Depositional microfacies identification plays a key role in the exploration and development of oil and gas reservoirs. Asmari Formation in Oligo-Miocene is one of the most important reservoir Formations for the production and exploration of hydrocarbons in the Middle East and has a high reputation globally for a long time. In the Lorestan region, the sequences of the Asmari Formation have a carbonate-evaporate mixture of the late Miocene. The main aim of this research is to describe and interpret the different facies observations. Investigation of this sequence in one of the wells in this region has led to the identification of 17 sedimentary microfacies that belong to a homoclinal ramp-type carbonate platform. The nature and distribution of facies and environmental conditions of the Asmari Basin have undergone fundamental changes over time so that in the first part of this Formation (containing the first sequence of this Formation), the facies and their distribution pattern are similar to those of Tertiary and also others Zagros regions like Khuzestan and Fars. Still, in the second part (second sequence), there is a significant change in the Asmari basin, the most important of which is the replacement of red coral algae by a rare group of red algae with Aragonite wall. Our findings allows better characterizing and understanding which sedimentological features control the mechanical and its distribution throughout the formation.
The Upper Cretaceous Sarvak Formation in the Zagros and the Persian Gulf (Southwestern Iran) forms an important reservoir succession. Oil reserves in Sarvak, together with Ilam Formations, make up one-fourth of the total reserves of Iran. This study aimed to determine the petrophysical parameters influencing the reservoir properties within the carbonate sequence of the Sarvak Formation and to identify its productive zones. The latter formation is dominantly composed of limestone and dolomite with subordinate shale units. The studied Sarvak succession has been subdivided into six zones based on petrophysical criteria, whereby zones 3 and 4 have the highest reservoir potential based on the low water saturation and low shale amounts. The main diagenetic processes identified include dolomitization, dissolution, and cementation. The latter process obviously destroys reservoir properties, while dolomitization and dissolution enhance reservoir properties. Measurement of shale volume indicates that its amount is less than four percent of the rock volume. The dominant clay mineral consists of illite or mixed clay minerals with montmorillonite, and their presence is related to well depth and pressure.
This research studies a subterraneous section of the Dalan Formation in well X in one of the Persian Gulf gas field. The Dalan Formation, Permian in age, in folded Zagros region and the Persian Gulf contains giant gas resources. The lower boundary of the Dalan Formation is continuous and gradual, along with the siliciclastics of Faraghun Formation. The Upper Dalan is overlain by the Kangan Formation. The boundary of these Formations is the Permo-Triassic erosional surface. Diagenesis processes that affected the Dalan Formation include Cementation, Bioturbation, Micritization, Geopetal fabric, Dissolution, Compaction, Neomorphism, Pyritization, Ironzation and Dolomitization. Dolomitization, dissolution and cementation are the predominant diagenetic processes in this Formation. Marine, Meteoric and Burial diagenetic environments affected the Dalan Formation. According to sedimentary structure, texture and biota content 16 microfacies are determined for the Dalan Formation. These microfacies are presented in 3 facies belts, including Tidal flats, Lagoon and Carbonate shoal. The sedimentary environment of the Dalan Formation is introduced as a homoclinal carbonate ramp deposition. Dissolution along with microfractures had a positive effect on the improvement of reservoir quality.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.