In the region of the north of Iraq using the method of analyzing thin section microfacies to 38 of rockyslices which were gathered from a place near Aqra city. These slides are divided into seven microfacies depending on lithologcal component and fossils.

1) Dolostone facies.

2)Recrystallized bioclastic wackestone facies.

3) Bioclastic packstone microfacies

4)Sucrosic dolomite facies.

 5) Bioclastic grainstone in microfacies.

 According to water energy, these facies were divided to three zone:

1. a) Low energy environment.
2. b) Transitional zone.
3. c) High energy environment.

     Yamama Formation is an important sequence in southern Iraq. Petrographic analysis was used to determine and analyze the microfacies and pore types. The diagenetic processes and the impacts on the petrophysical properties of the rocks were also identified. The petrographic identification was based on data of 250 thin sections of cutting and core samples from four wells that were supplied by the Iraqi Oil Exploration Company (O.E.C). The present study focuses on the depositional environment and the microfacies analysis of Yamama Formation. The results revealed several types of microfacies, including  peloidal wackestone-packstone, algal wackestone-packstone, bioclastic wackestone-packstone, fo

     The carbonate ramp facies of the Late Albian-Early Cenomanian Mauddud Formation were studied in the Ratawi Oilfield, Basra Governorate, south of Iraq using integrated borehole data set that included, core and cutting samples in three drilled wells to analyze the petrography of the Mauddud Formation, two hundred and eighty-one (281) thin sections were prepared and examined for the three selected wells. The results show that the formation is composed of light grey dolomitized limestone and pseudo-oolitic creamy limestone with green to bluish shale. The petrographic observations results show four facies’ associations in the Mauddud Formation. These include:  Mid–Ramp environment which is represented by Argillaceous mudstone mi

    The early Carboniferous Harur Formation from the Ora outcrop section of northern Iraq consists of black shale, calcareous shale and carbonate. The mineralogical and geochemical investigations (major and trace elements) of the black shale and calcareous shale units have been conducted to evaluate paleoenvironmental conditions including paleoclimate, paleoredox conditions, paleoproductivity, sedimentary rate, and to evaluate their effects on organic matter accumulation. The geochemical proxies such as the Chemical Index of Alteration (CIA), A-CN-K plot, Sr/Cu ratio, and the relation between the ratio of Ga/Rb and Sr/Cu suggest moderate to intense chemical weathering under humid conditions. The Rb/K and Sr/Ba ratios indicate a freshw

Mauddud Formation (Albian stage-the Early Cretaceous) is an important oil reservoir in Ratawi field of southern Iraq. Four wells, R T-2, R T-3, R T-6, and R T-7, located 70 km northwest of Basra, were selected to study microfacies properties and petrophysical associations with the probability of oil production. Seventy-seven core samples are collected, and thin sections for petrographic analysis. The self-potential, Gamma-ray, resistivity, and porosity logs are used to determine the top and bottom of the Mauddud Formation. Water saturation of the invaded and uninvaded zones, shale volume, and porosity were calculated. The study area results showed that the quantity of shale is less than 15% for most of the wells, and the dominant po

The Late Maastrichtian–Danian phosphatic succession prevails as a deposit to the west of Rutbah region, Western Iraq. This is manifested through the lithostratigraphic sections of boreholes (K.H5\6 and K.H 5\8) drilled previously in the area. The succession is mainly composed of phosphate, shale, porcelanite, oyster and foraminiferal carbonate lithofacies belonging to Digma and Akashat formations. Three facies associations are distinguished during the study: the phosclast planktonic (FA1) that dominates the outer ramp, the phosclast foraminiferal (FA2) that dominates the mid ramp, and the quartz dolomitic phosclast (FA3) present in the inner ramp. These facies’ associations are differentiated into se

Ghar Formation outcrop at the Iraqi western desert was studied by microfacies analysis
of (13) thin sections collected from wadi Al-Ratgha ( west of Qaim ) . According to
petrographic com position and organisms content ,rocks were subdivided into (4)
microfacies units :bioclastic wackestone , mudstone , miliolids wackestone , and grainstone
with aggregate grains microfacies .Microfacies units reflect shallow marine environment of
low circulation of very warm water at the middle part . The lower and middle part
interbedded with quite open marine environment below the wave base . The upper part was
deposited at shallow marine environment of low circulation . The main diagenetic processes
were the transformation ( ty

Six main microfacies are identified which are Lime Mudstone, Bioclastic Wackeston, Bioclastic Packstone-Wackestone, Bioclastic Wackestone- Mudestone, Pelagic Mudstone–Wackestone, Bioclastic Packstone -Grainston Microfacies in addition to their associated depositional environment. The diagenesis process have affected the Mishrif rocks and played a role in deteriorating reservoir porosity in well Ga-2 and enhancing it in well Ga1,3.These processes include: cementation, micritization, recrystallization,dissolution,compaction pressure solution and dolomitization.

     Mishrif Formation is the most important succession in the southern part of Iraq and has extensive distribution in the Arabian Plate. The present study  focuses upon the sequence stratigraphy and development of Mishrif Formation basin in four oil fields within the eastern part of the Mesopotamian Zone are:-  Halfaya (Hf-1), Noor (No-1) and Abu Ghirab (AG-3) and Fauqi oil fields (Fq-1).

     There are several types of microfacies were distinguished in the succession of the Mishrif Formation. Their characteristic of the grain types and carbonate texture enabled to interpret of five facies associations (depositional environments) were observed in this formation, they are: deep ma