The middle Cenomanian – early Turonian Mishrif Formation, a major carbonate reservoir unit in southern Iraq, was studied using cuttings and core samples and wireline logs (gamma‐ray, density and sonic) from 66 wells at 15 oilfields. Depositional facies ranging from deep marine to tidal flat were recorded. Microfacies interpretations together with wireline log interpretations show that the formation is composed of transgressive and regressive hemicycles. The regressive hemicycles are interpreted to indicate the progradation of rudist lithosomes (highstand systems tract deposits) towards distal basinal locations such as the Kumait, Luhais and Abu Amood oilfield areas. Transgressive hemicycles (transgressive systems tract deposits)

The Barremain-Aptian succession represented by two types of deposits, Clasits deposits of Zubair Formation. This formation is the most significant sandstone reservoir in Iraq, Deposited in fluvio- deltaic, deltaic and marine environments during the Barremain to Early Aptian age.

The area of study is located in the Mesopotamian Zone at S

The Barremain-Aptian succession represented by the Clasits deposits of Zubair Formation. This formation is the most significant sandstone reservoir in Iraq which deposited in fluvio- deltaic, deltaic and marine environments during the Barremain to Early Aptian age. The area of study is located in the Mesopotamian Zone at Southern part of Iraq which represented by five oil fields (Nasira, L

The Mishrif Formation is one of the most important formation in oil fields, which is located in southern part of Iraq, and it is of Upper Cretaceous age. Tuba field is located nearly 40 km SW – Basrah city. It is bounded from east by Zubair oil field (5 km distance) and from west by Rumaila (2 km distance). The Tuba oil field is situated between Zubair oil field in the east and Rumaila in the west, and is separated by two depressions.
The rock (core and chips) samples have been collected systematically from cores of Mishrif Formation that are available from stores of southern oil company to prepare thin sections and slides—these slides have been examined by using microscope. These samples have been taken from all parts of the rese

This study deals with establishing the depositional environment of the Fatha Formation through facies analysis. It also deals with dividing the formation into units based on the rhythmic nature. Data from selected shallow wells near Hit area and deep wells at East Baghdad Oil field are used. Five major lithofacies are recognized in this study, namely, greenish grey marl, limestone, gypsum (and/or anhydrite), halite and reddish brown mudstone (with occasional sandstone).The limestone lithofacies is divided into three microfacies: Gastropods bioclastic wackestone microfacies, Gastropods peloidal bioclastic packstone, and Foraminiferal packstone microfacies.The lithofacies of the Fatha are nested in a rhythmic pattern or what is known as sh

The Middle Cenomanian-Early Turonian Mishrif Formation includes important carbonate reservoirs in Iraq and some other surrounding countries due to their high reservoir quality and wide geological extension. The 2D models of this study for facies, effective porosity and water saturation indicate the vertical and lateral heterogeneity of the Mishrif Formation reservoir properties in the Majnoon oil field. Construction of 2D reservoir model of the Mishrif Formation to explain the distribution of facies and petrophysical properties (effective porosity and water saturation) by using RockWorks software. The increase of effective porosity is attributed to the presence of shoal facies.The high water saturation is attributed to the existence of rest

The reservoir units of Mishrif Formation in Majnoon oil field were studied by using available wireline logs (gamma ray, porosity and resistivity) and facies that derived from core and cutting samples for three wells including Mj-1, Mj-15, and Mj-20. The reservoir properties were determined and interpreted by using IP software. The results showed that unit D have the best reservoir properties due to high effective porosity, low water saturation and very low volume of shale. Furthermore, a large part of this unit was deposited in shoal environment. The other reservoir units are then graded in reservoir properties including units B, A, F & E respectively, except unit C, which is considered as a cap unit, because it consists of rest

The reservoir units of Mishrif Formation in Majnoon oil field were studied by using available wireline logs (gamma ray, porosity and resistivity) and facies that derived from core and cutting samples for three wells including Mj-1, Mj-15, and Mj-20. The reservoir properties were determined and interpreted by using IP software. The results showed that unit D have the best reservoir properties due to high effective porosity, low water saturation and very low volume of shale. Furthermore, a large part of this unit was deposited in shoal environment. The other reservoir units are then graded in reservoir properties including units B, A, F & E respectively, except unit C, which is considered as a cap unit, because it consists of restricte

In this study, different oil fields in Mesopotamian basin, southern Iraq (Siba, Zubair, Nahr - Umr, Majnoon, Halfaya, Kumait, and Amara) were selected for studying burial history. PetroMod software 1D was used for basin constructing and to evaluate burial history of the basin. Results showed that in the upper Jurassic to the Recent, Mesopotamian Basin exhibited a complex subsidence history over a period of about 152 Ma.There are different periods of subsidence: high, moderate, and slow. High subsidence occurred at upper Jurassic- mid Cretaceous and at Miocene due to Tectonic subsidence. Slow subsidence occurred at upper Cretaceous and moderate subsidence at Paleogene. In the upper Jurassic, rapid subsidence is driven under the effect of

     This study is achieved in the local area of the Eridu oil field, where the Mishrif Formation is considered the main productive reservoir. The Mishrif Formation was deposited during the Cretaceous period in the secondary sedimentary cycle (Cenomanian-Early Turonian as a part of the Wasia Group, a carbonate succession widespread throughout the Arabian Plate.

     The Mishrif Formation already have been evaluated in terms of depositional environments and their diagenetic processes. Here, it will test the previous conclusions with petrophysical properties delineated by using well logging. The results show there is a fully matching with two reservoir units (MA and MB). Dissolution and primary porosity are responsible for f