, mainly in the inner and middle ramp, with outer ramp conditions in some parts of the formation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
